Comparison of Contralateral Acceleromyography and Electromyography for Posttetanic Count Measurement.

BACKGROUND: Electromyography has advantages over mechanomyography and acceleromyography. Previously, agreement of the train-of-four counts between acceleromyography and electromyography was found to be fair. The objective of this study was to assess the agreement of posttetanic count including agreement of neuromuscular blockade status (intense block, posttetanic count equal to 0; or deep block, posttetanic count 1 or greater and train-of-four count equal to 0) between acceleromyography and electromyography. METHODS: Thirty-six patients, aged 20 to 65 yr, participated in this study. A dose of 0.6 mg/kg rocuronium, with additional dose of 0.3 mg/kg if required, was administered to the patients. The train-of-four and posttetanic counts were monitored in the contralateral arm using electromyography at the first dorsal interosseus or adductor pollicis, and acceleromyography at the adductor pollicis. Posttetanic count measurements were performed at 6-min intervals; the responses were recorded until the train-of-four count reached 1. The authors evaluated the agreement of degree of neuromuscular blockade (intense or deep block) and that of posttetanic count between acceleromyography and electromyography. RESULTS: The authors analyzed 226 pairs of measurements. The percentage agreement indicating the same neuromuscular blockade status (intense or deep block) between acceleromyography and electromyography was 73%. Cohen's kappa coefficient value was 0.26. After excluding data with acceleromyography-posttetanic counts greater than 15, a total of 184 pairs of posttetanic counts were used to evaluate the agreement between the two monitoring methods. For acceleromyography-posttetanic count, 42 (23%) pairs had the same electromyography-posttetanic count, and 93 (50%) pairs had more than the electromyography-posttetanic count. The mean posttetanic count on electromyography was 38% (95% CI, 20 to 51%) lower than that on acceleromyography (P = 0.0002). CONCLUSIONS: Acceleromyography frequently counted more twitches than electromyography in posttetanic count monitoring. Acceleromyography- and electromyography-posttetanic counts cannot be used interchangeably to assess the degree of neuromuscular blockade.

Intravenous Versus Perineural Dexamethasone for Reducing Rebound Pain After Interscalene Brachial Plexus Block: A Randomized Controlled Trial.

BACKGROUND: Interscalene brachial plexus block (ISB) is a common regional technique to manage acute postoperative pain for arthroscopic rotator cuff tear repair. However, rebound pain may compromise its overall benefit. Our aim was to investigate the primary hypothesis that perineural and intravenous dexamethasone have different effects on rebound pain after resolution of ISB for arthroscopic rotator cuff tear repair. METHODS: Patients aged ≥ 20 years scheduled for elective arthroscopic rotator cuff tear repair under general anesthesia with preoperative ISB were included. The participants were randomized to receive dexamethasone either perineurally (perineural group) or intravenously (intravenous group). In the perineural group, patients received ISB with 12 mL of 0.5% ropivacaine containing 5 mg of dexamethasone; simultaneously, 1 mL of 0.9% normal saline was administered intravenously. In the intravenous group, patients received ISB with 12 mL of 0.5% ropivacaine; simultaneously, 1 mL of dexamethasone 5 mg was administered intravenously. The primary outcome was the difference in the pain score (0-10 on numeric rating scale) between before and after ISB resolution. The secondary outcomes were the incidence of rebound pain; onset, duration, and intensity of rebound pain; time to the first analgesic request; and pain-related sleep disturbance. RESULTS: A total of 71 patients were randomized to either perineural group (n = 36) or intravenous group (n = 35). After block resolution, pain scores increased significantly more in the perineural group (mean ± standard deviation, 4.9 ± 2.1) compared to the intravenous group (4.0 ± 1.7, P = 0.043). The duration of ISB was more prolonged in the perineural group (median [interquartile range], 19.9 [17.2-23.1] hours) than the intravenous group (15.1 [13.7-15.9] hours, P < 0.001). The incidence of rebound pain and pain-related sleep disturbance during the first postoperative week was significantly higher in the perineural group than in the intravenous group (rebound pain: 44.4% vs. 20.0%, P = 0.028; sleep disturbance: 55.6% vs. 25.7%, P = 0.011). The duration and intensity of rebound pain were similar between the two groups. CONCLUSION: Although perineural dexamethasone provided longer postoperative analgesia, intravenous dexamethasone was more beneficial in reducing pain increase after ISB resolution, incidence of rebound pain, and pain-related sleep disturbance. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0006795.

