Multicentre validation of a machine learning model for predicting respiratory failure after noncardiac surgery.

BACKGROUND: Postoperative respiratory failure is a serious complication that could benefit from early accurate identification of high-risk patients. We developed and validated a machine learning model to predict postoperative respiratory failure, defined as prolonged (>48 h) mechanical ventilation or reintubation after surgery. METHODS: Easily extractable electronic health record (EHR) variables that do not require subjective assessment by clinicians were used. From EHR data of 307,333 noncardiac surgical cases, the model, trained with a gradient boosting algorithm, utilised a derivation cohort of 99,025 cases from Seoul National University Hospital (2013-9). External validation was performed using three separate cohorts A-C from different hospitals comprising 208,308 cases. Model performance was assessed by area under the receiver operating characteristic (AUROC) curve and area under the precision-recall curve (AUPRC), a measure of sensitivity and precision at different thresholds. RESULTS: The model included eight variables: serum albumin, age, duration of anaesthesia, serum glucose, prothrombin time, serum creatinine, white blood cell count, and body mass index. Internally, the model achieved an AUROC of 0.912 (95% confidence interval [CI], 0.908-0.915) and AUPRC of 0.113. In external validation cohorts A, B, and C, the model achieved AUROCs of 0.879 (95% CI, 0.876-0.882), 0.872 (95% CI, 0.870-0.874), and 0.931 (95% CI, 0.925-0.936), and AUPRCs of 0.029, 0.083, and 0.124, respectively. CONCLUSIONS: Utilising just eight easily extractable variables, this machine learning model demonstrated excellent discrimination in both internal and external validation for predicting postoperative respiratory failure. The model enables personalised risk stratification and facilitates data-driven clinical decision-making.

Effect of driving pressure-guided positive end-expiratory pressure on postoperative pulmonary complications in patients undergoing laparoscopic or robotic surgery: a randomised controlled trial.

BACKGROUND: Individualised positive end-expiratory pressure (PEEP) improves respiratory mechanics. However, whether PEEP reduces postoperative pulmonary complications (PPCs) remains unclear. We investigated whether driving pressure-guided PEEP reduces PPCs after laparoscopic/robotic abdominal surgery. METHODS: This single-centre, randomised controlled trial enrolled patients at risk for PPCs undergoing laparoscopic or robotic lower abdominal surgery. The individualised group received driving pressure-guided PEEP, whereas the comparator group received 5 cm H2O fixed PEEP during surgery. Both groups received a tidal volume of 8 ml kg-1 ideal body weight. The primary outcome analysed per protocol was a composite of pulmonary complications (defined by pre-specified clinical and radiological criteria) within 7 postoperative days after surgery. RESULTS: Some 384 patients (median age: 67 yr [inter-quartile range: 61-73]; 66 [18%] female) were randomised. Mean (standard deviation) PEEP in patients randomised to individualised PEEP (n=178) was 13.6 cm H2O (2.1). Individualised PEEP resulted in lower mean driving pressures (14.7 cm H2O [2.6]), compared with 185 patients randomised to standard PEEP (18.4 cm H2O [3.2]; mean difference: -3.7 cm H2O [95% confidence interval (CI): -4.3 to -3.1 cm H2O]; P<0.001). There was no difference in the incidence of pulmonary complications between individualised (25/178 [14.0%]) vs standard PEEP (36/185 [19.5%]; risk ratio [95% CI], 0.72 [0.45-1.15]; P=0.215). Pulmonary complications as a result of desaturation were less frequent in patients randomised to individualised PEEP (8/178 [4.5%], compared with standard PEEP (30/185 [16.2%], risk ratio [95% CI], 0.28 [0.13-0.59]; P=0.001). CONCLUSIONS: Driving pressure-guided PEEP did not decrease the incidence of pulmonary complications within 7 days of laparoscopic or robotic lower abdominal surgery, although uncertainty remains given the lower than anticipated event rate for the primary outcome. CLINICAL TRIAL REGISTRATION: KCT0004888 (http://cris.nih.go.kr, registration date: April 6, 2020).

The effect of goal-directed hemodynamic therapy on clinical outcomes in patients undergoing radical cystectomy: a randomized controlled trial.

