OBSTETRIC ANESTHESIA RESIDENT HANDBOOK

Transcription

1 OBSTETRIC ANESTHESIA RESIDENT HANDBOOK RESIDENT SCHEDULE OPERATING ROOM SET UP PREANESTHETIC EVALUATION HIGH RISK CONSULT SERVICE ASEPTIC TECHNIQUE EPIDURAL PLACEMENT AND MAINTENANCE COMBINED SPINAL EPIDURAL (CSE) PLACEMENT CESAREAN DELIVERY WITH IN SITU EPIDURAL TOPPING OFF LABOR EPIDURALS CATHETER PULLS SUBARACHNOID BLOCKS COMPLICATIONS OF NEURAXIAL TECHNIQUES OBSTETRIC ANESTHESIA CURRICULUM

2 RESIDENT SCHEDULE The resident schedule is as follows: on months when 2 residents are rotating on the service, one will be designated the a.m. resident and the other will be the p.m. resident. The a.m. resident should arrive no later than 6:45 and will stay until 3 p.m.; the other resident will arrive at 11 a.m. and stay until 7 p.m. There is often a flurry of epidural placements between 6:30 and 7:00 a.m., so the early resident might consider coming earlier when possible. Each week the a.m. and p.m. resident will alternate. You are responsible for agreeing who will be the a.m. and p.m. resident the first week and for alternating thereafter. The first day on the service both residents can arrive at 6:45 so that the more senior resident can orient the other. When only one resident is on the rotation, he/she should arrive no later than 6:45 a.m. and stay until 5 p.m. In the near future, we hope to have overnight call facilities for residents, and at that time we will tweak the schedule once again to ensure optimal exposure to procedures on the L&D ward. Please note that you are responsible for contacting both Patty Burke and the staff member on L&D if you have an unanticipated emergency or illness and are unable to get to work. The same applies if you request an additional vacation day that was not originally scheduled. When the a.m. resident arrives, he/she should check the anesthesia machine and ensure that emergency drugs and equipment for the administration of a general anesthetic are immediately available. The cases for the day are usually posted on the white bulletin board; scheduled labor inductions are listed in a binder at the nursing station or, if the patient is already in house, on the bulletin board. The CRNA on L&D can also provide updates for the day s schedule. Daily resident duties include: attend the safety rounds at 7:30 a.m. each morning in the 2 nd floor neonatal conference room, when possible; fill out the pre anesthesia evaluation papers on each patient requesting an epidural or scheduled for Cesarean delivery, cerclage, tubal ligation, etc. (the packet of papers is usually in the patient s chart or on the clipboard in the anesthesia work room); place epidurals once properly trained and prepared, and fill out all the relevant paperwork; troubleshoot and top off epidurals, as needed; provide neuraxial or general anesthesia for operative procedures, remaining with the patient and charting appropriately throughout; attend all lectures offered by staff, colleagues, and fellows; perform postoperative visits on all patients from the preceding day (a list of patients will be provided); and provide continuity of care for all antepartum patients (these are the patients being observed on the floor whose status should be reassessed on a daily basis). If two residents are available during the hours between 11 a.m. and 3 p.m. (when shifts overlap), one will be expected to run the floor, placing and troubleshooting epidurals, while the other is in charge of surgical cases. Antepartum and postpartum visits can be divided between residents, or residents can alternate these duties week by week.

3 In addition to the above duties, each resident is responsible for making a PowerPoint on a subject of interest for presentation during the final week on the rotation. We will also assign a series of Jackpot questions at the beginning of the rotation; we expect you to research the answers and be prepared to answer these questions at a designated Jackpot answer session each week (below is a list of resources to aid in your research). Further, when time permits, you will be expected to take over surgical procedures already underway, relieving the CRNA and assuming responsibility for those obstetric patients in the operating suites. Finally, occasionally you will be asked to perform preoperative assessments on both high risk parturients and non obstetric patients scheduled for outpatient surgery at Tulane Lakeside in the anesthesia preoperative evaluation clinic on the 1 st floor. These preoperative evaluations require your familiarity with preoperative guidelines, anesthetic implications of a variety of disease processes, and with further work up algorithms that might be necessary to optimize a patient for surgery. The preoperative evaluation clinic provides a good learning opportunity, particularly in preparation for the Oral Boards. The L&D ward is marked by peaks and lulls; residents should take advantage of downtime by studying, reading, preparing the final PowerPoint presentation, and answering the Jackpot questions. The third floor office has several texts and question books, as well as three computers with PowerPoint capacity. Please take advantage of these facilities for study, research, etc. Finally, a very informative and recently updated reference book to help guide you during this rotation is Obstetric Anesthesia Handbook by Sanjay Datta, Bhavani Shankar Kodali, and Scott Segal. It is available at Amazon and other on line companies. You should also be intimately familiar with the 2007 ASA Practice Guidelines for Obstetric Anesthesia (see Anesthesiology 2007;106: or simply Google ASA Obstetric Anesthesia Guidelines ; these guidelines are also printed in the back of Chestnut s Obstetric Anesthesia text). Other resources you may find helpful include: Chestnut s Obstetric Anesthesia: Principles and Practice, 4 th Ed; Clinical Anesthesiology by Morgan, Mikhail and Murray (with particular emphasis on the Local Anesthetics and Obstetric Anesthesia chapters); and Anesthesia Review: A Study Guide to Anesthesia and Basics of Anesthesia by Lorraine Sdrales and Ronald Miller (again, with emphasis on the Local Anesthetics and Obstetric Anesthesia chapters). These and other texts, including Longnecker s Anesthesiology, Miller s Anesthesia: 2 Volume Set, and Barash s Clinical Anesthesia are in the 3 rd floor office, although I encourage you to purchase the Obstetric Anesthesia Handbook. OPERATING ROOM SET UP Each morning and after each case, the anesthesia machine and all equipment must be checked and left ready for any emergency that might arise. The following items must be immediately available and ready to use:

