Case Presentation: A 66-year old woman with a history of obesity and hypertension presented with a right femoral neck fracture after a mechanical fall. She underwent a right total hip arthroplasty and the anesthesiologist reported transient intraoperative hypoxia during cement placement. In the recovery room, the patient was hypotensive, tachycardic and hypoxic requiring up to 4 liters of oxygen. The anesthesiologist performed a bedside echo that showed an underfilled and hyperdynamic left ventricle with a normal right ventricular function and no obvious wall motion abnormalities. The patient’s chest x-ray was normal. The patient was given a blood transfusion for a postoperative hemoglobin of 7.8 g/dL and intravenous normal saline after which her hypotension improved. On postoperative day one, the patient continued to require 3 liters of oxygen with activity, and she remained tachycardic to 120 beats per minute. A CT angiogram of the chest showed no pulmonary embolism. A transthoracic echo showed a right ventricular systolic pressure of 35 mmHg but no other abnormalities. The patient had a normal venous blood gas, but her brain natriuretic peptide was elevated at 1200 pg/mL and she was given furosemide 10 mg intravenously. On postoperative day two, the patient was still requiring 2.5 liters of oxygen and was tachycardic to 100 beats per minute with activity. The pulmonary service was consulted to evaluate for other causes of hypoxia including bone cement implantation syndrome. They recommended a transthoracic echo with agitated saline which was normal including a normalized right ventricular systolic pressure. By postoperative day three, the patient was improving clinically and down to 1 liter of oxygen with activity and her tachycardia improved to 90 beats per minute. The patient’s diagnosis was thought to be consistent with bone cement implantation syndrome given her clinical improvement with minimal medical intervention. By postoperative day five, the patient’s hypoxia had fully resolved.
Discussion: The patient’s hypoxia progressively improved with minimal intervention. There was no clear etiology of her hypoxia on radiographic or cardiac imaging. She was ultimately diagnosed with bone cement implantation syndrome (BCIS) which is a diagnosis of exclusion. The incidence of BCIS ranges from 28-37% in patients undergoing cemented arthroplasties with a higher percentage in patients undergoing hip hemiarthroplasty or with a malignancy. The most common findings are hypoxia and hypotension but pulmonary hypertension, arrhythmias, loss of consciousness, and cardiac arrest can also occur. The symptoms occur primarily at cementation, prosthesis insertion, joint reduction, and tourniquet deflation. The pathophysiology is thought to be related to an embolic effect or a hypersensitivity activation pathway. The prognosis depends on the severity of the patient’s symptoms but typically, it is a reversible and time-limited phenomenon with many patients having normalization of pulmonary artery pressures within the first 24 hours. Treatment is primarily supportive with providing 100% oxygen and maintaining euvolemia.
Conclusions: BCIS is a rare phenomenon but should be considered in patients with unexplained hypoxia and hypotension postoperatively after cement placement. The mainstay of treatment is supportive, but hospitalists need to be aware of this phenomenon given the high incidence of BCIS and the growing field of perioperative medicine where hospitalists are managing orthopedic surgery patients.