Complex OB Flashcards

Question

What are some various fetal heart rate patterns?

Answer 1

* **A. Early Decelerations** * Fetal head compression → baroreceptor activation * Uniform in nature – mirrors contraction * ~ 10 – 40 beat/min –NOT associated w/ fetal distress * **B. Late Decelerations** * **Uteroplacental insufficiency** * Decrease FHR at or following peak of uterine contraction * Decrease varies b/t 10 – 20 beats/min * Gradual and smooth return to baseline * ***can be concerning*** * **C. Variable Decelerations** * Most common fetal pattern * Variable in onset, duration, and magnitude * \> 30 BPM * R/t cord compression * _Associated with**: FETAL HYPOXIA**_ * FHR declines \< 60 BPM * lasts \> 60 seconds * persists \> 30 minutes Late decels and ominous variable decels → emergent c/s

Answer 2

All of the following: * Baseline rate 110-160 bpm * Baseline FHR variability moderate * Late or variable decels- absent * early decel present or absent * accelerations: present or absent

Answer 3

* Categroy II FHR tracings include all FHR tracings not categorized as category I or Category III * Category II tracings may represent an appreciable fraction of those encountered in clinical care * Examples include any of the following: * baseline rate * bradycardia not accompanied by absent baseline variability * tachycardia * baseline FHR variability * minimal baseline variability * absent baseline variability not accompanied by recurrent decelerations * marked baseline variaiblity * accelerations * absence of induced accelerations after fetal stimulation * periodic or episodic decels * recurrent varaibile decels- accompanied by minimal or moderate baseline variability * prolonged decelerations \>2 minutes but \<10 minutes * recurrent late decelerations with moderate baseline variaiblity * variable decelerations with other characteristics such as slow return to baseline "overshot" or "shoulders"

Answer 4

* Absent baseline FHR varaibility and any of the following: * recurrent late decels * recurrent varaibile decels * bradycardia * sinusoidal pattern * concerning and need to go to OR

Answer 5

* Preoperatively 1. History /Physical * Airway evaluation 2. Informed Consent 3. LUD (left uterine displacement) * **\> 20 weeks – Aortic Caval Syndrome** 4. IV access *(free flowing 18-16 gauge)* 5. *Hydration (minimal 500 mL)* 6. Aspiration prophylaxis *(bicitra, metoclopramide, ranitidine)* 7. Supplemental O2 8. Anesthetic plan/ postoperative analgesia plan * **Choice of anesthetic depends on** 1. Indications for surgery 2. Degree of urgency 3. Maternal status 4. Condition of fetus 5. Desires of the patient * Sometimes too emergent → put to sleep

Answer 6

**Rule of 3’s** * Oxytocin 3 units (prepack syringe in 5 ml*)* * 3 min evaluation intervals * 3 total doses * Oxytocin infusion 3 units/hr maintenance * 3 units are given as a slow bolus * Uterine tone reassessed at 3 and 6 minutes * If inadequate, additional 3 doses are given after each reassessment * If uterine atony persists after 3 dosesà switch to another drug * After establishment of uterine tone, infuse 3 units/hr X 5 hours * **Oxytocin as a rapid IV bolus:** * Direct SM relaxant à SVR, hypotension, and tachycardia (going in too fast) * Hypotension may result in CV collapse * Chest pain, myocardial ischemia may develop (*can give op)* * Water intoxication and hyponatremia (Structural similarities b/t oxytocin and vasopressin)

Answer 7

* **Methylergonovine (Methergine-ergot alkaloid)** * **Dosage: 0.2 mg IM** * Onset: 10 min * Duration: 2-4 hours * **Can it be given IV:** **NOT RECOMMENDED** * Intense vasoconstriction, acute HTN, seizures, retinal detachment, coronary artery spasms, CVA * May be repeated x1 after 30 min * Contraindications: HTN, preeclampsia, CAD