BACKGROUND: This study investigated the effects of intraoperative goal-directed hemodynamic therapy (GDHT) on postoperative outcomes in patients undergoing open radical cystectomy. METHODS: This prospective, single-center, randomized controlled trial included 82 patients scheduled for open radical cystectomy between September 2018 and November 2021. The GDHT group (n = 39) received the stroke volume index- and cardiac index-based hemodynamic management using advanced hemodynamic monitoring, while the control group (n = 36) received the standard care under the discretion of attending anesthesiologists during surgery. The primary outcome was the incidence of a composite of in-hospital postoperative complications during hospital stays. RESULTS: A total of 75 patients were included in the final analysis. There was no significant difference in the incidence of in-hospital postoperative complications (28/39 [71.8%] vs. 30/36 [83.3%], risk difference [95% CI], -0.12 [-0.30 to 0.07], P = 0.359) between the groups. The amounts of intraoperative fluid administered were similar between the groups (2700 [2175-3250] vs. 2900 [1950-3700] ml, median difference [95% CI] -200 [-875 to 825], P = 0.714). The secondary outcomes, including the incidence of seven major postoperative complications, duration of hospital stay, duration of intensive care unit stay, and grade of complications, were comparable between the two groups. Trends in postoperative estimated glomerular filtration rate, serum creatinine, and C-reactive protein did not differ significantly between the two groups. CONCLUSIONS: Intraoperative GDHT did not reduce the incidence of postoperative in-hospital complications during the hospital stay in patients who underwent open radical cystectomy. TRIAL REGISTRATION: This study was registered at http://www. CLINICALTRIALS: gov (Registration number: NCT03505112; date of registration: 23/04/2018).

Relationships between common carotid artery blood flow and anesthesia, pneumoperitoneum, and head-down tilt position: a linear mixed-effect analysis.

This study investigated the effects of pneumoperitoneum and the head-down tilt position on common carotid artery (CCA) blood flow in surgical patients. METHODS: This prospective observational study included 20 patients who underwent gynecological surgery. CCA blood flow was measured using Doppler ultrasound at four-time points: awake in the supine position [T1], 3 min after anesthesia induction in the supine position [T2], 3 min after pneumoperitoneum in the supine position [T3], and 3 min after pneumoperitoneum in the head-down tilt position [T4]. Hemodynamic and respiratory parameters were also recorded at each time point. Linear mixed-effect analyses were performed to compare CCA blood flow across the time points and assess its relationship with hemodynamic parameters. RESULTS: Compared with T1, CCA blood flow decreased significantly at T2 (345.4 [288.0-392.9] vs. 293.1 [253.0-342.6], P = 0.048). CCA blood flow were also significantly lower at T3 and T4 compared with T1 (345.4 [288.0-392.9] vs. 283.6 [258.8-307.6] and 287.1 [242.1-321.4], P = 0.005 and 0.016, respectively). CCA blood flow at T3 and T4 did not significantly differ from that at T2. Changes in CCA blood flow were significantly associated with changes in cardiac index and stroke volume index (P = 0.011 and 0.024, respectively). CONCLUSION: CCA blood flow was significantly decreased by anesthesia induction. Inducing pneumoperitoneum, with or without the head-down tilt position, did not further decrease CCA blood flow if the cardiac index remained unchanged. The cardiac index and stroke volume index were significantly associated with CCA blood flow. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov (NCT04233177, January 18, 2020).

Impact of hemodynamic instability during cytoreductive surgery on survival in high-grade serous ovarian carcinoma.

