Obstetrics (part 1) Flashcards

Question

Which drugs do NOT cross the placenta?

Answer 1

All Neuromuscular blocking agents Glycopyrrolate Insulin Heparin

Answer 2

Uterus 1kg Fetus and placenta 4kg Blood volume/fluid 4kg Additional Fat 3kg (Normal weight pt with BMI 18.5-24.9) is recommended total weight gain of 25-35lb

Answer 3

Overweight BMI 25-29.9 kg/m2 6.8-11.3 kg (15-25 pounds)

Answer 4

Half of pregnant women are overweight or obese C/S rates: BMI 29 or less= 20% BMI 35-39= 47%

Answer 5

Obesity-INCREASED RISK OF COMPLICATIONS Gest DM HTN/PEC Fetal Macrosomia Premature labor Stillborn/anomalies Infection w C/S- 2 abx Off spring of obese mothers are at increased risk of childhood and adult obesity Obesity related insulin resistance and inflammatory pathways linked to development of PEC

Answer 6

Labor duration nulliparas increased .3 hours for each 10kg increment in maternal weight Failed induction rate twice as likely C/Section rate BMI greater than 60kg/m2--- 69% Obese women and C/S -ABX and closure of subQ layer (reduce wound disruption)

Answer 7

Normal BMI 143/10,000 women; Class 3 obesity (BMI 40 or higher…) 203/10,000 women Hemorrhage require transfusion, serious cardiac respiratory hematologic, thrombus, embolism, sepsis shock, hepatic renal failure, uterine rupture

Answer 8

Heart rate only increased 15% LVH SVR decreased 20% at term

Answer 9

Cardiac output increased 40% above non pregnant levels mostly due to 30% increase in stroke volume

Answer 10

Immediately after delivery of placenta Cardiac output increases 60%-80% above pre-labor values CO returns to non pregnant value 2 weeks postpartum CO increased mostly due to INCREASE in stroke volume… uterine contraction 300-500cc

Answer 11

Normally no change in Systolic BP SVR is decreased by 20%

Answer 12

Watch for supine hypotension syndrome in about 10% of patients at term…ie decreased venous return due to compression of the IVC by gravid uterus Use left uterine displacement(LUD)!!!!

Answer 13

ASA practice guidelines for OB anesthesia….both ephedrine and phenylephrine are acceptable agents for treating hypotension during neuraxial anesthesia.

Answer 14

Minute ventilation increased 50% d/t progesterone (also relaxes bronchial smooth muscle)

Answer 15

TV increased 40%

Answer 16

Resp rate increased 10%

Answer 17

ERV decreased 20%

Answer 18

Residual volume decreased 20%

Answer 19

FRC decreased 20%

Answer 20

Thoracic cage increased diameter

Answer 21

Minimal/No change in VC or TLC

Answer 22

Changes in anesthetic depth with GA is faster in pregnancy (decreased MAC)

Answer 23

Increased oxygen consumption by 20%

Answer 24

Left shift of oxyhemoglobin dissociation curve (fetal hemoglobin) Respiratory alkalosis….Increased affinity for fetal hemoglobin/holds onto oxygen shift left for fetal hemoglobin diss curve…. Right shift of oxyhemoglobin dissociation curve (maternal term hemoglobin) Maternal P50 increases from 26 to 30mmhg at term(maternal O2 diss curve shifts to RIGHT to offload Oxygen to fetus….)

Answer 25

- Increases minute ventilation - Bronchial smooth muscle relaxed - Hyperventilation in active labor worsens respiratory alkalosis - Maternal P50 shift from 26-30mmHg at term so shift to right to “offload oxygen to fetus”

Answer 26

Tidal volume increased Slight increase in respiratory rate FRC decreased 20% Increased minute ventilation at term Minute ventilation increases 100%-200% with 1st / 2nd stages of labor FRC normal 2 weeks post partum

Answer 27

- Capillary engorgement - Mucosa is very friable - Increased risk of bleeding - Smaller size cuffed ETT (size 6-7) - Preoxygenate!!!!!!!!!!! Increased oxygen consumption + Decreased FRC - Engorgement of mucosa even greater in Preeclampsia (PEC)!!! - Mallampati worsens after labor

