Anesthesiology
-
Randomized Controlled Trial
Hemodynamic and hormonal stress responses to endotracheal tube and ProSeal Laryngeal Mask Airway™ for laparoscopic gastric banding.
The stress responses from tracheal intubation are potentially dangerous in patients with higher cardiovascular risk, such as obese patients. The primary outcome objective of this study was to test whether, in comparison with the endotracheal tube (ETT), the Proseal™ Laryngeal Mask Airway (PLMA™) (Laryngeal Mask Airway Company, Jersey, United Kingdom) reduces blood pressure and norepinephrine responses and the amounts of muscle relaxants needed in obese patients. ⋯ PLMA™ reduces stress responses and postoperative complaints after laparoscopic gastric banding.
-
Randomized Controlled Trial
High intraoperative inspired oxygen does not increase postoperative supplemental oxygen requirements.
Although a high fraction of inspired oxygen (FIO2) could reduce surgical site infection, there is concern it could increase postoperative pulmonary complications, including hypoxemia. Intraoperative positive end-expiratory pressure can improve postoperative pulmonary function. A practical measure of postoperative pulmonary function and the degree of hypoxemia is supplemental oxygen requirement. We performed a double-blind randomized 2 × 2 factorial study on the effects of intraoperative FIO2 0.3 versus more than 0.9 with and without positive end-expiratory pressure on the primary outcome of postoperative supplemental oxygen requirements in patients undergoing lower risk surgery. ⋯ Use of intraoperative FIO2 more than 0.9 was not associated with increased oxygen requirement, suggesting it does not induce postoperative hypoxemia beyond anesthetic induction and surgery. Therefore, it may be reasonable to use high inspired oxygen in surgical patients with relatively normal pulmonary function.
-
Randomized Controlled Trial
A simulation study of common propofol and propofol-opioid dosing regimens for upper endoscopy: implications on the time course of recovery.
Using models of respiratory compromise, loss of response to esophageal instrumentation, and loss of responsiveness, the authors explored through simulation published dosing schemes for endoscopy using propofol alone and in combination with selected opioids. They hypothesized that models would predict adequate conditions for esophageal instrumentation and once drug administration is terminated, rapid return of responsiveness and minimal respiratory compromise. ⋯ Propofol alone would likely lead to inadequate conditions for esophageal instrumentation but would provide a rapid return to responsiveness and low probability of respiratory compromise once the procedure ended. The addition of remifentanil or fentanyl improved conditions for esophageal instrumentation and had an equally rapid return to responsiveness. The time required to achieve a low probability of respiratory compromise was briefly prolonged; this is likely inconsequential given that patients are responsive and can be prompted to breathe.
-
Perioperative optimization of spatially resolved near-infrared spectroscopy determined cerebral frontal lobe oxygenation (scO2) may reduce postoperative morbidity. Norepinephrine is routinely administered to maintain cerebral perfusion pressure and, thereby, cerebral blood flow, but norepinephrine reduces the scO2. We hypothesized that norepinephrine-induced reduction in scO2 is influenced by cutaneous vasoconstriction. ⋯ The results confirm that spatially resolved near-infrared spectroscopy detects cerebral deoxygenation with systemic hypoxic exposure and hyperventilation. However, a commonly used vasopressor norepinephrine disturbs skin oxygen saturation to an extent that influences scO2.
-
Invasion of extracellular matrix is a hallmark of malignant tumors. Clamping maneuvers during cancer surgery reduce blood loss, but trigger reperfusion injury (RI). RI increases cancer recurrence in the reperfused organ through up-regulation of matrix metalloproteinase-9 (MMP-9). Interleukin-8 is an important cytokine in RI promoting accumulation of neutrophils, a major source of MMP-9. Volatile anesthetics were demonstrated to reduce RI. We hypothesized that these anesthetics might attenuate MMP-9 up-regulation and consequently tumor cell invasion in RI. ⋯ Volatile anesthetics impair neutrophil MMP-9 release and interfere with pathways downstream of CXCR2, but upstream of protein kinase C. Through down-regulation of MMP-9, volatile anesthetics decrease Matrigel breakdown and reduce subsequent migration of cancer cells in vitro.