Evaluation of Sedation Failure in the Outpatient Oral and Maxillofacial Surgery Clinic

Transcription

1 Evaluation of Sedation Failure in the Outpatient Oral and Maxillofacial Surgery Clinic Figen Cizmeci Senel, DDS, PhD,* James M. Buchanan, Jr, DDS, Ahmet Can Senel, MD, and George Obeid, DDS J Oral Maxillofac Surg 65: , 2007 Purpose: Our goal was to report on the incidence of sedation failures in our outpatient oral surgery clinic. Sedation failure is the inability to complete a procedure under intravenous sedation. There is very little in the oral surgery literature on this subject. Materials and Methods: Proper Institutional Review Board approval was obtained from the appropriate governing body for this project. The medical records of 539 intravenous sedation patients treated at the Oral and Maxillofacial Surgery Clinic at our institution were retrospectively evaluated to determine the incidence of failed sedation. Patients sedated with midazolam and fentanyl were placed in group A. There were 323 patients in group A. We placed patients sedated with midazolam, fentanyl and methohexital into group B. There were 216 patients in group B. The gender, medical history, type of procedure being performed, amount of drug given, and the patient s vital signs throughout the procedure were recorded. Results: There were 9 failed sedations with a rate of 1.6% (9/539); 3 in group B (1%) and 6 in group A (2%). Five of our failures were undergoing multiple tooth extractions. Two of the failures were undergoing surgical removal of impacted third molars. Two patients underwent mandibular fracture reduction. Failure was attributed to increased agitation and ness, uncontrolled hypertension, tachychardia and desaturation. Conclusion: The mandible fracture population and multiple teeth extraction patients had higher rates of failure than other groups. This may be the result of procedure length, type of procedure, or a preoperative anxiety and attitude toward treatment expressed by the patient making sedation unpredictable. Level of training and experience of the practitioner may contribute to sedation failure. These results allow us to develop a prospective study protocol of outpatient sedation and to quantify more detailed information about preoperative anxiety, medical status, and social history than we had available during our chart review. More specific conclusions may help us determine if certain patient populations are at a higher risk for failed sedations American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 65: , 2007 Deep sedation/general anesthesia (DS/GA) is often indicated for the relief of anxiety for outpatient oral surgery. DS/GA is defined as an induced state of depressed consciousness or unconsciousness accompanied by partial loss of protective reflexes, including the inability to continually maintain an airway independently or respond purposefully to physical stimulation or verbal command, and is produced by a pharmacologic or nonpharmacologic method or combination thereof. 1,2 In combination with local anes- *Formerly, Research Fellow, Department of Oral and Maxillofacial Surgery, Washington Hospital Center, Washington, DC; Currently, Assistant Professor, Department of Oral and Maxillofacial Surgery, Karadeniz Technical University, Faculty of Dentistry, Trabzon, Turkey. Former Senior Resident, Department of Oral and Maxillofacial Surgery, Washington Hospital Center, Washington, DC. Associate Professor, Department of Anesthesiology and Reanimation, Karadeniz Technical University, Faculty of Medicine, Trabzon, Turkey. Chairman, Department of Oral and Maxillofacial Surgery, Washington Hospital Center, Washington, DC. Address correspondence and reprint requests to Dr Cizmeci Senel: Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Karadeniz Technical University, Trabzon, Turkey; fcsenel@hotmail.com 2007 American Association of Oral and Maxillofacial Surgeons /07/ $32.00/0 doi: /j.joms