Reliability of submaximal stimulation for the train-of-four test using acceleromyography and electromyography with individualized stimulation currents.

PURPOSE: The supramaximal stimulation (SMS) of the TOF test causes uncomfortable sensations in patients. We aimed to determine whether the submaximal stimulation would be reliable in TOF tests with reduced painful sensation. METHODS: The accelomyography (AMG) and electromyography (EMG) monitor was applied at each arm and general anesthesia was induced and maintained by total intravenous anesthesia. At extubation, we conducted TOF test three times at each of four different currents: SMS, 70% SMS, 50% SMS, and 30% SMS. The same procedure was performed in the postanesthesia care unit (PACU) only with EMG, and the pain scores on the numerical rating scale (NRS) during the tests were recorded. RESULTS: A total of 36 patients were enrolled. At extubation, TOF ratios with SMS in AMG and EMG were 112.0 ± 13.1% and 93.7 ± 8.9%, respectively. There were no significant differences in TOF ratios between the SMS and lower stimulation intensities. However, 30% and 50% SMS showed significantly higher rates of the unmeasurable results of tests in the PACU. In terms of the stimulation pain, NRS showed a downward pattern as the current decreased and was significantly lower at 50% and 30% SMS than the NRS at SMS. CONCLUSION: The TOF test with submaximal stimulation is still reliable and can reduce stimulation pain. Considering the importance of the TOF results in determining extubation, the authors suggest the minimal current for the TOF test as 70% SMS.

Cut-off points between pain intensities of the postoperative pain using receiver operating characteristic (ROC) curves.

BACKGROUND: Pain assessment and management are important in postoperative circumstances as overdosing of opioids can induce respiratory depression and critical consequences. We aimed this study to check the reliability of commonly used pain scales in a postoperative setting among Korean adults. We also intended to determine cut-off points of pain scores between mild and moderate pain and between moderate and severe pain by which can help to decide to use pain medication. METHODS: A total of 180 adult patients undergoing elective non-cardiac surgery were included. Postoperative pain intensity was rated with a visual analog scale (VAS), numeric rating scale (NRS), faces pain scale revised (FPS-R), and verbal rating scale (VRS). The VRS rated pain according to four grades: none, mild, moderate, and severe. Pain assessments were performed twice: when the patients were alert enough to communicate after arrival at the postoperative care unit (PACU) and 30 min after arrival at the PACU. The levels of agreement among the scores were evaluated using intraclass correlation coefficients (ICCs). The cut-off points were determined by receiver operating characteristic curves. RESULTS: The ICCs among the VAS, NRS, and FPS-R were consistently high (0.839-0.945). The pain categories were as follow: mild ≦ 5.3 / moderate 5.4 ~ 7.1 /severe ≧ 7.2 in VAS, mild ≦ 5 / moderate 6 ~ 7 / severe ≧ 8 in NRS, mild ≦ 4 / moderate 6 / severe 8 and 10 in FPS-R. The cut-off points for analgesics request were VAS ≧ 5.5, NRS ≧ 6, FPS-R ≧ 6, and VRS ≧ 2 (moderate or severe pain). CONCLUSIONS: During the immediate postoperative period, VAS, NRS, and FPS-R were well correlated. The boundary between mild and moderate pain was around five on 10-point scales, and it corresponded to the cut-off point of analgesic request. Healthcare providers should consider VRS and other patient-specific signs to avoid undertreatment of pain or overdosing of pain medication.

A randomized double-blind comparison of the double-space technique versus the single-space technique in combined spinal-epidural anesthesia for cesarean section.

