Friday, October 28, 2011

Prior to Incision I

A middle aged woman is getting a revision hip replacement. She has a significant cardiac history, mild congestive heart failure, gastroesophageal reflux disease, asthma, and severe arthritis. She underwent a primary total hip replacement six months ago, but unfortunately, the prosthesis was infected. It was subsequently removed and an antibiotic spacer was placed. Cultures grew methicillin resistant Staphylococcus aureus (MRSA) and she finished a course of vancomycin. After being cleared by the infectious disease specialists, she was scheduled for a revision hip arthroplasty.

After a smooth IV induction of anesthesia and an uneventful intubation, we placed a radial arterial line to follow blood pressures and blood gases, a second IV, and then positioned her in the lateral decubitus position. Her anesthesia was maintained through volatile anesthetics (sevoflurane), and vancomycin was started. The surgeons went out to scrub, and during that time, the patient's blood pressure and oxygen saturation dropped like a stone. Within thirty seconds, she went from 100% O2 saturation to 85%, and her blood pressures went from a mean arterial pressure of 70 to 30. I immediately started bagging with 100% oxygen, turned off the inhaled anesthetic, and pushed phenylephrine. Despite my best efforts, I could only modestly raise her oxygen and blood pressures. It was pretty terrifying. The orthopedic surgeons came back to find me in a flurry, drawing up medications while squeezing the bag, listening to breath sounds, inspecting the circuit, running my IVs wide open. There did not appear to be any problems with the ventilator or circuit, the airway pressures felt reasonable, I was delivering adequate tidal volumes, and yet on 100% inspired oxygen, the patient was at a meager 90% oxygen saturation. The patient had bilateral breath sounds, a mild tachycardia, but pulses were barely palpable. I went through sticks and sticks of phenylephrine trying to stave off a code. The exciting conclusion to this case will come tomorrow.

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