Obstetrics Flashcards

Question

What does surveillance of Preeclampsia involve? \*Preop testing for patient with preeclampsia\*

Answer 1

* Ex: renal, liver * Laboratory * CBC * PLT count (most important) * \> 100,000 * \< 100,000 – additional tests * PT/PTT/INR * Chemistry * Urine protein/creatinine * LFTs * Uric acid testing – conflicting evidence

Answer 2

* **Control BP**- important * **Considerations:** * Rapid maternal perfusion pressure changes can adversely affect uteroplacental perfusion pressure * → uteroplacental perfusion pressure form arteries are already maximally dilated * \*If drop BP rapidly → negatively affect perfusion to placenta * **Targets:** * 15 – 25% reduction BP * Initial BP \> 160 (labetalol, Hydralazine, nifedipine) * Systolic: 120 – 160 mmHg * Diastolic: 80 – 105 mmHg * 1st line agents: * **Labetalol** * Crosses placenta but does NOT cause fetal bradycardia * B:A of 7:1 * **Dose:** * **1^st: 20 mg IV** * **2^nd: 40 mg q10min** * **Max: 220 mg** * **Hydralazine** * MOA: Potent direct vasodilator * decreases MAP and SVR * increasing HR and CO * **Dose**: 5 mg IV q20 minutes * Max: 20 mg * 2nd Line Agents: * **Nifedipine** * **Dose:** 10 mg PO q20 min * **Max:** 50 mg * **Nicardipine** * **Dose:** 1– 6 mg/hr * **CAUTION:** * Combo Ca+ blockers + Mg  * profound hypoTN * myocardial depression

Answer 3

* Methergine- any form of HTN in peripartum period * Lead to HTN crisis * Sensitive to exogenous and endogenous catecholamines (adrenergic agents) * Magnesium- utilized for preeclampsia * Leads to uterine atony → increased PP bleeding

Answer 4

* **Magnesium Sulfate** * Bolus: 4 – 6 grams over 10 - 30 minutes * Maintenance of 1 -2 gm’s/hour * Continued for 24 hours following delivery * **Maternal Side-effects:** * flushing, HA, dizziness * skeletal muscle weakness, decreased deep tendon reflex * respiratory depression * hypotension * pulmonary edema * uterine atony (pp) → increase bleeding risk * **Fetal side effects****:** * neonatal hypotonia * respiratory depression

Answer 5

* **Normal: 1.7 – 2.4 mg/dl** * **Therapeutic: 5 – 9 mg/dl (prevent szs)** * **EKG changes: 6 – 12 mg/dl** * **Loss of DTR: 11 – 12 mg/dl** * **Respiratory arrest: 15 – 20 mg/dl** * **Cardiac arrest: \> 25 mg/dl** * **Treatment- Mag toxicity** * Calcium gluconate: 1 gm over 10 minutes * Calcium chloride: 300 mg over 10 minutes * Ex: stop mag → admin Ca → monitor for EKG changes

Answer 6

* **Labor Management – neuraxial (CLE or CSE)** * Preferred method of pain control * Recommendation → EARLY placement * Ex: analgesia → dec level catecholamines/stress hormones circulating → increase uterine BF, less CV effects * **Advantages:** * Provision of high quality analgesia * Decreased levels of catecholamines and stress hormones * Conversion of analgesia to anesthesia - avoids general anesthesia * Increase uterine blood flow * **Considerations:** * Coagulation status (Plt\*\*) * \> 100,000 = traditional level * **\> 80,000 = currently acceptable w/o other risk factors** * **\< 50,000 = unacceptable risk** * **50,000 – 80,000** * risk vs benefits of regional vs. general anesthesia * Platelet count trends over last 24 – 48 hours * If platelet count is decreasing – may want to place epidural catheter early * Coexisting coagulopathies * Evaluate * Coagulation studies * LFTs * TEG and platelet function analysis * **Platelet count \< 100,000 mm3** * Chestnut Recommendations: * 1. Most skilled provider * 2. Single shot technique * 3. Use of a flexible, wire-embedded epidural catheter * Less trauma * 4. Monitor S/S of neurological complication (ex: epidural hematoma) * 5. Check plt count before removal * NEED: \> 75 – 80,000 BEFORE REMOVING * 6. Imaging studies should be obtained immediately if question to neuro fx * CT * MRI * Intravascular volume status * Contracted intravascular space → need volume prior to placement * BUT restrictive management- 250 ml bolus good * HypoTN tx * tx promply * Vasopressor use * Exaggerated response to endo/exogenous catecholamines (in preeclamptic pts)- careful titration * Small doses!! * Ephedrine (5 – 10 mg) * Phenylephrine (25 – 50 mcg)