BACKGROUND: Combined spinal-epidural anesthesia (CSEA) can be performed with either a single-space technique or a double-space technique for cesarean section. We performed a double-blind randomized controlled study to compare the effect of the double-space technique with that of the single-space technique on sensory block level and side effects. METHODS: Parturients undergoing elective cesarean section under regional anesthesia were randomized to receive CSEA with either the double-space technique (double group, n = 20) or the single-space technique (single group, n = 20). In the double group, an epidural catheter was inserted at the L1-2 interspace, and dural puncture was performed at the L3-4 interspace. In the single group, the procedure was performed at the L3-4 interspace using the needle-through-needle technique. RESULTS: There were no differences in time to readiness or intraoperative level of sensory block between the two groups. The postoperative sensory level was maintained at a higher level in the double group than in the single group (1 h postoperatively, P = 0.029; 6 h postoperatively, P = 0.016). There was no difference between the two groups in terms of side effects. The parturient satisfaction scores 48 h postoperatively were significantly different between groups (9.5 in the double group vs. 8 in the single group, P = 0.004). CONCLUSIONS: We conclude that there were no differences in intraoperative variables between the double-space technique and the single-space technique for CSEA. However, double-space CSEA for cesarean section may be beneficial for controlling postoperative pain and improving parturient satisfaction. TRIAL REGISTRATION: The study was retrospectively registered at https://cris.nih.go.kr under the trial ID KCT0002514. Date of registration: October 27, 2017.

Effects of Intraoperative Ventilation Strategy on Perioperative Atelectasis Assessed by Lung Ultrasonography in Patients Undergoing Open Abdominal Surgery: a Prospective Randomized Controlled Study.

BACKGROUND: Protective mechanical ventilation using low tidal volume has been introduced to surgical patients to reduce the incidence of postoperative pulmonary complications. We investigated the effects of protective ventilation (PV) techniques on anesthesia-induced atelectasis identified via lung ultrasonography in patients undergoing abdominal surgery. METHODS: A total of 42 adult patients who were scheduled for open abdominal surgery with an expected duration > 2 hours were included in the study. Patients were randomized to receive either conventional ventilation (CV; tidal volume of 9-10 mL/kg predicted body weight [PBW] with no positive end-expiratory pressure [PEEP]) or PV (tidal volume of 6-8 mL/kg PBW and 5 cmH2O PEEP) via pressure-controlled ventilation with volume guaranteed. Lung ultrasonography was performed at four predefined time points to assess perioperative atelectasis by dividing each hemithorax into six quadrants based on a modified lung ultrasound (LUS) scoring system. RESULTS: The tidal volume delivered to patients was 9.65 ± 1.65 mL/kg PBW in the CV group and 6.31 ± 0.62 mL/kg PBW in the PV group. Ventilation using low tidal volume led to similar LUS scores in all lung areas and at all time points compared to ventilation using high tidal volume. There was no significant difference between the groups in the number of patients requiring recruitment maneuvers at the end of surgery. CONCLUSION: Ventilation with low tidal volume combined with 5 cmH2O PEEP did not cause further loss of aeration compared to ventilation with high tidal volume. Low tidal volume ventilation can be used in patients without lung injury based on lung assessment by bedside lung ultrasonography. TRIAL REGISTRATION: Clinical Research Information Service Identifier: KCT0003746.

Pre-anaesthesia ultrasonography of the subclavian/infraclavicular axillary vein for predicting hypotension after inducing general anaesthesia: A prospective observational study.

BACKGROUND: Bedside sonography of the inferior vena cava has been demonstrated to be a reliable tool for assessing intravascular volume status. Subclavian vein (SCV) assessment was proposed as a reasonable adjunct for measuring the inferior vena cava. OBJECTIVE: We examined whether the preoperative diameter and collapsibility index of the SCV or the infraclavicular axillary vein could predict the incidence of hypotension after induction of general anaesthesia in patients undergoing laparoscopic cholecystectomy. DESIGN: Prospective, observational study. SETTING: Tertiary university hospital. PATIENTS: Adults scheduled for laparoscopic cholecystectomy. INTERVENTION: Sonographic evaluation of the SCV or the axillary vein (SCV-AV) before induction of anaesthesia. MAIN OUTCOME MEASURES: The main outcome was the association between the SCV-AV measurements (diameter an collapsibility index) and intra-operative hypotension (IOH) after induction of anaesthesia. RESULTS: Patients who developed IOH had a higher collapsibility index of the SCV-AV during spontaneous breathing (P = 0.009) and deep inspiration (P = 0.002). After adjusting for confounding variables, the collapsibility index of the SCV-AV during spontaneous breathing was not a significant predictor of a decrease in mean arterial blood pressure (MAP) after inducing anaesthesia (P = 0.127), whereas the collapsibility index of the SCV-AV during deep inspiration was a significant predictor (P < 0.001). CONCLUSION: The collapsibility index of the SCV-AV during deep inspiration was a significant predictor of IOH occurrence and the percentage decrease in MAP after inducing anaesthesia. Further studies in patients with higher collapsibility index are needed to confirm our findings, before the collapsibility index of the SCV-AV can be recommended unequivocally for clinical use. TRIAL REGISTRATION: This trial was registered on 8 September 2017 at the Clinical Trial Registry of Korea (https://cris.nih.go.kr/cris/index.jsp; Identifier: KCT0001078KCT0002457), and the first patient was enrolled on 14 October 2017.