Answer 8

* 15-Methylprostaglandin F_2a(carboprost - **Hemobate)** * Dose: 250 mcg IM * May repeat every 15 min x 8 doses (2 mg) * SE: fever, chills, n/v, diarrhea, and **bronchoconstriction** **\*\*\*Who should not receive this drug?** **Asthmatics**

Answer 9

* Immediate danger to life of mother or fetus * OB Code/Crash with failed intubation * Why more difficult- *can't wake up patient* * What options are available to you?- *emergency airway management. OB uses local/infiltration technique*

Answer 10

* Preop assessment of airway * Large bore IV * Aspiration prophylaxis (Non-particulate antacid, H2-blocker, Reglan) * Monitors/suction/ emergency airway cart * Optimal airway positioning/ LUD * **Preoxygenate! (3 min or longer)** * Prep + drape –surgeon ready * **RSI w/cricoid** (10 N while awake; inc to 30 N after LOC) → start putting force before even asleep * Agents available * Ketamine (used with maternal hypotensive crisis) 1 mg/kg * Etomidate 0.3 mg/kg * Propofol 2-2.5 mg/kg * Succinylcholine 1-1.5 mg/kg * Preferred muscle relaxant

Answer 11

* **Intubate** * Expect difficult intubation * Proper positioning * Short handled laryngoscope (Datta) recommended * Use minimal amount of time; first attempt best attempt * Smaller ETT 6.0 or 6.5 * Use caution…friable tissues and decreased airway size * **Verify placement of ETT** → tell surgeon! * Then…Surgeon makes skin incision (after tube placement verified) * Ventilate with 50% O2/50% N2O & VA (~1 MAC) → overpressure! * Don’t forget to turn on gas! Tremendous recall * Secure ETT, tape eyes, OGT * \*\*\*\*Critical interval of 3 minutes between uterine incision and delivery of fetus * **Tremendous recall risk** → medications waring down and youre busy (mom remembers) * Delivery of baby * PCA pump (bc didn’t do spinal) * As soon as baby is delivered→ can give Versed, Fent, etc.

Answer 12

* **AFTER DELIVERY:** * **Reduce VA (.75 MAC**) → may increase N2O to 70%, and give opioids and benzodiazepine * **Reduce MAC → don’t want to vasodilate & bleed out** * Possible NDMR * Delivery of placenta * Then can add oxytocin to IV → start contracting of uterus so that mom doesn’t hemorrhage * At end: * Suction OGT * Reverse NDMR if necessary * Extubate AWAKE * **Emergence and recovery is a critical period for anesthesia-related deaths from airway factors!**

Answer 13

* Profound decrease b/t 1991- 2002 * Decreased morbidity/mortality from GA and increased from neuraxial (preg = DAW) * *move from always GA to neuraxial, esp good with increased risk DAW in pregnancy* * Most often related to cesarean delivery * Failed intubations = 23% * Respiratory failure = 20% * High spinal/epidural = 16% * Others: * LAST * PDPHa * Nerve injury

Answer 14

* Most frequent cause of HTN **during pregnancy** * Incidence: * ~ 7% parturients * Characterizations: * Elevated BP after 20 weeks gestation (bp \>140/90) * **_Without proteinuria_** * Most cases develop \> 37 weeks’ gestation * Self-limiting: Resolves by 12 weeks postpartum * ~ ¼ will develop preeclampsia * True diagnosis only made after delivery when chronic hypertension can be ruled out

Answer 15

* **Systolic BP \> 140 and/or diastolic BP \> 90** * **Starts _before_ pregnancy or _PRIOR_ to 20 weeks** * Elevated blood pressure that fails to resolve after delivery * Consequences: * Develops into preeclampsia ~ 1/5- ¼ affected patients * Still an important risk factor for unfavorable maternal and fetal pregnancy outcomes

Answer 16

* Occurs when preeclampsia develops in a woman with chronic HTN * **Dx: proteinuria onset** * Or sudden increase in proteinuria, blood pressure, or both * Morbidity increased for both the mother and fetus compared to preeclampsia