4 Anesthesia machine with breathing circuit (that has been tested for leaks) and mask BP cuff, EKG, and SpO2 cable Laryngoscopes and blades (be sure to check each handle and blade) Styletted ETT of all sizes (6.0, 6.5, 7.0) Immediately available ephedrine, phenylephrine, and succinylcholine. Atropine, glycopyrrolate, and epinephrine should be readily accessible A secure, readily available induction agent and syringe Working suction with tip attached Ambu bag Oral airways Stethoscope A fully stocked obstetric hemorrhage cart and difficult airway cart are immediately available in the OR common area PRE ANESTHETIC EVALUATION Patients on the L&D floor are to be seen and evaluated upon nurse or obstetrician request. In addition, we often elect to evaluate all patients considered high risk as soon as possible, including patients scheduled for trial of labor after Cesarean (TOLAC), obese patients, patients with known or suspected difficult airways, multiple gestation parturients, severe preeclamptics, etc. A focused H&P should include age, gravid and para state, weeks gestation, any complications of current pregnancy, reason for C/S (if applicable), reason for prior C/S (if applicable), previous anesthetics, height, weight, allergies, comorbidities, airway, heart and lung examination, any relevant labs (platelets for a patient with known gestational thrombocytopenia, platelet disorder, HELLP, or clinical history of bleeding; urine protein for patients with preeclampsia; blood glucose for patient with DM, etc.), NPO status, and anesthetic assessment and plan. A baseline maternal blood pressure and fetal heart tones (FHTs) should also be documented. For review of systems, it is important to evaluate whether patients with preeclampsia have visual changes, edema, abdominal pain, headache, or any signs of easy bleeding/bruising. Ask all parturients about GERD, as well as n/v, SOB, CP, and palpitations, when appropriate. HIGH RISK CONSULT SERVICE In concert with the Obstetrics Department, we recently launched a high risk consult service. Obstetricians have been asked to identify parturients considered high risk and send them for an anesthesia consult in advance of the estimated date of confinement (EDC). High risk patients include, among others, super morbidly obese women with other comorbidities, patients with severe scoliosis, patients at risk for hemorrhage (previa, accreta, percreta, for example), patients with bleeding disorders or congenital heart disease, etc. This consult service also gives us an

5 opportunity to meet patients with anesthesia concerns, including those with a history of difficult epidural placement, in advance. Our goal is to assess these patients, order any relevant consults or further work up, and craft an anesthetic assessment and plan, which, in turn, will be circulated among all relevant parties. Residents will, on occasion, be asked to conduct a full H&P on high risk patients in the preoperative evaluation clinic on the 1 st floor at Tulane Lakeside, present their findings to the staff or fellow, and dictate a report. We will provide a template for dictation and ensure access to the dictation services. Importantly, remember to ask the patient to inform the anesthesiologist that she was seen in the high risk clinic when she comes in for her delivery. Also, record the name of the obstetrician on the H&P, the patient s telephone number (in the event that we have to contact her for follow up), and the EDC on the H&P. We have separate binders for high risk patients, both those to be delivered and those already delivered, in the anesthesia stock room on the L&D floor. Printed copies of our dictation or of our H&P are to be placed in alphabetic order in the to be delivered binder until the patient presents for delivery, at which time we can pull the copies and attach them to the patient s clipboard. ASEPTIC TECHNIQUE Infectious complications of neuraxial techniques are rare, but on the rise. The causative organism in the case of meningitis is most often traced to the nasopharnygeal bacteria (specifically, alpha hemolytic streptococci) of the anesthesia provider. As a result, it is considered standard of care to wear a mask, as well as sterile gloves and a scrub hat, while performing neuraxial procedures. It is also reasonable to consider routinely placing a cap on the patient. Chloroprep has been proven to be superior to Betadine in terms of its bactericidal properties. It is not yet available in (or FDA approved for) spinal and epidural kits, but can be dropped onto your open sterile field if you prefer to use it for prepping the patient s back. Finally, handwashing has been shown to be the most effective way to prevent the spread of nosocomial infection; changing gloves is not a substitute for washing hands with each new patient contact. For more information, please refer to Terese Horlocker and Denise Wedel s Infectious complications of regional anesthesia in Best Practice & Research Clinical Anaesthesiology Vol. 22, No. 3, pp , EPIDURAL PLACEMENT AND MAINTENANCE After your H&P is complete and you have withdrawn the appropriate epidural medications (more below) and pressors (ephedrine and phenylephrine), roll one of the two epidural carts into the patient s room (one cart is located in the anesthesia stock room; the other is in the common area between the OR s). Make sure that the cart is properly stocked before using it. The epidural solution of 0.1% bupivacaine with 2 mcg/ml of fentanyl and the ephedrine are located in the Pyxis in the OR common area. Pre made syringes of a loading dose are located in the anesthesia stock room, along with a pre made solution of phenylephrine at a concentration of 100 mcg/ml.

6 Confirm that the patient has a working IV and consider either a crystalloid preload (this is controversial please refer to the ASA Obstetric Anesthesia Guidelines and to your attending staff s clinical judgment) or coload. Although we do not routinely administer aspiration prophylaxis for epidural placement, it is reasonable to consider giving Bicitra 30 ml PO before starting, particularly if there is any concern that the patient may go for an urgent/emergent Cesarean delivery (for example, if there is fetal distress or imminent breech delivery). Nursing guidelines (AWHONN) state that a nurse should be present during all epidural placements in order to monitor both the mother and the fetus and in the event of unanticipated complications. The ASA Obstetric Anesthesia guidelines state: the fetal heart rate should be monitored by a qualified individual before and after administration of neuraxial analgesia for labor. Wash hands; wear gloves, hat and mask. The patient can be placed in either lateral or seated position during placement. The former may provide greater comfort, decrease patient movement, and decrease the incidence of intravascular cannulation, while the latter position may facilitate visualization of the patient s anatomical landmarks. Our epidural kits are equipped with Tuohy needles (we currently stock both 17 G and 18 G needles); either loss of resistance to air or saline (per your comfort level and your staff s preference) is suitable for advancing into the epidural space. Warn the patient of the possibility of a paresthesia before threading the catheter. The literature states that threading the catheter 3 5 cm into the epidural space reduces the incidence of unilateral block, intravascular cannulation, paresthesias, and catheter knotting. Defer to your staff s judgment when threading the catheter. Note that it is important to document both the distance to the epidural space and where the catheter is taped to the skin. Place the patient in a slight lateral tilt during epidural dosing; the nurses are very helpful with positioning, and most rooms are equipped with hip rolls/pillows specifically for this purpose. The catheter should be tested with 3 ml increments of local anesthetic with frequent negative aspirations (i.e., draw back the syringe before each injection to ensure that there is no blood backflow) and frequent blood pressure readings. The traditional test dose with 1.5% lidocaine with epinephrine can be substituted by administering your choice of local anesthetic solution (see next bullet) incrementally with frequent negative aspirations.