Cervical transforaminal epidural block using low-dose local anesthetic: a prospective, randomized, double-blind study.

OBJECTIVES: Intra-arterial injections of local anesthetic during cervical transforaminal epidural block (TFEB) can cause rare but fatal neurologic complications. We hypothesized that using a dose of local anesthetic lower than seizure threshold during cervical TFEB would not be associated with seizure activity in cases of accidental intra-arterial injection. METHODS: Patients were randomized to one of two groups: group I received injections of 1 mL of 1% lidocaine mixed with dexamethasone 2.5 mg (n = 15), and group II received 1 mL of 0.125% lidocaine mixed with dexamethasone 2.5 mg (n = 15). When the numeric rating scale (NRS) for pain was greater than 3, cervical TFEBs were performed three times at 2-week intervals. Patients were evaluated up to 3 months. RESULTS: Thirty patients with cervical radicular pain were enrolled in this study. The NRS pain score on the day of procedure and at 2 weeks, 4 weeks, 6 weeks, and 3 months following the initial procedure were similarly significantly reduced in both groups. The total number of procedures performed and the outcomes evaluated according to Odom's criteria at the 3-month follow-up visit were not different between groups. Overall, 73.3% and 80% patients in groups I and II, respectively, rated the degree of their symptom relief as excellent or good. CONCLUSION: Cervical TFEB performed using 0.125% lidocaine with dexamethasone achieved similar satisfactory effects as 1% lidocaine with dexamethasone for the treatment of cervical radicular pain. Therefore, the use of low-dose lidocaine with dexamethasone is reasonable for cervical TFEB, as this may reduce the incidence of rare but fatal complications.

Doxepin and imipramine but not fluoxetine reduce the activity of the rat glutamate transporter EAAT3 expressed in Xenopus oocytes.

BACKGROUND: Many researchers have suggested that the glutamatergic system may be involved in the effects of antidepressant therapies. We investigated the effects of doxepin, imipramine, and fluoxetine on the excitatory amino acid transporter type 3 (EAAT3). METHODS: EAAT3 was expressed in Xenopus oocytes by injection of EAAT3 mRNA. Membrane currents were recorded after application of L-glutamate (30 µM) in the presence or absence of various concentrations of doxepin, imipramine, and fluoxetine. To study the effects of protein kinase C (PKC) activation on EAAT3 activity, oocytes were pre-incubated with phorbol 12-myristate-13-acetate (PMA) before application of imipramine and doxepin. RESULTS: Doxepin at 0.063-1.58 µM significantly decreased EAAT3 activity. Imipramine reduced EAAT3 activity in a concentration-dependent manner at 0.16-0.95 µM. However, fluoxetine did not affect EAAT3 activity, and PMA increased EAAT3 activity. At 0.32 µM, imipramine caused an equivalent decrease in EAAT3 activity in the presence or absence of PMA. However, 0.79 µM doxepin did not abolish the enhancement of EAAT3 activity by PMA. CONCLUSIONS: We showed that doxepin and imipramine, but not fluoxetine, inhibited EAAT3 activity at clinically relevant concentrations. This reveals a novel mechanism of action for doxepin and imipramine; that they increase glutamatergic neurotransmission. PKC may be involved in the effects of doxepin on EAAT3, but is not involved in the effects of imipramine at the concentrations studied.