Answer 7

* ALWAYS do AW evaluation - generalized edema, DAW same neuraxial considerations: * **Coagulation** status (Plt\*\*) * \> 100,000 = traditional level * \> 80,000 = currently acceptable w/o other risk factors * \< 50,000 = unacceptable risk * 50,000 – 80,000 * risk vs benefits of regional vs. general anesthesia * Platelet count trends over last 24 – 48 hours * If platelet count is decreasing – may want to place epidural catheter early * **If Coexisting coagulopathies (**evaluate) * Coagulation studies * LFTs * TEG and platelet function analysis * Platelet count \< 100,000 mm3 Chestnut Recommendations: * 1. Most skilled provider * 2. Single shot technique * 3. Use of a flexible, wire-embedded epidural catheter * Less trauma * 4. Monitor S/S of neurological complication (ex: epidural hematoma) * 5. Check plt count before removal * NEED: \> 75 – 80,000 BEFORE REMOVING * 6. Imaging studies should be obtained immediately if question to neuro fx * CT * MRI * **Intravascular volume status** * Contracted intravascular space → need volume prior to placement * BUT restrictive management- 250 ml bolus good * **HypoTN tx** * **Vasopressor use** * **Exaggerated** response to endo/exogenous catecholamines (in preeclamptic pts)- careful titration * **Small** doses!! * Ephedrine (5 – 10 mg) * Phenylephrine (25 – 50 mcg)

Answer 8

* **Airway** * Generalized edema → DAW * Increased vascularity of Nasopharynx * Tissue swollen/friable → tendency to bleed * **Hemodynamic Monitoring** * Noninvasive blood * Mild and uncomplicated severe * A-line- for sick/uncontrolled HTN * Need for frequent ABG measurement * Continuous monitoring during induction/emergence in poorly controlled hypertension * Calculated systolic pressure variation * Central- severe * Careful considerations and placement * TEE- severe * Useful technique for assessing cardiopulmonary status * AW swollen/vascular as is → CAREFUL w/ probe * **Hypertensive response to laryngoscopy** * \*Laryngoscopy most sympathetic response! * \< 160/110 before induction and extubation * Maintain: * 140 - 160/90-100 throughout * Tx: HTN * Labetalol * Remifentanil (0.5 mcg/kg) * Good drug: esterases fetus already mature → able to metabolize at same rate as mom

Answer 9

* **General Anesthesia** * Airway considerations * Edema * **Hypertensive response to laryngoscopy** * \*Laryngoscopy most sympathetic response! * \< 160/110 before induction and extubation * Maintain: * 140 - 160/90-100 throughout * Tx: HTN * Labetalol * Remifentanil (0.5 mcg/kg) * Good drug: esterases fetus already mature → able to metabolize at same rate as mom * **Muscle relaxants** * Continue muscle relaxants throughout surgery * Considerations: * Very small doses * Monitor with nerve stimulator * Esp w/ Mag admin → decrease muscle tone/delay NMF * NM & Mag * Steriodal: DOA and potency increased * Ex: rocuronium, vecuronium, and mivacurium * Succinulcholine: DOA NOT affected by magnesium * Reversal agents – including sugammadex is acceptable * (Chestnut Chapter 35; Box 35.5) 1. Place radial arterial line if BP severe 2. Verify difficult airway equipment & smaller sized tubes available (6.0, 6.5) 3. Administration of H2 blocker or reglan 30 – 60 minutes before 4. Sodium citrate 30 ml’s prior to induction 5. De-nitrogenate 6. Labetalol 10 mg iv boluses to get BP to \<160/110 7. Monitor FHR- s/s fetal distress 8. Consider remifentanil 0.5 mcg/kg or other adjuncts to help blunt 9. RSI with Propofol/succinylcholine or etomidate/succinylcholine 10. Maintain with ½ MAC volatile and 50% N2O * After delivery → * Decrease VA * Admin: * Benzo- Versed * Opioid * Propofol 11. Small doses of opioids and avoid muscle relaxants if possible (bc Mag) 12. Reverse muscle relaxants and administer more labetalol/hydralazine to prevent hypertension on extubation