7 Once subarachnoid and intravascular catheter placement have been ruled out, the full loading dose should be administered in slow, divided doses with frequent negative aspirations. We currently have 2 loading dose options: a pre made syringe with % bupivacaine with 100 mcg of fentanyl can be administered, followed by patient controlled epidural anesthesia (PCEA) pump settings of 12 ml/hour, with 4 ml bolus every 10 minutes (12/4/10). Alternatively, withdraw 20 ml of the epidural solution (0.1% bupivacaine solution with 2 mcg/ml) from the bag and administer in divided doses, followed by PCEA settings of 8 ml/hour, with bolus of 8 ml every 15 minutes (8/8/15). Evaluate the quality and level of the block, observing the patient for roughly 15 minutes and recording 3 blood pressure readings. Our new Hospira PCEA pumps are excellent for delivering labor analgesia and are fairly simple to use. They require special tubing, so be sure to grab the dedicated tubing from the stock room before you enter the patient s room; alternatively, extra tubing is stocked in the epidural placement carts. Each pump is encased in a hard plastic case/lockbox and has a key (attached via a rubberband) for securing our epidural solutions. When programming the pump, first plug it in (the nurses routinely unplug the pumps after deliveries). Next, press the ON/OFF button. The pump performs a self test and asks that you press ENTER. Next you get 3 program options: press #3 (CLEAR PROGRAM, SHIFT, and HISTORY). If it says KEYPAD LOCKED, press OPTIONS and then press # 3 (FULL LOCK). It then asks you to enter the lock sequence number; to unlock the pump so that you can reprogram it, enter Then resume programming, electing CLEAR PROGRAM, SHIFT, and HISTORY. It will say CLEARING PROGRAM. Next it asks whether you want continuous, bolus only, or continuous + bolus. Choose #3 (CONT + BOLUS). The next page asks you to set the rate and press ENTER WHEN DONE. Next it asks you whether you want to program a loading dose. Say NO. The next page asks for the BOLUS dose; set it and press ENTER. The following page asks for BOLUS LOCKOUT; enter 10 or 15 minutes, depending on your regimen, and press ENTER. Next it asks for your hourly limit; select #4 (NO LIMIT SELECTED). Next it asks you to enter CONTAINER SIZE; enter 250 ml if you haven t removed any solution from the bag; enter 230 ml if you have withdrawn a 20 ml loading dose from the bag. The next page is for AIR SENSITIVITY. Press 2 ml (option #2). Then there s a program review option, and you must press the down arrow to review the program parameters you have selected. When the review is complete, press ENTER. The program will be saved and you must press START to begin the infusion. Program the PCEA pump at either 12/4/10 or 8/8/15, depending on which loading dose you administered, and explain to the patient that she should press the patientcontrolled analgesia button as often as she likes to get a little extra medicine. Explain that the pump is programmed and will not deliver too much medicine or permit an overdose (that is, it will deliver the bolus only every 10 or 15 minutes,

8 depending on your settings, regardless of how often she presses the button). Emphasize the importance of pressing the button as soon as she feels the slightest discomfort in order to optimize her pain management. Several studies have demonstrated broader, improved spread of the epidural solutions when the patient uses the PCEA button; faster boluses are thought to be superior to a continuous slow infusion without the intermittent boluses. After an epidural has been placed, please write the time of placement on the board next to patient s room number (write, for example, Epi at 6:45 am ). COMBINED SPINAL EPIDURAL (CSE) PLACEMENT CSEs are ideal for multiparous parturients who present at an advanced stage of dilation, as well as for laboring patients who present in pain early in labor. They are also routinely performed for C/S (with higher doses of local anesthetic and opioids) when the length of the surgery might outlast the duration of a spinal (e.g., for repeat C/S with tubal ligation, an extremely obese patient whose surgery might take a long time, etc.). That said, the decision to use a particular analgesic or anesthetic technique should be individualized, based on obstetric or fetal risk factors, the preferences of the patient, and the judgment of the anesthesiologist. Discuss whether a CSE is appropriate for your patient with staff. For a laboring CSE, we are having pharmacy provide premade syringes with 1 ml of 0.25% bupivacaine and 15 mcg of fentanyl. Check out the premade syringe from the anesthesia stock room refrigerator. Note that these syringes are not currently available and that several solutions with varying amounts of local anesthetic and opioid are suitable for a CSE; your attending staff will guide you on this front. Identify the epidural space with a Touhy needle via the loss of resistance (LOR) technique. LOR to either air or saline is appropriate; some prefer air to ensure that droplets upon dural puncture are CSF and not saline seeping out of the epidural space. Pass the 25 G Whitacre spinal needle through the Touhy needle until you appreciate a give or dural pop. Then withdraw the stylette from the 25 G Whitacre and, once CSF is visualized, attach a sterile 3 ml syringe in which you have drawn up your solution of 0.25% bupivacaine and fentanyl, and inject without prior aspiration. Using a non Luer lok (i.e., slip tip) 3 ml syringe may facilitate injection of the CSE solution, as you can avoid having to twist the syringe to the 25 G Whitacre and thereby reduce your risk of dislodging the needle. 3 ml non Luer lok syringes are stocked in the epidural carts. Other approaches to a CSE technique include the ESPOCAN combined spinal epidural anesthesia set, equipped with an 18 G Touhy and a 27 G spinal needle, and the individually wrapped 27 G Whitacre, which passes with ease through the 18 G

