Use of intraoperative transesophageal echocardiography and epiaortic ultrasound to diagnose false lumen enlargement of chronic aortic dissection.

In communicating aortic dissection, if only the entry or reentry is closed, residual blood flow may cause enlargement of the false lumen. In this case, surgeons were unable to occlude the entry with a stent graft due to the strong flexion of the bilateral common iliac arteries, so they closed only the reentry in the hope that blood flow from the reentry would be high. Unfortunately, due to the high blood flow from the entry, the false lumen was enlarged. But the use of transesophageal echocardiography and epiaortic ultrasound contributed to its diagnosis.

Integrated Assessment of Discrepancy Between Tracheal Tube and Tube Exchanger as Advancement: A Manikin Simulation Study.

BACKGROUND: Advancing a tracheal tube over a tracheal tube exchanger into the trachea frequently causes difficulties because of the tube impingement on laryngeal structures. In the present study, we measured the resistance of tube advancement both objectively and subjectively with a variety of combinations of tube exchanger sizes and tracheal tubes using a manikin simulator. METHODS: Lubricated 7.5 mm ID standard and Parker Flex-Tip (PFT) tracheal tubes were railroaded over the tube exchangers (OD 1-6 mm) into the trachea through the oral route in a manikin. Consequently, 12 combinations of tracheal tube-exchanger tube assemblies were evaluated. Tube advancing resistance at the laryngeal inlet was subjectively evaluated. The objective tube advancing resistance (force) at the laryngeal inlet was evaluated using a digital force gauge. The execution of each tracheal tube-exchanger trial was conducted 10 times. RESULTS: With a 1-mm tube exchanger, all intubation attempts with both standard and PFT tubes failed. Esophageal intubation or severe impingement at the right arytenoid accompanied with a bent tracheal tube was observed. With a 2-mm tube exchanger, during intubation with a standard tracheal tube, rotation of the tube was sometimes required; however, all other intubations were done without problems. When PFT tubes were used, all intubation attempts were performed without problems. The rest of the trials were successfully performed regardless of the combinations of tube exchangers and tracheal tubes; however, one attempt of intubation with a combination of a 5 mm tube exchanger and a standard tracheal tube required withdrawal and rotation of the tube because of impingement at the epiglottis. In cases where there was no gap resistance, which means tube advancing resistance generated by a gap between an introducer and a tracheal tube, the pressing force was approximately less than 10 N. However, in the cases requiring some interventions to overcome the gap, the pressing force reached around 15 N. When intubation failed, for example when the tube bent, or esophageal intubation, the pressing force reached around 30 N. CONCLUSIONS: Impingement due to the gap between the tube exchanger and the tracheal tube is thought to occur in the PFT tube less frequently. Once an impingement occurs, we can feel approximately twice the amount of resistance as usual, which may be a chance to consider taking some interventions. When the impingement is not released, regardless of interventions, excessive force may result in esophageal intubation or tracheal injury.

Prevalence and Risk Factor Analysis of Post-Intensive Care Syndrome in Patients with COVID-19 Requiring Mechanical Ventilation: A Multicenter Prospective Observational Study.

INTRODUCTION: Post-intensive care syndrome (PICS) is an emerging problem in critically ill patients and the prevalence and risk factors are unclear in patients with severe coronavirus disease 2019 (COVID-19). This multicenter prospective observational study aimed to investigate the prevalence and risk factors of PICS in ventilated patients with COVID-19 after ICU discharge. METHODS: Questionnaires were administered twice in surviving patients with COVID-19 who had required mechanical ventilation, concerning Barthel Index, Short-Memory Questionnaire, and Hospital Anxiety and Depression Scale scores. The risk factors for PICS were examined using a multivariate logistic regression analysis. RESULTS: The first and second PICS surveys were obtained at 5.5 and 13.5 months (mean) after ICU discharge, with 251 and 209 patients completing the questionnaires and with a prevalence of PICS of 58.6% and 60.8%, respectively, along with the highest percentages of cognitive impairment. Delirium (with an odds ratio of (OR) 2.34, 95% CI 1.1-4.9, and p = 0.03) and the duration of mechanical ventilation (with an OR of 1.29, 95% CI 1.05-1.58, and p = 0.02) were independently identified as the risk factors for PICS in the first PICS survey. CONCLUSION: Approximately 60% of the ventilated patients with COVID-19 experienced persistent PICS, especially delirium, and required longer mechanical ventilation.