BACKGROUND: To evaluate the impact of intraoperative hypotension and hemodynamic instability on survival outcomes in patients with high-grade serous ovarian carcinoma (HGSOC). METHODS: We retrospectively identified patients with HGSOC, who underwent primary or interval debulking surgery between August 2013 and December 2019. We collected anesthesia-related variables, including the arterial blood pressure measurements (at 1-min intervals) during the surgery of patients. The cumulative duration of mean arterial blood pressure (MAP) readings under 65 mmHg and two performance measurements (median performance error [MDPE] and wobble) were calculated. We investigated associations between the factors indicating hemodynamic instability and prognosis. RESULTS: In total, 338 patients were included. Based on the cumulative duration of MAP under 65 mmHg, we divided patients into two groups: ≥30 min and <30 min. The progression-free survival (PFS) was worse in the ≥30 min group (n = 107) than the <30 min group (n = 231) (median, 18.2 vs. 23.7 months; P = 0.014). In multivariate analysis adjusting for confounders, a duration of ≥30 min of MAP under 65 mmHg was identified as an independent poor prognostic factor for PFS (adjusted HR, 1.376; 95% CI, 1.035-1.830; P = 0.028). Shorter PFS was observed in the group with a MDPE <-4.0% (adjusted HR, 1.351; 95% CI, 1.024-1.783; P = 0.033) and a wobble ≥7.5% (adjusted HR, 1.445; 95% CI, 1.100-1.899; P = 0.008). However, no differences were observed in overall survival. CONCLUSION: This study suggests that the three intraoperative variables for hemodynamic instability, cumulative duration of MAP <65 mmHg, MDPE, and wobble, might be novel prognostic biomarkers for disease recurrence in patients with HGSOC.

Intraarterial catheter diameter and dynamic response of arterial pressure monitoring system: a randomized controlled trial.

The dynamic response (DR) of the arterial pressure monitoring system (APMS) may depend on the intraarterial catheter (IAC) diameter. We hypothesized that adequate DR would be more common when using a smaller IAC. We compared the DR of the AMPS (Auto Transducer™) between three IACs (BD Angiocath Plus™) with different diameters. 353 neurosurgical patients were randomized into three groups undergoing catheterization with a 20-, 22-, or 24-gauge IAC: 20G (n = 119), 22G (n = 117), and 24G (n = 117) groups, respectively. The DR, which depends on the natural frequency and damping coefficient, was divided into four types: adequate (primary outcome measure), underdamped, overdamped, and unacceptable. The frequency of intraoperative IAC malfunction was noted. Adequate DR was observed more frequently in the 22G and 24G groups than the 20G group (13.7% and 15.4% vs. 4.2%, P = 0.011 and 0.004, respectively). The frequency of underdamped DR was higher in the 20G group than the 24G group (86.6% vs. 69.2%, P = 0.001), whereas overdamped DR was more frequent in the 24G group than the 20G and 22G groups (6.0% vs. 0.0% and 0.0%, P = 0.007 and 0.014, respectively). IAC malfunctioned more frequently during surgery in the 24G group than the 20G and 22G groups (15.4% vs. 0.0% and 1.7%, P < 0.001 and P < 0.001, respectively). The frequency of adequate DR was low regardless of the IAC diameter. Nonetheless, in terms of DR and IAC malfunction, a 22-gauge BD Angiocath Plus™ was more suitable for invasive blood pressure monitoring with Auto Transducer™ than a 20- or 24-gauge BD Angiocath Plus™. Registration Registry: ClinicalTrials.gov. Registration number: NCT03642756. Date of Registration: July 27, 2018.

Cephalocaudal tumor diameter is a predictor of diabetes insipidus after endoscopic transsphenoidal surgery for non-functioning pituitary adenoma.

PURPOSE: Diabetes insipidus (DI) develops commonly after endoscopic transsphenoidal surgery (ETS). We retrospectively investigated the incidence, onset, duration and predictors of DI after ETS in patients with non-functioning pituitary adenoma (NFPA). METHODS: A total of 168 patients who underwent ETS to remove NFPAs were included. Various perioperative data on demographics, comorbidities, previous treatments, perioperative hormone deficiencies, tumor characteristics, surgery, anesthesia, intraoperative fluid balance, perioperative laboratory findings, postoperative complications, readmission and hospital length of stay were collected and analyzed. Patients were diagnosed with DI and treated with desmopressin when they showed urine output > 5 mL/kg/hr with a serum sodium concentration > 145 mmol/L or an increase ≥ 3 mmol/L in serum sodium concentration between two consecutive tests after surgery. DI was considered permanent when desmopressin was prescribed for > 6 months after surgery. RESULTS: Seventy-seven (45.8%) patients experienced postoperative DI and 10 (6.0%) patients suffered from permanent DI. The median onset of DI and the median duration of transient DI were postoperative day 1 and 5 days, respectively. In multivariable logistic regression analysis, cephalocaudal tumor diameter (odds ratio [95% confidence interval] 2.59 [1.05-6.36], P = 0.038) was related to postoperative DI. In receiver operating characteristic analysis, its area under the curve was 0.68 (95% confidence interval 0.59-0.76, P < 0.001). Its optimal cutoff value that maximized the sum of sensitivity and specificity for postoperative DI was 2.7 cm. CONCLUSIONS: Postoperative DI was observed in 45.8% of patients undergoing ETS to remove NFPAs. A large cephalocaudal tumor diameter was predictive of postoperative DI in such patients.

