Interleukin-15 production during liver allograft rejection in humans.

BACKGROUND: The activity of interleukin (IL)-15, a cytokine produced by macrophages, is similar to that of IL-2. We investigated whether IL-15 plays a role in liver allograft rejection. METHODS: We evaluated plasma levels and intrahepatic expression of IL-15 in 35 patients after liver transplantation, and then analyzed in vitro the influence of anticalcineurin drugs or steroids on IL-15 production and secretion. Finally, we examined the effects of IL-15 on lymphocyte proliferation in mixed lymphocyte culture in the presence or absence of anticalcineurin drugs or steroids. RESULTS: Plasma levels and in situ expression of IL-15 were enhanced during liver allograft rejection, particularly during steroid-resistant acute rejection and during chronic rejection. In vitro, IL-15 production and secretion were inhibited by neither anticalcineurin drugs nor steroids. Exogenous IL-15 enhanced cell-mediated immune response, and this effect was not inhibited by immunosuppressive drugs. CONCLUSIONS: IL-15 can play a role in the initiation and outcome of acute and chronic rejection. Anti-IL-15 therapy in combination with classic immunosuppression therapy might thus be beneficial in the prevention of acute, and especially chronic, allograft rejection.

Airway management using the intubating laryngeal mask airway for the morbidly obese patient.

UNLABELLED: We studied the effectiveness of the intubating laryngeal mask airway (ILMA) in morbidly obese patients scheduled for bariatric surgery. We included 118 consecutive morbidly obese patients (body mass index, 45 +/- 5 kg/m(2)). After the induction of general anesthesia, the laryngeal view was classified by the first observer according to the method of Cormack and Lehane. The ILMA was then inserted, and the trachea was intubated through the ILMA by a second observer. The rate of successful tracheal intubation with ILMA was 96.3%. The success rate, the number of attempts, and the total duration of the procedure were not different among patients with low-grade (Cormack 1-2) and patients with high-grade (Cormack 3-4) laryngeal views. The time required for insertion of the ILMA was slightly longer in patients with high-grade laryngeal views. Failures of the technique were not explained by the experience of the practitioner or airway characteristics. No adverse effect related to the technique was reported. Results of this study suggest that using the ILMA provides an additional technique for airway management of morbidly obese patients. IMPLICATIONS: The intubating laryngeal mask airway (ILMA) provides an additional technique for airway management of morbidly obese patients. The best choice of the primary technique (laryngoscopy or ILMA) for tracheal intubation of an adult obese patient remains to be determined.

The clinical relevance of systolic pressure variations in anesthetized nonhypotensive patients.

OBJECTIVE: To assess the accuracy of respiratory-induced systolic pressure variation and its components to detect low left ventricular preload. DESIGN: Prospective study. SETTING: University hospital. PARTICIPANTS: Sixty-seven patients undergoing major surgery under general anesthesia. INTERVENTIONS: Transesophageal echocardiographic measurements during apnea and mechanical ventilation. MEASUREMENTS AND MAIN RESULTS: Respiratory-induced systolic pressure variation and its components and left ventricular end-diastolic area obtained by transesophageal echocardiography were noted simultaneously. Arterial pressure indices did not allow a reliable diagnosis of a low left ventricular end-diastolic area using a cut-off value of 7.9 cm(2)/m(2) (inferior boundary of the interquartile range of the areas measured in the authors' group). CONCLUSIONS: These results suggest that systolic pressure variations noticed after induction of general anesthesia do not reflect low left ventricular preload in nonhypotensive patients.

Prediction of arterial oxygen tension during one-lung ventilation: analysis of preoperative and intraoperative variables.

OBJECTIVE: To determine whether currently available preoperative and intraoperative variables related to arterial oxygen tension (PaO(2)) can be used as predictors for low PaO(2) during one-lung ventilation (OLV). DESIGN: A prospective cohort study. SETTING: Primary university hospital. PARTICIPANTS: Adult patients (n = 92) undergoing thoracic surgery requiring OLV. INTERVENTIONS: Preoperative and intraoperative data, including past medical history, physical examination, and usual preoperative and intraoperative tests, were collected and used as explanatory variables for PaO(2) during OLV by univariate and multivariate analysis. A stepwise logistic regression including the same independent variables was used to identify patients who should be expected to develop arterial hypoxemia (PaO(2) <70 mmHg). Arterial blood gas samples were analyzed 15 minutes after the onset of OLV and after thoracotomy to determine the lowest PaO(2) value during OLV. MEASUREMENTS AND MAIN RESULTS: Preoperative (age, hematocrit, relative perfusion of the nondependent lung) and intraoperative (PaO(2) during 2-lung ventilation and mean arterial pressure at the lowest PaO(2)) variables were identified as independent factors affecting PaO(2) in OLV. PaO(2) during 2-lung ventilation was the only independent variable accounting for arterial hypoxemia when multivariate logistic regression was performed. CONCLUSION: The PaO(2) during OLV can be predicted using routinely available preoperative and intraoperative data. From a clinical point of view, this study failed to identify patients at risk of arterial hypoxemia when OLV is instituted because mainly intraoperative independent variables are involved in the decrease of PaO(2) in this situation.