9 Touhy in the Braun kit. Also, a 25 G Whitacre can pass through an 18 G Touhy, but you may detect some resistance. After the spinal solution is administered, the patient s feet should start to feel warm and contractions should begin to feel less painful within a few minutes. Patients might become hypotensive from the rapid and profound pain relief associated with CSE placement, so be ready to treat with ephedrine. Also, fetal bradycardia associated with the opioid in the CSE solution is not uncommon, and may also be treated with ephedrine, fluids, oxygen by face mask, and by placing the patient in different positions (the nurse is very helpful with these maneuvers). Once the CSE solution has been administered, withdraw the 25 G (or 27 G) needle, while keeping the Touhy needle in place, and quickly thread the epidural catheter. Do not dose the epidural catheter. Rather, start the epidural infusion at the routine settings. Sufficient epidural solution should accumulate in the epidural space by the time the CSE solution wears off. From time to time, it is helpful to ask the patient to press the PCEA button within 30 minutes after the procedure and, again, 30 minutes later to ensure that enough epidural solution has accumulated before the CSE wears off. Warn the patient that she might expect pruritus, which is usually self limited. CESAREAN DELIVERY WITH IN SITU EPIDURAL When a C/S is called on a patient with an epidural in place, first confirm that the epidural is working. Assess the quality and level of the block with the white plastic swords that are stocked in the top drawer of our epidural cart. Feel the patient s legs to assess whether they are both warm (from local anesthetic induced vasodilation). Ask the patient whether she has been comfortable, and ask her to roll slightly to the side while you assess whether the catheter is still in place and still at the site where it was originally taped (refer to the labor anesthetic record for this information). Withdraw the following medications from the Pyxis: 2 vials of 2% lidocaine with epinephrine (also available in the epidural carts), fentanyl 100 mcg (50 mcg per ml concentration), duramorph 5 mg (0.5 mg per ml concentration), midazalam 2 mg, three 10 unit vials of oxytocin, ondansetron, and ephedrine 50 mg and phenyephrine 10 mg (if you no longer have the pressors that were drawn during epidural placement for that patient). If there s any reason to suspect uterine atony (for a patient who has had a prolonged induction, a patient with suspected fetal macrosomia, or a multiple gestation parturient, for example), pull methergine +/ hemabate from the icebox in the stock room. The nurses can pull Cytotec (Misoprostol) from their Pyxis (we do not have access to it). Please be familiar with dosing regimens, indications and contraindications of each of these drugs. In patient s room, ensure that Reglan 10 mg IV, Bicitra 30 ml PO, and Ancef have been administered and that the patient has a working IV for fluid administration.

10 Note that some obstetricians hold off on administration of Ancef until after the baby is delivered; the nurse is aware of individual obstetrician preferences. Disconnect the pump infusion and discard the remaining solution. Then, for nonemergent cases, slowly dose the catheter with 2% lidocaine with epi and bicarbonate (8.4% solution) in a ratio of 9 ml of lidocaine to 1 ml of the bicarbonate. The bicarbonate serves to raise the ph of the local anesthetic closer to its pka and hasten onset. Depending on the patient s block prior to dosing, you may need up to 20 ml of the lidocaine with epi/bicarbonate solution to achieve a T4 block (block at the nipple line). Give this solution in 3 5 ml increments with negative aspiration between each dose and with frequent blood pressure readings. Note that patients who have had the higher PCEA infusion rate of 12 ml/hr, patients who have had a documented wet tap with an 18 G or 17 G needle, and those who have received a CSE may require significantly less 2% lidocaine with epi and bicarb. For emergent cases, test the catheter in the usual fashion, ruling out intravascular and intrathecal migration, and dose with 20 ml of 3% 2 chloroprocaine with bicarbonate (2 ml bicarbonate per 20 ml of chloroprocaine). If the epidural block is equivocal, it is prudent not to dose more than 10 mls of 2% lidocaine with epi and bicarb (as always, in divided doses) prior to considering other anesthetic alternatives such as a spinal for the C/S. 10 ml of 2% lidocaine is more than sufficient to confirm that an epidural is or is not working, as the patient should get a clear level and dense motor block with that amount. If more than 10 ml of the 2% lidocaine is administered in an epidural that is equivocal, you risk a high spinal if the decision is made to abandon that epidural and convert to a spinal. Have the patient s husband or significant other wait in the labor suite (OR clothes are stocked in each room) or outside the OR, where OR pants, shirt, hat, and mask are available, until the patient is prepped and draped and checked for an adequate anesthetic level. In the OR, place the patient in left uterine displacement (LUD) and administer oxygen by nasal canula or face mask. Administer fentanyl 100 mcg per epidural once it has been confirmed that the epidural quality and level are adequate. We routinely administer Duramorph (preservative free morphine) at a dose of mg per epidural for post operative pain relief. From time to time, the epidural blocks unexpectedly provides inadequate anesthesia/analgesia during a C/S, and the patient requires IV analgesic adjuvants such as ketamine, fentanyl or, occasionally, propofol, per your staff s preference. If you withdraw ketamine from the Pyxis, please ensure that it is the 10 mg/ml concentration, as another, higher concentration is also available. Also, ensure that

11 the patient s pain is not due to failure to redose the epidural at the appropriate interval. Once the baby is delivered, start your oxytocin infusion. Premade bags of 20 units pitocin in D5LR are available. Alternatively and more often, we place 30 units in 500 ml of LR. Keep the oxytocin infusion open initially; then reassess uterine tone within a minute or two and turn down infusion if tone is good. When you start the infusion, inform the patient that she might feel flushed or lightheaded and that she might develop a headache. Please be familiar with side effects and adverse effects of oxytocin. Document all doses of local anesthetic administered, in both the labor room and in the OR, as well as vital signs during dosing. Document time of fentanyl and duramorph administration, in addition to your routine careful documentation of all intraoperative events. We currently record intraoperative events on the labor epidural document when we transfer to the OR rather than change to a separate OR record. Indicate on the record the transfer to OR, time, and indication for C/S. Post operative orders are to be filled out for each patient who receives duramorph. After an operative delivery, you are responsible for setting up the OR for the next possible emergency. Ensure that clean equipment, including breathing circuit, nasal canula, ETTs, masks, EKG leads, pulse oximeter, blood pressure cuff and cable, and suction are readily available. Dispose of all used syringes, and waste all unused narcotics. Accompany the patient back to the room and document a final set of vital signs and the end time. TOPPING OFF LABOR EPIDURALS If you get called for inadequate analgesia in a patient with a labor epidural, ask the patient where exactly she hurts and whether her block was adequate earlier in the course of her labor; check the sensory dermatome level with the white plastic sword; evaluate whether the patient has a motor block; feel whether both legs are equally warm; check the labor anesthetic record for previous dose, time and result of last top off and for whether the epidural was a difficult placement; and turn the patient slightly to her side to assess whether the catheter is still in place and still at the original insertion site (see anesthetic record to see where catheter was taped at the skin). Check the infusion pump, tubing, and bag of bupivacaine solution to rule out malfunctions, leaks, or empty bags. Determine the position of the fetus, the station, and the latest cervical exam from the nurse. This may influence the drug you choose to administer.