Answer 17

* Preeclampsia is a multisystem disease unique to human pregnancy * Occurs in 3 - 8% of all pregnancies * Accounts for 15 – 19% of maternal deaths in the US and UK * Doubled in the last decade

Answer 18

* BP \> 140/90 after 20 wks gestation * Proteinuria * 300 mg/24 hours * 1+ on dipstick * protein/creatine ratio \> 0.3

Answer 19

* BP \> 160/110 * Proteinuria * \> 5g/24 hours * \>3+ on dipstick) * Thrombocytopenia * platelet \< 100,000 * Serum creatinine * \> 1.1 mg/dl (or 2x’s baseline) * Pulmonary edema * New onset cerebral or visual disturbances * Impaired liver function * Epigastric pain * Intrauterine growth restriction

Answer 20

* Coexisting * Chronic renal disease * Lupus * Protein S deficiency * Increased pulse pressure during 1st trimester * Obstetric Factors * African American * Nulliparity * Advanced age (\> 40) * Smoking * Obesity * Diabetes * Multiple gestation * History of pre-eclampsia

Answer 21

* **Unknown Exact pathogenic mechanism** * Hypothesis: Immune maladaptation → leads to inflammation * Focus on the placenta * Delivery of placenta resolves preeclampsia * Can occur in absence of a fetus (molar pregnancy) * **2 stage disorder** * 1^st stage = asymptomatic * 2^nd stage = symptomatic

Answer 22

* Impaired remodeling of spiral arteries * End branch of the uterine artery that supplies placenta * **Normally** * Cytotrophoblasts invade the spiral arteries changing them to low resistance and high flow vessels * Adrenergic denervation * **Preeclampsia** * Invasion is incomplete leaving small and constricted vessels that are responsive to adrenergic stimuli * *basically vessels to uterus do not undergo necessary remodeling, so it leaves a high pressure system. still have response to adrenergic stimuli*

Answer 23

* Widespread endothelial dysfunction that is organ specific develops * Insufficient placental BF → leads to placental hypoxia * → IUGR * Increased production of free radicals and lipid peroxides * Imbalances * Vasoconstrictors: (thromboxane A2 = ⇧) * Vasodilators (prostacyclin's = ⇩) * Hypoxia → * increase antiangiogenic factors (sFlt-1 and soluble endoglin) factors → decrease vascular endothelial growth factors and placental growth factors.

Answer 24

* unknown cause * leads to endothelial damage * Cascade of events * Plt aggregation * Dec production of vasodilatory substances * Increase vascular sensitivity to vasoconstrictive sub (Angiotension, NE) → vasospasms * Consequences: * Increase capillary permeability * → proteinuria * Hemolytic anemia * Increase Liver enzymes * HELLP * Increase SVR * Decrease aldosterone escapre * Increase Na/H2O retention → * HTN * Edema → preeclampsia/eclampsia

Answer 25

**Neurological** * Headache * Visual disturbances * Hyperreflexia * Seizures (\*eclampsia) * Cerebral edema * Increased risk **Cardiovascular** * Increased BP * Decreased intravascular volume (d/t contraction of vascular space) * Increased arteriolar resistance * Heart failure

Answer 26

* **Respiratory changes** * Pharyngeal and laryngeal edema → airway management difficult * **Potentially WORSE d/t Na/H2O retention** * Pulmonary edema

Answer 27

* **Hepatic** * Impaired function * Elevated enzymes * Hematomas * Ruptures * **Renal** * Proteinuria * Na retention * Decreased GFR * Oliguria * Increased serum uric acid – decreased urate clearance

Answer 28

* **Coagulopathy** * Thrombocytopenia (both) * Quantitative: number * Qualitative: function * Platelet dysfunction * Prolonged PTT * \*risk of cerebral hemorrhage → so need to tx HTN * Tx: (SBP \>160) w/ labetolol, Hydralazine, nifedipine

