NMS Q&A Family Medicine

286 NMS Q&A Family MedicineExamination Answers1. The answer is B. At less than 1 week of age, the lowercabin pressure brings a lower partial pressure of oxygen.This may be insufficient for the cardiorespiratory systemof the newborn as it adapts to extra-uterine life. Thisapplies to full-term babies without congenital heart diseaseresulting in desaturation such as right to left shuntinglesions.2 . The answer is D. In Thailand, travelers diarrhea ismore likely to be caused by a fluoroquinolone-resistantinvasive bacterium such as Campylobacter pylori. Azithromycinis thus the drug of choice at this point in time. LatinAmerica where toxin-producing bacteria are the mostlikely cause of travelers diarrhea, the malady is best treatedwith something like loperamide titrated to dose responsivenessand perhaps a single dose of ciprofloxacin, levofloxacin,or fluoroquinolone. If that approach fails, then100 mg azithromycin is appropriate.3. The answer is A. Diarrhea is the most common medicalproblem in travelers. Those who spend at least 1 monthin the other country face a 60% chance of becoming illand a 1% chance of being admitted to hospital. Antibiotic/antibacterialprophylaxis against travelers diarrhea isbest employed in anticipation of short stays, presence ofdiabetes, or chronic diarrhea, and, in those situations, is90% successful. Prophylactic antibiotics are generally notrecommended except in the above situation. Bismuthsubsalicylate is about 65% effective in preventing travelersdiarrhea, but salicylate contraindications must beobserved. For travel to South Asia, the best regimen is aquinolone, such as norfloxacin 400 mg/day, ciprofloxacin500 mg/day, or ofloxacin 200 mg/day.4. The answer is E. Viral hepatitis, of those mentioned inthe question, is the most serious common medical problemencountered in travel. Not only is it commonlyencountered, but it is also likely to be particularly disablingto a traveler. Unless the traveler has participated inparenteral illicit drug use or risky sexual practices, anyhepatitis encountered will be hepatitis A or E, contractedfrom water or uncooked raw vegetables in an underdevelopedcountry.5. The answer is D. B. Doxycycline is presently the firstchoice for malaria prophylaxis in areas known to harbormultiple drug resistance.6. The answer is C. Travel during pregnancy to areas ofhigh risk for malaria should be avoided, especially in areasnoted for chloroquine resistance. Malaria has a moremalignant course in pregnancy and the alternative therapiesin event of chloroquine resistance are more toxic,even in nonpregnant patients. Air travel is best done inthe second trimester. Most airlines require a physician’spermission for air travel by a pregnant woman only aftershe has reached 35 or 36 weeks of gestation. Althoughampicillin is safe in pregnancy, astemizole and terfenadineshould not be used in the first trimester. For diarrhea duringpregnancy, trimethoprim/sulfamethoxazole, erythromycin,and loperamide are safe to use.7. The answer is C. A measure of 61 mm Hg is the alveolarPO 2 at an altitude of 10,000 ft (3,048 m). Remember,the alveolar PO 2 is, at best, the ambient PO 2 minus thepartial pressure of alveolar CO 2 and H 2 O, the latter constantat 47 mm Hg; 47 mm Hg is the constant partial pressureof water vapor at all ambient pressures. Note that79 mm Hg is the ambient PO 2 at 18,000 ft (5,486 m), thealtitude beneath which lies half the atmosphere; 46 mmHg is the alveolar PO 2 at an altitude of 15,000 ft (4,572 m);88% represents the arterial blood saturation, normally95%, in a healthy person at 7,500 ft (2,286 m).8. The answer is B. Height of 6,500 ft (1,981 m) is thealtitude above which it can be said that symptoms ofmountain sickness occur in 25% of travelers. This degreeof illness is called acute mountain sickness. The incidenceincreases to 50% as altitude rises to 10,000 ft (3,048 m).These symptoms are likely to be classified as mild,consisting of headache, dysphoria, nausea, peripheraledema, unexpected sighing, and nocturnal Cheyne–Stokesbreathing. Nearly always, resting at altitude for 1 to 2 dayswill result in abatement of mild symptoms of altitudesickness. Wrong advice would be to exercise strenuouslyduring the first 2 days at altitude to prevent altitude sickness.All others are correct. The saying is “climb high, sleeplow,” especially at higher altitudes, to avoid HAPE andHACE.9. The answer is A. Acetazolamide (Diamox) administration,one 750-mg tablet, perhaps repeated, or 250 mgevery 6 hours, will probably be enough to treat the symptomsin the scenario presented. The other measures aregenerally not needed for acute mountain sickness.10. The answer is D. Height of 12,500 ft (3,810 m). PulmonaryHAPE and cerebral HACE are the most serioussymptoms that may occur with mountain sickness. Bothare emergencies. HAPE symptoms, which are more likelyand worse if ascent is rapid, consist of tachycardia, tachypnea,severe dyspnea, frothy or blood-tinged sputum,