OB/Peds Flashcards
In the United States, the leading cause of maternal death associated with a live birth is:
- pregnancy-induced hypertension - pulmonary embolus - cardiomyopathy - hemorrhage
pulmonary embolus
On a per kilogram basis, ventilatory parameters that remain unchanged from birth through adulthood include:
- dead space - minute ventilation - functional residual capacity - closing capacity
Tidal volume and dead space per kilogram remain constant during development.
Well-oxygenated fetal blood from the placenta has a PaO2 of approximately:
40 mmHg 60 mmHg 80 mmHg 100 mmHg
During a normal pregnancy, umbilical vein blood has a PaO2 of approximately 40 mmHg
A preterm (33 week gestation) neonate is delivered emergently by cesarean section. The baby shows tachypnea, grunting, intercostal retractions and is cyanotic. The most likely cause of the cyanosis is:
insufficient surfactant production transposition of the great vessels insufficient hemoglobin F production tetralogy of Fallot
insufficient surfactant production: The most common cause of respiratory distress in preterm neonates is the respiratory distress syndrome (RDS) also known as hyaline membrane disease. The syndrome is responsible for 50 - 75% of deaths in preterm neonates. It is the result of deficient production and secretion of surfactant, which is produced by type II pneumocytes. Mature levels of surfactant are not present until 35 weeks of gestation.
Electrocardiographic changes associated with the third trimester of pregnancy include:
right axis deviation first degree AV block left axis deviation sinus bradycardia
left axis deviation: Elevation of the diaphragm shifts the heart position in the chest resulting in the appearance of an enlarged heart on a plain chest film and in left axis deviation and T wave changes on the electrocardiogram.
After delivery of a 4.0 kg neonate recurrent bradycardia is noted. An umbilical artery catheter is placed at which time the neonate becomes asystolic. An appropriate dose of epinephrine would be:
0. 01 mg 0. 25 mg 0. 04 mg 0. 50 mg
0.04 mg: Epinephrine 0.01 - 0.03 mg/kg is indicated for neonatal bradycardia (
The most common morbidity encountered in obstetrics is:
severe sepsis severe preeclampsia HELLP syndrome severe hemorrhage
severe hemorrhage: The most common morbidities encountered in obstetrics are severe hemorrhage (6.9/1000) and severe preeclampsia (3.9/1000).
A 9-year-old patient with a history of cerebral palsy is scheduled for release of contractures of the Achilles tendons. The patient is receiving phenytoin for control of seizures. Anesthetic considerations in this patient include:
- an increased sensitivity to nondepolarizing blockers
- the likelihood of gastroesophageal reflux disease
- the possibility of severe hyperkalemia with the use of succinylcholine
- the avoidance of volatile anesthetics because of an increased incidence of MH in these patients
Management of anesthesia in children with cerebral palsy includes tracheal intubation because of the propensity for GERD and poor function of laryngeal and pharyngeal reflexes. There is no increase in the incidence of MH in these patients and the use of volatile anesthetics has been shown to be safe. Patients receiving anticonvulsants may be more resistant to the effects of nondepolarizing relaxants. Despite the skeletal muscle spasticity, succinylcholine does not produce abnormal potassium release in these patients.
You are asked to evaluate 31-year-old G3P2 woman for a repeat cesarean section. Her past medical history is significant for 2 previous cesarean sections. She has been laboring for the previous 7 hours with little progress despite an oxytocin infusion. During the interview, the patient complains of sudden severe continuous abdominal pain radiating to her left shoulder. These symptoms are most consistent with:
preeclampsia abruptio placentae uterine rupture placenta previa
Uterine rupture is often heralded by severe abdominal pain, referred to the shoulder due to subdiaphragmatic irritation by intra-abdominal blood. Uterine rupture is associated previous uterine scars and excessive oxytocin stimulation. Current recommendations discourage VBAC in women with two or more previous uterine incisions.
As compared to regional anesthesia, the risk of maternal death from general anesthesia is approximately:
the same three times greater eight times greater sixteen times greater
sixteen times greater: Based on data collected between 1985 and 1990, maternal mortality from general anesthesia is approximately 32 per 1,000,000 live births. In comparison, mortality from regional anesthesia is only 1.9 per 1,000,000 live births.
In the fetus, blood entering the right atrium from the inferior vena cava is preferentially directed to the:
ductus arteriosus right ventricle foramen ovale ductus venosus
foramen ovale: Right atrial anatomy preferentially directs blood from the inferior vena cava through the foramen ovale into the left atrium.
Functional residual capacity is decreased in the neonate as a result of:
increased lung compliance and decreased chest wall compliance decreased lung compliance and increased chest wall compliance increased lung compliance and increased chest wall compliance decreased lung compliance and decreased chest wall compliance
decreased lung compliance and increased chest wall compliance: The small and limited number of alveoli in neonates and infants reduces lung compliance; in contrast, their cartilaginous rib cage makes their chest wall very compliant. The combination of these two characteristics promotes chest wall collapse during inspiration and relatively low residual lung volumes at expiration.
Of the following, the lowest degree of placental drug transfer occurs with the use of:
bupivacaine chloroprocaine lidocaine ropivacaine
chloroprocaine: Chloroprocaine has the least placental transfer because it is rapidly broken down by plasma cholinesterase in the maternal circulation.
