J Oral MaxlllofacSurg 48:1130-1134,199o
Abstracts Comparison of Omnipaque with Hypaque in Temporomandibular Arthrography. Kaplan PA, Lieberman RP, Chu W. 153:1225, 1989
use, then one might expect that other common ancillary services are also substantially overused.-S.J. McKENNA Reprint requests to Dr Erban: Division of General Medicine and Primary Care, S7-715, University of Massachusetts Medical
Significant complications from temporomandibular joint (TMJ) arthrography are uncommon. The purpose of this study was to compare the morbidity and image quality associated with the use of ionic and nonionic contrast agents in TMJ arthrography. Forty patients referred for TM joint arthrography were randomized to receive either Omnipaque (nonionic, iohexol) or Hypaque (ionic, diatrizoate meglumine) in a double-blind fashion. Patients rated their pain on a numerical scale from 30 minutes to 72 hours following an injection of contrast medium. lmage quality was evaluated by two radiologists blinded to the type of contrast agent used. No difference in image quality could be related to the contrast agent used. There was no statistically significant difference in pain at the time of injection or any time thereafter between the Hypaque and Omnipaque groups. The most discomfort was experienced at 30 minutes and 24 hours following injection. The authors conclude that the use of more expensive nonionic agents in TMJ arthrography may not be justified, on the basis of either film quality or pain.-S.J.
Center, 55 Lake Avenue North, Worcester, MA 01655. A Comparative Study of Methods of Detection of Esophageal Intuhation. Sum-Ping ST, Mehta MP, Anderton JM. Anesth Analg 69:627, 1989 The most frequent and reliable method for confirming proper placement of an endotracheal tube (ET) is capnometry, ie, presence of a high expired Co, and a Co, waveform. Cases have been reported showing spurious high end-tidal Co, and Co, waveforms suggesting endotracheal intubation when, in fact, the tubes were esophageally placed. In an effort to provide additional tests to confirm ET placement, the authors studied volume and temperature of expired gases from an ET versus an esophageally placed tube (ES) in 21 healthy patients undergoing general anesthesia. Three “ventilations” were applied to each tube and Co, concentration and waveform was recorded, as well as temperature waveform and volume of exhaled gases. Similar inhaled and exhaled volumes were noted in the ET, whereas there was a significant decrease in exhaled volume in the ES. Temperature waveforms distinctly peaked with the ET and appeared flattened with the ES. The peak temperature of exhaled gases from the ES was significantly lower than that of the ET. In 7% of the patients, a Co, waveform was recorded from the ES, but the mean Co, concentration was significantly lower than that obtained from the ET. The authors conclude that the limitations inherent in relying on CO, concentration and waveform to confirm intubation may be offset by measuring volume and temperature of exhaled gases as well as to indicate proper tube placement. They caution that when the vocal cords have not been visualized during laryngoscopy and intubation, one should rely on two or three independent monitors rather than one monitor alone to confirm intubation.-J.
MCKENNA Reprint requests to Dr Kaplan: Department of Radiology, University of Nebraska Medical Center, 42nd & Dewey Avenue, Omaha, NE 68105.
Routine Use of the Prothrombin and Partial Thromboplastin Times. Erban SB, Kinman JL, Schwartz JS. JAMA 26212428, 1989 The prothrombin time (PT) and activated partial thromboplastin time (APTT) tests are commonly ordered by clinicians as part of routine admission laboratory testing for medical and surgical patients. Previous studies have demonstrated a very low positive predictive value of these tests in asymptomatic patients. Hospital records were obtained for all patients admitted to an internal medical service during a 3-week period. Eighty-one percent of 372 patients had a PT and APTT test ordered at the time of admission. Thirty percent of these met a modification of the guidelines proposed by the Medical Necessity Project of the Blue Cross and Blue Shield Association of America and approved by the American College of Physicians. Sixteen percent of the admission PT tests were beyond the reference range. Twelve percent of the APTT tests were above the reference range. Of patients having an initial PT above the reference range, 70% had at least one repeated PT test and 77% of those with an initial APTT above the reference range had at least one repeat test. The authors conclude that more than 70% of admission PT and APTT tests ordered at the study hospital could be eliminated with no detriment to patient care. More appropriate use of these assays could result in substantial savings for hospitals seeking reduced costs without compromising patient care. Moreover, if these tests for which consensus guidelines exist are subject to mis-
DEURBO Reprint requests to Dr Sum-Ping: Department of Anesthesia, University of Iowa College of Medicine, Iowa City, IA 52242. Craniosynostosis: An Assessment of Blood Loss and Transfusion Practices. Kearney RA, Rosales JK, Howes WJ. Can J Anaesth 36:473, 1989
The most important risk to the infant during primary craniosynostosis repair is blood loss. There are few published estimates of blood loss for this procedure. Assessment and accurate replacement of blood loss during primary craniosynostosis repair is difficult because of patient size and surgical technique. From 1970 to 1986, 85 surgical procedures for repair of primary craniosynostosis were performed on 80 patients in a major children’s hospital. The charts of all patients undergoing these repairs were reviewed to determine blood loss and to assess 1130