The effects of chest drainage on pressure-controlled ventilation.

BACKGROUND: The use of pressure-controlled ventilation (PCV) for anesthesia management is becoming more commonly used. Chest drainage is commonly performed after thoracic surgery, and the negative pressure it generates might affect the transpulmonary pressure (TPP). In the present study, we investigated how chest drainage could affect ventilating conditions during PCV. METHODS: We created a hand-made simple thoracic and lung model, which was connected to an anesthesia machine. The tidal volume (TV) was measured with positive end-expiratory pressure (PEEP) 0 and no chest drainage (baseline), followed by 10 cmH2O PEEP/no drainage, 10 cmH2O PEEP/drainage with - 10 cmH2O and 10 cmH2O PEEP/drainage with - 20 cmH2O. Finally, TV with 20 cmH2O and 30 cmH2O PEEP/no drainage was measured. Driving (inspiratory) pressure was maintained at 20 cmH2O during the whole experiment. RESULTS: TV was significantly increased by applying 10 cmH2O PEEP compared with baseline, further increased by applying - 10 cmH2O by drainage, similar to the value with PEEP 20 cmH2O with no drainage (end-tidal TPP of 20 cmH2O for both). TV decreased to < 50% of the baseline by applying 10 cmH2O PEEP with - 20 cmH2O by drainage, which was similar to that with 30 cmH2O PEEP with no drainage (end-tidal TPP of 30 cmH2O for both). CONCLUSIONS: TV was maintained at similar levels with the same TPP, regardless of PEEP or negative pressure by chest drainage change, suggesting that negative intrapleural pressure by the chest tube drainage system might mimic PEEP from the point of TV.

A case requiring re-thoracotomy due to a significant reduction of tidal volume after commencement of chest tube drainage under pressure control ventilation following lower lobectomy.

BACKGROUND: The use of pressure-controlled ventilation (PCV) during one lung ventilation (OLV) has been popular to avoid high airway pressure. We experienced a case of a significant reduction of tidal volume (TV) after commencement of chest tube drainage under PCV following lower lobectomy, which required re-thoracotomy to evaluate the degree of air leak. CASE PRESENTATION: A 70-year-old man was scheduled for a lower lobectomy. OLV was managed by PCV. The driving pressure was set at 15-20 cmH2O with 4 cmH2O of positive end-expiratory pressure (PEEP). A chest drainage tube was placed after completion of lobectomy. To switch OLV to two lung ventilation (TLV), PCV settings were changed to the driving pressure at 10 cmH2O with 4 cmH2O of PEEP, which generated 450 ml of TV. Immediately after applying drainage (-10 cmH2O), TV decreased down to 250 ml. To maintain 450 ml of TV, PCV was switched to volume-controlled ventilation with 450 ml of TV, which raised the plateau pressure close to 24 cmH2O. Re-thoracotomy was done; however, significant findings were not detected. CONCLUSIONS: We experienced a case of a significant reduction of TV immediately after chest tube drainage following lower lobectomy. Probably, negative intrapleural pressure increased the residual volume, which might have significantly affected the limited lung volume after lobectomy, resulting in decreasing TV during PCV.

The use of the Sanuki airway™ in three patients with suspected difficult airway.

