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.

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.

The influence of neuromuscular blockade on phase lag entropy and bispectral index: A randomized, controlled trial.

The aim of this study is to compare the effects of neuromuscular blockade (NMB) on phase lag entropy (PLE) and the bispectral index (BIS). We recorded the BIS, electromyograph (EMG) activity on a BIS monitor (EMG_BIS), PLE, and EMG activity on a PLE monitor (EMG_PLE) in 40 patients receiving general anesthesia. During the awake state, we analyzed the changes in parameters before and 2 min after the eyes were closed. During sedation, we compared the changes in the parameters before and at 4 min after injecting rocuronium (group R) or normal saline (group C) between the two groups. During anesthesia, we compared the changes in parameters before and at 4 min after injecting sugammadex (group B) or normal saline (group D) between the two groups. During the awake state, the BIS, EMG_BIS, and EMG_PLE, but not PLE, decreased significantly with closed eyes. An effect of EMG on the BIS was evident, but not on PLE. During sedation, the BIS decreased with the decrease in EMG_BIS regardless of NMB caused by rocuronium, but NMB decreased PLE, although the degree of the decrease in EMG_PLE after NMB was similar to that after placebo. To determine the effect of NMB on electroencephalograms (EEGs) in groups R and C, we plotted the power spectra before and at 4 min after injecting rocuronium or normal saline. Changes in slow and delta frequency bands were observed at 4 min after injecting rocuronium relative to before injecting rocuronium. There was no effect of EMG on either the BIS or PLE during anesthesia. In conclusion, the effect of electromyograph activity and/or neuromuscular blockade on BIS or PLE depends on the level of consciousness.

Perineural dexamethasone reduces rebound pain after ropivacaine single injection interscalene block for arthroscopic shoulder surgery: a randomized controlled trial.

BACKGROUND AND OBJECTIVES: A single injection interscalene block (ISB) is a common regional analgesic technique in patients undergoing arthroscopic shoulder surgery. However, rebound pain after ISB resolution may reduce its overall benefit. Our primary aim was to assess whether perineural dexamethasone reduces the intensity and incidence of rebound pain in patients undergoing arthroscopic shoulder surgery under general anesthesia combined with a preoperative single injection ISB. METHODS: The patients were randomly assigned to receive single injection ISB using either 0.5% ropivacaine (control) or 0.5% ropivacaine containing 5 mg of dexamethasone. The primary outcomes were the pain score difference before and after ISB resolution, and the incidence of rebound pain. The secondary outcomes were the onset and duration of rebound pain, the presence of sleep disturbances due to postoperative pain, the first time when an analgesic was requested, and pain scores at various predefined time points. RESULTS: Pain increase following ISB resolution was lower in the dexamethasone group compared with the control group (4.5±2.4 and 6.9±2.2, respectively, p<0.001). The incidence of rebound pain was significantly lower in the dexamethasone group compared with the control group (37.1% and 82.9%, respectively, p<0.001). The controls experienced greater sleep disturbance during the postoperative period compared with those who received ISB with perineural dexamethasone. CONCLUSIONS: Perineural dexamethasone added to ISB using ropivacaine led to a much smoother resolution of ISB, reflected in a significantly smaller increase in pain after block resolution, a lower incidence of rebound pain and a lower sleep disturbance during the first postoperative week. TRIAL REGISTRATION NUMBER: Clinical Trial Registry of Korea (KCT0004418).

Risk Factors for Perioperative Respiratory Adverse Events in Children with Recent Upper Respiratory Tract Infection: A Single-Center-Based Retrospective Study.