2 646 SEDATION FAILURE IN THE OUTPATIENT OMS CLINIC thesia, it is a safe and effective method of treatment. However, it is not always effective in allowing the physician to complete the planned oral surgical procedure. On occasion, a procedure is left unfinished due to patient ness and discomfort in spite of increases in sedative doses. In a review by Egelhoff et al 3 of 6,006 patients sedated for diagnostic and invasive procedures, a 1% sedation failure rate utilizing different drug regimens including pentobarbital, chloral hydrate, and other regimens was found. Hoffman et al 4 reviewed multiple complications encountered during non-anesthesiologist-administered sedation and found a 1.35% rate of sedation failure out of 960 cases of radiologic procedures, emergency department procedures, and invasive medical interventions. Slovis et al 5 found a failure rate of 1.4% (40 of 2,857). This was a study of pediatric patients sedated for imaging procedures utilizing a drug regimen of pentobarbital, chloral hydrate, midazolam, diazepam and fentanyl. Mason et al 6 looked at sedation failure rates for magnetic resonance imaging and computed tomography studies of pediatric patients using different drug regimens. He found a 0.6% sedation failure rate using pentobarbital and midazolam; a 1% sedation failure rate using pentobarbital, midazolam and fentanyl; and a 3% sedation failure rate using pentobarbital alone. There is very little in the oral and maxillofacial surgery literature investigating DS/GA failures. The invasive procedures referred to in the above studies included central line placement, laceration closure, and other less stressful procedures. Our purpose in this study was to determine the incidence of failed DS/GA in patients undergoing oral and maxillofacial surgery and identify risk factors for failed sedation. Study Design Table 1. SURGICAL PROCEDURES PERFORMED Procedures Total Patients Third molar removal 265 Multiple tooth extraction 157 Single extraction 31 Implant placement 21 Closed reduction of mandible fracture 17 Arch bar removal 13 Bone graft 8 Sinus lift 6 Biopsy 5 Canine exposure 5 Arthrocentesis 4 Excision of cyst 2 Torus excision 1 Ridge expansion 1 Alveoplasty 1 Soft tissue reconstruction 1 Removal of sialolith from submandibular duct 1 Senel et al. Sedation Failure in the Outpatient OMS Clinic. J Oral Maxillofac Surg The medical records of 539 patients treated under DS/GA at the Oral and Maxillofacial Surgery outpatient clinic at our institution from December 2000 through May 2002 were retrospectively reviewed to determine the incidence of failures. We separated our patient population into group A and group B. Group A patients were sedated using intravenous (iv) fentanyl and midazolam. Group B patients received fentanyl, midazolam, and methohexital. There were 323 patients treated in group A (129 male and 194 female) aged between 12 and 80 years, with a mean age of 46 years. Group B had a total of 216 patients (87 male and 129 female) with an age range between 13 and 55 years, with a mean age of 35 years. All patients included ASA I II III and had no contraindications to the study medications. Appropriate medical consults are obtained when necessary. We also examine the oral airway and physical characteristics of the neck to rule out tracheal deviation, masses, or other mechanical interferences that would compromise the patient s ability to breathe under DS/GA. The patients are given clear instructions to have nothing to eat or drink after midnight prior to their appointment except for their medications; they can be taken with a sip of water. In group A, the procedures were started with 0.03 to 0.06 mg/kg midazolam and 1.5 g/kg fentanyl. Two percent lidocaine with 1:100,000 epinephrine was administered to all patients for local anesthesia. According to patients responses to local anesthesia administration, body habitus, etc, an additional dose of midazolam in the range of 0.03 to 0.15 mg/kg was added and then the procedure was started. It was uncommon to administer more than 1.5 g/kg of fentanyl. In group B, the procedures began with 2 to 4 mg of midazolam and 100 g fentanyl. A bolus dose of methohexital to desired levels of anesthesia in doses of 10 to 15 mg was administered. The total dose of methohexital varies from 50 to 200 mg, depending on patient body habitus, length of procedure, and overall response to anesthesia and the procedure being performed. We used lidocaine 2% with 1:100,000 epinephrine to achieve local anesthesia. No patients were converted from group A to group B by adding methohexital to complete a DS/GA. The procedures were performed by a senior resident who was supervised by a member of the attending staff. A summary of the surgical procedures performed is shown in Table 1. We defined failed sedation as the inability to complete the planned procedure.