Answer 10

* Life threatening emergency * Most often occurs 2^nd half of pregnancy * \> 20 wks gestation * **Risk factors:** * young maternal age * nulliparity * multiple gestation * pre-existing HTN * preeclampsia * 80% develop premonitory signs: * Headache * visual disturbances * photophobia * altered mental status * epigastric pain * Seizure * Abrupt onset of facial twitching → then tonic phase → followed by clonic phase (often with apnea) * ~ lasts about 1 minute

Answer 11

* Aspiration * cerebral hemorrhage * kidney failure * cardiac arrest * placental abruption * extreme prematurity

Answer 12

* Stop the convulsions * Benzodiazepine * Propofol * Magnesium * Establish an airway * Turn patient to left side * Administer 100% oxygen * Apply VS monitors - frequent assessment * Check BP frequently – control hypertension (DBP \< 110 mmHg) * Labetolol * Hydralazine * Nifedipine * Ensure adequate IV access * Ensure adequate ventilation/oxygenation * Maintain circulation * Deliver the baby expeditiously

Answer 13

* Stable * Epidural and spinal acceptable * **Unstable** * GA preferred * Techniques for patients with increased intracranial pressure * Propofol- positive effects on cerebral BF * Maintain cerebral perfusion pressure * MAP – ICP (MAP up, ICP down) * **Avoid anything decreasing CPP** * Hypoxemia * Hypoventilation * hyperglycemia * Persistent neurological evaluations

Answer 14

* Defined: * **Hemolysis** * **Elevated levels of liver enzyme** * **Low platelets** * Maybe a variant of severe preeclampsia * Associated with: DIC, abruption, pulmonary edema, acute renal failure, liver failure, sepsis, & death * 70% deliver pre-term * **Hemolysis** * Microangiopathic hemolytic anemia * Abnormal peripheral blood smear * Schistocytes * burr cells * echinocytes * **Bilirubin \> 1.2 mg/dl** * **Elevated Liver Enzymes** * AST \> 70 IU/L * LDH \> 600 IU/L * **Low Platelets** * \< 100,000 * **Platelet transfusion** * \< 20,000 or significant bleeding in all paturients * **\< 40,00 scheduled for cesarean section** * Rupture of subcapsular hematoma of liver (possibility) * Life threatening complication of HELLP syndrome * S/S: * abdominal pain * N/V * Headache * enlarged liver * hypotension * Dx - Ultrasound or CT scan * Tx – emergency surgery * volume resuscitation * coagulation management

Answer 15

* Thrombocytopenia- 10% pregnancies * Etologies: * \> 20 wks → sign of HELLP * Typically benign → Gestational Thrombocytopenia * Plts * Normal: Plts # decrease 10% * Threshold * ~100,000 safe (varies) * 70-100,000 * NO \< 50,000 * Coexisting bleeding disorders → increased risk * Ex: VWF Deficiency → risk of peripartum hemorrhage * Increased risk of clotting * DVT/PE → d/t hormone changes * Preexisting factor 5 leiden, Protein S/C/AT/Antiphospholipid deficiencies → increase risk clotting * Tx: anticoag therapy → impacts delivery plan

Answer 16

* Present if placenta implants in advance of presenting part of fetus * (placenta partially or totally covers cervix) * Dx: (Miller) * Placenta low in uterus * in front of presenting fetus * Either covering or encroaching on cervical os * Classifications: * **Marginal** * Lies close to, but does not cover the cervical os * **Partial** * Partially covers the cervical os * **Complete** * Placenta completely covers cervical os * Considerations: * \***Can impair uterine contractions --\> _risk for high blood loss_** * Risk factors * **Previous cesarean section** (prior scar tissue) * Prior placental previa * **Multiparity** * advanced maternal age * assisted pregnancy * smoking * Diagnosis: * Painless vaginal bleeding during the 2^nd or 3^rd semester * Self-limited * Transvaginal ultrasound * Digital or speculum exam requires “double set-up” * OB Management * Bed rest * Between 24 and 34 weeks – betamethasone * → accelerate fetal lung maturity/surfactant development * C-Section delivery

Answer 17

* All patients admitted with vaginal bleeding should be evaluated by anesthesia on arrival to the labor deck * Increased risk for intraoperative BL * Placenta maybe injured during incision * Lower uterine segment may not contract as well * Increased risk for placenta accreta * Prepare for massive BL * T&C * 2 large bore IV’s * fluid warmer * blood tubing * rapid infuser * invasive monitoring equipment (a-line)