Effect of Propofol and Desflurane on Immune Cell Populations in Breast Cancer Patients: A Randomized Trial.

Several factors can affect the perioperative immune function. We evaluated the effect of propofol and desflurane anesthesia on the surgery-induced immune perturbation in patients undergoing breast cancer surgery. The patients were randomly assigned to receive propofol (n = 20) or desflurane (n = 20) anesthesia. The total and differential white blood cell counts were determined with lymphocyte subpopulations before and 1 hr after anesthesia induction and at 24 hr postoperatively. Plasma concentrations of interleukin (IL)-2 and IL-4 were also measured. Both propofol and desflurane anesthesia preserved the IL-2/IL-4 and CD4(+)/CD8(+) T cell ratio. Leukocytes were lower in the propofol group than in the desflurane group at 1 hr after induction (median [quartiles], 4.98 [3.87-6.31] vs. 5.84 [5.18-7.94] 10(3)/µL) and 24 hr postoperatively (6.92 [5.54-6.86] vs. 7.62 [6.22-9.21] 10(3)/µL). NK cells significantly decreased 1 hr after induction in the propofol group (0.41 [0.34-0.53] to 0.25 [0.21-0.33] 10(3)/µL), but not in the desflurane group (0.33 [0.29-0.48] to 0.38 [0.30-0.56] 10(3)/µL). Our findings indicate that both propofol and desflurane anesthesia for breast cancer surgery induce a favorable immune response in terms of preservation of IL-2/IL-4 and CD4(+)/CD8(+) T cell ratio in the perioperative period. With respect to leukocytes and NK cells, desflurane anesthesia is associated with less adverse immune responses than propofol anesthesia during surgery for breast cancer. (Clinical trial registration at https://cris.nih.go.kr/cris number: KCT0000939).

Dose-dependency of dexamethasone on the analgesic effect of interscalene block for arthroscopic shoulder surgery using ropivacaine 0.5%: A randomised controlled trial.

BACKGROUND: Dexamethasone prolongs the duration of single-shot interscalene brachial plexus block (SISB). However, dose-dependency of dexamethasone as an adjuvant for SISB remains insufficiently understood. OBJECTIVE: The objective of this study is to evaluate the effect of different doses of dexamethasone on the duration of SISB using ropivacaine 0.5%. DESIGN: A randomised, double-blind controlled trial. SETTING: Single university tertiary care centre. PATIENTS: One hundred and forty-four patients scheduled for elective arthroscopic shoulder surgery were allocated randomly to one of four groups. INTERVENTIONS: Patients received 12 ml of ropivacaine 0.5% in 0.9% saline (control group), or containing dexamethasone 2.5, 5.0 or 7.5 mg for SISB. MAIN OUTCOME MEASURES: The primary endpoint was the time to the first analgesic request. Pain scores and adverse effects were also assessed up to 48 h postoperatively. RESULTS: Inclusion of dexamethasone 2.5, 5.0 and 7.5 mg resulted in significant (P < 0.001) increases in time to the first analgesic request by factors of 1.6, 2.2 and 1.8, respectively. The percentages of patients not requiring analgesics in the first 48 h postoperatively with dexamethasone 0.0, 2.5, 5.0 and 7.5 mg were 3, 22, 39 and 33%, respectively (P < 0.001). There were no significant effects on pain scores or incidences of adverse effects. CONCLUSION: Dexamethasone demonstrated significant beneficial dose-dependent effects on duration to the first analgesic request, the number of patients not requiring analgesics and analgesic use in the first 48 h after SISB for arthroscopic shoulder surgery. There were no significant effects on pain scores or incidences of adverse effects. TRIAL REGISTRATION: the trial was registered with the Clinical Trial Registry of Korea: https://cris.nih.go.kr/cris/index.jsp. Identifier: KCT0001078.

Does intravenous ketamine enhance analgesia after arthroscopic shoulder surgery with ultrasound guided single-injection interscalene block?: a randomized, prospective, double-blind trial.