Answer 29

* Lots of overlap between obstetricians and anesthesia General Overview 1. Timing of delivery * R/o regional technique d/t coagulopathy? 2. Fetal and maternal surveillance 3. Treatment of hypertension 4. Seizure prophylaxis

Answer 30

* **_Delivery only cure_** * **\> 37 weeks** * Induction of labor * **\> 34 weeks with severe symptoms** * **\< 34 weeks** * Expectant management * Delay delivery for 24 – 48 hours * Administer steroids to facilitate fetal lung function * Ex: betamethasone- mature fetal lungs * Should be undertaken at facilities with neonatal and maternal intensive care resources

Answer 31

* S/S of end organ damage * 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 32

* **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

Answer 33

* **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

Answer 34

* **Nifedipine** * **Dose:** 10 mg PO q20 min * **Max:** 50 mg * **Nicardipine** * **Dose:** 1– 6 mg/hr * **CAUTION:** * Combo Ca+ blockers + Mg+ è * profound hypoTN * myocardial depression * Others: sodium nitroprusside and nitroglycerine

Answer 35

* 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 36

* **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 37

* **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 38

* Generalized edema → obscure anatomical landmarks * Be prepared for a difficult airway, *even more so than normal pregnant pt due to edema* * Increased vascularity of Nasopharynx * Tissue swollen/friable → tendency to bleed

Answer 39

* 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

Answer 40

**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\*\*) * Intravascular volume status * Contracted intravascular space → need volume prior to placement * HypoTN tx * Change in autoreg curve * Use of epinephrine containing solutions (ex: 2% Lido w/ 1:200,000 epi for loading dose) * Impact on BP?

Answer 41

* **Coagulation: Plts** * \> 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 * **Considerations** * 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 * unproved technology in thrombocytopenia in pregnant patients * d/t multifactorial issues in preg

Answer 42

* 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

Answer 43

* Preloading vs co-loading = equivocal outcomes * \*Do not delay initiation of neuraxial techniques simply to administer a fixed volume of fluids * **Considerations:** * Restrictive fluid management: small 250 ml fluid boluses * Do not want to fluid overload → pulm edema

Answer 44

* Exaggerated response to endo/exogenous catecholamines (in preeclamptic pts) * Small doses!! * Ephedrine (5 – 10 mg) * Phenylephrine (25 – 50 mcg) * Careful titration – severe preeclamptics may have exaggerated response * Epinephrine in labor epidural = equivocal * **Absence of malignant HTN (\>160/110)** * **→ epinephrine unlikely pose sig HTN crisis risk** * **But AVOID:** * **Reduction of uterine BF in animals** * **Preeclamptics exaggerated vasoactive response** * Used for decades in obstetric anesthesia * Prudent to avoid epinephrine containing solutions * Reduced chronotropic response during pregnancy * Maternal heart rate variability during contractions * Reduction of uterine blood flow in animal models * Patients with preeclampsia may have increased vasoactive response

Answer 45

* Preferred Anesthesia → Neuraxial * Spinal vs epidural * Initially – spinal anesthetics were avoided in patients with severe preeclampsia * Now, not supported by the evidence * Hypotension did occur – only 1 minute longer and easily treated ephedrine/phenylephrine * No significant difference in neonatal outcomes * Epidural * Initiated with 2% lidocaine or 3% 2-chloroprocaine

Answer 46

* 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 d/t magnesium** * Ex: rocuronium, vecuronium, and mivacurium * Succinylcholine: DOA NOT affected by magnesium * Reversal agents – including sugammadex is acceptable once baby out

Answer 47

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 1. After delivery → 1. Decrease VA 2. Admin: 1. Benzo- Versed 2. Opioid 3. 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 48

* Life threatening emergency * 0.1 – 5.9 per 10,000 pregnancies * 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

Answer 49

* **Eclampsia (Seizure) onset:** * Abrupt onset of facial twitching → then tonic phase → followed by clonic phase (often with apnea) * ~ lasts about 1 minute * **Complications:** * Aspiration * cerebral hemorrhage * kidney failure * cardiac arrest * placental abruption * extreme prematurity