Post-intubation laryngotracheobronchitis (croup) is most commonly seen in children of:
0 - 1 year of age 1 - 4 years of age 4 - 7 years of age 7 - 9 years of age
1 - 4 years of age: Post-intubation croup is due to glottic or tracheal edema and is associated with early childhood (ages 1 - 4), repeated intubation attempts, large endotracheal tubes, prolonged surgery, head and neck procedures and excessive movement of the endotracheal tube. Nebulized racemic epinephrine is an effective treatment
Renal changes seen during pregnancy include a reduction in:
plasma levels of renin and aldosterone the tubular threshold for glucose and amino acids glomerular filtration renal plasma flow
the tubular threshold for glucose and amino acids: Renal vasodilation increases renal blood flow, glomerular filtration and renal plasma flow. Increased renin and aldosterone levels promote sodium retention. A decreased renal tubular threshold for glucose and amino acids is common and often results in mild glycosuria or proteinuria.
The appropriate endotracheal tube diameter for a full-term neonate is approximately:
2. 0 mm 3. 0 mm 4. 0 mm 4. 5 mm
3.0 mm: For pediatric patients, the appropriate diameter of the endotracheal tube can be estimated by the formula: Tube diameter = 4 + (age/4)Exceptions include premature neonates (2.5 - 3.0 mm) and full-term neonates (3.0 - 3.5 mm).
Pain during the latent phase of labor is usually confined to dermatomes:
T11 - T12 L1 - L2 L3 - L4 L5 - S1
T11 - T12: Pain during the first stage of labor is mostly visceral pain resulting from uterine contractions and cervical dilatation. It is usually initially confined to the T11 - T12 dermatomes during the latent phase, but eventually involves the T1- - L1 dermatomes as the labor enters the active phase.
A 12-year-old patient is scheduled for an excision of a sellar craniopharyngioma. Suspected preoperative laboratory abnormalities in this patient include:
a decreased thyroxine (T4) level with an elevated thyrotropin level an elevated plasma cortisol level hypernatremia an elevated growth hormone level
hypernatremia: Craniopharyngioma is the most common intracranial tumor of nonglial origin in the pediatric population. Because the tumor can affect the pituitary, endocrine dysfunction is common. Secondary hypothyroidism, growth hormone deficiency, secondary hypocortisolism and diabetes insipidus should all be suspected. Diabetes insipidus can present preoperatively as hypernatremia, but may also be seen 4 - 6 hours postoperatively, due to surgical damage to the pituitary.
A 34-year-old patient presents to the emergency room in labor with contractions occurring every 4 minutes. She is at 32 weeks of gestation. Pharmacologic inhibition of uterine contractions can be accomplished with:
intravenous calcium chloride therapy intravenous betamethasone therapy intravenous metoprolol therapy intravenous ritodrine therapy
intravenous ritodrine therapy: The most commonly used tocolytics are β2-agonists (ritodrine or terbutaline) and magnesium. Although betamethasone may be given to induce fetal production of surfactant, it is not effective as a tocolytic agent. More recently, oxytocin antagonist, atosiban, has show effectiveness in patients of greater than 28 weeks gestation
At 20 weeks’ gestation, frequently found changes in heart sounds include:
loss of split of the first heart sound grade I to II diastolic murmur presence of a third heart sound all of the above
presence of a third heart sound: Several changes in heart sounds occur during pregnancy. Early closure of the mitral valve may cause a split first heart sound. A third heart sound can be heard in most women by 20 weeks’ gestation. A benign grade I or II systolic murmur is also common. Diastolic murmurs are pathologic.
As compared to the non-pregnant patient, the incidence of pulmonary aspiration of gastric contents in the obstetric patient is:
approximately equal if cricoid pressure is applied twice as great 4 - 5 times greater 8 - 10 times greater
4 - 5 times greater: Pulmonary aspiration of gastric contents is 4 - 5 times greater in the obstetric patient with an incidence of 1:400 - 500 as compared to an incidence of 1:2000 in the non-pregnant patient.
The position of the larynx in the neonate is at approximately:
C2 C4 C6 C8
C4: Neonates and infants have a proportionately larger head and tongue, narrow nasal passages, an anterior and cephalad larynx (at vertebral level C4 versus C6 in adults), a long epiglottis and a short trachea
Clinically significant placental drug transfer has NOT been shown to occur with the use of:
ephedrine labetelol glycopyrrolate metoclopramide
glycopyrrolate: Most commonly used anesthetic adjuncts readily cross the placenta. Maternally administered ephedrine, labetalol, esmolol, vasodilators, phenothiazines, antihistamines, metoclopramide, atropine and scopolamine cross the placenta in clinically signifcant amounts. Glycopyrrolate administration, as a result of the drug’s quaternary ammonium structure, results in only limited placental transfer.
A 38-postconception week neonate is scheduled for an emergent repair of an incarcerated inguinal hernia. The patient was delivered at 34 weeks of gestation. Anesthetic management of this patient should include:
maintenance of the arterial PaO2 above 100 mmHg permissive hypercapnea to reduce barotrauma to the lungs maintenance of oxygen saturation between 89 - 94% the use of 3% NaCl for fluid replacement
maintenance of oxygen saturation between 89 - 94%: In this preterm neonate there exists a substantial risk for the development of retinopathy of prematurity. Because the optimal intraoperative oxygen saturation for these infants is not known, it is prudent to limit oxygen supplementation during the period of retinal vascularization (up to 44 weeks postconception). Efforts should be made to maintain PaO2 between 50 - 80 mmHg and PaCO2 between 35 - 45 mmHg. This results in a pulse oximetry target of 89 - 94%.