Case Review of Respiratory Distress During Pregnancy

Transcription

1 Case Review of Respiratory Distress During Pregnancy John J. Folk, MD Associate Professor Maternal Fetal Medicine Division Department OB GYN SUNY Upstate Medical University

2 That Mandatory Slide I report that I have no conflicts of interest or relevant financial relationships with any commercial interests. At this time, I would like to report that I have nothing to report; at this time. LTC Henry Blake, MD, M*A*S*H 4077 th

3 Respiratory System Physiologic Changes of Normal Pregnancy Respiratory tract changes: Are major in their scope and impact on function Clearly notable on multiple levels including: gross anatomic relationships, microscopic structure and respiratory physiology Assessment of respiratory illness during pregnancy is enhanced by understanding these changes and their impact on physiologic and laboratory data obtained

4 Time course of percent increases in minute ventilation, oxygen uptake, and basal metabolism during pregnancy Prowse, CM, Gaensler, EA, Anesthesiology 1965; 26:381

5 Physiologic Changes of the Chest Subcostal angle from 68 o up to 103 o Chest diameter at least 2 cm barrel chested appearance of pregnancy What about the diaphragm?

6 Ultrastructural Changes Lung During Pregnancy mean pulmonary artery pressure pulmonary capillary wedge pressure plasma oncotic pressure pulmonary capillary permeability

7 Serial measurements of lung volume compartments during pregnancy Prowse, CM, Gaensler, EA, Anesthesiology 1965; 26:381

8 ABG Reference Ranges Patient ph PaCO 2 PaO 2 HCO 3 GYN Maternal Fetus PaCO 2 and PaO 2 = mmhg HCO 3 = meq/l

9 Normal CXR Findings in Pregnancy

10 Women Admitted to ICU During Pregnancy Incidence < 2% of pregnant women admitted ICU; per 1,000 deliveries Most often 36 weeks gestation 4 weeks post-delivery Maternal mortality is high (3.4 20% in reported case series) Rising incidence associated with increasing maternal age, obesity, pregestational diabetes mellitus, essential hypertension

11 Women Admitted to ICU During Pregnancy: Indications Hemorrhage Hypertensive disorders Respiratory failure (multiple etiologies) Sepsis Cardiac disease Trauma Anesthesia complications Cerebrovascular accident Drug overdose

12 Women Admitted to ICU During Pregnancy: Causes Maternal Death Hemorrhagic shock Complications hypertensive disorders Thromboembolism Sepsis Anaphylactoid syndrome of pregnancy [AFE] Peripartum cardiomyopathy; acute coronary syndromes

13 What is the most common associated condition with maternal ICU admission? Cesarean delivery Women admitted to ICU 50 90% had cesarean delivery Most commonly associated with hemorrhage, but can include amniotic fluid embolism syndrome, sepsis, intra-abdominal or pelvic organ injury, etc Among antepartum patients admitted to ICU, 82% result in delivery with 78% having cesarean delivery

14 Case 1 24 year old woman, Gravida 1, presents for prenatal care. She reports asthma since elementary school. She follows with her PCP who maintains her on an inhaled glucorticoid MDI and a rescue albuterol MDI. She took a home pregnancy test about 2 weeks after she expected her next menses to begin. With the positive result, she immediately stopped the inhaled glucorticoid MDI. She has been wheezing at least 4 days a week but did not use the albuterol MDI for rescue due to fear regarding harm to her baby.

15 Case 1 She is afebrile, with stable vital signs. General physical exam is normal except her chest exam reveals that she is able to move air well bilaterally with bilateral expiratory wheezing noted. There is no stridor. SpO 2 = 98% on room air. Point-of-care pelvic ultrasound reveals a normal first trimester intrauterine gestation with fetal heart at 6.6 weeks gestation.

16 Case 2 32 year old woman, Para 2002, presents at 28 weeks gestation to L&D with 4 day history of coughing, generalized aches, feeling feverish, and mild shortness of breath. She reports some chills but no frank rigors. No nausea, vomiting or diarrhea. No major medical or surgical history. She had 2 prior vaginal deliveries at term without complication. She reports her children have similar symptoms but not as severe. There is a bug going around the daycare where the children attend.

17 Case 2 Vitals: Temp = 101 o F or 38.8 o C, BP = 108/62, P = 120, R = 28, SpO 2 = 90% on room air. General exam is normal including uterus with chest exam significant for course breath sounds bilaterally, scattered expiratory wheezes, diminished bilateral lung sounds at bases. There is no JVD. Cardiac exam in normal except for tachycardia. Electronic fetal monitoring reveals FHR = 180 BPM, decreased to minimal variability, no decelerations, no accelerations of the FHR. Uterine irritability is noted, but no contractions are seen.

18 Case 2 ABG = 7.52, PaCO 2 = 30 mmhg, PaO 2 = 88 mmhg, HCO 3 = 20 meq/l. Blood work is sent for CBC, a chest X-ray with shielding is ordered. IV access is obtained with LR going at 100 ml/hr. Nasal cannula O 2 is placed at 6 L/min. Her SpO 2 = 98%, her respiratory rate is reduced to 18, FHR comes down to 160 with minimal to moderate variability. Her minute ventilation is estimated to be 10 L/min with FiO 2 estimated = 0.40 or 40%.