Correction to: Development and forensic validation of human genomic DNA quantification kit.

The above article was published with two author names being incorrect. The published paper states "'Hyeun Kyu Yoon and Ki min Seong", whereas it should be "'Hyun Kyu Yoon and Ki Min Seong".

McGrath MAC Videolaryngoscope Versus Optiscope Video Stylet for Tracheal Intubation in Patients With Manual Inline Cervical Stabilization: A Randomized Trial.

BACKGROUND: Manual inline stabilization of the head and neck is a recommended maneuver for tracheal intubation in patients with a suspected cervical injury. However, because applying this maneuver inevitably restricts neck flexion and head extension, indirect intubating devices such as a videolaryngoscope or a video stylet could be required for successful tracheal intubation. In this study, we compared the clinical performance of the McGrath MAC videolaryngoscope versus the Optiscope video stylet in patients with manual inline cervical stabilization during tracheal intubation. METHODS: In 367 consecutive patients undergoing elective cervical spine surgery, tracheal intubation was randomly performed with manual inline stabilization using either the McGrath MAC videolaryngoscope (group M, n = 183) or the Optiscope video stylet (group O, n = 184) by 2 experienced anesthesiologists in a single institution. The primary outcome was the first-attempt success rate of tracheal intubation. Secondary outcomes were intubation time and the incidence of postoperative airway complications, such as sore throat, hoarseness, blood in the oral cavity, and blood staining on the endotracheal tube. RESULTS: The first-attempt success rate of tracheal intubation was significantly higher in group M compared with group O (92.3% vs 81.0%; risk difference [95% confidence interval], 0.11 [0.05-0.18]; P = .002). The intubation time was significantly shorter in group M than in group O (35.7 ± 27.8 vs 49.2 ± 43.8; mean difference [95% confidence interval], 13.5 [5.9-21.1]; P = .001). The incidence of postoperative airway complications was not significantly different between the 2 groups. CONCLUSIONS: The McGrath MAC videolaryngoscope showed a higher first-attempt success rate for tracheal intubation and a shorter intubation time than the Optiscope video stylet in cervical spine patients with manual inline stabilization during tracheal intubation. These results suggest that the McGrath MAC videolaryngoscope may be a better option for tracheal intubation in such patients.

Effects of anesthetics on post-operative 3-month neuroendocrine function after endoscopic transsphenoidal non-functional pituitary adenoma surgery.

BACKGROUND: Anesthetic techniques can affect perioperative neuroendocrine function. The objective of this study was to compare 3-month post-operative neuroendocrine functional outcomes between sevoflurane and propofol anesthesia in patients undergoing endoscopic transsphenoidal surgery (ETS) for removal of non-functional pituitary adenomas (NFPAs) retrospectively. METHODS: Among 356 patients who underwent ETS for removal of NFPAs under sevoflurane-remifentanil anesthesia (sevoflurane group, n = 103) or propofol-remifentanil anesthesia (propofol group, n = 253), 92 patients in each group were selected and their 3-month post-operative neuroendocrine functional outcomes (primary outcome measure) were compared after propensity score matching. RESULTS: Overall changes in post-operative 3-month neuroendocrine function compared to pre-operative baseline did not differ between the sevoflurane and propofol groups (worsened: 32.6% vs 29.3%, persistently decreased: 9.8% vs 12.0%, improved: 12.0% vs 20.7%, normalized: 9.8% vs 12.0%, persistently normal: 18.5% vs 19.6%; P = .400). The incidence of pituitary hormone deficiency at 3 months post-operatively did not differ between the sevoflurane and propofol groups (adrenocorticotropic hormone deficiency: 18.5% vs 17.4%, P = 1.000; thyroid-stimulating hormone deficiency: 10.9% vs 3.3%, P = .081; gonadotropin deficiency: 54.3% vs 48.9%, P = .555; growth hormone deficiency: 45.7% vs 48.9%, P = .768; panhypopituitarism: 1.1% vs 1.1%, P = 1.000). CONCLUSION: In patients undergoing ETS for removal of NFPAs, the effects of both sevoflurane-remifentanil and propofol-remifentanil anesthetic techniques on post-operative 3-month neuroendocrine functional outcomes were similar, suggesting that propofol and sevoflurane can be freely used in such patients in terms of post-operative intermediate-term neuroendocrine functional outcome.