3 SENEL ET AL 647 Results Nine failed DS/GA were found in all patients (1.6%). Three of the 9 were in group B (1%) and the other 6 were in group A (2%). DS/GA failures were due to increased levels of agitation and ness by the patient, blood pressure above the level safe to continue the procedure, paroxysmal ventricular contractions manifested during the sedation, and paroxysmal ventricular contractions with desaturation. Patients who failed DS/GA ranged in age from 15 to 54 years of age, with a mean age of 28 years. Five of 157 (3.18%) patients having multiple teeth extracted experienced DS/GA failure. Two of 265 patients (0.75%) undergoing surgical removal of impacted third molars and 2 of 17 patients (11.76%) undergoing mandibular fracture reduction experienced DS/GA failure. A summary of the failures is shown in Table 2. Discussion Nine of 539 patients failed DS with a rate of 1.6%. This is consistent with failure rates reported by others. However, it is hard to compare our study with those of others. Most studies used medication regimens different from ours, including diazepam, pentobarbital, meperidine, chloral hydrate, and propofol. Oral and maxillofacial procedures are also always invasive in nature, causing pain and discomfort to the patient. Radiological procedures are noninvasive even though some may cause claustrophobia and anxiety in pediatric populations. 7,8 Oral surgery causes pain and requires local anesthesia and iv medications when indicated Most studies looked at sedation failures in noninvasive or minimally invasive procedures. They considered central line placement, suturing of lacerations, and starting an iv as invasive. The study by Hoffman et al 4 included noninvasive and invasive procedures performed in a pediatric emergency department and found a 1.35% (13/960) sedation failure rate. Pena and Krauss, 12 in a similar study of invasive and noninvasive procedures in a pediatric emergency department, found a 0.85% (10/1180) failure rate. Invasive procedures performed in the emergency department are often shorter and less stressful than those performed by an oral surgeon. Stress from pain, pressure and auditory stimuli of a roto-osteotome during oral surgery are very challenging to manage during DS. The above studies include pediatric and adolescent populations, whereas our study includes older patients. The maturity of a patient may affect their level of anxiety toward oral surgery, which can affect the success of a DS. Even though our DS failures were mostly adults (aged years), a preconceived notion about dental procedures should be assessed when studying patient populations that may fail. A preoperative dental anxiety level can be evaluated using the Corah Dental Anxiety Scale. This was described for use in general dentistry and later modified for oral surgical procedures. This is a questionnaire of the patient s attitude to certain dental scenarios. A numerical score is given, based on how the questions are answered, that correlates to a high or low level of anxiety by the patient toward their oral surgical treatment. 13 Our patients choose to have their procedures performed under DS because they have an increased level of anxiety toward dental procedures in general. It has been shown that DS versus local anesthetic decreases this anxiety level and allows the oral and maxillofacial surgeon to perform surgery successfully. 13 Malviya et al 7 found that patients who failed noninvasive radiologic procedure sedation were less well adapted to medical treatment than those who were successful. They conclude that a preoperative assessment of the patient s temperament should be obtained to determine whether patients can be successfully sedated. There is nothing published that studies anxiety levels on the success or failure of sedation in adult populations. The alleviation of preoperative dental fear can be facilitated by a comforting atmosphere in the operatory. This soothing environment can be very difficult to establish in a hospital oral surgery clinic for many reasons. Because of this, a patient s sense of security may not be established as effectively as in a private office. It is difficult to objectively evaluate your clinic environment, but we need to consider the effect of clinic atmosphere on our patient s perception of their treatment when evaluating sedation failure. Oral surgery often uses local anesthesia in addition to the iv medications used. Inadequate local anesthesia creates an obvious challenge during DS and cannot generally be overcome by an increase in the dose of a sedative agent. Some of our failures may be due to missed mandibular blocks and a lack of profound anesthesia. Successful anesthesia of an abscessed tooth with swollen surroundings can, at times, be difficult. Some procedures can be quite uncomfortable even with good local anesthesia. Two of 17 (11.76%) of our mandibular fracture group failed DS. The manipulation of a fractured mandible can be quite uncomfortable. Obtaining adequate local anesthesia to cover a fractured site as well as the surrounding bruised area is difficult to accomplish. The painful stimuli in an already suffering and frightened patient are enough to arouse them during DS. It is reasonable to expect that longer DS/GA may be more prone to failure, but this was not found to be a significant factor in our study. Eight of our failures

