SCIENTIFIC ARTICLES 367

Wang JS, Lin CY, Hung WT, et al: In vitro effects of aprotinin on activated clotting time measured with different activators. J Thorac Cardiovasc Surg 104: 11351140,1992

Aprotinin in concentrations from 80 to 180 KIUimL or saline was added to blood samples obtained from 21 patients before, during, and after cardiopulmonary bypass, and activated clotting times (ACT) measured. Both celite- and kaolin-activated ACT tubes were studied. In vitro addition of aprotinin did not increase ACT of unheparinized blood in either tube and did not increase ACT of heparinized blood in kaolin-activated tubes. Aprotinin prolonged ACT of heparinized blood measured in celite-activated tubes by 47% to 71% compared with saline-added controls.

Maughan BE, Mohan C, Nathan IM, et al: Intrathe- cal perfusion of an oxygenated pet-fluorocarbon pre- vents paraplegia after aortic occlusion. Ann Thorac Surg 54:818-825,1992.

Arterial blood pressure, cerebral spinal fluid pressure, spinal cord perfusion pressure, and somatosensory evoked potentials were measured in 12 dogs during 70 minutes of normothermic aortic occlusion. Animals were randomized to receive oxygenated fluosol-DA 20% or saline by intrathecal perfusion (15 mlimin) before and during the ischemic interval. There were no differences in hemodynamics or spinal cord perfusion pressure during clamp- ing in the two groups. Negative spinal cord perfusion pressure was observed in both groups and related, in part, to increased cerebral spinal fluid pressure during intrathecal perfusion. Electrophysio- logic conduction was regained earlier and neurologic function spared in all treated animals compared with controls. An oxygen extraction ratio from fluosol of 29.6% was measured between the in-flow and out-flow intrathecal catheters.

Schittek A, Bennink GBWE, Cooley DA, Langford LA: Spinal cord protection with intravenous nimo- dipine. A functional and morphologic evaluation. J Thorac Cardiovasc Surg 104:1100-1105,1992

Intravenous nimodipine (2 ug/kg/min) administered before, during, and after thoracic aortic cross-clamping reduced functional neurologic and histologic spinal cord injury in nine pigs compared with control animals. Spinal cord protection in nimodipine-treated animals occurred despite lower perfusion pressures and negative spinal cord perfusion pressure gradients during clamping in these animals. The authors speculate protective effects may be related to calcium channel blocker dose.

Perttunen K, Kalso E, Heinonen J, Salo J: IV diclofenac in post-thoracotomy pain. Br J Anaesth 68:474-480,1992

Thirty patients receiving patient-controlled intravenous mor- phine after thoracotomy were randomized in a double-blind, placebo-controlled study to receive a continuous infusion of the nonsteroidal anti-inflammatory drug, diclofenac, 2 mgikgid, or placebo. Morphine consumption was reduced by 60% on day 1 and 76% on day 2 in the diclofenac group compared to controls. Pain

scores and arterial blood gases were also improved. Urine output on the first postoperative day was decreased in the diclofenac group (41 2 30 mL) a greater degree than in the controlled group (230 t- 77 mL) in this fluid-restricted patient population. Urine output was normal on postoperative day 2 in both groups. There were no differences in serum creatinine levels or coagulation studies between the groups.

Bitchie AJ, Danton M, Gibbons JRP: Prophylactic digitalization in pulmonary surgery. Thorax 47:41-43, 1992

In a prospective, nonblinded, controlled, randomized study, 58 of 111 patients received oral digoxin, 1 mg in divided doses, over 24 hours preoperatively, and 0.25 mg daily for nine postoperative days. The incidence of post-thoracotomy arrhythmias detected by continuous electrocardiographic monitoring with automatic arrhyth- mia recording was studied during the first 4 postoperative days. Atrial fibrillation was the most common rhythm disturbance (42% of arrhythmias). The incidence of arrhythmias in digitalized pa- tients (50%) did not differ from control patients (36%). The onset of arrhythmias was more common in the first 48 hours than afterward. Five digitalized patients had electrocardiographic changes consistent with digoxin toxicity and elevated serum digoxin levels. The incidence of arrhythmias was not related to type of pulmonary resection or patient age.

Tiballs J, Hochmann M, Osborne A, Carter B: Accuracy of the BoMED bioimpedence cardiac output monitor during induced hypotension: An experimen- tal study in dogs. Anaesth Intens Care 20:326-331, 1992

The accuracy of the BoMED NCCOM3 cardiac output monitor (measures changes in thoracic bioimpedence during cardiac cycle to determine cardiac output) was compared to dye dilution (COno)-measured cardiac output during conditions of induced hypotension and recovery in 23 dogs. In the resting state (blood pressure 112 mmHg, COpo 3.22 Limin) the BoMED was cali- brated to the COoo. During induced hypotension (blood pressure 55 mmHg, CObo 1.10) the mean difference between BoMED cardiac output and COno was 0.29 f 0.47 Limin with limits of agreement (mean difference *SD) of + 11.8% and -59.1% of the mean hypotensive COoo. During the recovery phase the mean differences between the two techniques were also too variable to allow substitution of one technique for the other. Statistical analysis in studies examining different techniques purporting to measure the same parameter is discussed.

ACKNOWLEDGMENT

Papers reviewed in this issue were selected from those published in the following journals: Anaesthesia and Intensive Care, Annals of Thoracic Surgery, British Journal of Anaesthesia, Journal of the American College of Cardiology, Journal of the American Medical Association, Journal of Thoracic and Cardiovascular Surgery, Thorax, and Transfusion.

Contributions to the literature review in this issue were made by Dr Michael Davies, Melbourne, Australia, and Dr Peter Slinger, Montreal, Quebec.