Ketamine has anti-inflammatory, analgesic and antihyperalgesic effect and prevents pain associated with wind-up. We investigated whether low doses of ketamine infusion during general anesthesia combined with single-shot interscalene nerve block (SSISB) would potentiate analgesic effect of SSISB. Forty adult patients scheduled for elective arthroscopic shoulder surgery were enrolled and randomized to either the control group or the ketamine group. All patients underwent SSISB and followed by general anesthesia. During an operation, intravenous ketamine was infused to the patients of ketamine group continuously. In control group, patients received normal saline in volumes equivalent to ketamine infusions. Pain score by numeric rating scale was similar between groups at 1, 6, 12, 24, 36, and 48 hr following surgery, which was maintained lower than 3 in both groups. The time to first analgesic request after admission on post-anesthesia care unit was also not significantly different between groups. Intraoperative low dose ketamine did not decrease acute postoperative pain after arthroscopic shoulder surgery with a preincisional ultrasound guided SSISB. The preventive analgesic effect of ketamine could be mitigated by SSISB, which remains one of the most effective methods of pain relief after arthroscopic shoulder surgery.

Preoperative Frailty Is an Independent Risk Factor for Postinduction Hypotension in Older Patients Undergoing Noncardiac Surgery: A Retrospective Cohort Study.

BACKGROUND: Intraoperative hypotension is a risk factor for perioperative adverse outcomes and is highly prevalent in older patients. Frailty has been associated with hemodynamic instability but its impact on postinduction hypotension is unclear. Therefore, we assessed the association between frailty and postinduction hypotension in older patients. METHODS: We retrospectively evaluated electronic medical records of patients aged ≥65 years who were assessed for preoperative frailty and underwent noncardiac surgery under general anesthesia. Reported Edmonton Frail Scale (REFS) scores were used to stratify patients into a nonfrail (REFS scores 0-5), prefrail (6-7), and frail (8-18) groups. Postinduction hypotension was defined as a mean blood pressure below 65 mmHg or 20% from baseline occurring within the first 20 minutes after anesthesia induction and evaluated using multivariate logistic regression analysis. RESULTS: Independent factors related to postinduction hypotension in our sample (421 patients) were status of frail (REFS score ≥8) compared to nonfrail (odds ratio [OR], 2.73; 95% confidence interval [CI], 1.44-5.18; p = .002), lower baseline mean blood pressure in the operating room (OR, 0.98; 95% CI, 0.96-0.999; p = .034) and at the presurgical center (OR, 0.96; 95% CI, 0.94-0.99; p = .003), and orthopedic (compared to urologic) surgery (OR, 2.22; 95% CI, 1.14-4.30; p = .019). CONCLUSION: Preoperative frail status based on REFS scores is associated with postinduction hypotension. Frailty screening tool for older patients may enhance traditional risk calculators and improve patient selection for noncardiac surgery under general anesthesia.

Predictive Value of Ultrasound-Measured Quadriceps Depth and Frailty Status for Hypotension in Older Patients Undergoing Reverse Total Shoulder Arthroplasty in the Beach Chair Position under General Anesthesia.

The beach chair position (BCP) is widely used in shoulder surgery; however, it frequently leads to hypotension. Hypotension in BCP is prevalent among older patients who are at risk of secondary complications such as ischemic injuries. Therefore, this prospective study aimed to investigate the association and predictive value of frailty, as assessed by ultrasound-measured quadriceps depth and questionnaire, in patients aged ≥65 years undergoing elective shoulder surgery under general anesthesia. A multivariable logistic regression analysis was performed to identify independent risk factors for hypotension in BCP under general anesthesia. Receiver operating characteristic curves were constructed to assess the predictive values of various parameters. The results indicated that a quadriceps depth < 2.3 cm and BCP for an extended period significantly increased the risk of hypotension. The combined consideration of quadriceps depth < 2.3 cm and frailty demonstrated markedly superior predictive power compared with each factor individually. In conclusion, the study findings facilitate the screening and identification of risk factors for older patients undergoing surgery in BCP, thereby enhancing perioperative management.

Transcutaneous Carbon Dioxide Monitoring More Accurately Detects Hypercapnia than End-Tidal Carbon Dioxide Monitoring during Non-Intubated Video-Assisted Thoracic Surgery: A Retrospective Cohort Study.