Answer 28

Incidence of failed intubation = 8-10X higher parturient than the NON pregnant patient “O2-prop-sux-tube” FIRST THINK RSI For ACLS cardiac arrest: intubation attempts per experienced laryngoscopist. Bleeding and airway edema. No more than 2 attempts at either DL or videolaryngoscopy before insertion of a supraglottic airway Supraglottic airway is preferred rescue strategy after failed intubation difficult airway algorithm-cricothyroidotomy

Answer 29

* Increased BMI * Mallampati score III or IV * Small hyoid to mentum distance * Limited jaw protrusion * Limited mouth opening * Cervical spine limitations

Answer 30

(SCORE) 30 institutions USA. 1K-10Kdeliveries per institution (2004-2009) 257,000 parturients; 5,000 GA with NO aspiration 1 in 533 general anesthetics…resulted in Failed INTUBATION 2014: 31.3% of deliveries were via c/section 94.4% neuraxial anesthetics for c/s 5.6% general anesthetics for c/s Failed neuraxial anesthetics for cesarean delivery of 1.7%

Answer 31

This is the most common serious *****“anesthesia related” complication**** Obesity Spinal after failed epidural anesthetic 58 out of 85 anesthetic related complications gives 1 in 4,336 incidence

Answer 32

**Cesarean section** was the mode of delivery of **88**% of those who had cardiac arrest 32.6% of those with cardiac arrest survived …12 of 14 who survived full recovery.

Answer 33

Decreased LES tone (lower esophageal sphincter tone)

Answer 34

Decreases LES tone

Answer 35

WOMEN IN LABOR --> RSI

Answer 36

Displaced pylorus upward and backward ***lower esophageal sphincter tone*** Onset of uterine contractions gastric emptying is “SLOWED IN LABOR” ALWAYS TREAT AS FULL STOMACH

Answer 37

* **Metoclopramide**: context of C/S decreases incidence of Nausea AND Vomiting * Sodium citrate/ nonparticulate * **H2 receptor antagonist**: Pepcid does not affect ph of gastric fluid already in the stomach

Answer 38

Clear liquids by laboring patients without additional risk factors is acceptable Risk factors: morbid obesity, diabetes, known difficult airway etc. (Gastric emptying studies found emptying is not delayed with pregnancy) /risk factors Think ph meds for aspiration prophylaxis

Answer 39

All laboring patients considered full stomach…planned RSI in emergent C/S For elective C/S want NPO solids for 6hrs and clear liquids for 2 hours ALL AT RISK for aspiration

Answer 40

Overall hepatic function and blood flow is unchanged **Mild decrease in serum albumin **due to increase in plasma volume Watch for HELLP syndrome

Answer 41

Fibrinogen (Factor I), Factor VII, VIII, IX, X and XII are **increased** at term relative to nonpregnant state [1, 7, 9, 10, and 12 cause I suck with roman numerals]

Answer 42

Decreased levels of Protein S

Answer 43

Physiologic changes to minimize intraoperative blood loss 6 fold increase risk of thromboembolism pregnancy and postpartum period --> Venodyne boots for C/S

Answer 44

Progesterone leads to dilation of renal calyx, pelvis

Answer 45

Renal blood flow and GFR are increased 50% by 4th month of pregnancy

Answer 46

Decreased BUN and Creatinine (.6-.8mg/dL normal for term parturient)

Answer 47

increased pain threshold

Answer 48

not necessarily abnormal

Answer 49

Impaired tubular reabsorption of glucose=more UTIs

Answer 50

Plasma cholinesterase activity is decreased by 25%-30% at term (not much clinical significance)normal by 6 wks post partum

Answer 51

First stage-onset of regular contractions Second stage-begins with complete cervical dilation(10cm) Third Stage- from delivery of baby to placenta is expelled

Answer 52

**Visceral** is caused by uterine contactions and dilation of the cervix= FIRST STAGE Afferent viscera first stage impulses from uterus and cervix…sympathetic n.s. T10 –L1