Answer 18

* Choice of anesthetic technique depends on: * urgency of delivery * maternal vital signs * pregnancy history * Without active bleeding & normal vital signs * Epidural or CSE acceptable (one RCT showed epidural superior to GA) * Active bleeding or altered vital signs (d/t prolonged bleeding) * RSI- CV instability * Induction agent based on hemodynamic status * Low dose Propofol or etomidate & ketamine all have been used * Maintenance * Depends on hemodynamic status * Benzodiazepine/ketamine vs nitrous/volatile * Bleeding management (Uterotonics) * Oxytocin * Hemabate * Methergine * D/C VA if bleeding continues * → Increase N2O [] + midaz or low dose Propofol/ketamine infusion * Activate massive transfusion protocol

Answer 19

* Defined: * Complete or partial separation of placenta from the uterine wall (decidua basalis) \> 20 wks gestation but before delivery of fetus * **S/S:** * **Vaginal bleeding** * Significant BL trapped behind placenta (remain in uterus) * → Coagulopathy!! * **PAINFUL/tenderness w/ examination** * **Coagulopathies** * **hypotension** * **increased uterine activity****** * Fetal compromise occurs * Loss of placental surface area * → Oxygen tissue exchanging surfaces area reduced → fetal distress * Non-reassuring FHR * Bradycardia * loss of variability * Risk factors: * advanced maternal age * Chorioamnionitis * PROM * Hx of abruption * multiparity * preeclampsia * hypertension * **substance abuse- cocaine \*** * ETOH/tobacco use * **direct/indirect trauma \***

Answer 20

Delivery of infant and placenta * Degree of compromise determines timing and route * Expectant * Vaginal * Emergent cesarean section * **Anesthesia Management** * Labor * Epidural * Cesarean delivery * Stable – adequate volume resuscitation and normal coagulation * Epidural, Spinal, CSE * Severe ( \>50% placenta detached) – fetal death rate approaches 50% * Crash GA * ketamine/etomidate and succinylcholine * Multiple large bore IV’s – place a-line/CVP * Volume resuscitation – 1:1:1 ratio * Monitor for DIC * PT/INR, PTT * CF * Monitor for uterine atony (uterotonics\*)

Answer 21

* Uterine wall defect with maternal hemorrhage and/or fetal compromise * require emergency C-section or postpartum laparotomy(after delivery) * Disastrous for mother and fetus * **Conditions associated rupture** * Obstetric: * Prior uterine surgery * induction of labor * high dose oxytocin * Trial of labor after cesarean (TOLAC) * Scar dehiscence * Trauma: * OB: * Forceps application * internal podalic version * excessive fundal pressure * Non-OB: Blunt or penetrating trauma * **Diagnosis** * Abnormal FHR and fetal distress – most common sign * Abdominal pain (sudden & severe), abnormal FHR, and vaginal bleeding (\<9%) * Hypotension, vaginal bleeding, change in uterine contour, and changes in contraction pattern – cessation of labor * Breakthrough pain and need for frequent redosing of neuraxial labor * **Obstetric Management** * Antepartum – emergent laparotomy with delivery * Uterine repair * Arterial ligation – may not control bleeding and delay definitive treatment * Hysterectomy

Answer 22

* When placenta abnormally adheres to uterus * Types: (3) * **Placenta accreta vera** **– uterine wall** * Adherence of the basal plate directly to the uterine myometrium without an intervening decidual layer * Miller: Abnormal adherence to myometrium w. absent decidual line of separation (w/o entering decidual layer) * **Placenta increta-** **uterine muscle** * When the chronic villi invade the myometrium * Miller: Abnormal implantation and growth of placenta into myometrium * **Placenta percreta-** **through** * Invasion through the myometrium into the serosa and adjacent organs * Miller: Growth of placenta through uterine wall (myometrium) with placental implantation onto surrounding tissue (bladder, bowel, ovaries, etc) * **Risks:** * Mirrors the cesarean section rate * Previous cesarean delivery or other uterine surgery increase the risk * # C/S deliveries → Increase risk!! * 0 = 3% * 1 = 11% * **2 = 40%** * **3 = 61%** * **4 or \> = 67%**

