Acute Influenza Infection Presenting with Cardiac Tamponade: A Case Report and Review of Literature.

INTRODUCTION: Cardiac complications associated with influenza infection can occur either via a direct effect of the virus on the heart or through exacerbation of preexisting cardiovascular disease. We present a case of a 57-year-old man with acute influenza infection complicated by pericardial effusion and cardiac tamponade. CASE PRESENTATION: A 57-year-old white man presented to the Emergency Department with sudden onset of severe, nonexertional, retrosternal, pressure-like chest pain for a few hours and with fever and muscle aches for 2 days. The patient was initially admitted because of suspected acute coronary syndrome. The next morning, he complained of acute-onset shortness of breath and had hypotension and tachycardia. On examination, his peripheral extremities were cold and heart sounds were distant. Pulsus paradoxus was 20 mmHg. The electrocardiogram showed low-voltage QRS complex with electrical alternans. An urgently performed bedside echocardiogram showed moderate pericardial effusion with a small right ventricular cavity with diastolic collapse. Emergent pericardiocentesis was performed, with removal of 250 mL of fluid from the pericardial space. The patient's hemodynamic status immediately improved. Analyses of pericardial fluid demonstrated no bacteria, acid-fast bacilli, or malignant cells. The result of a rapid influenza diagnostic test with polymerase chain reaction was positive for influenza A virus, with other viral panels yielding normal results. The patient was treated with oseltamivir for 5 days. DISCUSSION: Pericardial involvement is a rare and perhaps underreported complication of influenza infection. Early recognition of cardiac symptoms and appropriate diagnostic workup in a patient presenting with influenza-like symptoms is important to avoid life-threatening complications.

Pembrolizumab-Induced Pancytopenia: A Case Report.

INTRODUCTION: Programmed death receptor-1 blockade with pembrolizumab is approved by the US Food and Drug Administration to treat patients with metastatic melanoma. Activating T cells to fight cancer may cause immune-mediated adverse events. Pembrolizumab-induced pancytopenia has not been previously reported in the medical literature, to our knowledge. CASE PRESENTATION: A 52-year-old Caucasian woman with a diagnosis of metastatic melanoma of the rectum experienced multiple adverse events along her course of therapy with pembrolizumab, ranging from colitis, hepatitis, gastritis, and vitiligo after the fifth cycle of pembrolizumab; to knee synovitis after the 14th cycle; and to severe pancytopenia after the 18th cycle of pembrolizumab. Severe pancytopenia improved after high-dose corticosteroids and a 5-day course of intravenous immunoglobulin therapy. DISCUSSION: In our case, pembrolizumab-induced Grade 4 pancytopenia resolved via a combination of corticosteroids and intravenous immunoglobulins. Pancytopenia reached a nadir in 10 weeks, and it took 16 weeks for meaningful recovery.