OB I Flashcards
What makes a pregnancy high risk?
- Hypertensive disorders
- antepartum hemorrhage
- diabetes, cardiac, renal, thyroid, neurologic disease, asthma, obesity, drug abuse
- advanced maternal age
- prematurity
- multiple gestation
- fetal malpresentation, placental abruption, compression of umbilical cord, intrauterine infections
What is the maternal mortality rate?
most frequent causes?
What are the anesthesia related complications?
- Maternal mortality in US is 7.5 per 100,000 live births
- pregnancy-induced HTN
- hemorrhage
- PE
- Anesthesia related complications- accounted for 5.2% of maternal deaths
- airway problems/aspiration
- LA toxicity or high block
How is hypertension defined in pregnancy?
What can it cause?
- 7-10% of all pregnancies are complicated by HTN
- mild HTN >140/90 or a rise in SBP of 30 mmHg above baseline or rise in DBP of 15 over baseline
- Severe HTN >160/110
- HTN can cause:
- abruptio placentae
- DIC
- hepatic failure
- cerebral hemorrhage
- others on separate card
What are the complications caused by hypertension during pregnancy?
Neurological
pulmonary
CV
- Neurological
- HA
- visual disturbances
- hyperexcitability
- sz
- intracranial hemorrhage
- cerebral edema
- Pulmonary
- upper airway edema
- pulmonary edema
- CV
- decreased intravascular volume
- increased arteriolar resistance
- heart failure
What are the complications caused by hypertension during pregnancy?
Hepatic
Renal
Hematological
- Hepatic
- impaired function
- elevated enzymes
- hematoma
- rupture
- Renal
- proteinuria
- Na retention
- decreased GFR
- renal failure
- Hematological
- coagulopathy
- thrombocytopenia
- platelet dysfunction
- prolonged PPT?
- DIC
- coagulopathy
How does maternal HTN during pregnancy affect the fetus?
Impaired uteroplacental perfusion
What conditions predispose a woman to pregnancy-induced hytension (PIH)?
- Primaparity
- maternal age >40
- african american race
- chronic HTN
- chronic renal disease
- Insulin-dependent diabetes
- history of preeclampsia (maternal- familial)
- Obesity
- multiple gestation
What is preeclampsia?
What can it cause?
When does it return to normal?
- Condition characterized by:
- vasoconstriction
- hypovolemia
- coagulation abnormalities
- poor organ perfusion
- Defines as new onset HTN that occurs after the 20th week gestation with proteinuria
- Can cause:
- cerebral bleeds
- pulmonary edema
- hepatic rupture
- HELLP syndrome
- Returns to normal within 3 months after delivery
How is preeclampsia categorized (mild vs severe)?
- Mild
- HTN:
- 140/90 or greater or
- increase of 30 mmHg above systolic or
- 15 above diastolic
- Proteinuria: >500 mg/day
- HTN:
- Severe
- HTN:
- 160/110 or greater
- Proteinuria:
- >5 g/day and/or
- oliguria (UOP < 500 ml/day)
- evidence of severe end-organ damage
- oliguria
- cerebral disturbances
- pulmonary edema
- epigastric pain or impaired liver fxn
- intrauterine growth retardation
- HTN:
What is Eclampsia?
When does it usually occur?
What are early manifestations?
Treatment?
- Preeclampsia (HTN, edema, and proteinuria) with seizures
- Life-threatening emergency
- most common in 3rd trimester
- Early CNS manifestations are HA and visual disturbances
- Treatment:
- Oxygen (ABC’s)
- LUD
- IV access
- Mag sulfate
- antihypertensives
- fluid balance
- coag studies
- fetal monitoring and resuscitation
How is preeclampsia treated?
- Mainstay of therapy is to control HTN, prevent seizures, and deliver fetus
- Treatment of maternal HTN (a-line)
- goal is DBP <110
- labetalol and hydralazine commonly used
- other options Nitroglycerine or nifedipine
- want to gradually decrease BP- may cause fetal distress to drop too quick
- Seizure prophylaxis with Magnesium sulfate
- Correct hypovolemia (hydration, foley)
- Correct coagulation abnormalities
- Correct acid/base and electrolyte abnormalities
- assure fetal viability
How does Magnesium sulfate work?
- drug of choice for hyperreflexia, prevention and control of sz related to preeclampsia and eclampsia
- Causes relaxation of vascular, bronchial and uterine smooth muscle
- decreases cerebral irritability and prevents/treats sz
- mildly sedates
- vasodilates (caution hypotension)
- decreases uterine tone
- potentiates the action of depolarizing and non depolarizing muscle relaxants
- croses placenta and causes neonatal hypotonia and respiratory depression
What is the Magnesium sulfate dose?
What are the maternal side effects?
How can you reverse Magnesium sulfate?
- Dose:
- bolus 4 g IV over 10 minutes
- maintenance: 1 6/hr IV infusion
- Maternal side effects:
- flushing
- HA
- dizziness
- skeletal muscle weakness
- deep tendon reflex depression
- respiratory depression
- pulmonary edema
- **monitor serum levels for toxicity
- Revers the effects of Mag sulfate by administering Calcium
- Calcium gluconate 1 gm or calcium chloride 300 mg
How does magnesium therapy affect the anesthetic management?
- It potentiates depolarizing and non-depolarizing neuromuscular blockers
- Never administer defisiculating dose of NMB
- Standardize dose of Sch to 1 mg/kg
- Administer 1/2 to 1/3 maintenance dose of non-depolarizers
- Dose by PNS
- Mag sulfate antagonizes vasoconstrictive effects of alpha agonists, so ephedrine and phenylephrine are less effective
What are the key points in managing the anesthetic for a preeclamptic or eclamptic patient?
- Assess sz control and neurologic status
- assess airway
- correct hypovolemia with colloid fluid bolus (250-500 ml)
- control BP (DBP <100)
- Consider A-line, CVP, SWAN
- continuous FHR monitoring
- oxygen to parturient
- Lab workup:
- CBC
- renal profile
- liver function tests
- Pt/PTT
- FDP- fibrin degredation products
- FSP- fibrin split products
- TEG
- platelet count