PURPOSE: In pediatric patients, the most common reason for delaying surgical intervention is an upper respiratory tract infection (URI). To date, there has been no consensus regarding the optimal timeframe for deferring surgery in children with URI. We conducted this study to evaluate whether a URI symptom-free period and other risk factors affect the incidence of perioperative respiratory adverse events (RAEs). PATIENTS AND METHODS: The study population included 267 pediatric patients (aged 0 to 13 years) with a recent URI episode who underwent surgery under general anesthesia. Following a retrospective review of medical records, several risk factors including a URI symptom-free period for intra- and postoperative RAEs were analyzed using univariate and multivariate logistic regression analyses. RESULTS: RAEs occurred in 23 of 267 patients (8.6%). Univariate analysis revealed that abnormal preoperative chest images (odds ratio [OR], 7.48; 95% confidence interval [CI], 2.46-22.68, p < 0.001) and emergency operations (OR, 2.84; 95% CI, 1.03-7.81, p = 0.04) were associated with RAEs. Four variables (abnormal preoperative chest images, emergency operations, age under 1 year and symptom-free period of 7-13 days) with a significance of <0.20 in the univariate logistic regression analysis were selected as candidate risk factors for the multivariate model. Among the four variables, abnormalities in preoperative chest images (OR, 7.60; 95% CI, 2.28-25.3, p = 0.001) and a symptom-free period of 7-13 days (OR, 0.13; 95% CI, 0.02-0.88, p = 0.04) were independently associated with RAEs in multivariate logistic regression analysis. CONCLUSION: For pediatric patients who require surgery and have a recent history of URI, procedures should be performed after a URI symptom-free period of at least 1-2 weeks. Confirming the absence of abnormalities in preoperative chest images can reduce the incidence of perioperative RAEs.

Heparin-free veno-venous extracorporeal membrane oxygenation in a multiple trauma patient: A case report.

RATIONALE: Extracorporeal membrane oxygenation (ECMO) in multiple trauma patients with post-traumatic respiratory failure can be quite challenging because of the need for systemic anticoagulation, which may lead to excessive bleeding. In the last decade, there is a growing body of evidence that veno-venous ECMO (VV-ECMO) is lifesaving in multiple trauma patients with acute respiratory distress syndrome, thanks to technical improvements in ECMO devices. PATIENT CONCERNS: We report a case of a 17-year-old multiple trauma patient who was drunken and had confused mentality. DIAGNOSES: She was suffered from critical respiratory failure (life-threatening hypoxemia and severe hypercapnia/acidosis lasting for 70 minutes) accompanied by cardiac arrest and trauma-induced coagulopathy during general anesthesia. INTERVENTIONS: We decided to start heparin-free VV-ECMO after cardiac arrest considering risk of hemorrhage. OUTCOMES: She survived with no neurologic sequelae after immediate treatment with heparin-free VV-ECMO. LESSONS: Heparin-free VV-ECMO can be used as a resuscitative therapy in multiple trauma patients with critical respiratory failure accompanied by coagulopathy. Even in cases in which life-threatening hypoxemia and severe hypercapnia/acidosis last for >1 hours during CPR for cardiac arrest, VV-ECMO could be considered a potential lifesaving treatment.

The tidal volume challenge improves the reliability of dynamic preload indices during robot-assisted laparoscopic surgery in the Trendelenburg position with lung-protective ventilation.

BACKGROUND: The reliability of pulse pressure variation (PPV) and stroke volume variation (SVV) is controversial under pneumoperitoneum. In addition, the usefulness of these indices is being called into question with the increasing adoption of lung-protective ventilation using low tidal volume (VT) in surgical patients. A recent study indicated that changes in PPV or SVV obtained by transiently increasing VT (VT challenge) accurately predicted fluid responsiveness even in critically ill patients receiving low VT. We evaluated whether the changes in PPV and SVV induced by a VT challenge predicted fluid responsiveness during pneumoperitoneum. METHODS: We performed an interventional prospective study in patients undergoing robot-assisted laparoscopic surgery in the Trendelenburg position under lung-protective ventilation. PPV, SVV, and the stroke volume index (SVI) were measured at a VT of 6 mL/kg and 3 min after increasing the VT to 8 mL/kg. The VT was reduced to 6 mL/kg, and measurements were performed before and 5 min after volume expansion (infusing 6% hydroxyethyl starch 6 ml/kg over 10 min). Fluid responsiveness was defined as ≥15% increase in the SVI. RESULTS: Twenty-four of the 38 patients enrolled in the study were responders. In the receiver operating characteristic curve analysis, an increase in PPV > 1% after the VT challenge showed excellent predictive capability for fluid responsiveness, with an area under the curve (AUC) of 0.95 [95% confidence interval (CI), 0.83-0.99, P < 0.0001; sensitivity 92%, specificity 86%]. An increase in SVV > 2% after the VT challenge predicted fluid responsiveness, but showed only fair predictive capability, with an AUC of 0.76 (95% CI, 0.60-0.89, P < 0.0006; sensitivity 46%, specificity 100%). The augmented values of PPV and SVV following VT challenge also showed the improved predictability of fluid responsiveness compared to PPV and SVV values (as measured by VT) of 6 ml/kg. CONCLUSIONS: The change in PPV following the VT challenge has excellent reliability in predicting fluid responsiveness in our surgical population. The change in SVV and augmented values of PPV and SVV following this test are also reliable. TRIAL REGISTRATION: This trial was registered with Clinicaltrials.gov, NCT03467711 , 10th March 2018.

