The effects of the administration sequence and the type of hypnotics on the development of remifentanil-induced chest wall rigidity: a randomized controlled trial.

BACKGROUND: Research on remifentanil-induced chest wall rigidity is limited. Furthermore, its incidence is unknown, and the clinical factors influencing its development remain unclear. This prospective, double-blind, randomized controlled trial aimed to investigate the effects of the administration sequence of hypnotics and remifentanil as well as the type of hypnotic administered on the development of remifentanil-induced chest wall rigidity. METHODS: A total of 125 older patients aged [Formula: see text] 65 years, who were scheduled to undergo elective surgery under general anesthesia, were enrolled in this study. Participants were randomly assigned to one of four groups; Thio-Remi, Pro-Remi, Remi-Thio, or Remi-Pro. After confirming the loss of consciousness and achieving a target effect-site concentration of 3 ng/mL remifentanil, the development of remifentanil-induced chest wall rigidity was evaluated. RESULTS: The incidence of chest wall rigidity was significantly higher in the remifentanil-hypnotic group than in the hypnotic-remifentanil (opposite sequence) group (55.0% vs. 21.7%, P < 0.001). Logistic regression analysis revealed that remifentanil-hypnotic administration was a significant predictor of the development of chest wall rigidity (crude odds ratio 4.42, 95% confidence interval 1.99; 9.81, P < 0.001). CONCLUSIONS: Pretreatment with hypnotics potentially reduces the development of chest wall rigidity during the induction of balanced anesthesia with remifentanil in older patients. TRIAL REGISTRATION: This article was registered at WHO International Clinical Trials Registry Platform (Trial number: KCT0006542).

The Effects of Body Composition Characteristics on the Functional Disability in Patients with Degenerative Lumbar Spinal Stenosis.

Several research studies suggest that obese patients are at a higher risk of developing lumbar spinal disorder, including degenerative lumbar spinal stenosis (LSS), compared to normal-weight individuals. However, there are few investigations of how obesity affects functional disability in activities of daily living (ADL) in patients who were diagnosed with LSS. This prospective observational study aimed to determine if an association exists between body composition parameters, such as body fat and skeletal muscle, and functional disability in ADL of LSS patients. In the results of the current study, there were significant differences in percent body fat between the mild/moderate and severe disability groups. However, there were no differences in skeletal muscle mass or index between the two groups. Furthermore, we found a positive linear relationship between percent body fat and functional disability in male sex. This study suggests that increased percent body fat predicts potential severe functional disability in ADL in LSS patients. Body composition analysis may provide useful information for predicting the disease severity of various lumbar spinal disorders in clinical practice.

Effects of hypercarbia on arterial oxygenation during one-lung ventilation: prospective randomized crossover study.

Background: This study aimed to evaluate the effects of hypercarbia on arterial oxygenation during one-lung ventilation (OLV). Methods: Fifty adult patients undergoing elective video-assisted thoracoscopic lobectomy or pneumonectomy were enrolled. Group I patients (n = 25) were first maintained at normocarbia (PaCO2: 38‒42 mmHg) for 30 min and then at hypercarbia (45‒50 mmHg). In Group II patients (n = 25), PaCO2 was maintained in the reverse order. Arterial oxygen partial pressure (PaO2), respiratory variables, hemodynamic variables, and hemoglobin concentration were compared during normocarbia and hypercarbia. Arterial O2 content and O2 delivery were calculated. Results: PaO2 values during normocarbia and hypercarbia were 66.5 ± 10.6 and 79.7 ± 17.3 mmHg, respectively (mean difference: 13.2 mmHg, 95% CI for difference of means: 17.0 to 9.3, P < 0.001). SaO2 values during normocarbia and hypercarbia were 92.5 ± 4.8% and 94.3 ± 3.1% (P = 0.009), respectively. Static compliance of the lung (33.0 ± 5.4 vs. 30.4 ± 5.3 ml/cmH2O, P < 0.001), arterial O2 content (15.4 ± 1.4 vs. 14.9 ± 1.5 ml/dl, P < 0.001) and O2 delivery (69.9 ± 18.4 vs. 65.1 ± 18.1 ml/min, P < 0.001) were significantly higher during hypercarbia than during normocarbia. Conclusions: Hypercarbia increases PaO2 and O2 carrying capacity and improves pulmonary mechanics during OLV, suggesting that it may help manage oxygenation during OLV. Therefore, permissive hypercarbia may be a simple and valuable modality to manage arterial oxygenation during OLV.