Answer 50

* 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 51

* 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 52

* 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

Answer 53

* **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**

Answer 54

* 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- *delivery of fetus* * volume resuscitation * coagulation management

Answer 55

* Thrombocytopenia- 10% pregnancies * Etologies: * \> 20 wks → can be 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 56

* Antepartum hemorrhage- Leading cause maternal mortality * #/Need of blood transfusions → morbidity indicator * blood loss * typically underestimated * delay to treat-- *since magnitude of loss is underapprecieated*

Answer 57

* Present if placenta implants in advance of fetal presenting part of fetus * Dx: (Miller) * Placenta low in uterus * in front of presenting fetus * Either covering or encroaching on cervical os * Occurs in 0.4 -1% of pregnancies (0.5%)

Answer 58

* **Marginal** * Lies close to, but does not cover the cervical os * **Partial** * Partially covers the cervical os * **Complete** * Placenta completely covers the cervical os

Answer 59

* Previous cesarean section (prior scar tissue) * Prior placental previa * Multiparity * advanced maternal age * assisted pregnancy * smoking

Answer 60

* 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 61

* 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 * 2 large bore IV’s, fluid warmer, blood tubing, rapid infuser, invasive monitoring equipment, a-line

Answer 62

* **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 63

* 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** * *****placenta **previa** is **painless*** * Fetal compromise occurs * Loss of placental surface area * → Oxygen tissue exchanging surfaces area reduced → fetal distress

Answer 64

* advanced maternal age * Chorioamnionitis * PROM * Hx of abruption * multiparity * preeclampsia * hypertension * **substance abuse- cocaine \*** * ETOH/tobacco use * **direct/indirect trauma \***

Answer 65

* Vaginal bleeding (clotted dark blood) * Coagulopathies * uterine tenderness * hypotension * increased uterine activity * Bleeding may be concealed and gross underestimation of hemorrhage can occur * Fetus: * Non-reassuring FHR * Bradycardia * loss of variability * Ultrasound examination

Answer 66

* Delivery of infant and placenta * Degree of compromise determines timing and route * Expectant * Vaginal * Emergent cesarean section

Answer 67

* 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 * Monitor for uterine atony (uterotonics\*)

Answer 68

* Uterine wall defect with maternal hemorrhage and/or fetal compromise * require emergency C-section or postpartum laparotomy(after delivery) * Disastrous for mother and fetus

Answer 69

* 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

Answer 70

* 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

Answer 71

* Antepartum – emergent laparotomy with delivery * Uterine repair * Arterial ligation – may not control bleeding and delay definitive treatment * Hysterectomy

Answer 72

* Stable * May proceeded with preexisting epidural for labor analgesia * Unstable * Emergency cesarean section and laparotomy * Aggressive volume resuscitation

Answer 73

* When placenta abnormally adheres to uterus * Types: (3) * **Placenta accreta vera** * 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** * When the chronic villi invade the myometrium * Miller: Abnormal implantation and growth of placenta into myometrium * **Placenta percreta** * 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)

Answer 74

* 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 75

* 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 * Efforts to stop bleeding: * Internal iliac artery balloon catheters * resuscitative endovascular balloon occlusion of aorta

Answer 76

* 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 77

* 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

Answer 78

* **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 79

* 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 80

**Uterine Atony** * 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

Answer 81

* 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 82

Oxytocin * First line drug therapy for uterine atony prophylaxis * Synthetic preparation with 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 * **Side Effects:** * Vasodilation * Hypotension * Tachycardia * coronary vasoconstriction (don’t push large doses) * hyponatremia (with large dosages)

Answer 83

**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,

Answer 84

**Prostaglandins** * 15-Methylprostaglandin (carboprost) **– Hemabate** * **Dose: 0.25 mg IM 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