12 Several top off regimens are appropriate, depending on nature of the patient s pain. For example, if the patient has a dense motor block but a low dermatomal sensory level, you might consider administering a relatively large volume of a low concentration local anesthetic such as 1/8 % bupivacaine or 1% lidocaine or a bolus from the 0.1% bupivacaine epidural pump solution. Alternatively, if the patient has a weak or equivocal block and is in great discomfort, a few mls of 2% lidocaine or ¼ % bupivacaine is appropriate. Fentanyl 100 mcg per epidural and/or a few mls of a high concentration local anesthetic such as ¼ % bupivacaine or 2% lidocaine is often helpful when delivery is imminent and the patient is complaining of perineal pain. Similarly, a high concentration local anesthetic and fentanyl per epidural are useful prior to vacuum or forceps delivery and for manual extraction of the placenta and laceration repairs. Record the sensory level both before and after your intervention, as well as vital signs (including fetal heart tones). Be sure that you have ephedrine readily available as well as a working IV prior to any top offs. Also, stay in constant communication with the patient during top offs in order to evaluate CNS changes that may result from an unanticipated bolus of local anesthetic in the intravascular or intrathecal space. Be aware that catheters can migrate into subarachnoid and intravascular locations; it is essential also to administer top offs in divided doses with frequent negative aspirations. CATHETER PULLS If you have the opportunity, it is good practice to pull the epidural catheter yourself, documenting that the tip is in tact. If resistance is met, it is often helpful to ask the patient to flex her back or assume the position that she was in during epidural placement. After the catheter is pulled, you can close out the chart, documenting the delivery time, Apgars, etc. Empty the infusion bag and document waste in mls on the anesthetic record. If a patient has any complications such as atony, concern for retained products, or excessive bleeding during delivery, it is prudent to leave the catheter in situ until concerns have been resolved and the nurse is ready to transfer the patient to the postpartum unit. SUBARACHNOID BLOCKS When a spinal anesthetic is indicated for a Cesarean delivery, ensure that the patient has a working IV and has received Reglan 10 mg, Bicitra 30 ml PO, and Ancef (unless the obstetrician prefers to hold antibiotics until after delivery). Consider an IV crystalloid preload or coload. According to the ASA Obstetric

13 Anesthesia guidelines: Intravenous fluid preloading may be used to reduce the frequency of maternal hypotension after spinal anesthesia for Cesarean delivery; although fluid preloading reduces the frequency of maternal hypotension, initiation of spinal anesthesia should not be delayed to administer a fixed volume of intravenous fluid. The timing of your fluid administration is controversial; defer to your staff. Ensure that the OR is properly equipped with suction, a breathing circuit, a face mask, nasal cannula, working laryngoscope and blade, ETTs of varying sizes, emesis basin, emergency medications, succinylcholine, an induction agent, etc. Withdraw fentanyl, duramorph, versed, pitocin, ephedrine and phenylephrine (unless a bag with phenylephrine 100 mcg/ml has been prepared already) from the Pyxis, as in the case of an epidural for C/S. Open and prepare the spinal tray (located in the neuraxial block cart in each OR) equipped with a 25 G pencil point needle. Note that we have more than one spinal tray, so review the box contents before opening. In a sterile fashion, draw up mls (depending on patient s height, weight, and number of prior Cesarean deliveries, as well as on your staff s preference; we often use 1.6 mls) of the 0.75% bupivacaine into the sterile syringe. Use the filter straw that is provided in the kits to draw up your local anesthetic, as glass particles from the glass bupivacaine vial can otherwise contaminate your anesthetic solution. Have an assistant draw up fentanyl (10 20 mcg, depending on your staff s preference) and duramorph ( mcg, depending on staff s clinical judgment) in a TB syringe and insert it into your bupivacaine solution. Alternatively, drop a TB syringe onto your sterile field and withdraw the appropriate amount of each opioid while an assistant holds the vials for you. Push air bubbles out your spinal mix prior to starting the procedure. Occasionally we also add epinephrine to our local anesthetic/opioid mix for subarachnoid blocks in order to prolong the effect and, possibly, for enhanced analgesia. The epinephrine is available in the kits, and you can do an epi wash before drawing up your 0.75% bupivacaine by showering the inside of your syringe with epi. Alternatively, consider adding mcg of epinephrine to your local anesthetic/opioid solution. Note that some practitioners prefer to avoid epinephrine in the setting of preeclampsia or hypertension. Also, please be careful to distinguish between the epinephrine and bupivacaine glass vials, both of which are supplied in the kits. When drawing up your medications, look at the vial, read the expiration date and concentration of the bupivacaine, and keep the smaller epinephrine glass vial a safe distance away in order to minimize medication errors. The patient may be seated or in the lateral position during placement of a subarachnoid block. All monitors should be in place and your pressors should be immediately available (some may prefer to pretreat with IV or IM ephedrine). After the 25 G pencil point needle is advanced through the introducer until a dural pop is detected, withdraw the stylette and watch for CSF backflow. Attach the syringe with the spinal solution carefully to the 25 G and hold steadily in place; it is helpful to visualize a small whirl of CSF in the syringe prior to injecting the solution