Answer 53

Somatic pain-stretching of the vagina and perineum as fetus descends=SECOND STAGE Late first stage and second stage of labor somatic pain receptors via pudendal nerve S2-S4

Answer 54

1st stage T10-L1 2nd stage S2-S4 Labor epidurals do not prolong 2nd stage of labor when inserted at appropriate time

Answer 55

Basic airway equipment =immed FOS/Code cart=easily accessible Cardiac arrest manual LUD=C/S within 5 minutes/PMCD

Answer 56

Difficult airway algorithm-airway eval!!! LMA use- think rescue only Fewer GA/ trend for more regionals 20% Intralipid fat emulsion/LA Toxicity ASRA guidelines for anticoagulated pts Infection prevention ****mainly safer because more expertise with use of AIRWAY DEVICES****

Answer 57

indivdual heparin dose of SQ Heparin 7500-10000 U BID or a daily dose of <= 20,000 U We suggest neuraxial block occur 12 hours after SC Heparin administration and assessment of coag status-new recommendation for higher dose UGH thromboprophylaxis in the pregnant patient...

Answer 58

Patient refusal Infection at site of injection Clinical bleeding Ongoing anticoagulation Severe uncorrected hypovolemia Severe aortic/mitral stenosis Increased ICP

Answer 59

Hypovolemia Thrombocytopenia Hemorrhage Fetal status Severe spinal deformity Preexisting neurological deficit

Answer 60

* 35% Prior C/S * 30% CPD/Dystocia * 12% Breech * 9% Non reassuring fetal tracing * 14% other: * Placenta Previa, Suspected Accreta -HIV mother, active genital herpes -previous classical incision -previous uterine surgery -macrosomia, twins, PEC with SEVERE sxns ( etc/eclampsia)

Answer 61

Persistent LATE decelerations Uteroplacental insufficiency Category III tracings are predictive of abnormal fetal acid base status. * Absent baseline fetal heart rate variability AND any one of the following: * Recurrent Late Decelerations * Recurrent Variable Decelerations * Bradycardia or sinusoidal pattern

Answer 62

Vascular dysfunction of placenta Abnormal prostaglandin metabolism Thromboxane A2-potent vasoconstrictor Platelet aggregation Inflammatory evidence- increased cytokine levels Risk factor PEC in past pregnancy Definitive goal is “delivery of placenta”!

Answer 63

Headache SOB Eye sight changes-spots / blurry vision Pain upper abdomen or shoulder Edema face and/or hands N/V 2nd half of pregnancy Sudden weight gain (higher risk long term –health risk- heart attack/ stroke/kidney dz/htn)

Answer 64

* Age <20 or >35 (extremes of age) * Nulliparity as well as Twins/triplets * Family hx of preeclampsia * sister/mother - genetic risk * paternal antigen father fetus - if male has previously fathered a preeclampic pregnancy * previous pregnancy with preeclampsia * Incidence 6-8% of all pregnancies * Type I or Type 2 DM, Obesity, lupus, IVF * Chronic HTN renal dz or both (ACOG 2013)

Answer 65

* Low dose aspirin (controversial 81-150mg/day) * Greatest benefit to women at moderate or high risk * Low dose ASA reduces frequency of PEC as well as adverse outcome - Preterm birth/ growth restriction - Decreases thromboxane synthesis - Modulates inflammation

Answer 66

BP >140/90 on two separate measurements >4 hours apart Gest age <20 wks

Answer 67

Same criteria for BP Gest age>20wks WITHOUT proteinuria… And resolves by 12 wk PP

Answer 68

BP>140/90 on two separate measurements >4 hours apart Gestational age >20 weeks AND….. **PROTEINURIA** Greater than or equal to 300mg protein in 24 hour urine collection Or P:C Protein to creatinine ratio greater than or equal to 0.3mg/dl

Answer 69

* BP>160/110 on two separate measurements at least 4 hours apart/Gestational age >20wks * Proteinuria NOT essential * **ANY END ORGAN DYSFUNCTION----YES!!** * Thrombocytopenia (<100k) * renal insufficiency (serum CR>1.1mg/dl) * LFT 2x normal * pulmonary edema * new H/A or visual sxns * RUQ or epigastric pain sign of liver involvement

Answer 70

Ranges from mild condition to severe multisystem organ failure Hemolysis (abnormal blood smear) Increased Liver enzymes AST>70U/L and LDH>600U/L Platelet <100,000mm3 Clinical application: What is platelet count before regional?