Comparison of low and high positive end-expiratory pressure during low tidal volume ventilation in robotic gynaecological surgical patients using electrical impedance tomography: A randomised controlled trial.

BACKGROUND: The appropriate level of positive end-expiratory pressure (PEEP) during intra-operative mechanical ventilation remains unclear. OBJECTIVE: The aim of this study was to investigate the effects of different levels of PEEP with low tidal volume (low-VT) ventilation in a steep Trendelenburg position (30°) and pneumoperitoneum on oxygenation, respiratory mechanics and ventilation distribution using electrical impedance tomography. DESIGN: A randomised controlled trial. SETTING: Single university secondary care centre, conducted from January 2017 to December 2017. PATIENTS: Forty female patients, aged 20 to 60 years, and of American Society of Anesthesiologists' (ASA) physical status 1 or 2, undergoing elective robotic gynaecological surgery were included. INTERVENTION: Forty patients were allocated randomly to a PEEP4 (PEEP 4 cmH2O) group or a PEEP8 (PEEP 8 cmH2O) group. MAIN OUTCOME MEASURES: The primary outcomes were respiratory mechanics. The secondary outcomes included changes in ventilation distribution across the ventral and dorsal regions of interest and postoperative pulmonary complications (PPCs) using a modified clinical pulmonary infection score. RESULTS: There was no difference in PaO2 at any time point. The peak inspiratory pressure (PIP) and mean airway pressure (MPAW) of the PEEP4 group were lower than those of the PEEP8 group (P < 0.001). The oxygenation factor in the PEEP4 group was higher than that in the PEEP8 group during mechanical ventilation at all times. There was no difference in the fractional distribution of end-expiratory ventilation according to region of interest between the two groups. CONCLUSION: Both 4 and 8 cmH2O of PEEP with low-VT ventilation can be used for robotic gynaecological surgery that requires a steep Trendelenburg position and pneumoperitoneum. However, 8 cmH2O of PEEP had no benefit over 4 cmH2O of PEEP with respect to oxygenation and improvement of dorsal regional ventilation. TRIAL REGISTRATION: The trial was registered at the Clinical Trial Registry of Korea (KCT0002255). https://cris.nih.go.kr.

Optic nerve sheath diameter changes during gynecologic surgery in the Trendelenburg position: comparison of propofol-based total intravenous anesthesia and sevoflurane anesthesia.

BACKGROUND: Elevated intracranial pressure (ICP), a disadvantage of laparoscopic or robotic surgery, is caused by the steep angle of the Trendelenburg position and the CO2 pneumoperitoneum. Recently, sonographically measured optic nerve sheath diameter (ONSD) was suggested as a simple and non-invasive method for detecting increased ICP. This study aimed to explore the changes in ONSD in relation to different anesthetic agents used in gynecologic surgery. METHODS: Fifty patients were randomly allocated to two groups, sevoflurane (group SEV, n = 25) and propofol-based total intravenous anesthesia (TIVA) group (group TIVA, n = 25). The ONSD was measured at five time points (T0-T4): T0 was measured 5 min after induction of anesthesia in the supine position; T1, T2, and T3 were measured at 5, 15, and 30 min after CO2 pneumoperitoneum induction in the Trendelenburg position; and T4 was measured at 5 min after discontinuation of CO2 pneumoperitoneum in the supine position. Respiratory and hemodynamic variables were also recorded. RESULTS: The intra-group changes in mean ONSD in the Trendelenburg position were significantly increased in both groups. However, inter-group changes in mean ONSD were not significantly different at T0, T1, T2, T3, and T4. Heart rates in group TIVA were significantly lower than those in group SEV at points T1-T4. CONCLUSIONS: There was no significant difference in the ONSD between the two groups until 30 min into the gynecologic surgery with CO2 pneumoperitoneum in the Trendelenburg position. This study suggests that there is no difference in the ONSD between the two anesthetic methods.

The effect of anesthetic agents on cerebral vasospasms after subarachnoid hemorrhage: A retrospective study.

