Case Presentation: An 83-year-old female with a past medical history of COPD, CAD s/p CABG 2022, hypertension, hyperlipidemia presented to the hospital for an elective revision right hip total arthroplasty. She is on no home oxygen for her COPD and is prescribed steroids and Trelegy Ellipta by her PCP. She does not see a pulmonologist. She is a heavy smoker. Patient was noted to be hypoxic post procedure in PACU. Upon evaluation she denied dyspnea, chest pain, nausea, vomiting, and other symptoms. Her surgery was uncomplicated and was extubated to room air. Her peripheral oxygen saturation was 100% at first but started to decrease from 90% to 68% on non-rebreather mask. Of note copious secretions were suctioned out as well. Status post 1 Liter of fluids and DuoNebs. Vital signs were within normal limits. On physical exam she is alert and mentating well on BiPAP. Rhonchorous breath sounds were heard throughout all lung fields. Arterial blood gas revealed pH of 7.365, pCO2 of 29.8 mmHg, pO2 of 48.9 mmHg, and HCO3 of 16.6 mEq/L, consistent with acute hypoxic respiratory failure and non-anion gap metabolic acidosis. She was started on BiPAP, and her oxygen saturation increased to the low 80s, however at maximum oxygen settings. Chest x-ray revealed left basilar atelectasis. Electrocardiogram showed normal sinus rhythm at a rate of 86 beats/minute. The patient was given steroids, lasix, and CT Chest PE protocol was ordered. The read was negative for PE and acute pulmonary embolus. However, upon visually reviewing the imaging an air embolus was found in the main pulmonary artery. Oxygen was increased to 100% FiO2 and patient encouraged to sit in the left lateral decubitus position. Patient was weaned from BiPAP to HFNC to NC and eventually to room air. Her ICU course was also complicated by C Diff colitis for which she completed a PO Vancomycin course. She was eventually transferred out of the ICU. She was also cleared by orthopedic surgery and was discharged home in stable condition.
Discussion: Air embolism during total hip replacement surgery is potentially hazardous and sometimes may even be fatal. It is commonly seen in cemented total hip arthroplasty. As a result of manipulating the medullary cavity the intramedullary pressure rises and fat, bone marrow, and air embolize into the venous system and to the lung. Our patient had a 46 mm Stryker Trident Liner cemented in place in the acetabulum. Patients with air embolus can present with dyspnea, tachypnea, wheezing, chest pain, high central venous distention, hypotension, respiratory failure, and even shock-like state depending on the amount of air embolism in the pulmonary circulation. In these patient immediate imaging tests such as thorax CT should be obtained to diagnose air embolism and other possible etiologies. Luckily, our patient was hemodynamically stable besides hypoxia. Hypoxia due to air embolus can be treated with 100% oxygen, left-lateral decubitus, and head down positioning of the body to decrease air entry into the right ventricle. Depending on the severity of the patient presentation volume resuscitation, vasopressors or inotropes to enhance resorption, and hyperbaric therapy to ensure dissolution of gases may be used.
Conclusions: Air embolism is rare but can be fatal. Not just critical care providers, but providers in general should be familiar with the clinical signs and features of air embolism and be ready to perform therapeutic maneuvers. Early detection of this clinical condition is essential to prevent morbidity and mortality.