Answer 71

20% of patients with preeclampsia with severe features will develop HELLP DELIVER ASAP Watch trend of platelets (?epid removal) - don't remove until rechecking PLT count Platelets usually return to normal 72hr post delivery

Answer 72

**Control HTN**- 1st line labetalol/hydralazine nifedipine(oral) **Prevention of seizures** -Magnesium Sulfate Eclampsia = seizure Delivery of fetus Blunt hemodynamic response intubation

Answer 73

Agent of choice SZ control pre-eclamptic(PEC) Raises seizure threshold Also used for preterm labor Hypotension Maintain infusion during C/S +24hr after delivery Potentiates action of both nondepolarizers and depolarizing muscle relaxants careful reversal

Answer 74

Initial loading dose is 4 Gm MgSO4 IV over 10 minutes then maintenance infusion of 1-2 Gm/hr (Some load dose with 6 Gm MgSO4) Want serum range 4-6 meq/L (SSH) Toxicity 10cc of 10% calcium gluconate Narrow therapeutic index….5-10meq/L with EKG changes prolonged PR widened QRS…. 10 meq/L decreased deep tendon reflexes….15 meq/l respiratory arrest

Answer 75

think therapeutic range Magnesium 4-6 meq/L ( Apex Magnesium range 2.1-2.9 mmol/L) SE: feel weak/blurred vision/nausea/ hot/**diminished deep tendon reflexes/////////** Avoid 6-10 meq/L EKG changes = prolonged PR/wide QRS, HYPOTENSION 10 meq/L LOSS OF deep “TENDON” reflexes 15 meq/l range is respiratory arrest… cardiac arrest Magnesium affects uterine tone so higher risk of PPH

Answer 76

SEE Handout Triage in ER -less than 6 weeks post partum Stabilize/ OB consult/Labs fibrinogen liver fxn type and screen / strict I and O Initial IV Mag sulfate load dose or **IM if no IV** AntiHTN meds: Labetalol IV or **PO if no access** Hydralazine IV Immediate release oral nifedipine

Answer 77

Scheduled Urgent within 30 minutes STAT Repeat Airway evaluation must be performed prior to GA

Answer 78

Engorgement of epidural veins as intraabdominal pressure increases Reduces volume of CSF in subarachnoid space Facilitates spread of local anesthetic Decrease dose requirements of local anesthetics for epidural/spinal by 30-50%

Answer 79

5cm... Remember platelet trend prior to removing epidural in suspected low platelet patient scenario….??? Think do you want to repeat platelet count prior to removal? OB Epidural hematoma epidural abcess very RARE- 1:200,000- 1:250,000(SOAP 2018)... Symptoms hematoma rapidly preogressive neurologic deficits muscle weakness back pain sensory deficit and urinary retention Risk factors hematoma are hard to tell but defects of coagulation and multiple attempts at placement/ Also think STAT MRI AND NEUROSURGEON CONSULT

Answer 80

**.25 % Bupivacaine or .125% Bupivacaine More motor block with Xylocaine 1.5%** PCEA with 1mg/cc of Bupiv+2.5mcg/cc of Fentanyl at 8-10cc/hr with 6cc bolus/6min lockout/60cc 4 hour limit 6/6/60 ALWAYS aspirate before injecting Bolus “AMIDE” Local Anesthetics Awareness of platelet trend removal cath?