Cerebral vasospasm is the most important cause of morbidity after an aneurysm clipping in the early postoperative period. The aim of this retrospective study was to evaluate whether the incidence of vasospasms differs when using propofol or desflurane for an emergent aneurysm clipping.The data from 102 patients (50 in the propofol group, 52 in the desflurane group) were analyzed. The occurrence of vasospasm based on daily transcranial Doppler, angiography, and cerebral infarction during 14 days after surgery were compared by anesthetic agents. Postoperative data including Glasgow Coma Scale (GCS) score on day 14 after surgery, and the Glasgow Outcome Scale (GOS) score at 3 months were documented.Patients that intraoperatively received propofol for anesthesia maintenance, had higher incidence of transcranial Doppler (TCD)-evident vasospasm than those that received desflurane (54% vs 30.8%, P = .027). The occurrence of TCD-evident vasospasm was still higher (odds ratio: 2.84; 95% confidence interval: 1.12-7.20) in the propofol group than in the desflurane group after adjusting for confounding factors. However, the incidence of angiographic vasospasm, cerebral infarction, and interventions to treat cerebral vasospasms were similar between both groups. GCS score on day 14 after surgery and the GOS score at 3 months were similar between groups.No effect of anesthetic agents on angiographic vasospasm, cerebral infarction, or clinical outcome was observed, whereas desflurane anesthesia was associated with a lower incidence of TCD-evident vasospasms compared to propofol anesthesia. Our study provides a basis for further randomized controlled studies in a larger patient population to clarify the effects of anesthetic agents on the occurrence of cerebral vasospasms.

The recovery from transient cognitive dysfunction induced by propofol was associated with enhanced autophagic flux in normal healthy adult mice.

Propofol is the most widely accepted intravenous anesthetic available for clinical use. However, neurotoxicity of propofol in the developing brain has been reported. This study investigated the effects of propofol on cognitive function in normal healthy adult mice. Thirty-three GFP-LC3 adult mice were included. Propofol was injected for anesthesia (n = 22). The sham control (n = 11) received intralipid injections. The mice completed a Y-maze test on 3 and 7 days after being anesthetized. Western blotting, immunofluorescence staining, and transmission electron microscopic (TEM) analyses were performed with their hippocampi. In addition, we conducted a separate ex vivo experiment using organotypic hippocampal slice cultures (OHSCs) to investigate the effects of propofol on induced autophagy. There was a significantly lower percentage of alternation in the Y-maze test on day 3 after propofol anesthesia than the control, but no difference was observed on day 7. Western blot analyses and immunofluorescence assays showed that the levels of cognitive function-related proteins significantly decreased in the propofol group compared to the control on day 3 but had recovered by day 7. In terms of autophagy-related proteins, western blot analyses and immunofluorescence assays showed that propofol increased autophagic induction, flux, and degradation of autophagosomes. Ex vivo experiments showed that propofol enhanced autophagic flux of the induced autophagy. In conclusion, although transient cognitive dysfunction occurred, adult mice recovered their cognitive function after the administration of propofol anesthesia. And this finding may be associated with enhanced autophagic flux.

Aminophylline and Ephedrine, but Not Flumazenil, Inhibit the Activity of the Excitatory Amino Acid Transporter 3 Expressed in Xenopus Oocytes and Reverse the Increased Activity by Propofol.

We investigated the effects of flumazenil, aminophylline, and ephedrine on the excitatory amino acid transporter type 3 (EAAT3) activity and the interaction with propofol. EAAT3 was expressed in the Xenopus oocytes. L-Glutamate-induced membrane currents were measured using the two-electrode voltage clamp at various drug concentrations. Oocytes were preincubated with protein kinase C- (PKC-) activator, or inhibitor, and phosphatidylinositol 3-kinase (PI3K) inhibitor. To study the interaction with propofol, oocytes were exposed to propofol, propofol + aminophylline, or ephedrine. Aminophylline and ephedrine significantly decreased EAAT3 activity. Aminophylline (95 µM) and ephedrine (1.19 µM) significantly decreased Vmax, but not Km of EAAT3, for glutamate. The phorbol 12-myristate-13-acetate-induced increase in EAAT3 activity was abolished by aminophylline or ephedrine. The decreased EAAT3 activities by PKC inhibitors (staurosporine, chelerythrine) and PI3K inhibitor (wortmannin) were not significantly different from those by aminophylline or ephedrine, as well as those by PKC inhibitors or PI3K inhibitor + aminophylline or ephedrine. The enhanced EAAT3 activities induced by propofol were significantly abolished by aminophylline or ephedrine. Aminophylline and ephedrine inhibit EAAT3 activity via PKC and PI3K pathways and abolish the increased EAAT3 activity by propofol. Our results indicate a novel site of action for aminophylline and ephedrine.