Transcutaneous carbon dioxide (PtcCO2) monitoring is known to be effective at estimating the arterial partial pressure of carbon dioxide (PaCO2) in patients with sedation-induced respiratory depression. We aimed to investigate the accuracy of PtcCO2 monitoring to measure PaCO2 and its sensitivity to detect hypercapnia (PaCO2 > 60 mmHg) compared to nasal end-tidal carbon dioxide (PetCO2) monitoring during non-intubated video-assisted thoracoscopic surgery (VATS). This retrospective study included patients undergoing non-intubated VATS from December 2019 to May 2021. Datasets of PetCO2, PtcCO2, and PaCO2 measured simultaneously were extracted from patient records. Overall, 111 datasets of CO2 monitoring during one-lung ventilation (OLV) were collected from 43 patients. PtcCO2 had higher sensitivity and predictive power for hypercapnia during OLV than PetCO2 (84.6% vs. 15.4%, p < 0.001; area under the receiver operating characteristic curve; 0.912 vs. 0.776, p = 0.002). Moreover, PtcCO2 was more in agreement with PaCO2 than PetCO2, indicated by a lower bias (bias ± standard deviation; -1.6 ± 6.5 mmHg vs. 14.3 ± 8.4 mmHg, p < 0.001) and narrower limit of agreement (-14.3-11.2 mmHg vs. -2.2-30.7 mmHg). These results suggest that concurrent PtcCO2 monitoring allows anesthesiologists to provide safer respiratory management for patients undergoing non-intubated VATS.

Depth of double-lumen endobronchial tube: a comparison between real practice and clinical recommendations using height-based formulae.

BACKGROUND: The depth of double-lumen endobronchial tube (DLT) is reportedly known tobe directly proportional to height and several height-based recommendations have beensuggested. This retrospective study was designed to find out the difference between calculated depths using height-based formulae and realistic depths in clinical practice of DLTplacement by analyzing pooled data from patients intubated with left-sided DLT. METHODS: The electronic medical records of adults, intubated with DLT from February 2018to December 2020, were reviewed. Data retrieved included age, sex, height, weight, andsize and depth of DLT. The finally documented DLT depth (depth final, DF) was comparedwith the calculated depths, and the relationship between height and DF was also evaluated.A questionnaire on endobronchial intubation method was sent to anesthesiologists. RESULTS: A total of 503 out of 575 electronic records of consecutive patients were analyzed.Although the relationship between height and DF was shown to have significant correlation(Spearman's rho = 0.63, P < 0.001), DF was shown to be significantly greater than calculated depths (P < 0.001). Despite 57.1% of anesthesiologists have knowledge of clinical recommendations to anticipate size and depth of DLT, no one routinely utilizes those recommendations. CONCLUSIONS: Anesthesiologists tend to place DLTs in a deeper position than expected whendepths are calculated using height-based recommendations. Although such discrepanciesmay not be clinically meaningful, efforts are needed to standardize the methods of endobronchial intubation to prevent potential complications associated with malposition.

Predictability of Radiologically Measured Psoas Muscle Area for Intraoperative Hypotension in Older Adult Patients Undergoing Femur Fracture Surgery.

This retrospective study aimed to determine the predictive value of radiologically measured psoas muscle area (PMA) for intraoperative hypotension (IOH) using receiver operating characteristic (ROC) curves in older adult patients with hip fractures. The cross-sectional axial area of the psoas muscle was measured by CT at the level of the 4th lumbar vertebrae and normalized by body surface area (BSA). The modified frailty index (mFI) was used to assess frailty. IOH was defined as an absolute threshold of mean arterial blood pressure (MAP) < 65 mmHg or a relative decrease in MAP > 30% from baseline MAP. Among the 403 patients, 286 (71.7%) had developed IOH. PMA normalized by BSA in male patients was 6.90 ± 0.73 in the no-IOH group and 4.95 ± 1.20 in the IOH group (p < 0.001). PMA normalized by BSA in female patients was 5.18 ± 0.81 in the no-IOH group and 3.78 ± 0.75 in the IOH group (p < 0.001). The ROC curves showed that the area under the curve for PMA normalized by BSA and modified frailty index (mFI) were 0.94 for male patients, 0.91 for female patients, and 0.81 for mFI (p < 0.001). In multivariate logistic regression, low PMA normalized by BSA, high baseline systolic blood pressure, and old age were significant independent predictors of IOH (adjusted odds ratio: 3.86, 1.03, and 1.06, respectively). PMA measured by computed tomography showed an excellent predictive value for IOH. Low PMA was associated with developing IOH in older adult patients with hip fractures.