No radiographic index predicts difficult intubation using the Optiscope™ in cervical spine surgery patients: a retrospective study.

BACKGROUND: The Optiscope™ can be used for intubation with minimal neck motion. We retrospectively investigated radiographic predictors of difficult intubation using the Optiscope™ by analyzing preoperative radiographic images. METHODS: One hundred eighty-four patients who were intubated with the Optiscope™ under manual in-line cervical stabilization for cervical spine surgery were enrolled. Radiographic indices were measured on preoperative cervical spine lateral X-ray and magnetic resonance imaging images. Difficult intubation was defined as failure or time consumption more than 90 s on the first attempt. To identify significant predictors of difficult intubation using the Optiscope™ and evaluate their diagnostic value, multivariable logistic regression and receiver operating characteristic analyses were used. RESULTS: Fourty-seven patients showed difficult intubation. There was no significant difference in radiographic indices between the difficult and easy intubation groups, but higher body mass index (BMI) (26.5 [3.0] vs. 24.6 [3.5] kg/m2, P = 0.001), shorter sternomental distance (SMD) (122.0 [104.0 to 150.0] vs. 150.0 [130.0 to 170.0] mm, P = 0.001), shorter interincisor gap (40.0 [35.0 to 45.0] vs. 43.0 [40.0 to 50.0] mm, P = 0.006), and higher incidence of excessive oral secretions (10.6% vs. 2.9%, P = 0.049) were observed in patients with difficult intubation. In multivariable analysis, BMI (odds ratio [95% confidence interval]; 1.15 [1.03 to 1.28], P = 0.011) and SMD (odds ratio [95% confidence interval]; 0.98 [0.97 to 1.00], P = 0.008) were associated with difficult intubation with the Optiscope™. In receiver operating characterstic analysis, the area under the curve for body mass index was 0.68 (95% confidence interval; 0.60 to 0.77, P < 0.001) and that for sternomental distance was 0.66 (95% confience interval; 0.57 to 0.75, P = 0.001). CONCLUSIONS: The incidence of difficult intubation using the Optiscope™ under manual in-line cervical stabilization was 25.5% in cervical spine surgery patients. No significant predictor of difficult intubation with the Optiscope™ was identified among the measured radiographic indices. Although high BMI and short SMD were predictive of difficult intubation with the Optiscope™, their discrimination power was weak.

Effects of ipsilateral tilt position on the cross-sectional area of the subclavian vein and the clinical performance of subclavian vein catheterization: a prospective randomized trial.

BACKGROUND: The cross-sectional area of the subclavian vein (csSCV) is a crucial factor in the successful catheterization of the subclavian vein. This randomized controlled study investigated the effects of the csSCV on landmark-based subclavian vein catheterization. METHODS: This study was performed using a two-stage protocol. During stage I, the csSCV was measured in 17 patients placed in the supine, 20° ipsilateral tilt, and 20° contralateral tilt positions in a random order. During stage II, landmark-based subclavian vein catheterization was randomly performed in patients placed in either the supine (group S, n = 107) or the ipsilateral tilt (group I, n = 109) position. The primary outcome measure was the csSCV in stage I and the primary venipuncture success rate in stage II. Secondary outcome measures were the time to successful venipuncture, the total catheterization time, the first-pass success rate, and the incidence of mechanical complications during catheterization. RESULTS: The csSCV was significantly larger in the ipsilateral tilt than in either the supine or contralateral tilt position (1.01 ± 0.35 vs. 0.84 ± 0.32 and 0.51 ± 0.26 cm2, P = .006 and < .001, respectively). The primary venipuncture success rate did not differ significantly between the group S and I (57.0 vs. 64.2%, P = .344). There were also no significant differences in the secondary outcome measures of the two groups. CONCLUSIONS: The csSCV was significantly larger in patients placed in the ipsilateral tilt than in the supine position, but the difference did not result in better clinical performance of landmark-based subclavian vein catheterization. TRIAL REGISTRATION: NCT03296735 for stage I ( ClinicalTrials.gov , September 28, 2017) and NCT03303274 for stage II ( ClinicalTrials.gov , October 6, 2017).