Answer 85

1. Manual message 2. Intrauterine balloon tamponade 3. Uterine compression sutures 4. Embolization of arteries supplying the uterus 5. Cesarean hysterectomy

Answer 86

* BL: * \> 500 ml vaginal * \> 1000 ml cesarean * VS: Normal * Labs: Normal * Treatment: * Place 100% oxygen * Start large bore IV * increase IV fluids * T/C 2 units

Answer 87

* BL: * **\> 1500 ml’s** or * \> 2 uterotonics * VS: Normal * Labs: Normal * **Treatment**: * 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

Answer 88

* BL: * \> 1500 ml’s EBL * \> 2 units PRBC’s admin * VS/labs: abnormal * oliguria Treatment: * Move to OR – mobilize additional resources * **_Initiate massive transfusion protoco_**l * 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

Answer 89

CV collapse

Answer 90

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

Answer 91

**Breech** **Transverse or Shoulder** * **Shoulder Dystocia** * Emergency * Occurs after delivery of head, the shoulders cannot be delivered secondary to impaction on maternal pelvis * A/w: * Prolonged gestation * Labor induction * Obesity * High fetal wt * Prolonged dilation from 8-10 cm * Epidural analgesia

Answer 92

* Approximately 1:150 births * 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 93

* 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

Answer 94

* Vaginal Twin A/Operative Twin B * Epidural = same as vaginal devliery * May require rapid conversion to general anesthesia with high concentration of volatile anesthetic

Answer 95

* 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 96

* Regular contractions occurring b/t 20 – 37 wks gestation * Result: dilation or effacement of cervix * Approximately 8% - 10% of births in US * Indicated in 50 -80% of perinatal deaths * Survivability depends on: * gestational age * maturity of organ systems * weight

Answer 97

* History of preterm delivery, * preterm rupture of membranes, * age (\< 18 or \>35), * trauma * , infection, s * moking, * drug history, * multiple gestation, * low socioeconomic status, * acute illness, * abdominal surgery during pregnancy & * abnormal uterine or cervical anatomy.

Answer 98

* Bedrest with FHR monitoring * Corticosteroids for fetal lung development (Betamethasone) * Tocolytics (suppression of uterine activity)

Answer 99

* **Magnesium** * Same as before * **Calcium channel blockers** * Inhibit influx of calcium * Nifedipine PO * SE: Hypotension, flushing, dizziness, nausea Tocolytics * **Cyclooxygenase inhibitors** * Blocks arachidonic conversion * Ex: Indomethacin * Maternal SE: Nausea/vomiting * Fetal SE: * **constriction of ductus arteriosus** * pulmonary HTN * renal dysfunction * intraventricular hemorrhage * **Beta-agonists** * Ex: 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

Answer 100

* Goal is a slow controlled delivery with minimal pushing * Large episiotomy and low forceps are often used * Spinal/general * Complete pelvic relaxation * Better Apgar scores than with general * Minimize fluids with beta agonists – pulmonary edema * General * Fetus is more vulnerable to sedative effects of opioids and anesthetics

Answer 101

* Rare but often fatal complication that can occur during labor * Pathophysiology remains poorly understood * Epidemiology * No universally accepted definition for identifying cases * Differing ascertainment methods yield different rates * Ultimately a diagnosis of exclusion * **_Society for Maternal-Fetal Medicine and Amniotic Fluid Foundation_** * Sudden onset of cardiovascular arrest or both hypotension and respiratory arrest * Documentation of overt DIC, after the appearance of initial signs or symptoms. * The coagulopathy must be detected before sufficient blood loss is lost to account for dilutional or shock related to consumptive coagulopathy. * Clinical onset during labor or within 30 minutes of delivery of the placenta * **No fever during labor**

Answer 102

* 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

Answer 103

* Older age * Obstetric factors 1. Abnormal placenta 2. Placental abruption 3. Eclampsia 4. Multiple gestation 5. Induction of labor 6. Operative delivery