Association between anesthetic method and postpartum hemorrhage in Korea based on National Health Insurance Service data.

BACKGROUND: Postpartum hemorrhage (PPH) is a major cause of maternal mortality and the risk factors for PPH differ among studies. In this large-scale study, we investigated whether the anesthetic method used was associated with PPH after cesarean section. METHODS: We extracted data on cesarean sections performed between January 2008 and June 2013 from the National Health Insurance Service database. The anesthetic methods were categorized into general, spinal and epidural anesthesia. To compare the likelihood of PPH among deliveries using different anesthetic methods, crude and adjusted odds ratios (ORs) and 95% confidence intervals were calculated using logistic regression analysis. RESULTS: Data from 330,324 cesarean sections were analyzed, and 21,636 cases of PPH were identified. Univariate analysis showed that general and epidural anesthesia increased the risk of PPH compared to spinal anesthesia. The OR for PPH was highest for morbidly adherent placenta, followed by placenta previa, placental abruption, and hypertension. When other clinical covariates were controlled for, general and epidural anesthesia still remained significant risk factors for PPH compared to spinal anesthesia. CONCLUSIONS: This study showed that general and epidural anesthesia elevated the risk of PPH compared to spinal anesthesia during cesarean section. Since we could not consider the potential bias of group differences in indications, more in-depth clinical trials are needed to validate our findings. Obstetric factors such as placental abnormalities had high odds ratios and thus are more important than the choice of anesthetic method, which should be based on the patient's clinical condition and institutional resources.

Strategy to Reduce Hypercapnia in Robot-Assisted Radical Prostatectomy Using Transcutaneous Carbon Dioxide Monitoring: A Prospective Observational Study.

Purpose: Monitoring end-tidal carbon dioxide partial pressure (PETCO2) is a noninvasive, continuous method, but its accuracy is reduced by prolonged capnoperitoneum and the steep Trendelenburg position in robot-assisted radical prostatectomy (RARP). Transcutaneous carbon dioxide partial pressure (PTCCO2) monitoring, which is not affected by ventilator-perfusion mismatch, has been suggested as a suitable alternative. We compared the agreement of noninvasive measurements with the arterial carbon dioxide partial pressure (PaCO2) over a long period of capnoperitoneum, and investigated its sensitivity and predictive power for detecting hypercapnia. Patients and Methods: The patients who underwent RARP were enrolled in this study prospectively. Intraoperative measurements of PETCO2, PTCCO2, and PaCO2 were analyzed. The primary outcome was the agreement of noninvasive monitoring with PaCO2 during prolonged capnoperitoneum. Bias and precision between noninvasive measurements and PaCO2 were assessed using Bland-Altman analysis. The bias and mean absolute difference were compared using a two-tailed Wilcoxon signed-rank test for pairs. The secondary outcome was the sensitivity and predictive power for detecting hypercapnia. To assess this, the Yates corrected chi-square test and the area under the receiver operating characteristic curve were used. Results: The study analyzed 219 datasets from 46 patients. Compared with PETCO2, PTCCO2 had lower bias, greater precision, and better agreement with PaCO2 throughout the RARP. The mean absolute difference in PETCO2 and PaCO2 was larger than that of PTCCO2 and PaCO2, and continued to exceed the clinically acceptable range of 5 mmHg after 1 hour of capnoperitoneum. The sensitivity during capnoperitoneum and overall predictive power of PTCCO2 for detecting hypercapnia were significantly higher than those of PETCO2, suggesting a greater contribution to ventilator adjustment, to treat hypercapnia. Conclusion: PTCCO2 monitoring measured PaCO2 more accurately than PETCO2 monitoring during RARP requiring prolonged capnoperitoneum and a steep Trendelenburg position. PTCCO2 monitoring also provides more sensitive measurements for ventilator adjustment and detects hypercapnia more effectively than PETCO2 monitoring.