Neutrophil/Lymphocyte Ratio in Patients Undergoing Noncardiac Surgery After Coronary Stent Implantation.

OBJECTIVE: Perioperative cell count-associated predictors, including the neutrophil/lymphocyte ratio (N/LR) and platelet/lymphocyte ratio (P/LR), are associated with poor clinical outcomes including myocardial injury. Study investigators aimed to examine the association among the perioperative N/LR, P/LR, and postoperative major adverse cardiovascular and cerebral events (MACCE) after noncardiac surgery in patients with drug-eluting stent (DES) insertion. DESIGN: Retrospective and observational. SETTING: Single university hospital. PARTICIPANTS: The study comprised 965 patients who underwent noncardiac surgery within 6 months after DES implantation. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Baseline perioperative clinical parameters, including N/LR and P/LR measured before surgery, immediately after surgery, and on postoperative day (POD) 1, were obtained. MACCE was defined as a composite of nonfatal myocardial infarction, coronary revascularization, nonhemorrhagic stroke, and pulmonary embolism within 1 month after surgery. Multivariate logistic regression analysis and propensity score matching were used to identify predictors of MACCE after surgery. MACCE occurred in 67 patients (6.9%) and was more common in patients with N/LR on POD 1 >4.3 (multivariable-adjusted odds ratio [OR] 2.03, 95% confidence interval [CI] 1.12-2.79; p = 0.040 and as a continuous N/LR [OR 1.17, 95% CI 1.08-1.27; p < 0.001]). This association was consistent after propensity score matching and was stronger when the antiplatelet agent was stopped before surgery (OR 3.02, 95% CI 2.14-4.48; p = 0.006 for stopping dual antiplatelet therapy). CONCLUSIONS: In patients undergoing noncardiac surgery within 6 months after DES implantation, elevated N/LR on POD 1 is independently associated with postoperative MACCE. Elevated postoperative N/LR as a marker of systemic inflammation may help to predict the development of MACCE in these high-risk patients.

Cervical Spine Motion During Tracheal Intubation Using an Optiscope Versus the McGrath Videolaryngoscope in Patients With Simulated Cervical Immobilization: A Prospective Randomized Crossover Study.

BACKGROUND: In patients with an unstable cervical spine, maintenance of cervical immobilization during tracheal intubation is important. In McGrath videolaryngoscopic intubation, lifting of the blade to raise the epiglottis is needed to visualize the glottis, but in patients with an unstable cervical spine, this can cause cervical spine movement. By contrast, the Optiscope, a rigid video-stylet, does not require raising of the epiglottis during tracheal intubation. We therefore hypothesized that the Optiscope would produce less cervical spine movement than the McGrath videolaryngoscope during tracheal intubation. The aim of this study was to compare the Optiscope with the McGrath videolaryngoscope with respect to cervical spine motion during intubation in patients with simulated cervical immobilization. METHODS: The primary outcome of the study was the extent of cervical spine motion at the occiput-C1, C1-C2, and C2-C5 segments. In this randomized crossover study, the cervical spine angle was measured before and during tracheal intubation using either the Optiscope or the McGrath videolaryngoscope in 21 patients with simulated cervical immobilization. Cervical spine motion was defined as the change in angle at each cervical segment during tracheal intubation. RESULTS: There was significantly less cervical spine motion at the occiput-C1 segment using the Optiscope rather than the McGrath videolaryngoscope (mean [98.33% CI]: 4.7° [2.4-7.0] vs 10.4° [8.1-12.7]; mean difference [98.33% CI]: -5.7° [-7.5 to -3.9]). There were also fewer cervical spinal motions at the C1-C2 and C2-C5 segments using the Optiscope (mean difference versus the McGrath videolaryngoscope [98.33% CI]: -2.4° [-3.7 to -1.2]) and -3.7° [-5.9 to -1.4], respectively). CONCLUSIONS: The Optiscope produces less cervical spine motion than the McGrath videolaryngoscope during tracheal intubation of patients with simulated cervical immobilization.