Answer 23

* Plan: * Planned preterm c/s and hysterectomy with placenta left in situ * → removing likely to initiate massive hemorrhage * Goal: Gestation \> 34 weeks * Most often at institutions that manage complex OB patients * However must be prepared for emergency delivery and hysterectomy at any institution the care for parturients * Crash GA * RSI * Blood loss can be massive * Prepare for massive transfusion- T&C * Efforts to stop bleeding: * Internal iliac artery balloon catheters * resuscitative endovascular balloon occlusion of aorta

Answer 24

* Placenta that has not undergone expulsion w/in 30 min of birth * whole placenta * placenta parts * **Consequences:** post-partum hemorrhage * Therapy: * Epidural = top up +/- conscious sedation * Intravenous = nitroglycerine 1 mcg/kg * May also try sublingual spray 400 mcg * GA with high dose volatiles * All the risks that go with general anesthesia

Answer 25

* The uterus inverts through the cervix into the vagina * Rare – 1: 2,000 – 10,000 deliveries * Risk factors: * Pulling on the umbilical cord * uterine atony * placenta previa * connective tissue disorders * S/S: * postpartum hemorrhage * hypotension * \*Bradycardia – traction on uterine ligament * **Tx: Immediate uterine relaxation followed by uterine contraction** * Nitroglycerine * 50 – 200 mcg IV * 400 mcg sublingual * GETA with high dose VA * Monitor fluid volume status * **Uterine contraction** * Oxytocin * Hemabate * methergine

Answer 26

* Normal Blood Loss * Vaginal delivery = 500 ml * Cesarean section = 800 – 1000 ml’s * Well tolerated d/t physiological increase plasma volume (compensates) * Post-partum hemorrhage * American College of Obstetrician and Gynecologists * \> 1,000 ml’s * Signs and symptoms of hypovolemia * Within 24 hours of birth * US rate = 3% * Most common cause of maternal mortality world wide

Answer 27

* Most common cause of severe post-partum hemorrhage * 80% of cases * Patho: * Uterine atony results from inability of uterus to contract and constrict uterine vessels * **Risk factors: (Chestnut- box 37**.3) * OB: * Multiple gestation * Polyhydramnios * high parity * prolonged labor * choriamnionitis * induced/augmented labor * c-section * Maternal: * advanced maternal age * hypertension * diabetes * Other: * tocolytic drugs – slows down labor * ex: Magnesium * high VA []

Answer 28

* **Oxytocin (Pitocin)** * First line drug therapy for uterine atony prophylaxis * MOA: increasing Ca [] inside muscle cells that control contraction of uterus. Increased Ca increases contraction of uterus * Synthetic preparation of oxytocin w/ 6 minute half life * Rapidly metabolized by the liver and cleared in the urine and bile * **Dosage:** * **20 units/L crystalloid @ 200 – 500 ml/hour** – (uncomplicated c/s) * can double if ineffective 40 Units * Some newer protocols: * Ex: 3 unit boluses of oxytocin, rest on infusion pump * 3 units bolus (slow) * 3 doses total * 3 units/hr * **Side Effects:** * Vasodilation * Hypotension * Tachycardia * coronary vasoconstriction (don’t push large doses) * hyponatremia (with large dosages) **Uterine Atony Treatment \*\*\*** * **Ergot alkaloids** * Methylergonovine or ergonovine (methergine) * **Dose: 0.2 mg IM Q 30 minutes x’s 1** * Relative contraindications: * Hypertensive * CAD * preeclampsia * Side effects: Nausea/vomiting, increased blood pressure, chest pain, blurred vision and headache, seizure, * **Prostaglandins** * 15-Methylprostaglandin (carboprost) **– Hemabate** * **Dose: 0.25 mg Q 15 min to 2 mg** * Relative contraindications: * **Reactive airway disease (asthma)** * pulmonary hypertension * hypoxemia * Side effects: Bronchoconstriction, nausea, vomiting, diarrhea, * Misoprostol * Dose: 600 – 1000 mcg PR * Relative contraindications: None * Side effects: fever, chills, nausea, vomiting, & diarrhea * Others 1. Manual message 2. Intrauterine balloon tamponade 3. Uterine compression sutures 4. Embolization of arteries supplying the uterus 5. Cesarean hysterectomy