The Sanuki airway is a single-use intubation oral airway designed for fiberoptic bronchoscope intubation. Sanuki airway has a bite block function and a wide lumen for the tracheal tube to pass through. Here, three cases are reported in which Sanuki airway was used for oral fiberoptic bronchoscope intubation. Case 1 is a patient who presented with reduced mouth opening and intraoral edema due to facial bone fracture. Case 2 is a patient who suffered from severe neck stiffness and had reduced mouth opening due to systemic psoriatic arthritis. Case 3 is a patient who suffered from multiple facial traumas and was in a full-stomach state. In all patients, advancing the tip of the bronchofiber into the larynx using Sanuki airway was possible under dexmedetomidine sedation, which contributed to the successful tracheal intubation. Using Sanuki airway may be considered an option for oral fiberoptic bronchoscope intubation in patients anticipated with difficult airways.

Correction to: Evaluation of pharmacokinetic models of intravenous dexmedetomidine in sedated patients under spinal anesthesia.

Inadvertently, the reference [8] was published incorrectly in the original publication of the article. The correct reference [8] is provided below.

Evaluation of pharmacokinetic models of intravenous dexmedetomidine in sedated patients under spinal anesthesia.

PURPOSE: Little information is available on the predictive ability of previously published pharmacokinetic models of dexmedetomidine in patients under spinal anesthesia. We evaluated nine published pharmacokinetic models that were constructed in different study settings. METHODS: Sixteen patients received dexmedetomidine infusions after spinal anesthesia according to the manufacturer's recommended regimen (6 µg/kg/h over 10 min followed by 0.2-0.7 µg/kg/h) or target-controlled infusion (initial target of 1.5 ng/ml using the Dyck model). Dexmedetomidine concentrations were measured and median performance error (MDPE), median absolute performance error (MDAPE), and wobble were calculated. RESULTS: A total of 84 blood samples were analyzed. The pharmacokinetic model reported by Hannivoort et al. had the greatest ability to predict dexmedetomidine concentrations (MDPE 5.6%, MDAPE 18.1%, and wobble 6.2%). CONCLUSIONS: Hannivoort et al.'s pharmacokinetic model, constructed with a dataset obtained from healthy volunteers, can predict dexmedetomidine concentrations best during continuous infusion under spinal anesthesia.

Effects of indigo carmine intravenous injection on noninvasive and continuous total hemoglobin measurement with using the Revision L sensor.

The effects of intravenous injection of indigo carmine on noninvasive and continuous total hemoglobin (SpHb) measurement were retrospectively evaluated with the Revision L sensor. The subjects were 18 patients who underwent elective gynecologic surgery under general anesthesia. During surgery, 5 mL of 0.4 % indigo carmine was injected intravenously, and changes in SpHb concentrations between before and after the injection were evaluated. The mean age was 52.4 ± 12.8 years. Before injection, the median SpHb level was 10.1 (range, 6.8-13.4) g/dL. The results demonstrated no change in SpHb concentration between before and after indigo carmine injection as detected by the Revision L sensor. SpHb measurements as determined with the Revision L sensor were not affected, even after the intravenous injection of indigo carmine.

Effects of indigo carmine intravenous injection on noninvasive and continuous total hemoglobin measurement.

The effects of an intravenous injection of indigo carmine on noninvasive and continuous total hemoglobin (SpHb) measurement were retrospectively evaluated. The subjects were 21 patients who underwent elective gynecologic surgery under general anesthesia. During surgery, 5 mL of 0.4 % indigo carmine was intravenously injected, and subsequent changes in SpHb concentrations were evaluated. The results demonstrate that the pre-injection SpHb level was 10 g/dL, and the minimum post-injection SpHb level was 8.3 g/dL. The amount of decrease was 1.8 g/dL. The time to reach the minimum value was 4 min, and the time to return to the pre-injection value was 15 min. The decrease in SpHb was greater in the group with a perfusion index (PI) < 1.4 than in the group with a PI > 1.4. The assessment of SpHb after an intravenous injection of indigo carmine necessitates caution.

THE EFFECT OF OBESITY ON DOSE OF DEXMEDETOMIDINE WHEN ADMINISTERED WITH FENTANYL DURING POSTOPERATIVE MECHANICAL VENTILATION--RETROSPECTIVE.

