Brian A. Hall

Requirements for muscle relaxants during radical retropubic prostatectomy.

BackgroundThe need for the routine use of muscle relaxants to provide an adequate surgical field for intraabdominal surgery has not been established. This study tested the hypothesis that vecuronium decreases the frequency of unacceptable operating conditions for patients undergoing radical retropubic prostatectomy who are anesthetized with isoflurane and fentanyl. MethodsAfter obtaining informed consent, patients in this blinded, placebo-controlled study were randomized to receive either an infusion of vecuronium or saline (placebo) beginning 5 min after fascial incision during the maintenance of anesthesia with at least 1 minimum alveolar concentration end-tidal isoflurane and fentanyl infusion. The surgical field was graded from 1 (excellent) to 4 (unacceptable) by the surgeons at 15-min intervals. If a grade 4 rating occurred (defined as a treatment failure), the patient received rescue vecuronium. ResultsA total of 120 patients are included in this report (59 in the vecuronium group and 61 in the placebo group). The frequency of treatment failure in the placebo group was 17 of 61 (27.9%) versus 1 of 59 (1.7%) in the control group who received vecuronium (P < 0.001). Thirty-eight patients (62.3%) in the placebo group and 52 patients (88.1%) in the vecuronium group had surgical field ratings of ≤ 2 (good to excellent) at each time assessed throughout the procedure. ConclusionThe study hypothesis was confirmed. However, an isoflurane–fentanyl anesthetic alone produced a good to excellent surgical field in approximately two thirds of patients undergoing radical retropubic prostatectomy without the use of muscle relaxants. Thus, the routine use of muscle relaxants in adequately anesthetized patients undergoing this procedure may not be indicated.

Indoleamine 2,3-dioxygenase–expressing antigen-presenting cells and peripheral T-cell tolerance: Another piece to the atopic puzzle?

There is growing evidence that dendritic cells, the major antigen-presenting cells and T-cell activators, have a broad effect on peripheral T-cell tolerance and regulation of immunity. Very recently, a new feature of regulatory antigen-presenting cells was observed. Certain dendritic cells, monocytes, and macrophages express the enzyme indoleamine 2,3-dioxygenase, and thus because of enhanced degradation of the essential amino acid tryptophan, they modulate T-cell activity in specific local tissue environments. In this review we discuss the various and apparently disparate effects of indoleamine 2,3-dioxygenase induction in cells of the immune system. We place current knowledge about this mechanism in the context of atopy. We introduce the hypothesis that tryptophan degradation might add to the ability to control and downregulate allergen-specific T-cell responses in atopic individuals.

Predictors of mortality following symptomatic pulmonary embolism in patients undergoing noncardiac surgery

PurposeTo determine 30-day mortality and predictors of mortality following perioperative pulmonary embolism (PE).MethodsWe searched both the Mayo Clinic electronic medical records and Autopsy Registry, between January 1, 1998 and December 31, 2001, for patients who developed PE within 30 days after noncardiac surgery performed under general or neuraxial anesthesia. Medical records of all identified patients were reviewed using standardized data collection forms. The association between risk factors for PE and 30-day post-PE mortality was assessed using t tests, exact binomial tests, and logistic regression.ResultsWe identified 158 patients with probable or definite perioperative PE. The overall 30-day mortality from the day of PE was 25.3%, i.e., 40 patients died. Hypotension requiring treatment, need for mechanical ventilation, and intensive care unit admission were the prominent univariate predictors of 30-day mortality (all P ≤ 0.001). Other significant factors were exact bi normal tests, and higher ASA physical status (P = 0.002), longer surgical time (P = 0.030), recent central vein cannulation (P = 0.021) and intraoperative use of either blood transfusions or other blood products (P = 0.010). Using multi-variable analysis, hemodynamic instability was found to be the dominant independent risk factor associated with mortality.ConclusionsPerioperative PE is associated with a high 30-day mortality. Patients who experience hemodynamic instability and require vasoactive treatment at presentation of PE have extremely low survival rates; therefore, for these patients the most aggressive therapeutic modalities should be considered.RésuméObjectifDéterminer la mortalité à 30 jours et les indicateurs de mortalité suite aux embolies pulmonaires (PE) périopératoires.MéthodeNous avons consulté les dossiers médicaux électroniques de la clinique Mayo et son registre des autopsies pour la période allant du Ier janvier 1998 au 31 décembre 2001 afin de trouver les patients ayant développé une embolie pulmonaire dans les 30 jours suivant une chirurgie non cardiaque pratiquée sous anesthésie générale ou neuraxiale. Les dossiers médicaux de tous les patients identifiés comme tels ont été passés en revue à l’aide de formulaires de récolte de données standardisés. L’association entre les facteurs de risque d’une embolie pulmonaire et la mortalité dans les 30 jours suivant l’embolie a été évaluée par régression logistique.RésultatsNous avons identifié 158 patients avec une embolie pulmonaire périopératoire probable ou certaine. La mortalité totale à 30 jours depuis le jour de l’embolie pulmonaire était de 25,3 %, soit 40 décès. Une hypotension nécessitant un traitement, le besoin de ventilation mécanique et l’admission aux soins intensifs ont été les indicateurs univariés majeurs d’une mortalité à 30 jours (tous P ≤ 0,001). Un score ASA plus élevé (P = 0,002), une durée de chirurgie plus longue (P = 0,030), une canulation veineuse centrale récente (P = 0,021) et l’utilisation peropératoire de transfusions sanguines ou d’autres produits sanguins (P = 0,010) sont d’autres facteurs significatifs. L’instabilité hémodynamique a été déterminée comme le facteur de risque dominant associé à la mortalité, sur la base d’une analyse multivariable.ConclusionL’embolie pulmonaire périopératoire est associée à une mortalité à 30 jours élevée. Les patients souffrant d’instabilité hémodynamique et nécessitant un traitement vasomoteur lors de l’apparition de l’embolie pulmonaire présentent un taux de survie très bas; pour cette raison, les modalités thérapeutiques les plus agressives devraient être disponibles pour ces patients.

Fatal acute pulmonary embolism in a patient with pelvic lipomatosis after surgery performed after transatlantic airplane travel

We describe a case of a 37-yr-old patient who traveled from Europe to the United States and succumbed to a massive pulmonary embolism 6 days after elective pelvic surgery despite routine postoperative thrombotic prophylaxis. In retrospect, he was likely to have developed a deep venous thrombosis during the transatlantic trip to our hospital. Anesthesiologists and other physicians involved in perioperative management need to be aware of the prevalence of venous thromboembolism in patients with a history of recent prolonged air travel. This is particularly true in tertiary referral centers, where patients with rare diseases may have a major surgical intervention within days of prolonged air travel.

Repeated episodes of difficulty with arousal following general anesthesia in a patient with ulnar neuropathy.

Delayed emergence following general anesthesia may be due to serious life-threatening disorders and deserves prompt evaluation. Rarely, delayed emergence has been attributed to a psychiatric or psychological cause. This report describes an otherwise healthy and mentally sound 52-year-old woman who experienced repeated dissociative episodes following general anesthesia for minor surgical procedures. These episodes lasted for 5 h and resulted in admission to the intensive care unit. The current literature is reviewed to identify commonalities among previously reported cases and to discuss different psychiatric and psychological mechanisms that can play a role in the development of this disorder.