A B S T R A C T S

shock, hemorrhagic; plasma

substitutes

Resuscitation fluids for the treatment of hemorrhagic shock in dogs: Effects on myocardial blood flow and oxygen transport Tait A, Larson L Crit Care Med 19.1561-1565 Dec 1991

The authors investigated the effects of different plasma substitutes on myocardial blood flow and oxygen transport after hemorrhagic shock to compare crystalloid versus colloid as resuscitation fluids. Forty-three dogs were anesthetized and bled into a Wiggers reservoir to a mean arterial pressure of 35 mm Hg and main- tained there for 90 minutes. The animals then were randomly divided into groups to receive one of five resuscitation fluids: succinylated gelatin, urea-linked gelatin, het- astarch, lactated Ringer's solution, or shed blood. Solutions were infused until the animal had been resuscitated to baseline pulmonary artery occlusive pressure. Homo- dynamic, blood gas/electrolyte, myocardial perfusion, and oxygen transport values were obtained at

baseline, after 90 minutes of shock, after resuscitation to baseline pul- monary artery occlusive pressure, and again 90 minutes later. The use of succinylated gelatin, urea-linked gelatin, or hetastarch restored the cardiac output to control values, whereas there was a significant reduction of cardiac output in ani- mals treated with lactated Ringer's solution or reinfused blood. There was a significant decrease in myocardial blood flow after hemor- rhage in all groups. However, dogs resuscitated with succinylated gelatin, urea-linked gelatin, or het- astarch demonstrated an increase in flow above control values while

dogs resuscitated with lactated Ringer's or blood had flows less than their control values. Myocardial oxygen transport was significantly decreased from control values in lactated Ringer's-treated animals. The authors conclude that the artifi- cial colloids succinylated gelatin, urea4inked gelatin, and hetastarch compensate for the reduced oxygen- carrying capacity caused by their hemodilation by increasing perfusion to the myo-cardium, in contrast to lactated Ringer's solution. These results suggest important differ- ences between crystalloids and colloids with respect to the restora- tion of myocardial oxygen supply after hemorrhage.

Mark Mahoney, MD

intubation, endotracheal;

neuromuscular blocking agents

The role of anesthetic induction agents and neuromuscular blockade in the endotracheal intubation of trauma victims Ligier B, Buchman TG, Breslon M J, et al

Surg Gynecol 0bstet 173.477-481 Dec 1991

This retrospective study reviewed 1,774 trauma resuscitations over a 20-month period. Of 154 intubations, 97 patients had complete charts available. Use of medications to facilitate oral intubation (36) result- ed in a success rate of 92% on the first attempt. Oral intubation without medication (18) resulted in a 39% failure rate. Addition of adjunctive drugs to these seven missed intuba- tions resulted in success in five of seven cases. Nasal intubation was successful in 60% of attempted cases, and no complications sec- ondary to drug administration were noted. Reasons for intubation were broken down into many categories with the majority of patients being

assault victims, although 31 were intubated for cardiac arrest on admission The authors discuss the limitations of the study, including its nonrandomized nature and the possi- bility of unreported complications.

Dave Compten, MD

common cold, histamine antagonists

Evaluation of oral terfenadine for treatment of the common cold Berkowitz RB, Tinkelman DG Ann Allergy 76:593-596 Dec t991

The authors compared the efficacy of terfenadine, an oral nonsedating antihistamine, to placebo, in treating rhinitis associated with the common cold. A dose of 120 mg twice a day of terfenadine was used on 49 sub- jects and compared with a placebo control group of 48 subjects over a five-day period The power of this study was calculated to be 41%. Evaluations by both subjects and physicians indicated that terfenadine only marginally improved sneezing and total symptom scores at day four. When comparing teffenadine with placebo, neither the symptoms nor the signs of the common cold improved in a clinically or statistical- ly significant manner. Although ter- fenadine was well tolerated with a low incidence of side effects, the authors concluded that it is ineffec- tive in the treatment of the signs and symptoms of the common cold.

David J Weist, MD

Doppler ultrasound; arteriography

Can Doppler p r e s s u r e

measurement replace "exclusion" arteriography in the diagnosis of occult extremity arterial trauma? K Lynch, K Johansen Ann Surg 737-741 Dec 1991

This prospective study evaluated Doppler-derived pressure measure- ments in the evaluation of occult arterial damage in injured extremi- ties. Arteriography has been shown to be accurate in precisely locating the level of arterial injury but is invasive, time consuming, costly, and rarely positive when wound proximity is the only indication. An arterial pressure index (API (Doppler systolic pressure in injured extremity]/ [Doppler systolic pressure in unin- volved extremity]) was calculated in 100 consecutive injured extremities of 93 blunt or penetrating trauma patients. An arterial pressure index of more than 0.90 was normal. Seventy-five of 100 extremities had both a normal arterial pressure index and arteriogram, but 20 extremities had an arterial pressure index of less than 0.90 and an abnormal arteri- ogram. Of the remaining five, one had a positive arteriogram but nor- mal arterial pressure index, two had an arterial pressure index less than 0.90 but normal arteriograms, and two had a normal arterial pressure index but false-positive arteriograms (determined at surgery). An arterial pressure index of less than 0.90 had a sensitivity of 87% and a specificity of 97% when compared with arteri- ography, and a sensitivity of 95% and specificity of 87.5% when com- pared with clinical outcome. Angiography had a sensitivity of 100% and specificity of 97.5% when compared with clinical outcome. The authors conclude that when •

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