Comparison of ramosetron and ondansetron for the treatment of established postoperative nausea and vomiting after laparoscopic surgery: a prospective, randomized, double-blinded multicenter trial.

BACKGROUND: Postoperative nausea and vomiting (PONV) is a common complication after surgery, which increases physical and psychological discomfort and delays recovery. The aim of this study was to test the hypothesis that ramosetron is comparable to ondansetron for the treatment of established PONV after laparoscopic surgery using a prospective, randomized, double-blinded, noninferiority study. METHODS: Patients who had at least two risk factors of PONV and underwent laparoscopic surgery under general anesthesia were assessed for eligibility. Patients who developed PONV within the first 2 h after anesthesia received ondansetron (4 mg) or ramosetron (0.3 mg) intravenously in a randomized double-blind manner. Patients were then observed for 24 h after drug administration. The incidence of nausea and vomiting, severity of nausea, rescue antiemetic necessity, and adverse effects at 0-2 or 2-24 h after drug administration was evaluated. The primary endpoint was the rate of patients exhibiting a complete response, defined as no emesis and no further rescue antiemetic medication for 24 h after drug administration. RESULTS: Among the 583 patients, 210 (36.0%) developed PONV and were randomized to either the ondansetron (n=105) or ramosetron (n=105) group. Patient's characteristics were similar between the groups. The complete response rate was 44.1% in the ondansetron group and 52.9% in the ramosetron group after 24 h of initial antiemetic administration. The incidence of adverse events was not different between the groups. CONCLUSION: We found evidence to support the noninferiority of ramosetron (0.3 mg) compared to ondansetron (4 mg) for the treatment of established PONV in moderate to high-risk patients undergoing laparoscopic surgery.

Dexmedetomidine-ketamine versus Dexmedetomidine-midazolam-fentanyl for monitored anesthesia care during chemoport insertion: a Prospective Randomized Study.

BACKGROUND: Dexmedetomidine as a sole agent showed limited use for painful procedures due to its insufficient sedative/analgesic effect, pronounced hemodynamic instability and prolonged recovery. The aim of this study was to compare the effects of dexmedetomidine-ketamine (DK) versus dexmedetomidine-midazolam-fentanyl (DMF) combination on the quality of sedation/analgesia and recovery profiles for monitored anesthesia care (MAC). METHODS: Fifty six patients undergoing chemoport insertion were randomly assigned to group DK or DMF. All patients received 1 µg.kg(-1) dexmedetomidine over 10 min followed by 0.2-1.0 µg.kg(-1)h(-1) in order to maintain 3 or 4 of modified Observer's Assessment of Analgesia and Sedation score checked every 3 min. At the start of dexmedetomidine infusion, patients in group DK or DMF received 0.5 mg.kg(-1) ketamine or 0.05 mg.kg(-1) midazolam + 0.5 µg.kg(-1) fentanyl intravenously, respectively. When required, rescue sedatives (0.5 mg.kg-1 of ketamine or 0.05 mg.kg-1 of midazolam) and analgesics (0.5 mg.kg-1 of ketamine or 0.5 µg.kg-1 of fentanyl) were given to the patients in DK or DMF group, respectively. The primary outcome of this study was the recovery parameters (time to spontaneous eye opening and the length of the recovery room stay). The secondary outcomes were parameters indicating quality of sedation/analgesia, cardiorespiratory variables, and satisfaction scores. RESULTS: There were no significant differences in the onset time, time to spontaneous eye opening, recovery room stay, the incidences of inadequate analgesia, hypotension and bradycardia between the two groups. Despite lower infusion rate of dexmedetomidine, more patients in the DMF group had bispectral index (BIS) < 60 than in the DK group and vice versa for need of rescue sedatives. The satisfaction scores of patients, surgeon, and anesthesiologist in the DMF group were significantly better than the DK group. CONCLUSIONS: The DK and DMF groups showed comparable recovery time, onset time, cardiorespiratory variables, and analgesia. However, the DMF group showed a better sedation quality and satisfaction scores despite the lower infusion rate of dexmedetomidine, and a higher incidence of BIS < 60 than the DK group. TRIAL REGISTRATION: Clinical Trial Registry of Korea KCT0000951 , registered 12/12/2013.