14 by gently withdrawing the syringe. Warn the patient that her legs will start feeling heavy and warm as the solution is administered into the intrathecal space. After administering the solution, have the patient immediately lie down (if she had been seated) or roll over on her back (if she had been in the lateral position) and place the patient in left uterine displacement. Administer oxygen by nasal cannula or face mask, take frequent blood pressure readings, and maintain constant communication with the patient for several minutes as the spinal sets up. Ask that the patient alert you if she begins to feel nauseated, light headed, confused or dizzy, as these are early signs of hypotension or a high block. Be prepared to treat with ephedrine or phenylephrine and IV hydration. Be familiar with the OR set up, particularly with where emergency equipment and drugs are located. If patients get anxious and feel that they cannot breathe, for example, reassurance and continuous communication is often helpful, as is having the significant other join you in the OR. Versed in 1 2 mg IV also helps alleviate the anxiety, although some practitioners prefer to hold off until after delivery. Assess the level of your block with the white plastic swords. Ask the patient to squeeze your hands is an effective way to rule out a high block, as is listening for a strong, unchanged voice. Alternative spinal kits and needles are available for difficult cases, such as super morbidly obese parturients. Please defer to your staff. For repeat Cesarean deliveries (a third or fourth C/S), patients who are super morbidly obese, patients who have had multiple abdominal procedures and have suspected adhesions, patients who desire tubal ligation after Cesarean delivery, patients with previas, accretas, or other uterine pathology, etc. a combined spinal epidural may prove an appropriate anesthetic technique. The CSE for a surgical procedure is performed in the same manner as a CSE for laboring patients, but the 0.75% bupivaine/opioid solution described in this section (+/ epinephrine) is administered in lieu of the lighter local anesthetic solution used during labor. When performing a CSE for surgical procedures, thread the catheter quickly after administration of the anesthetic solution and place patient supine with LUD as swiftly as possible. COMPLICATIONS OF NEURAXIAL BLOCKS Hypotension: Hypotension is a common side effect of administration of local anesthetic in the epidural or subarachnoid space. Confirm LUD, evaluate the patient for symptoms (n/v, dizziness, lightheadedness, etc.), and assess the fetal heart tracings. Open the IV fluids and administer ephedrine if the patient is symptomatic, the fetus is in distress, or if there is a greater than 20% drop in SBP. Consider oxygen by mask or positional maneuvers. Get help, if necessary. Check the patient s anesthetic level and rule out inadvertent spinal, accidental excess local anesthetic dose, etc.

15 Wet Tap: Remain calm and reassure patient. Immediately take a course of action: either thread the catheter intrathecally or remove the Tuohy needle and attempt epidural placement at another level. If you opt to thread the epidural catheter into the intrathecal space, 2 5 cm (maximum) should suffice. Confirm backflow of CSF, and dose the intrathecal catheter for a laboring patient per your staff s preference. You might start with 1 ml of 0.25% bupivacaine with fentanyl 15 mcg (as we do with CSEs for laboring patients), followed by a continuous infusion of 1 ml of 0.1% bupivacaine with 2 mcg/ml of fentanyl per hour. Adjust you dose as necessary, but be sure to opt for continuous infusion on the pump settings and to disable the patient controlled dosing option. Tell the patient that her catheter is in the CSF space and that she might be at risk of a headache, explaining that wet tap with headache is a not unusual complication of epidural placement. Label the catheter as intrathecal, advise the nurse and all staff, and write intrathecal catheter on the board next to the patient s name. If you opt to remove the Touhy and attempt epidural placement at another level, advise the patient that she might develop a headache. Also, be aware that dosing the epidural in the setting of a prior frank wet tap might require dosing adjustments. Dose the epidural prudently and with frequent assessements and blood pressure measurements; reassess the patient frequently during the course of her labor. Document that the patient had a wet tap on both the labor record and in our logbook in the stock room. Also, pass on the word to staff and team members who take over after you. Follow up on these patients for 3 5 days postpartum, assessing for any signs of postdural puncture headache (PDPH). On occasion it takes multiple attempts to locate the epidural space, placing the patient at risk for a dural tear even in the absence of a frank wet tap. Please inform the patient and team members who assume care once your shift is over that the patient may be at risk for a headache. Communication is essential in this scenario, as otherwise the patient may go untreated for a PDPH. PDPH: Whether the patient is in the hospital or at home, obtain and review the chart. Evaluate needle size, difficulty of placement, number of attempts, and whether there was a frank wet tap. The nursing supervisor is available 24 hours/day in the hospital and can obtain the anesthetic record from Medical Records at any hour. Evaluate the nature of the headache. When did it start? Is it positional? Where does it hurt? Is it totally relieved when lying down? Does patient have tinnitus, visual changes or nuchal rigidity? Does she recall whether the epidural placement was difficult or was she warned that she might develop a headache? Does she have a history of headaches, and is this headache similar to her usual headache? Has she resumed her normal caffeine intake and has she been eating? Does she have a history of high blood pressure, was her pregnancy complicated by high blood pressure or preeclampsia, and what is her blood pressure currently? Is she febrile?

16 Examine the spinal/epidural injection site and assess patient s motor strength. Assess also the patient s hydration status. Conservative management for a PDPH is a good option for 24 hours. Consider bed rest, with the head of the bed flat; hydration; scheduled motrin or fioricet; antiemetics, if necessary; have the patient resume her caffeine intake and avoid alcohol; explain the probable etiology of the headache and the epidural blood patch treatment option. A blood patch can be considered if the patient declines conservative treatment, is to be discharged that day, has documented evidence of a frank wet tap, or fails conservative treatment. Explain all the risks and benefits of an epidural blood patch and have patient sign a consent form prior to the procedure. An anesthetic record should be filled out for a blood patch. A fellow or staff member will either perform the blood patch or assist you. After a blood patch, instruct the patient to avoid straining, rapid bending, bearing down, or lifting heavy objects for several days. Also ask her to refrain from alcohol intake. She can continue taking motrin or fioricet (taper the latter in the usual fashion). Request that the patient return to the ER or for an anesthesia consult if the headache recurs, a fever or stiff neck develops, she develops numbness or weakness in her lower extremities or bowel/bladder dysfunction, if increased redness or tenderness develops at the injection site, or if she has any questions or concerns about her anesthetic care. Advise the patient that in a small percentage of the cases, a second epidural blood patch may be required. Give her statistics regarding the success rate of a first blood patch, the success rate of a second, the timeframe for resolution of the headache if it recurs, etc. Record that a blood patch was performed on that patient in the log in the stock room. Asymmetic Sensory Block: A unilateral block is a common complication of epidural procedures. It is often associated with a catheter being threaded (or migrating) too deep into the epidural space (literature suggests that threading the epidural catheter 3 5 cm is optimal) or with having the patient lie on one side for too long. To troubleshoot, roll the patient on her side and ensure that the catheter is at the proper depth at the skin; if it has migrated inward, pull it back to the site where it was originally taped at skin and, after repositioning the patient on the side without the block, either give a manual bolus of a local anesthetic solution or ask that the patient press her PCEA button. If the catheter is still where it was originally taped, roll the patient on the side that has diminished analgesia, withdraw the catheter 1 2 cm and bolus as above. Remember to aspirate prior to administering any bolus. Patchy Block: Assess where the patient is feeling discomfort. Does she have a window of pain? Is she experiencing perineal pain immediately prior to delivery?

