A Patient on Airway Pressure Release Ventilation With Sudden Hemodynamic Collapse

Abstract

We present a case of a man in his 50s with past medical history significant for schizophrenia and hypertension who was recently diagnosed with mycosis fungoides vs primary cutaneous T-cell lymphoma with extensive metastasis. Patient was admitted to the medical ICU and treated for sepsis of unknown source, likely pneumonia. Wound cultures grew Pseudomonas, methicillinresistant Staphylococcus aureus, and Proteus. Laboratory results were notable for the following: WBC count, 88,000/mL; uric acid, 10.6 mg/dL; potassium, 5.3 mEq/L; phosphate, 6.5 mg/dL; lactate dehydrogenase, 693 U/L. The patient was started on broad-spectrum antibiotics and treated for sepsis and tumor lysis syndrome. An official echocardiogram on admission showed unremarkable results. The patient's clinical condition improved and he was transferred to the ward. Twenty-four hours after transfer to the ward, the patient was found to be tachypneic and was subsequently transferred back to the ICU, intubated for hypoxemic respiratory failure, and placed on airway pressure release ventilation (APRV). Pressure support was increased progressively because of profound hypoxemia. The patient's medical ICU course was further complicated by oliguric renal failure, requiring renal replacement therapy. Forty-eight hours after intubation, the patient developed bradycardia and hypotension. A point-of-care ultrasound (POCUS) was done on an emergency basis at the bedside (Video 1).

Myths and Misconceptions of Airway Pressure Release Ventilation: Getting Past the Noise and on to the Signal

“…Several papers warn the use of APRV leads to an increase in right ventricular (RV) afterload, worsening of pulmonary hypertension and RV dysfunction, and reduction of venous return (VR) leading to systemic hypotension ( Kallet, 2011 ; Modrykamien et al, 2011 ; Chatburn et al, 2016 ; Chen et al, 2017 ). There are even claims that APRV theoretically has an increased risk of cor pulmonale ( Kallet, 2011 ; Chatburn et al, 2016 ; Chen et al, 2017 ). Indeed, applied airway pressure can result in a reduction of VR and cardiac output (CO).…”

“…It has also been implied that APRV caused RV failure likely due to high ΔP from APRV with no supporting data ( Chen et al, 2017 ). Conversely, ΔP was measured in 200 patients with a passive respiratory system such as post-operative patients (i.e., anesthesia or neuromuscular blocking agents) using a 4 s expiratory hold for equilibration ( Andrews et al, 2019 ).…”

Point-of-care Ultrasound (POCUS) Program for Critical Care Nurse Practitioners and Physician Assistants in an Oncological Intensive Care Unit and Rapid Response Team

“…These two groups collectively have performed approximately 1,560 POCUS examinations, with a predominant emphasis on cardiac, followed by lung and vascular imaging. These examinations have been instrumental in guiding resuscitation strategies, discerning various pathologies, and crafting appropriate treatment plans (Chen et al, 2017(Chen et al, , 2018a(Chen et al, , 2018b(Chen et al, , 2022.…”