Airway management in patients with deep neck infections: A retrospective analysis.

Securing the airway in patients undergoing surgical intervention to control a deep neck infection (DNI) is challenging for anesthesiologists due to the distorted airway anatomy, limited mouth opening, tissue edema, and immobility. It is critical to assess the risk of a potential difficult airway and prepare the most appropriate airway management method.We reviewed our anesthetic experiences managing patients with DNIs, focusing on the need for video-laryngoscope or awake fiberoptic intubation beyond a standard intubation from the anesthesiologist's perspective.When patients had infections in the masticatory space, mouth of floor, oropharyngeal mucosal space, or laryngopharynx, their airways tended to be managed using methods requiring more effort by the anesthesiologists, and more extensive equipment preparation, compared with use of a standard laryngoscope. The degree to which the main lesion influenced the airway anatomy, especially at the level of epiglottis and aryepiglottic fold was related to the airway management method selected.When managing the airways of patients undergoing surgery for DNIs under general anesthesia, anesthesiologists should use imaging with computed tomography to evaluate the preoperative airway status and a comprehensive understanding of radiological findings, comorbidities, and patients' symptoms is needed.

Monitored anesthesia care for great saphenous vein stripping surgery with target controlled infusion of propofol and remifentanil: a prospective study.

BACKGROUND: The aim of this study was to determine the appropriate target concentrations at the effect site of propofol and remifentanil when deep sedation was achieved by monitored anesthesia care (MAC) anesthesia and related respiratory depression during vein stripping surgery for varicose veins. METHODS: In total, 51 adult patients who were scheduled for varicose vein stripping surgery were sedated with propofol and remifentanil during the surgery, after administration of midazolam. Target concentrations at the effect site of the two drugs were changed based on the patient's status. Respiratory support was applied in the order of oxygen supply, chin lift, and assisted mask ventilation. Target concentrations at the effect site of propofol and remifentanil, the need for respiratory support, and a six-point rating scale satisfaction score were the outcome measurements. RESULTS: Only one patient did not require oxygen, eight patients needed oxygen alone, 22 patients required use of the chin lift technique, and 20 patients were assisted with mask ventilation. There was no significant difference in the target concentration of propofol or remifentanil between the patients who required mask ventilation and those who did not. Fifty of the 51 patients reported a satisfaction score of 6. CONCLUSIONS: Although MAC using low target concentrations of propofol and remifentanil during vein stripping surgery was satisfactory to patients, close observation regarding the need for respiratory assistance was necessary.

Effect of intraoperative infusion of ketamine on remifentanil-induced hyperalgesia.

BACKGROUND: Opioid induced hyperalgesia (OIH) is related with high opioid dosage, a long duration of opioid administration, and abrupt discontinuation of infused opioids in anesthetic settings. Ketamine is known to attenuate OIH efficiently, but methods of administration and methods to quantify and assess a decrease in OIH vary. We demonstrated the existence of remifentanil-induced hyperalgesia and investigated the ability of ketamine to attenuate OIH. METHODS: Seventy-five patients undergoing laparoscopic gynecologic surgery under remifentanil-based anesthesia were assigned to one of the following groups: (1) group RL (remifentanil 0.05 µg/kg/min), (2) group RH (remifentanil 0.3 µg/kg/min), or (3) group KRH (remifentanil 0.3 µg/kg/min + ketamine 0.5 mg/kg bolus with 5 µg/kg/min infusion intraoperatively). Desflurane was administered for maintenance of anesthesia to target bispectral index scores (40-60) and hemodynamic parameters (heart rate and blood pressure < ± 20% of baseline values). All parameters related to OIH and its attenuation induced by ketamine were investigated. RESULTS: There was no significant difference among the three groups related to demographic and anesthetic parameters except the end-tidal concentration of desflurane. Additional analgesic consumption, numerical rating scale scores at 6 and 24 h, and cumulative fentanyl dose were significantly higher in group RH than in the other two groups. The value difference of the Touch-Test sensory evaluation was significantly higher negative in group RH than in the other two groups. CONCLUSIONS: Remifentanil-induced hyperalgesia is significantly attenuated by intraoperative bolus and infusion of ketamine. Ketamine also decreased tactile sensitization, as measured by Touch-Test sensory evaluation.

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).