Answer 104

* 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

Answer 105

* **Presentation** * Initial – Prior to delivery * Seizure, loss of consciousness, and profound dyspnea * Maternal symptoms appear BEFORE abrupt onset of variable decelerations and fetal bradycardia * **Presentation Around Delivery** * Acute cardiovascular collapse * Pulmonary hypertension * Right ventricular dilation, decreased CO & profound V/Q mismatch * ABG’s 30 minutes on 100% FiO2 = \< 30 mmHg * Cardiovascular * Vary = ST segment/T wave abnormalities to arrhythmias or asystole * ECHO = dilated, akinetic RV with progressive dilation * Right ventricle dilation leads to decreased LV function and decreased CO * Massive hemorrhage & DIC * Thrombocytopenia and significant hypofibrinogenemia

Answer 106

* 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, or fibrinogen concentrate

Answer 107

* Cardiopulmonary bypass * Extracorporeal membrane oxygenation * Continuous hemofiltration * **Medication regime (A-OK)** * Atropine 1 mg * Blocks vagal reflex → blocks systemic hypoTN * Ondansetron 8 mg * Blocks serotonin pathway → ultimately decrease pulm vasoconstriction * Ketorlac 30 mg * Blocks thromboxane → typically releases inflam mediators

Answer 108

* Incidence of surgery → estimated at 0.75 – 2.2% * Indications: cervical incompetence, ovarian cysts, appendicitis, cholecystitis, malignancies, and trauma * Timing of surgery – Swiss Study * First trimester: 42% * Second: 35% (preferred- but not elective. Less risk) * Third: 23% * Practical considerations * Surgery should not be denied because of trimester considerations * Second trimester is preferred because of lowest risk of spontaneous abortion and preterm labor * Emergency surgery – primary goal is to preserve the life of the mother

Answer 109

* **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 110

* 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)

Answer 111

* 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

Answer 112

* 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 113

* Mothers \> 35 years of age * \> 35 = 20% * \> 40 = 4 % * Higher morbidity and mortality for both mother and fetus * Increased risk for miscarriage, congenital anomalies, preterm delivery, placental abruption & c-section (2x’s more likely to request) * Focus patients co-morbid conditions * 38% had pre-existing condition

Answer 114

* 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 115

* Failure of labor to progress normally * \< 0.5 cm dilation during 1st stage of labor after active labor is established * \> 2 hours pushing after full dilation and no change of station * Due to: * Ineffective uterine contraction * Arrest of cervical dilation * Treatment * Oxytocin * C-section

Answer 116

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

Answer 117

* 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** * *****severe AS, not good candidate neuraxial anesthetic* * **Regional anesthesia is good** * Analgesia = decrease pain and lowers catecholamine release * Epidural = slow onset – easier to maintain hemodynamic parameters * better choice * Careful fluid administration * Always provide supplemental oxygen * SBE prophylaxis = consult with OB

Answer 118

* 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 119

* Higher rates of chronic hypertension, gestational diabetes, preeclampsia and UTI * **Increased risk o**f * 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 120

* 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.

Answer 121

* 9% of pregnant women between 15 - 44 report drinking in the past month * **Associated wit**h 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

Answer 122

* Multiple effects on mother and fetus * Increased risk for preeclampsia and bleeding * Continue opioids through peripartum course * May have increased opioid requirements * Monitor neonates for abstinence syndrome

Answer 123

* **Consequences**: * 1st trimester = congenital anomalies * 2^nd/ 3^rd = premature labor, IUGR, placental insufficiency, or placental abruption * **Direct** vasodilators to avoid CV and CNS complications * Tx hypoTN with **direct acting** agents * Ex: **phenylephrine** * **General anesthesia** may be associated with **uncontrolled hypertensio**n/tachycardia and dysrhythmias * Chronic a/w thrombocytopenia * Abuse Requirement * **Chronic = decrease MAC** * **Acute use = increase MAC**

Answer 124

* 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

Answer 125

* 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**