Skin reactions at the femoral perineural catheter insertion site: retrospective summary of a randomized clinical trial.

change in HR or ECG tracing. The BP, however, increased from 168/80 to 195/89 mm Hg. Since the patient’s BP was frequently at 190s/90s during office visits, the test was considered negative. During surgery, repeat aspiration of the catheter yielded a tiny amount ( 0.1 mL in a 3-mL syringe) of blood-tinged fluid. To exclude a possible intravascular placement, a second epidural test dose consisting of lidocaine 45 mg and epinephrine 15 mcg was administered. Again the patient’s HR barely changed (from 52 to 58 bpm), but his BP increased from 155/75 to 185/95 mm Hg. This increased our suspicion that the catheter might be intravascular. However, because the patient was not receiving a systemic -antagonist, and his BP had not been that stable during the case, we were not convinced that the catheter tip was intravascular. In order to verify further, 3 mL of normal saline containing epinephrine 15 g was injected IV. This test was considered safe for the patient because he had tolerated the preoperative dobutamine stress test during which his BP reached a much higher level. The IV injection of epinephrine caused exactly the same cardiovascular responses as those following the epidural test doses, i.e., an obvious increase in BP (from 157/60 to 188/68 mm Hg) without significant change in HR and we concluded that the epidural catheter was likely intravascular and unsafe to use. In the postanesthesia care unit, the epidural catheter was withdrawn 2 cm and another epidural test dose consisting of lidocaine 45 mg and epinephrine 15 mcg caused no change in HR or BP, further suggesting that the epidural catheter had been intravascular before the adjustment. Unfortunately, we did not inject contrast media through the catheter prior to its being withdrawn. Administration of bupivacaine through the epidural catheter produced bilateral sensory loss in corresponding dermatomes. Timolol eye drops have been shown to cause significant systemic cardiac and respiratory side effects (5–9). The systemic bioavailability of the 0.5% timolol eye drops is nearly 80%, and its cardiopulmonary effects resembled those when administered IV (10). Timolol eye drops significantly reduced the HR increase caused by isoproterenol (11) or exercise (12). Together, these data suggest that the ophthalmic timolol the patient had been using until the evening before surgery was the cause for failure of IV administered epinephrine to increase his HR. Further evidence that the patient’s -receptors had been blocked is that during his preoperative dobutamine stress test, a maximal dose of dobutamine plus atropine 1 mg had been required to increase his HR to the target level. Timolol eye drops are widely prescribed but often fail to make to a patient’s medication list, because many patients do not consider eye drops as medicines. Indeed, a review of this patient’s chart revealed that timolol eye drops were not included in nearly half of the notes in which there was a medication list. We hope this case alerts our colleagues that ophthalmological preparations of -receptor antagonists may block the -agonist effects of epinephrine given as a test dose as part of epidural catheter management.