17 Rule out a subdural block; to do this, you must be familiar with the manifestations of a subdural block. If you feel certain that the patient is experiencing a subdural block, consider immediately replacing the catheter. If the patient is experiencing perineal pain, consider fentanyl 100 mcg per epidural or a few mls of a dense local anesthetic solution, as described in the troubleshooting section. If the epidural is working properly and the patient has a window of pain, consider a bolus of a dense local anesthetic solution with the patient lying with the unblocked segment down. Have a low threshold for replacing these catheters, as it is often difficult to remedy a window. Fetal Bradycardia: Ensure that the nurse is present and has placed the patient on her side to avoid compression of the blood vessels. Consider oxygen by mask. Evaluate the patient for symptoms of hypotension; take a blood pressure reading. If the patient is symptomatic or hypotensive, open the IV fluids and administer ephedrine. Administering ephedrine is often helpful also in the absence of overt hypotension. Notify your team if the bradycardia continues and if there is concern for imminent C/S. Have 20 ml of 3% 2 chloroprocaine with 2 ml of bicarbonate drawn up for immediate dosing of the epidural if proceeding to the OR emergently is imminent. Intravascular Injection: When testing a catheter, remember that every dose is considered a test dose. Use 3 ml increments of local anesthetic with frequent negative aspirations and frequent blood pressure readings. To assess for intravascular injections, ask if the patient has ringing in the ears, dizziness, circumoral numbness or a metallic taste on the tongue, restlessness, or sudden onset anxiety. Watch for tachycardia (if an epinephrine containing local anesthetic was used) and for seizure (if a large amount of high concentration local anesthetic was dosed at once). Also, take a small syringe and draw back for blood when evaluating a suspicious scenario. Hold the syringe below the level of the patient as you gently and protractedly draw back. Of note, remember that we routinely administer 100 mg of lidocaine intravenously in the OR without noting any of these signs and symptoms described above; several mls of the local anesthetic solution may be necessary for the patient to detect any sensory changes. Also, be reassured that we use low concentrations of local anesthetic in small, incremental doses with frequent aspirations in order to minimize complications of intravascular injections. Lastly, the soft, wire reinforced catheters in common use today have a lower incidence of intravascular cannulation. In the event of a known intravascular injection of doses greater than a test dose or if the patient is symptomatic, stop injecting, get help STAT, prepare for administering oxygen and protecting/supporting the airway, and prepare

18 emergency drugs, including lipid. Have a low threshold for transfer to the OR, if the problem persists. OBSTETRIC ANESTHESIA CURRICULUM: LEVEL 1 Note: For specifics on fulfilling the 6 core competency requirements, please refer to the Obstetric Anesthesia guidelines posted on the Tulane departmental Website. The following provides an abbreviated version of expectations for your manual skills development and your core knowledge acquisition over the course of your rotations in Obstetric Anesthesia. The curricula below are modified from the Society for Obstetric Anesthesia and Perinatology (SOAP), and are not intended to be exhaustive. Manual Skills Development: Residents are expected to learn and develop proficiency in the following skills during routine cases: 1) epidural catheter placement with a success rate of 70% by the end of the month; minimal number of wet taps 2) subarachnoid block placement with a success rate of 70 80% Core Knowledge Acquisition: A) Maternal physiology prior to labor and delivery a. Cardiovascular system: cardiac output, stroke volume, heart rate, systemic vascular resistance, blood pressure, and blood volume b. Describe the effects of supine position on blood pressure and uterine blood flow c. Pulmonary, respiratory and airway: functional residual capacity, tidal volume, respiratory rate, minute ventilation, alveolar ventilation, work of breathing, airway resistance, chest wall compliance, arterial blood gases, ventilation/perfusion matching, and Mallampati (both over the course of pregnancy and during labor) d. Gastrointestinal: gastric motility, gastric emptying, lower esophageal sphincter tone, gastric ph, risk of aspiration pneumonitis e. Hematologic: hematocrit, blood volume, platelets, white blood cells, coagulation factors, fibrinogen f. Renal: BUN, Cr, glomerular filtration rate, renal blood flow g. Endocrine and metabolism: progesterone, estrogen, prolactin, aldosterone, angiotensin, rennin, cortisol, prostacyclin, thromboxane, insulin and glucose, etc. h. Musculoskeletal: back pain, sciatica, carpel tunnel syndrome, lordosis i. Central nervous system: pain tolerance, anesthetic requirements for both general and regional anesthesia B) Fetal and placental physiology a. Embryogenesis b. Placental development and structure c. Placental gas exchange, nutrient transport, drug transfer d. Fetal circulation

19 e. Fetal evaluation: Intrauterine growth restriction (IUGR), non stress test (NST), biophysical profile (BPP), fetal heart rate (FHR), fetal blood gas values, etc. C) Neonatal physiology a. APGAR b. Physiologic adaptations to extrauterine life, including circulatory and respiratory changes c. Resuscitation of the newborn: what is the role of the anesthesiologist? D) Local anesthetics a. General principles of LA pharmacology b. Criteria for selecting specific LAs c. Describe effects on maternal circulation, uterine tone, uterine blood flow, and FHR d. Effect of vasoconstrictors e. Effect of sodium bicarbonate on onset and duration f. Signs and symptoms of systemic toxicity g. Neurotoxic effects E) Agents affecting uterine tone a. Agents that affect uterine tone: volatile agents, ketamine, nitroglycerine b. Tocolytics: Ethanol, Mg, calcium channel blockers, etc. c. Uterotonics: Pitocin, Cytotec, Methergine, Hemabate. F) Opioids: a. Opioid agonists for neuraxial blockade b. Treatment of opioid side effects c. Mixed agonist antagonists d. Effects on the fetus G) Drug interactions a. What are the effects of vasoactive agents on the onset, intensity, and duration of sensory and motor effects of LAs? b. What are the effects of opioids on the onset, intensity, and duration of sensory and motor effects of LAs? c. What is the effect of sodium bicarbonate on the onset, intensity, and duration of LAs? d. How does magnesium affect neuromuscular blocking drugs? H) Management of labor a. Describe the first (active and latent phases), second and third stages of labor b. Describe the effects of uterine contractions on placental exchange and fetal oxygenation c. Describe the anatomy of the epidural space d. What are the clinical manifestations of uterine hypertonus and hyperstimulation e. Does epidural analgesia affect labor? f. How does labor affect maternal hydration, ventilation, and hemodynamics?