Answer 29

* **Stage 1** * BL: * \> 500 ml vaginal * \> 1000 ml cesarean * VS: Normal * Labs: Normal * Place 100% oxygen * Start large bore IV * increase IV fluids * T/C 2 units * **Stage 2** * BL: * \> 1500 ml’s or * \> 2 uterotonics * VS: Normal * Labs: Normal * Call for help * Start 2^nd large bore IV * Draw stat labs (CBC, coags, fibrinogen) * Obtain 2 units RBC’s and FFP (1:1) → anticipate OR if not there already * Type specific better than O-negative * Provide analgesia * Prepare OR * **Stage 3** * BL: * \> 1500 ml’s EBL * \> 2 units PRBC’s admin * VS/labs: abnormal * **oliguria** * Move to OR – mobilize additional resources * Initiate massive transfusion protocol * Fixed ratio transfusion (1:1:1) * Add cryoprecipitate, TXA, and calcium * **TXA: crosses placenta** * Recommendation: wait until cord clamped to admin * Cell salvage- possible * Factor VIIa - not recommended for routine use * Admin per TEG studies * **Stage 4** * Cardiovascular collapse * **Goals of Massive Transfusion** * Lactate- Decrease * Base excess- Normalize * Hemoglobin: \> 7 g/dl * Platelets: \> 50,000/mm3 * Fibrinogen: \> 200 mg/dl * INR: \< 1.5 times normal

Answer 30

* **Goals of Massive Transfusion** * Lactate- Decrease * Base excess- Normalize * Hemoglobin: \> 7 g/dl * Platelets: \> 50,000/mm3 * Fibrinogen: \> 200 mg/dl * INR: \< 1.5 times normal

Answer 31

* Physiological changes * Accelerate and exaggerate physiological changes of pregnancy * Increased uterine size * **Pulmonary** * Reduced TLC and FRC * Aspiration risk - Increased * Tracheal intubation (Difficult)- Increased * **CV** * Additional 750 ml plasma volume increase * 20% greater increase in CO * SV 15% * HR 3% * Greater aortocaval compression

Answer 32

* Labor & Vaginal Delivery * Epidural – great flexibility and optimal analgesia * Low threshold to replace equivocal epidural * Move to OR for delivery * Establish 2^nd large bore IV → increased risk for uterine atony and bleeding * Be ready to convert epidural from analgesia to anesthesia- supplement * In case of uterine inversion: * Nitroglycerin * 400 mcg sublingual or * 150 – 250 mcg IV * Vaginal Twin A/Operative Twin B * Epidural = same as above * May require rapid conversion to general anesthesia with high concentration of volatile anesthetic * Planned Cesarean Delivery * Spinal vs CSE * Mean umbilical venous/arterial lidocaine [] were 35 – 53% higher in twin newborns compared to singletons (increased sensitivity to LA) * Increased plasma volume combined with a decreased plasma protein volume * Clinical relevance of these findings remain unclear (Chestnut – Chapter 34)

Answer 33

* Regular contractions occurring b/t 20 – 37 wks gestationResult: dilation or effacement of cervix * Survivability depends on: * gestational age * maturity of organ systems * weight * Treatments: * Corticosteriods- accelerate fetal lung development * **Tocolytic agents (2)** * **1. Magnesium- Ca antagonist = relaxes smooth muscle by turning off myosin light-chain kinase in vasculature, AW, uterus** * Bolus: 4 – 6 grams over 10 - 30 minutes * Maintenance of 1 -2 gm’s/hour * Continued for 24 hours following delivery * **Maternal Side-effects:** * CNS depression * skeletal muscle weakness, decreased deep tendon reflex * respiratory depression * hypotension * pulmonary edema * uterine atony (pp) → increase bleeding risk * **Fetal side effects****:** * neonatal hypotonia * respiratory depression * **2. Calcium channel blockers** * Inhibit influx of calcium- inhibit Ca release from SR * Nifedipine PO * SE: Hypotension, flushing, dizziness, nausea * **Cyclooxygenase inhibitors (indomethacin)** * Blocks arachidonic conversion * * Maternal SE: N/V * Fetal SE: * **constriction of ductus arteriosus** * pulmonary HTN * renal dysfunction * intraventricular hemorrhage Maternal SE: Nausea/vomiting * **Beta-2 agonists (**Terbutaline) * Smooth muscle relaxation (increase CAMP – activates protein kinase – inactivating myosin light chain kinase – decreasing contraction) * SE: Tachycardia, cerebral vasospasm, chest pain, arrhythmias, palpitations, hyperglycemia, hypokalemia, pulmonary edema * Fetal SE: tachycardia, hypoglycemia, hypocalcemia & hypotension * **Delivery**

