A phenylephrine infusion was started during induction of anesthesia for a patient undergoing a coronary artery bypass graft (cabg).Several minutes into induction, the patient became hypertensive (systolic blood pressure (bp) 180s baseline --> 140s shortly after propofol --> 200-210s).The phenylephrine infusion was paused on the pump, but the patient continued to be hypertensive and the bp did not come down despite additional propofol, fentanyl, and repeated boluses of nicardipine and nitroglycerin.The bp gradually decreased after induction was completed and no more boluses of medication were given, and sbp dropped to 100s systolic after the phenylephrine infusion was disconnected from the peripheral iv.At this point, the phenylephrine bag (starting volume 250ml) was noted to be half empty despite the infusion only running for a few minutes at a low rate.The infusion programming rate was confirmed to be the correct dose (0.3 mcg/kg/min) and the patient's weight was also correctly programmed so this was not a programming error.Suspect that the pump free flow mechanism was broken because at no point did the pump alarm that the door was open.Likely severe hypertension was related to bolusing other medications in the same iv line which effectively meant large doses of phenylephrine were simultaneously bolused due to the amount of medication remaining in the bag an hour after the infusion was started.The pump was removed from service and a tag was placed to explain the issue to clinical engineering.
|