A 62-year-old woman came to our hospital with worsening cough and dyspnea over the preceding week, during which time she had been treated with azithromycin and prednisone for suspected pneumonia. She had no fever, chills, or sweats, but her cough had become productive of clear to blood-tinged phlegm during the interval. Medical history was significant for insulin-dependent diabetes mellitus and OSA. She had quit smoking 44 years earlier and had no history of lung disease. She was a bank teller residing in southeastern Minnesota and described no relevant inhalational or environmental exposures, drug use, aspiration, or travels preceding her illness.

An 81-year-old man who currently smokes with a 30-pack-year history presented with involuntary rhythmic motion of his right hand that had started insidiously and progressively worsened over the past 5 months. His medical history included hypertension and dyslipidemia. He did not have a prior history of pulmonary disease and currently denied any shortness of breath or cough. He did however report an unintentional weigh loss of 5 kg within the past few months.

A 41-year-old man who currently smokes with previous sporadic use of cocaine and cannabinoids was admitted at the hospital suffering from hemoptysis which had developed 4 days before. The patient was on anticoagulant therapy with rivaroxaban due to paroxysmal atrial fibrillation diagnosed in 2018, for which he had undergone pulmonary vein electrical isolation by radiofrequency and ablation of cavotricuspid isthmus in January 2019. The procedure was completed in July 2019. Treatment with flecainide was introduced due to recurrences of atrial fibrillation. In February 2021, a new attempt at ablation was performed by electrical isolation of the left atrial posterior wall. The latest cardiologic checkup documented an echocardiographic framework of mild left atrial dilatation and normal-sized right ventricle with longitudinal shortening index at the lower limits, and a recurrence of asymptomatic atrial fibrillation at Holter ECG (March 2022).

A 36-year-old woman with a medical history of opioid use disorder and frequent urinary tract infections presented to the ED from her opioid use disorder clinic, where she was found to have an oxygen saturation by pulse oximetry (Spo2) of 82% on room air. Starting 3 days before presentation, the patient's family noted worsening pale complexion and blue lips at rest. These findings of cyanosis had occurred a few times before and always resolved within a couple days without any medical intervention. She had no pulmonary symptoms outside of long-standing dyspnea with moderate exertion when at work or doing chores around the house. Her medications included methadone 160 mg daily, acetaminophen 650 mg nightly as needed, and phenazopyridine 199 mg three times daily as needed for increased urinary frequency and urethral discomfort that lasted a maximum of 4 days at a time. She confirmed she had started taking a new course of phenazopyridine 4 days before presenting to the ED. She had no dietary restrictions, had been eating her normal diet, and lived in a mobile home with her family, two dogs, and a gerbil. The patient reported using less than 10 tobacco cigarettes per day, one marijuana cigarette nightly, and no alcohol or other drugs. She worked in a warehouse stacking prepackaged bread.

A 35-year-old woman at 36 weeks and 4 days gestation with known complete anterior placenta previa and no other medical history presented for routine obstetric follow-up. She reported increasing fatigue in the prior week but otherwise endorsed no new concerns. She denied recent vaginal bleeding or discharge, abdominal pain, contractions, or extremity swelling. On evaluation, her BP was 126/74 mm Hg with a heart rate of 72 beats per min. The results from the physical examination were normal. There was a category II fetal heart rate tracing and a 6/10 biophysical profile (ie, no fetal breathing movements, nonreactive nonstress test), which prompted referral to the hospital. On admission, sonogram confirmed cephalic presentation and redemonstrated complete anterior placenta previa with no evidence of hemorrhage. She received antenatal steroids and was scheduled for a cesarean section delivery. She received bupivacaine spinal anesthesia for the procedure. The surgical procedure progressed with a low transverse uterine incision and subsequent delivery of the baby with no complications noted. Immediately after delivery of the baby and during gentle traction of the placenta, the patient experienced rapid cardiovascular collapse in the form of hypotension and bradycardia.