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%.
Pulmonary aspiration during the induction of general anesthesia in the pregnant patient is more likely as a result of:
the posterior displacement of the stomach by the uterus placental gastrin secretion increased intragastric pressure progesterone-induced increase in lower esophageal sphincter tone
placental gastrin secretion: Upward and anterior displacement of the stomach by the uterus promotes incompetence of the GE sphincter. Elevated progesterone levels reduce the tone of the GE sphincter. Placental gastrin secretion causes hypersecretion of gastric acid. Intragastric pressure is unchanged during pregnancy.
A 10-kg child is scheduled for a resection of a skin lesion of the right thigh. The anesthetic plan calls for the use of a laryngeal mask airway. The appropriate size of the LMA for this patient is:
1 2 3 4
2
Size Age Weight Cuff Vol
1 Infant 30 kg up to 20
4 Adult 70 kg up to 30
Morphine is infrequently used as an analgesic during labor because at equianalgesic doses it appears to cause:
a higher incidence of fetal seizures as compared to fentanyl a higher incidence of fetal respiratory depression as compared to fentanyl a greater loss of fetal thermal regulation as compared to fentanyl a higher incidence of fetal bronchospasm as compared to fentanyl
a higher incidence of fetal respiratory depression as compared to fentanyl: Morphine is seldom used for maternal analgesia because in equianalgesic doses it appears to cause greater respiratory depression in the fetus than meperidine or fentanyl.
Factors complicating the airway management in the patient with trisomy 21 include:
microglossia prognathia hypertonicity of the masseter muscles occipitoatlantoaxial instability
occipitoatlantoaxial instability: Trisomy 21 or Down syndrome is the most common human chromosomal syndrome. Airway management in these patients can be difficult due to macroglossia, micrognathia, narrow hypopharynx and muscular hypotonia. There is also a risk of spinal cord compression due to occipitoatlantoaxial instability.
Pathophysiologic events associated with preeclampsia include:
an production imbalance between prostacyclin and thromboxane A2 intravascular volume expansion decreased vascular sensitivity to catecholamines thrombocytosis
an production imbalance between prostacyclin and thromboxane A2: Pregnancy-induced hypertension (PIH) encompasses a range of disorders, including gestational hypertension, preeclampsia and eclampsia. Three principal mechanisms serve as the etiology of PIH. These mechanisms are: abnormal sensitivity of vascular smooth muscle to catecholamines, placental vasculitis, and an imbalance in the production of vasoactive prostaglandins (thromboxane A2 and prostacyclin).
At term, maternal plasma volume has:
decreased by approximately 15% increased by approximately 15% increased by approximately 25% increased by approximately 50%
increased by approximately 50%: Maternal blood volume increases to between 85 and 100 ml/kg at term. Increases occur in both plasma volume (50%) and blood cell mass (up to 20%). Because the increase in plasma volume is greater, a relative dilutional anemia occurs.
Treatment of cardiac toxicity secondary to unintentional intravascular bupivacaine injection should include:
control of arrhythmias with intravenous lidocaine control of arrhythmias with intravenous verapamil avoidance of cardioversion the administration of a 20% lipid solution
the administration of a 20% lipid solution: Cardiac toxicity from bupivacaine may be difficult to treat. Hyperventilation with oxygen should be immediately instituted. Ventricular dysrhythmias may need large and multiple doses of electrical cardioversion, epinephrine, vasopressin and amiodarone. The use of calcium channel blockers is not recommended. The administration of a 20% lipid solution at an initial dose of 4 mL/kg has been found to improve survival.
In children under 5 years of age, the narrowest point of the airway is the:
rima glottis thyroid cartilage cricoid cartilage hyoid cartilage
cricoid cartilage: The cricoid cartilage is the narrowest point of the airway in children younger than 5 years of age; in the adult, the narrowest point is the glottis.
In the parturient, uterine hypertonus has been associated with the use of large induction doses of:
thiopental propofol etomidate ketamine
ketamine: Uterine hypertonus may occur with ketamine at doses > 2 mg/kg.
Kernicterus has been reported after the intravenous administration of drugs to neonates which contain the preservative:
metabisulfite p-amino benzoic acid EDTA benzyl alcohol
benzyl alcohol: Benzyl alcohol has been implicated in causing kernicterus by displacing bilirubin from albumin and facilitating its entry into the brain. Certain preparations of propofol and normal saline flush can contain benzyl alcohol and should be avoided in the neonate.
At term, pseudocholinesterase activity is:
increased by 10% increased by 30% decreased by 10% decreased by 30%
decreased by 30%: A 25 - 30% decrease in serum pseudocholinesterase activity is present at term, but rarely produces significant prolongation in the action of succinylcholine.
A 12-kg child is scheduled for repair of an inguinal hernia. The patient had an upper respiratory infection 2 weeks ago, but now has full resolution of symptoms. At this time, this patient is at increased perioperative risk for:
bronchospasm laryngospasm hypoxemia
all of the above all of the above: A viral infection within 2 - 4 weeks before general anesthesia and endotracheal intubation appears to place the child at risk for perioperative pulmonary complications such as bronchospasm (10 fold), laryngospasm (5 fold), hypoxia and atelectasis.
Nonsteroidal antiinflammatory agents, such as ketorloac, are not recommended as analgesics during labor because they are associated with:
delayed closure of the ductus arteriosus maternal and fetal respiratory depression suppression of uterine contractions impaired placental oxygen transfer to the fetus
suppression of uterine contractions: Nonsteroidal antiinflammatory agents are not recommended because they suppress uterine contractions and promote closure of the fetal ductus arteriosus.
Treacher-Collins syndrome:
results in anterior displacement of the tongue results in mandibular hyperplasia is often associated with other craniofacial abnormalities such as cleft palate follows an autosomal recessive inheritance pattern
is often associated with other craniofacial abnormalities such as cleft palate: Treacher-Collins syndrome is the most common of the mandibulofacial dysostoses. Inheritance is as an autosomal dominant trait. Hypoplasia of the mandible with posterior displacement of the tongue (glossoptosis) can result in early airway problems. Treacher-Collins syndrome is associated with cleft palate, ventricular septal defect, and gross deformites of the external ear canals and ossicular chain. These patients present extreme difficulty with airway management and facilities for surgical airway placement should be part of the anesthetic plan.
In the patient with pregnancy-induced hypertension, epidural analgesia during labor has been associated with:
increased maternal catecholamine levels improved uteroplacental blood flow increased uterine artery vasospasm fetal distress
. improved uteroplacental blood flow: Epidural analgesia is the preferred technique for labor analgesia in the patient with PIH if not contraindicated by coagulopathy. Epidural analgesia reduces maternal catecholamine levels and facilitates blood pressure control. Epidural analgesia improves intervillous blood flow thus improving uteroplacental performance and fetal well-being.
At term, maternal red cell mass has:
decreased by up to 15% increased by up to 10% increased by up to 20% increased by up to 50%
increased by up to 20%: Maternal blood volume increases to between 85 and 100 ml/kg at term. Increases occur in both plasma volume (50%) and red blood cell mass (up to 20%). Because the increase in plasma volume is greater, a relative dilutional anemia occurs.