We carried out a retrospective investigation on the effect of obesity on dexmedetomidine (DEX) requirements when administered with fentanyl (FEN) during mechanical ventilation after major surgeries. After Institutional Review Board approval, 14 obese patients with a body mass index (BMI) ≥ 30 kg/m(2) and the same number of non-obese patients with similar backgrounds to the obese patients were selected from medical records. Doses of DEX in the first 48 h or until the end of sedation or extubation were calculated for comparison. In addition to comparison of dosing between the groups, associations between total body weight (TBW), BMI, and lean body mass (LBM) values and doses of DEX (mcg/h), between BMI and various indices (i.e., amount per TBW per hour and amount per LBM per hour) of DEX doses, and between above indices of DEX and FEN doses were also examined. There were no significant differences in DEX dose indices between the groups. However, DEX requirements (mcg/h) were significantly increased with TBW (kg) (r = 0.51, P = 0.003), BMI (r = 0.49, P = 0.006) and LBM (kg) (r = 0.42, P = 0.02), which might have enhanced the DEX metabolism with physiological changes with obesity. These findings will be beneficial for future clinical pharmacological analysis of DEX.

Plasma ropivacaine concentration following ultrasound-guided subcostal transversus abdominis plane block in adults.

Ultrasound-guided subcostal transversus abdominis plane block (TAPB) is widely used for abdominal surgery; however, arterial plasma concentration of the anesthetic ropivacaine after the blockade is still unclear. We evaluated ropivacaine concentration after subcostal TAPB in adult patients undergoing upper abdominal surgery. Twelve patients with American Society of Anesthesiologists physical status 1-2 were enrolled. They received ultrasound-guided subcostal TAPB with 0.45 % ropivacaine at 3 mg/kg. Arterial plasma samples were collected at 15, 30, 45, 60, 90, and 120 min after the blockade and analyzed for total ropivacaine concentration using liquid chromatography and mass spectrometry. At every time point, the maximum concentrations (C(max)), and time to the C max (T(max)) were recorded. The mean C(max) and T(max) were 1.87 (0.78) µg/ml and 31.3 (16.7) min, respectively. No adverse events or clinical symptoms indicating systemic toxicity were observed during this study. The study demonstrated that administration of ropivacaine at 3 mg/kg during subcostal TAPB led to rapid increases in plasma concentration of the anesthetic during the first 2 h after the blockade. C(max) nearly reached the threshold for systemic toxicity.

Effects of dexmedetomidine, midazolam, and propofol on acetylcholine release in the rat cerebral cortex in vivo.

Acetylcholine plays an important role as a neurotransmitter in the central nervous system with involvement in both sleep and arousal. Dexmedetomidine, midazolam, and propofol are widely used for sedation of patients in intensive care medicine. In this study, we have examined the effect of continuous administration of dexmedetomidine, midazolam, and propofol on acetylcholine release in the rat cerebral cortex, using an in vivo microdialysis technique. Following infusion of a control solution, male Wistar rats (n = 6/group) were administered dexmedetomidine at 0.3 µg/kg/min, midazolam at 20 mg/kg/h, or propofol at 50 mg/kg/h over a 2-h period. Using a brain microdialysis method, extracellular acetylcholine concentrations were measured up to 2 h after administration of each agent at 15-min intervals. In the midazolam group, acetylcholine levels were significantly reduced with midazolam infusion, remaining low even after the drug was stopped. In the propofol group, acetylcholine levels were significantly decreased during propofol infusion, but returned to control levels once the infusion was stopped. Dexmedetomidine administration decreased acetylcholine release, but this finding was not statistically significant. From this study, midazolam and propofol but not dexmedetomidine significantly suppressed acetylcholine release in the cerebral cortex at sedative doses. Even though the righting reflex recovered almost the same after the cessation of drug administration, midazolam suppressed acetylcholine release longer than propofol.