20 I) Regional anesthetic techniques for the obstetric patient a. Describe techniques available for routine labor and vaginal delivery, vacuum or forceps delivery, manual extraction of the placenta, uterine inversion, non urgent and emergent Cesarean delivery, dilation and curettage (D&C), tubal ligation, and cervical cerclage b. Describe neurologic pathways that convey pain during the first and second stages of labor c. List all regional anesthetic techniques that can produce effective analgesia in the first and second stages of labor d. List absolute and relative contraindications of regional anesthesia e. Describe the hemodynamic effects of epidurals and subarachnoid blocks f. List complications of regional anesthesia, including PDPH, backache, nerve palsy, meningitis, abscess, and hematoma J) General anesthetics for obstetrics a. What are some of the concerns about administering general anesthesia to a parturient, both early in pregnancy and at term? b. List indications for general endotracheal anesthesia c. What are the ventilatory requirements for parturients? d. Describe how drugs used in the induction and maintenance of general anesthesia affect uterine tone, fetal perfusion, and the neonate e. Describe the steps of the difficult airway algorithm K) Resuscitation a. Describe clinical factors (both maternal and fetal) that are predictive of a need for neonatal resuscitation b. Describe ideal management of maternal resuscitation L) Complications of anesthesia during pregnancy a. Aspiration pneumonitis b. Failed intubation c. Complications during emergence d. PDPH e. Common neurologic complications M) Anesthetic management of non obstetric surgery during pregnancy a. Describe advantages and disadvantages of performing elective operations during the first, second and third trimesters of pregnancy b. When is fetal heart monitoring (FHM) indicated? c. Do our anesthetic agents affect the fetus? Which ones? How? d. Discuss the effects of maternal hypotension, hyperventilation, hypoventilation, and blood transfusion on fetal well being N) Ethical Issues a. Discuss the potential for maternal fetal conflicts of interest b. Discuss the current gestational age weight limits for fetal viability c. Discuss informed consent issues d. Demonstrate an understanding of divergent religious points of view O) Crisis aversion

21 a. Causes and management of fetal distress: umbilical cord prolapse, uterine rupture, vasa previa, uterine rupture, hemorrhage b. Causes and management of vaginal bleeding: placenta previa, abruptio placenta, uterine rupture, uterine atony, retained products of conception c. Causes and management of hypertension in pregnancy: chronic HTN, gestational HTN, preeclampsia, eclampsia d. Causes and management of coagulopathy in pregnancy: HELLP, abruption e. Diagnostic criteria and anesthetic management of preeclampsia and eclampsia: BP control, seizure prophylaxis, drug interactions OBSTETRIC ANESTHESIA CURRICULUM: LEVEL 2 Manual skills development: The goal at this level is to master skills, with emphasis on efficiency. By the end of the month you are expected to: 1) place epidurals in less than 10 minutes, with a low replacement rate, low wet tap/pdph rate, and high (80%) success rate 2) place subarachnoid blocks in 5 minutes, with a 90% success rate Anesthetic and obstetric management of high risk pregnancy: For each of the following disease processes, be prepared to: list common obstetric concerns and management strategies; describe the anesthetic implications, focusing on maternal and fetal considerations; assess the severity of the disease and determine when a patient s condition warrants ICU or high risk unit care; describe the anesthetic management options for vaginal and Cesarean delivery A) Hypertensive disorders of pregnancy a. Chronic HTN b. Preeclampsia/eclampsia: diagnostic criteria, epidemiology, pathophysiology, HELLP syndrome, and medical/obstetric management (with emphasis on term vs. preterm fetus, mild vs. severe disease, seizure prophylaxis and Mg effects, antihypertensive medication options, management of oliguria, and indications for invasive monitoring) B) Multiple gestation: a. List and compare risks associated with multiple gestations b. Distinguish these risks with twins vs. triplets vs. quadruplets C) Preterm labor: discuss risks (fetal and maternal) associated with preterm labor and tocolytic therapy D) Abnormal fetal presentations E) Antepartum and postpartum hemorrhage F) Maternal and fetal infection G) Endocrine disease

22 a. Diabetes, with emphasis on the criteria for diagnosis, indications for therapy, effect of pregnancy on the disease process, fetal effects of the disease, and the effects of treatment on both mother and fetus b. Thyroid disease, with emphasis on diagnosis and treatment of both hypothyroidism and hyperthyroidism H) Substance abuse a. Identify risks and complications b. Recommend postoperative pain control strategies c. Develop a plan for complications of withdrawal I) Immunologic disease J) Neurologic disorders a. Multiple sclerosis b. Spinal cord injury c. Myasthenia gravis d. Seizure disorders K) Respiratory disease a. Asthma, including the pathophysiology, the effects of pregnancy on asthma, and asthma s effects on pregnancy b. ARDS L) Cardiovascular disease a. Congenital heart disease b. Ischemic heart disease c. Valvular heart disease d. Peripartum cardiomyopathy M) Hematologic and thromboembolic disease a. Anemias b. Thalassemias c. Sickle cell disease d. Thrombocytopenias e. Platelet and bleeding disorders f. Anticoagulation medications N) Morbid Obesity O) Malignant Hyperthermia P) Renal disease Q) Liver disease R) Musculoskeletal disorders a. Scoliosis b. Rheumatoid arthritis c. Spina bifida d. Prior back surgery OBSTETRIC ANESTHESIA CURRICULM: LEVEL 3 A) Act independently as a consultant, formulating an anesthetic plan for highrisk parturients

23 B) Develop critical evaluation skills C) Develop management and leadership skills a. Demonstrate independence b. Develop communications skills c. Demonstrate leadership d. Supervise junior residents e. Teach junior residents and participate in management tasks f. Introduction to clinical research g. Bedside teaching