4 Table 2. SUMMARY OF SEDATION FAILURES Patient Group Cause of Failure 2 A Agitated and 4 A Agitated and Age (yrs) Gender Relevant Medical History Type of Surgery 18 M None Closed reduction fracture mandible 21 M Frequent alcohol consumption Closed reduction fracture mandible 5 A Significant hypertension 54 F HTN and an old stroke Multiple extractions 6 A Agitated and 24 F Mild anemia Third and molar hypothyroidism surgery 8 A Significant 47 M HTN/diabetes/ Multiple hypertension impaired tooth renal extraction function 9 A Agitated and 28 M None Full mouth extractions 1 B PVC 25 F None Third molar surgery 3 B Tachycardia and desaturation 7 B Agitated and 15 F Blind Multiple extractions 21 M HIV Multiple tooth extraction Senel et al. Sedation Failure in the Outpatient OMS Clinic. J Oral Maxillofac Surg Procedure Cancelled After (minutes) Fentanyl (mcg) Midazolam (mg) Methohexitone (mg) Local Anesthesia (mg) Vital Signs During Procedure Within Within /110 mmhg Within /120 mmhg Within Within Pulse beats/ min Within 648 SEDATION FAILURE IN THE OUTPATIENT OMS CLINIC

5 SENEL ET AL 649 were procedures terminated at less than 30 minutes. Patient 9 became agitated and after 75 minutes; 19 of 26 teeth were removed prior to terminating the procedure due to increased levels of agitation and ness. He received 6 mg midazolam and 200 ucg of fentanyl. He was a 28-year-old healthy African American male, but was and anxious from the start of the procedure, making the extraction of his teeth quite challenging. As in all the other procedures, the operator was a resident who may not have had enough experience to manage a full mouth of extractions on a difficult patient. This may have also contributed to the prolongation of the procedure. Five failures were due to patient agitation and ness. They only received 4 to 6 mg of versed and 100 to 200 ucg of fentanyl. This is a significant dose, and with adequate local anesthesia should allow for successful surgery. It is important to consider whether increased doses of versed with added local anesthesia would have allowed us to complete the procedure. However, with the increased level of alertness and the ness, it was believed that deepening the sedation would not allow us to accomplish the remaining invasive part of the procedure. The patient s confidence in the process was already lost, and it would be very hard to calm their fear once they reach this distrustful phase. One would think that converting patients from group A to group B would solve this problem by adding methohexital to the regimen, but this was not attempted with our patients. There is evidence that paradoxical reactions to barbiturates and benzodiazepines occur in select populations. These reactions are manifested as overt excitement in the presence of pain with the administration of barbiturates. This is explained by an overall suppression of inhibitory mechanisms and a lack of sedative effect by the medication. Benzodiazepines have documented paradoxical reactions including nightmares, ness and other untoward effects. 14,15 Morphine and other narcotics can cause histamine release. This has not been seen with fentanyl. Three procedures in our review were due to cardiovascular complications developing after the initiation of the procedure. General anesthetics alter a patient s response to painful stimuli and their internal hemodynamic control mechanisms. Hoffman et al s study 4 states that non-anesthesiologist-administered sedation is safe and effective, but that complications are avoided by adhering to a strict presedation protocol, including a risk assessment based on factors such as medical conditions and patient history of anesthetic complications. Pre-existing medical conditions that are well controlled should not exclude one as a candidate for DS. One of these 3 failures was a patient with a history of well-controlled hypertension. The other patient had no history of hypertension but developed premature ventricular contractions (PVCs) after initiating the procedure. The last patient had a history of hypertension and kidney failure and was on dialysis. These patients commonly develop hyper- and hypotension during sedation. Their volume status controlled by dialysis plays a large role in how they respond to sedative medications and painful stimuli. All of these patients had a thorough history and physical and were considered safe to undergo DS in the oral surgery clinic. Physiologic variations outside of the norm occur during DS. Epinephrine found in local anesthesia and released by the body during pain and stress causes tachychardia, increased mean arterial pressure, increased cardiac output, increased systemic vascular resistance, and cardiac dysrythmias, most commonly manifested as PVCs. Methohexital has excitatory effects, including tachychardia. 