Answer 34

* Appears to be a systemic inflammatory response associated with inappropriate release of endogenous inflammatory mediators and platelet activation * Exact trigger is unknown * A rare pathologic fetal antigen * Usual antigen presented in an unusual way – amount, timing, or frequency of entry into circulation * Fetal cells, lanugo hair, and mucin into the maternal pelvic vasculature is a common event * However, pulmonary artery aspirates of patients without AFE have shown fetal material in it * Systemic inflammatory response: * arachidonic acid metabolites like thromboxane, prostaglandins, leukotrienes, and endothelins. * Fetal squamous cells release tissue factor which activates platelets to release thromboxane and serotonin * --\> Sudden onset of cardiovascular arrest or both hypotension and respiratory arrest

Answer 35

**_US Amniotic Fluid Embolism Registry Entry Criteria_** * Acute Hypotension or cardiac arrest * Acute hypoxia (dyspnea, cyanosis, or respiratory arrest) * Onset during labor, cesarean delivery, dilation & evacuation, or within 30 minutes post partum * **Absence of an alternative explanation of the observed signs and symptoms** Risk factors * Older age * Abnormal placenta * Placental abruption * Eclampsia * Multiple gestation * Induction of labor * Operative delivery S/S: * Prior to delivery: * Seizure, LOC, and profound dyspnea (maternal symptoms BEFORE fetal decels) * At Delivery: * Acute CV collapse * Pulmonary HTN * RV dilation * decreased CO * profound V/Q mismatch * ABG’s 30 minutes on 100% FiO2 = \< 30 mmHg * Cardiovascular * Vary: * ST segment/T wave abnormalities * arrhythmias or asystole * ECHO: * RV → akinetic, progressive dilation * RV dilation → leads * decreased LV fx * decreased CO * Massive hemorrhage & DIC * Thrombocytopenia and significant hypofibrinogenemia

Answer 36

* 1. Maintain Oxygenation * Intubate and administer 100% oxygen * 2. Hemodynamic Support * Place a-line and central line as necessary * Administer fluids and vasopressors as necessary * Ensure left uterine displacement * TEE to guide fluid replacement therapy * Chest compressions as needed * 3. Correction of coagulation * Activate massive transfusion protocol * Serial laboratory assessments * Coagulopathy support: * TXA * recombinant Factor VIIa * prothrombin complex concentrates * fibrinogen concentrate TREATMENT: * A-OK regimen * **Atropine 1 mg- anticholinergic** * Blocks vagal reflex → blocks systemic hypoTN * **Ondansetron 8 mg- serotonin antagonist** * Blocks serotonin pathway → ultimately decrease pulm vasoconstriction * **Ketorlac 30 mg- nonselective COX inhib** * Blocks thromboxane → blocks release of inflam mediators *

Answer 37

* S/S: * Pulm: * Resp Distress * Hypoxia * Dyspnea * Cough * PHTN * CV: * CV collapse * HypoTN * DIC * Cyanosis * Fetal brady * Bradycardia * Neuro: * Altered mental status * Patho: * Unknown anaphylactoid rx * Previously thought squamous cells in maternal pulm circ → but present in healthy moms pp * Tx: early recognition and aggressive resuscitation * Oxygenation * Hemodynamic support * Coagulopathy correction

Answer 38

* **Teratogenicity** * Most structural abnormalities result from exposure during organogenesis * 31 – 71 days after first day of last menstrual period * Physiological derangements * Diagnostic procedures * Drugs * No anesthetic agents is proven teratogenic in humans * **Most anesthesia providers AVOID:** * **Nitrous oxide (inhibits methionine synthase)** * **Benzodiazepines – cleft lip/palate** risk

Answer 39

* Preoperative * Multi-disciplinary team available * Good airway exam (multiple different plans) * Pharmacological prophylaxis against acid aspiration (H2 blocker, reglan, bicitria) * \> 12 weeks * Choice of Anesthesia * Local * Regional * Neuraxial * General – only if necessary (avoid if can) * Monitoring * When fetus is viable (20 -24 weeks) and technically feasible * OB provider available for diagnosis and intervention * Prevention of compression * Beginning at 18 -20 weeks * Good left uterus displacement * When mom supine → significant hypoTN * Anesthesia management * De-nitrogenation * d/t dec FRC * RSI with cricoid pressure * Volatile, muscle relaxants, opioids, and reversals acceptable * No difference in maternal/fetal outcomes based on anesthetic agents * Maintain PaCO2 in normal pregnancy range * 28 – 32 mmHg * Avoid hypoxemia, hypotension, acidosis and hyperventilation * Use low pneumoperitoneum pressure and Trendelenburg position * Avoid NSAIDS – close PDA