Postoperative sore throat and subglottic injury after McGrath® MAC videolaryngoscopic intubation with versus without a stylet in patients with a high Mallampati score: a randomized controlled trial.

BACKGROUND: A tracheal tube stylet can be used to assist successful tracheal intubation, especially during videolaryngoscopic intubation because videolaryngoscopes with a Macintosh-type blade such as McGrath® MAC videolaryngoscope have more acute angle than conventional Macintosh laryngoscope. However, the use of a stylet during tracheal intubation can raise concerns about stylet-induced postoperative airway complications, such as sore throat, subglottic injury, and hoarseness. In this study, we compared the incidence of postoperative airway complications after McGrath® MAC videolaryngoscopic intubation with versus without a stylet in patients with a high Mallampati score. METHODS: In 104 patients with Mallampati score III or IV and who were scheduled for lumbar or thoracic spine surgery, McGrath® MAC videolaryngoscopic intubation was performed either with a stylet (group S, n = 52) or without a stylet (group N, n = 52). The primary outcome measure was the incidences of sore throat evaluated at 1 and 24 h postoperatively. Secondary outcome measures were the incidences of subglottic injury and postoperative hoarseness. RESULTS: The incidence of CL grade III in group S and N was 3.8 and 5.8%, respectively. No patient showed CL grade IV. The incidences of sore throat at 1 (26.9 vs 19.2%, P = 0.485) and 24 h (17.3 vs 13.5%, P = 0.786, respectively) postoperatively were not significantly different between the group S and N. However, the incidence of subglottic injury was significantly higher in the group S, compared with the group N (65.4 vs 42.3%, P = 0.030). The incidence of postoperative hoarseness did not differ significantly between the two groups. CONCLUSIONS: The use of a stylet during McGrath® MAC videolaryngoscopic intubation did not have a significant impact on the incidence of postoperative sore throat in patients with a high Mallampati score. Avoiding the use of a stylet during intubation with McGrath® MAC videolaryngoscope may reduce the incidence of subglottic injury in such patients. TRIAL REGISTRATION: Clinical Research Information Service (identifier: KCT0002427 , date of registration: June 12, 2017).

Preoperative 5-aminolevulinic acid administration for brain tumor surgery is associated with an increase in postoperative liver enzymes: a retrospective cohort study.

BACKGROUND: Besides 5-aminolevulinic acid (5-ALA), liver enzyme elevation after brain tumor surgery can be caused by anesthesia and medications. In this retrospective study, we determined whether preoperative 5-ALA administration is associated with postoperative elevation of liver enzymes (PELE) in brain tumor patients and identified predictive factors for PELE in patients treated with 5-ALA. METHODS: In 179 patients undergoing brain tumor surgery with preoperative normal values of liver enzymes, laboratory data on serum alanine transaminase (ALT), aspartate transaminase (AST), alkaline phosphatase (ALP), and total bilirubin (T.bil) levels were collected preoperatively and through postoperative day (POD) 45. RESULTS: Ninety-nine PELEs (ALT, 56; AST, 34; ALP, 5; and TB, 4) were observed in 62 (34.6%) patients. Four (4.2%) patients treated with 5-ALA showed grade 3 elevation of transaminases based on the Common Terminology Criteria for Adverse Effects. Preoperative 5-ALA treatment was predictive of PELE (odds ratio [95% confidence interval], 2.30 [1.14-4.67]; P = 0.021). In patients treated with 5-ALA (n = 95), 70 PELEs (ALT, 39; AST, 22; ALP, 5; and TB, 4) were observed in 41 (43.2%) patients and significant predictive factors for PELE were preoperative ALT level (1.10 [1.04-1.17]; P = 0.001) and body mass index (BMI, 1.29 [1.08-1.56]; P = 0.006). In patients treated with 5-ALA, 13 and 36 patients, of 39 patients whose maximum postoperative ALT levels > 40 U/L, showed the normal value of serum ALT on PODs 14 and 45, respectively. Only three patients showed ALT elevation > 40 U/L on PODs 15-45, with a downward trend. CONCLUSIONS: The use of 5-ALA for brain tumor surgery in patients with preoperative normal values of liver enzymes was associated with increased transient PELE, but a low incidence of severely elevated liver transaminases levels. When 5-ALA is administered to patients with the upper normal value of preoperative serum ALT and overweight, attention is paid to PELE.

