Hypoxic Respiratory Failure Due to Pneumocystis Jiroveci and Cytomegalovirus Co-Infection in a Severely Immunocompromised Patient

Abstract

Introduction:Immunocompromised individuals, such as those with HIV and low CD4 counts, are at increased risk for opportunistic infections. Although uncommon, these patients can be infected with multiple organisms, making diagnosis and management challenging for clinicians. Mortality remains high, as the data on initiating and adjusting antimicrobials when there is concern for co-infection is lacking. We present a case of Pneumocystis jiroveci (PCP) and cytomegalovirus (CMV) coinfection resulting in severe hypoxic respiratory failure and death. Case Report:A 38-year-old male with no past medical history presented with fever, dyspnea, and nonproductive cough. Vital signs were notable for a fever of 102.3°F, respiratory rate of 24, and oxygen saturation of 77% on room air. Physical examination revealed an ill-appearing male with bilateral rhonchi who became dyspneic with minimal conversation. Laboratory studies were significant for an elevated c-reactive protein, erythrocyte sedimentation rate, ferritin and lactate dehydrogenase. CT chest demonstrated bilateral ground glass opacities with multifocal consolidations. The patient was admitted for hypoxic respiratory failure secondary to suspected COVID pneumonia, despite negative testing. By hospital day 4, the patient had shown little improvement. Further work-up revealed that he was HIV positive with a CD4 count of 5, so he was empirically started on oral trimethoprim-sulfamethoxazole (TMPSMX) for presumed PCP pneumonia. On hospital day 9, the patient underwent endotracheal intubation for worsening hypoxia and subsequent bronchoscopy for further evaluation. PCP PCR confirmed the diagnosis, and the patient was transitioned to intravenous TMP-SMX. Still with minimal improvement, micafungin was added as potential salvage therapy. After 12 days of TMPSMX, treatment was changed to clindamycin/primaquine. CMV PCR from the bronchoalveolar lavage fluid came back positive at this time, so ganciclovir was added to the regimen. Despite multiple antimicrobials, the patient continued to decline. He was deemed not to be a candidate for ECMO given his profoundly immunocompromised status and ultimately died. Discussion:This case highlights the difficulties clinicians have in managing severely immunocompromised patients who worsen despite appropriate care. Little data exists providing guidelines on when to change to second and/or third-line agents in treating PCP pneumonia. Additionally, further studies need to be completed to delineate in whom empiric antimicrobials should be initiated early when co-infection is a possibility. ECMO may serve a purpose in this patient population given that lung rest is necessary to allow healing, but only a few cases of its use exist at this time.