Answer 40

* Trial of Labor After Cesarean Section * C-section rate was 32% in 2016 * Trial * Based on c-section type (classic vs low transverse) * 60 – 80% successful * **Contraindications** * Multiple gestations, two previous sections, severe preeclampsia, obesity, previous stalled labor * **Risk** * Uterine rupture * Uterine atony * Blood transfusions

Answer 41

* Intra-amniotic infection * S/S * Maternal leukocytosis * Maternal tachycardia * Fetal tachycardia * Uterine tenderness * Foul smelling odor * Tx * Antibiotics * Delivery

Answer 42

* Affects up to 1.6% of all pregnancies * Leading non-obstetric cause of maternal mortality * Optimal management begins at conception * Consult cardiology early * Most already know about * Tailor anesthetic plan to exact lesion * Regional anesthesia is good * Analgesia = decrease pain and lowers catecholamine release * Epidural = slow onset – easier to maintain hemodynamic parameters * better choice * Carful fluid administration * Always provide supplemental oxygen * SBE prophylaxis = consult with OB

Answer 43

* Occurs in about 3% of pregnancies * Blood sugar goal: **60 -120 mg/dl** * Problems: * placental insufficiency * preeclampsia * hypertension * No evidence that one anesthetic technique is superior to another * **Consequences:** * Maternal: DKA, HHNC, hypoglycemia, macro/microvascular disease, stiff joint syndrome, diabetic nephropathy, * Fetal: large for gestational age (shoulder dystocia/birth trauma) and structural malformations

Answer 44

* Higher rates of chronic hypertension, gestational diabetes, preeclampsia and UTI * Increased risk of premature labor, low birth weight, fetal/neonatal demise * Increased cesarean section rates, post partum hemorrhage, and hospital stays * Good preanesthetic evaluation * Particular to airway evaluation * Have multiple airway adjunct available * Establish IV access early * Apply supplemental O2 * Establish epidural early – high failure rate * LA → lower dose req (smaller epidural space) * Ensure LUD

Answer 45

* **Tobacco** * Most common abused substance in pregnancy = 18% * Nicotine causes vasoconstriction and may decrease placental blood flow and oxygenation * Associated with miscarriages, IUGR, placental previa, abruptio placentae, preterm delivery & SIDS. * **Alcohol** * 9% of pregnant women between 15 - 44 report drinking in the past month * Associated with liver disease, coagulopathy, cardiomyopathy, and esophageal varices * Fetal alcohol syndrome – 33% of heavy drinkers * Acute intoxication: * GETA w/ RSI and aspiration prophylaxis * May also undergo acute alcohol withdrawal during the intrapartum or postpartum period = 6 to 48 hours after cessation * Nausea, vomiting, tachycardia, tremors, agitation, hallucinations and seizures * **Opioids** * Multiple effects on mother and fetus * Increased risk: * Preeclampsia * bleeding * increased opioid requirements * Continue opioids through peripartum course * Monitor neonates for abstinence syndrome * **Cocaine** * Consequences: * 1st trimester = congenital anomalies * 2^nd/ 3^rd = premature labor, IUGR, placental insufficiency, or placental abruption * Considerations: * HTN Tx: Direct vasodilators (avoid CV and CNS complications) * HypoTN tx: direct acting agents * Ex: phenylephrine * GA: * may be a/w uncontrolled HTN, tachycardia, dysrhythmias * Chronic use: a/w thrombocytopenia * Abuse Requirement * Chronic = decrease MAC * Acute use = increase MAC * **Marijuana** * Frequently used = 4.7% * Readily crosses the placenta – however, no know effects * Preterm labor and IUGR can occur * Long term users = increased secretions, impaired cough & potentially increased airway reactivity * **Amphetamines** * Leads to indirect sympathetic stimulation (serotonin, norepi & dopamine) * Vasoconstriction with labile blood pressure and tachycardia * Both neuraxial and general anesthesia have been used * Acute use may increase risk for urgent cesarean section under general anesthesia * Treat like acute cocaine use