19 Case 2 CBC reveals WBC = 14,000/mcL, N banded = 4%, Hb = 10.6 g/dl, Hct = 34%, platelets = 160,000/mcL Electrolytes normal, BUN = 9, creatinine = 0.6 mg/dl Urinalysis reveals SG = 1.030, ph = 6.0, otherwise negative Nasal swab for rapid testing influenza A&B positive

20 Goals of O2 Supplementation SpO 2 95% PaO 2 70 mmhg PaCO 2 = mmhg HCO 3 = meq/l

21 Case 2 Treatment provided included: IV fluid hydration with LR Oseltamivir (Tamiflu) 75 mg PO BID x 5 days Azithromycin (Zithromax) 500 mg PO once, then 250 mg PO q Day x 5 days Ceftriaxone (Rocephin) 1 gram IV q 24 hours Over the next 2 hours her respiratory rate increased from 18 to 26 per minute. SpO 2 went from 98% to 94%, FHR remained normal with moderate variability

22 Case 2 O 2 Flow [L/min] FiO

23 Case 2 O 2 Flow [L/min] Minute Ventilation [L/min] FiO FiO 2 decreases as minute ventilation (tidal volume x RR) increases

24 Case 2: Face Masks

25 Case 2: Face Masks Device Reservoir Capacity [ml] O 2 Flow [L/min] FiO 2 Face Mask Partial Rebreather Nonrebreather

26 Case 2: Venturi Masks FiO 2 jet Color 24% Blue 28% Yellow 31% White 35% Green 40% Pink 50% Orange 60% --

27 Case 2: High O2 Flow, Heated & Humidified Nasal Cannula

28 Case 2: NIPPV Indication: short term support with relatively modest pressures to achieve improvement in oxygenation and ventilation. Early stage rapidly reversible process: CHF exacerbation, flash pulmonary edema COPD exacerbation Moderate asthma exacerbation Transient upper airway obstruction Avoids complications associated with intubation and mechanical ventilation Allows patient to talk, eat, expectorate Helpful with patients with advanced directive regarding intubation

29 Case 2: NIPPV

30 Case 3 16 year old Gravida 1 at 22 weeks gestation was evaluated on L&D with a 3-day history of fever, chills and right flank pain. Vital signs include: BP = 70/30 mmhg, P = 130/min, R = 36/min, Temp = o F (40.2 o C) FHR = 180/min. She appears quite ill and is using accessory muscles respiration to breathe.

31 Case 3 Lung sounds are bilaterally diminished with bibasilar rales, rhonchi and scattered wheezing. Heart is regular with tachycardia, no gallop. Uterus is soft, non-tender, abdomen is soft, non-tender, non-distended with occasional bowel sounds. Costovertebral angle tenderness is present, right side much greater than left. Extremities are warm, moist, non-tender, no erythema.

32 Case 3 Urinalysis revealed 4+ bacteria and numerous WBCs. CBC revealed WBC = 22,000/mcL with N banded = 12%, BUN = 22 mg/dl, creatinine = 0.9 mg/dl, plasma lactate = 4.2 mmol/l. ABG ph = 7.28, PaCO 2 = 38, PaO 2 = 66 on face mask O 2. Imaging including CXR, obstetrical and renal ultrasound was ordered. Blood cultures were sent Bedside ultrasound was done including lung fields, heart, and abdomen. IV access was obtained, IV hydration, IV antibiotics were started within an hour of admission

33 Case 3

34 Case 3 Criteria for acute respiratory distress syndrome [ARDS]: Acute onset PaO2/FiO2 ratio 200 Bilateral infiltrates Pulmonary artery occlusion (wedge) pressure 18 mmhg

35 Indications for Intubation/Ventilation Parameter Normal Initiate Support Respiratory rate [per min] Vital Capacity [ml/kg] Inspiratory Force [cmh 2 O] Compliance [ml/cmh 2 O] > 35 or apnea < < < 25 FEV 1 [ml/kg] < 10

36 Intubation during Pregnancy Indications the same during pregnancy as in the general population Lower threshold based on PaCO 2 criteria Indications: apnea, upper airway obstruction, inability to protect airway, respiratory muscle fatigue, mental status deterioration, hemodynamic instability Accomplished best by skilled/experienced personnel

37 Intubation during Pregnancy Rapid Sequence Intubation: cricoid pressure [Sellick s maneuver (1961)] Reduced size of endotracheal tube: by 0.5 mm based on maternal size Venous congestion of upper airway Risk for trauma, bleeding Naso-tracheal intubation: relatively contraindicated Pre-intubation oxygenation: Compensates for decreased functional residual capacity Excessive hyperventilation: possible utero-placental arterial constriction

38 Pressure-Controlled vs. Volume Controlled Ventilation Parameter Pressure Control Volume Control Setting Pressure target Volume target Setting Setting 1 o outcome variable 2 o outcome variable Inspiratory duration Inspiratory rise rate Tidal volume Auto-PEEP Flow rate Flow waveform Airway pressure Auto-PEEP

39 Our Next Speaker David M. Landsberg, MD Doctor of Medicine, Saba University School of Medicine Internship & Residency: Internal Medicine, Mount Sinai School of Medicine, New York, NY Fellowship: Critical Care Medicine, Memorial Sloan-Kettering Cancer Center, New York, NY Diplomat: American Board of Internal Medicine, Critical Care Medicine Fellow: American College of Physicians, American College of Chest Physicians Attending Physician: Critical Care Associates of Syracuse, PC Chief of Medicine: Crouse Hospital, Syracuse NY Associate Professor: Medicine and Emergency Medicine, SUNY Upstate Medical University, Syracuse, NY