14,15 The DS discontinued because of physiologic parameters outside of the norm were reasonable decisions. Hypertension often results from painful stimuli, but we could not control it with increased anesthesia. It is our professional judgment to discontinue a procedure after administering iv hypotensive medications or lidocaine to control PVCs. We believe that we were neither too cautious nor too aggressive in completing the procedures, but this is quite subjective and should be considered when evaluating DS failure. There is speculation that alcohol abuse leads to an up-regulation of the gamma aminobutyric acid A (GABA A )receptor in certain populations. This up-regulation causes a tolerance to gabaminergic drugs. Cheng et al 16 studied sedation failure using versed in patients being treated for chronic pain related to cancer in the intensive care unit setting. They believed that an upregulation of the GABA A receptor is a possible cause of the ineffectiveness of benzodiazepines. The GABA A receptor is the effector center for midazolam and methohexital. It is unknown how to determine which patients are susceptible to this effect on the GABA A receptor, but we can guess that midazolam may be unsuccessful because of the physiologic effects of chronic alcohol use on the central nervous system resulting in an increased tolerance to midazolam. We can infer a clinically relevant cause-and-effect relationship in the population of chronic alcohol users, but many of these patients are successfully treated with DS. More research is needed in pharmacology to show a clear effect of alcohol on the physiologic and pharmacologic function of the GABA A receptor in chronic alcohol users. The purpose of our survey was to evaluate DS failures in our clinic. Our mandible fracture population and population of patients with multiple teeth extractions had higher rates of failure than other

6 650 SEDATION FAILURE IN THE OUTPATIENT OMS CLINIC groups. This may be due to the length of the DS, type of procedure, level of stimuli, or a preoperative anxiety and attitude toward treatment expressed by the patient that makes DS more difficult. This study allows us to develop a protocol for a prospective study of outpatient DS procedures and to quantify more detailed information about patients preoperative anxiety, medical status and social history than we had available during our chart review. More specific conclusions may help the oral surgeon determine if certain patient populations are at a higher risk for failed DS. References 1. Coyle TT, Helfrick JF, Gonzalez ML, et al: Office-based ambulatory anesthesia: Factors that influence patient satisfaction or dissatisfaction with deep sedation/general anesthesia. J Oral Maxillofac Surg 63:163, Perrott DH, Juen JP, Andresen RV, et al: Office-based ambulatory anesthesia: Outcomes of clinical practice of oral and maxillofacial surgeons. J Oral Maxillofac Surg 61:983, Egelhoff JC, Ball WS Jr, Koch BL, et al: Safety and efficacy of sedation in children using a structured sedation program. AJR Am J Roentgenol 168:1259, Hoffman GM, Nowakowski R, Troshynski TJ, et al: Risk reduction in pediatric procedural sedation by application of an American Academy of Pediatrics/American Society of Anesthesiologists process model. Pediatrics 109:236, Slovis TL, Parks C, Reneau D, et al: Pediatric sedation: Shortterm effects. Pediatr Radiol 23:345, Mason KP, Zurakowski D, Karian VE, et al: Sedatives used in pediatric imaging: Comparison of IV pentobarbital with pentobarbital with midazolam added. AJR Am J Roentgenol 177:427, Malviya S, Voepel-Lewis T, Eldevik OP, et al: Sedation and general anesthesia in children undergoing MRI and CT: Adverse events and outcomes. Br J Anaesth 84:743, Mason KP, Koka BV: New challenges in anesthesia: New practice opportunities/anesthesia for pediatric radiology. Anesthesiol Clin North America 2:17, Moore PA, Finder RL, Jackson DL: Multidrug intravenous sedation/determinants of sedative dose of midazolam. Oral Surg Oral Med Oral Pathol 84:5, Ochs MW, Tucker MR, Owsley TG, et al: The effectiveness of flumazenil in reversing the sedation and amnesia produced by intravenous midazolam. J Oral Maxillofac Surg 48:240, Parworth LP, Frost DE, Zuniga JR, et al: Propofol and fentanyl compared with midazolam and fentanyl during third molar surgery. J Oral Maxilofac Surg 56:447, Pena BM, Krauss B: Adverse events of procedural sedation and analgesia in a pediatric emergency department. Ann Emerg Med 34:483, Bell GW, Kelly PJ: A study of anxiety and midazolam-induced amnesia in patients having lower third molar teeth extracted. Br J Oral Maxillofac Surg 38:596, Hardman J, Limbird L, Molinoff P, et al (eds): Goodman & Gilman s The Pharmacological Basis of Therapeutics. New York, NY, McGraw-Hill, Reves JG, Glass PSA, Lubarsky DA, et al: ltravenous nonopioid anesthetics, in Miller R (ed): Miller s Anesthesia. New York, NY, Churchill Livingstone, 2004, pp Cheng C, Roemer-Becuwe C, Pereira J: When midazolam fails. J Pain Symptom Manage 23:256, 2002