Comparative effectiveness of interventions for managing postoperative catheter-related bladder discomfort: a systematic review and network meta-analysis.

BACKGROUND: Although many drugs or interventions have been studied to manage catheter-related bladder discomfort (CRBD), their comparative effectiveness is unknown. We attempted to assess the comparative effectiveness of the strategies to manage CRBD in patients undergoing urologic surgery including amikacin, solifenacin, darifenacin, butylscopolamine, dexmedetomidine, gabapentin, glycopyrrolate, ketamine, oxybutynin, resiniferatoxin, tolterodine, tramadol, caudal block, dorsal penile nerve block, lidocaine-prilocaine cream. METHODS: We performed an arm-based network meta-analysis including 29 trials with 2841 participants. Goodness of model fit was evaluated by deviance information criteria (DIC). The incidence of CRBD at 0, 1, and 6 h after surgery and the incidence of moderate to severe CRBD at 0, 1, and 6 h after surgery were compared. RESULTS: Random effect model was selected according to DIC. Most of the drugs significantly decreased the incidence of CRBD except amikacin, tramadol at 0 and 1 h after surgery. Dexmedetomidine, solifenacin, caudal block, dorsal penile nerve block, resiniferatoxin, and gabapentin 1200 mg p.o. significantly decreased the incidence of CRBD at 6 h after surgery (gabapentin 1200: Odds ratio [OR] 0.02; SUCRA 95.6). Dexmedetomidine and tolterodine significantly decreased the incidence of moderate to severe CRBD at 0, 1, and 6 h after surgery (tolterodine at 6 h: OR 0.05; SUCRA 73.7). CONCLUSIONS: Gabapentin was ranked best regarding the overall incidence of CRBD, while tolterodine was ranked best in reducing the severity of CRBD. However, a firm conclusion cannot be made from our analysis due to small-study number and heterogeneity regarding study setting and outcome measurement.

A randomized controlled trial of the effect of preoperative dexmedetomidine on the half maximal effective concentration of propofol for successful i-gel insertion without muscle relaxants.

BACKGROUND: Dexmedetomidine is a useful anesthetic adjuvant for general anesthesia. We determined whether preoperative dexmedetomidine administration could reduce the half maximal effective concentration (EC50) of propofol for successful i-gel insertion without muscle relaxants. METHODS: Thirty-seven patients were randomly allocated to one of two groups. In the dexmedetomidine group (n = 19), dexmedetomidine (1 µg/kg) was loaded for 10 min preoperatively. In the control group (n = 20), the same volume of 0.9% normal saline was administered in the same manner. The EC50 of propofol for successful i-gel insertion was determined using Dixon's up-and-down method. The EC50 of propofol was calculated as the midpoint concentration after at least six crossover points had been obtained. For successful i-gel insertion, all of the following four factors were required­(1) no major movement of the body within 1 min of insertion, (2) no significant resistance to mouth opening, (3) cough ≤2, and (4) visible square wave capnogram without air leakage at a peak airway pressure of <10 cmH2O. Mean blood pressure (MBP) and heart rate (HR) were monitored during the peri-insertion period of i-gel. RESULTS: The EC50 of propofol for successful i-gel insertion was 3.18 µg/mL in the dexmedetomidine group and 6.75 µg/mL in the control group (p < 0.001). The incidence of hypotension (MBP <80% of the baseline) during the peri-insertion period of i-gel was higher in the control group (p = 0.001), whereas the incidence of bradycardia (HR <80% of the baseline) was higher in the dexmedetomidine group (p = 0.001). CONCLUSIONS: Preoperative dexmedetomidine reduced the EC50 of propofol for successful i-gel insertion without muscle relaxants.