Answer 81

Epidurals for C/SOxygen /Monitors/ LUD T4 level 15-25cc of 2%Xylo with Epi 1:200k (SSH) May add sodium bicarbonate 4.2% for quicker onset (2cc to 20cc) Increase in time of onset vs spinal Rarely 3% Chloroprocaine…faster onset….ester….short DOA-think 45 min redose

Answer 82

Oxygen/ Monitors/ LUD Pressors often used: ephedrine / phenylephrine Timeout/ Antibiotics **AFTER CORD CLAMPING -**-> oxytocin gtt (30u in 500cc) 2 mg EPIDURAL Duramorph(PF) Awareness of platelet trend removal cath?

Answer 83

Elective C/S Repeat C/S Approx 1.4-1.6 cc of .75% Bupivacaine with Dextrose (may adjust for patient’s height or previous record available) .15mg Duramorph(PF) +10mcg Fentanyl Consider Epinephrine in spinal dosing *Neo 80mcg/cc or Ephedrine 5-10mg doses incrementally…Some use IM Ephedrine 25mg …..Epi if Tubal ligation/hysterectomy possible. Fentanyl increases intensity and duration of block*

Answer 84

T4 level Fast onset Hypotension Cardioaccelerator Pain relief Duramorph Denser block than epidural for c/s

Answer 85

Lipophilic Quick onset Improves sensory blockade 10mcg for spinal

Answer 86

Hydrophilic Postop pain relief up to 12-24 hours .15mg for spinal

Answer 87

Oxygen/Monitors/LUD PRELOAD and Pressors often used: -Ephedrine/Phenylephrine Time out/Antibiotics After cord clamping oxytocin(30u in 500cc)

Answer 88

Options: Narcotic IV, Ketamine Convert to GA Consider combined spinal/epidural from the beginning!!!!

Answer 89

metoclopramide/Sodium Bicitrate/H2 Blocker? 4-5 breaths of 100% Oxygen/**LUD**/EKG SAT BP monitors TIME OUT/Antibiotics/ Drapes up…surgeon+equipment RSI – “prop-sux-tube”/**Cricoid Pressure** just before onset of LOC GLIDESCOPE vs direct laryngoscopy—think! Propofol/ Ketamine + Succinylcholine + ETT -6.5 smaller

Answer 90

Non depol? Inhal at half MAC 50%O2 + 50% N2O After delayed cord clamp: Oxytocin gtt 70% N20 decrease Inhalation Reverse neuromuscular blockade?/narcotic Be aware with magnesium and reversal!! OGT/ Extubate awake *Review of anesthesia related maternal deaths over 18 yr period showed airway factors occurred during emergence and recovery and not during induction of general anesthesia. NGT “bloody mess” use OGT*

Answer 91

Inhalation agent Succinylcholine may last slightly longer Sensitivity to Non depolarizers with patient on Magnesium Sulfate

Answer 92

**Uterine atony medications** - see handout **TXA**-lysine analogue-prevents fibrinolysis RSI- Think “Prop, Sux, Tube” **Suggamadex**- binds to and encapsulates progesterone-Early pregnancy-**advise AGAINST** **Suggamadex-At term-Avoid or use with caution as inform effects on lactation unknown**- see document SOAP website 4/22/19 Magnesium is for SEIZURE prevention

Answer 93

* Combination Decreased FRC and Increased Minute Ventilation --> accelerates uptake * MAC decreased 40% for inhalation anesthetics at term * PREOXYGENATE! * RAPID DESATURATION! * RSI with Cricoid pressure(smaller ETT) * OGT * ?muscle relaxation

Answer 94

Individualize care- speak up!10-15% of adult mothers have depressive symptoms lasting more than 6 months… Suicide hotline is 988 HOMICIDE:* HOMICIDE is leading cause of death during pregnancy* and 42 days exceeding pregnancy 3.62 homicides per 100,000 live births among females pregnant or one yr post partum 16 times higher than nonpregnant nonpostpartum females.

Answer 95

.5-2% of all pregnancies Think care plans- how would you manage? Most common types… What about elective surgery? When? Which trimester is best for non-elective surgery that cannot be postponed? What is normal FHR? Variability? >23 wks monitor FHR for end organ perfusion