Desaturation during the pandemic: Covid or cognitive bias?

The coronavirus pandemic has put an unprecedented strain on our health care system. An urgent need for timely and accurate diagnosis coupled with an inordinate caseload and myriad overlapping signs and symptoms with other differentials is leaving physicians fatigued. This often leads to the use of mental shortcuts - "heuristics" by the strained mind and the inadvertent use of intuitive thought processes rather than the more controlled analytical thinking to cope and speed up the decision-making process. Availability bias - making a recent or vivid patient diagnosis more readily accessible to the mind - and anchoring bias - relying too heavily on a single symptom for deducing diagnosis - are among the most prevalent cognitive biases. Therefore, it is not unexpected that any new cases of acute onset respiratory illness may be mis-diagnosed as coronavirus disease 2019 during the pandemic, significantly impacting the morbidity and mortality of true diagnosis. To reduce the risk of patient harm, it is therefore imperative that medical practitioners be aware of the existence and influence of cognitive bias in clinical decision making and maintain sight of a variety of differential diagnoses to ensure that no adverse condition is overlooked.

Management of complete heart block during pregnancy.

A 22-year-old second gravida presented to the antenatal clinic at 28 weeks of gestation with frequent fainting attacks (2-3 episodes/day), palpitations and dyspnea (New York Heart Association Functional Classification II). Her pulse rate was 40 b.p.m. A 12-lead electrocardiogram and 24-h Holter revealed complete heart block. A transvenous permanent pacemaker (ventricular demand rate-responsive), paced at a rate of 60 pulses/min, was successfully implanted. A multidisciplinary approach was taken and the patient delivered a healthy baby boy of 2.8 kg at 38 weeks. She remained asymptomatic and was discharged in good condition. Management varies from expectant management to temporary pacemaker insertion to permanent pacing during pregnancy. In a young patient with sinus bradycardia, the primary criterion for a pacemaker is the concurrent observation of a symptom (e.g., syncope) with bradycardia (e.g., heart rate 35-40 b.p.m. or asystole for 3 s). Symptomatic pregnant women should always be counseled for a permanent pacemaker.