Seokyung Shin

An evaluation of diaphragmatic movement by M-mode sonography as a predictor of pulmonary dysfunction after upper abdominal surgery.

BACKGROUND: Diaphragmatic dysfunction is a major factor in the etiology of postoperative pulmonary complications after upper abdominal surgery. M-mode ultrasonography is now an accepted qualitative method of assessing diaphragmatic motion in normal and pathological conditions. In this study, we evaluated whether diaphragmatic inspiratory amplitude (DIA) as measured by M-mode sonography can be a predictor of pulmonary dysfunction. METHODS: A prospective, single-center, single-unit, observational study was performed in 35 ASA physical status I and II nonsmoking patients undergoing open liver lobectomy. Diaphragmatic movements were assessed by M-mode sonography after a pulmonary function test preoperatively and on postoperative days (PODs) 1, 2, and 7. We measured the DIA (cm) during quiet, deep, and sniff breathing. RESULTS: After liver lobectomy, DIA during deep breathing and vital capacity (VC) showed significant reductions of 60% from their preoperative values on PODs 1 and 2 (P < 0.001). By POD 7, the variables recovered significantly, by 30% from the values on PODs 1 and 2 (P < 0.001). During deep breathing, DIA showed a significant correlation with VC (r = 0.839, P < 0.0001). The best cutoff values of DIA for detecting 30% and 50% decreases of VC from preoperative values, calculated by receiver operating characteristic analysis, were 3.61 and 2.41 cm, with sensitivity of 94% and 81% and specificity of 76% and 91%, respectively (P = 0.0001). Two patients showed postoperative diaphragmatic paralysis but did not complain of respiratory distress symptoms or need supplemental oxygen after being transferred to the general ward. CONCLUSIONS: DIA using M-mode sonography showed a linear correlation with VC measured by spirometry throughout the postoperative period. We conclude that using the M-mode sonographic technique at the bedside can be a practical way to investigate postoperative diaphragmatic dysfunction, and may also be an effective bedside screening method for diaphragmatic paralysis.

Total Intravenous Anesthesia with Propofol Reduces Postoperative Nausea and Vomiting in Patients Undergoing Robot-Assisted Laparoscopic Radical Prostatectomy: A Prospective Randomized Trial

Purpose We investigated the effect of total intravenous anesthesia (TIVA) with propofol on postoperative nausea and vomiting (PONV) after robot-assisted laparoscopic radical prostatectomy (RLRP) in patients at low risk of developing PONV, in comparison to balanced anesthesia with desflurane. Materials and Methods Sixty two patients were randomly assigned to the Des or TIVA group. Propofol and remifentanil were used for induction of anesthesia in both groups and for maintenance of the anesthesia in the TIVA group. In the Des group, anesthesia was maintained with desflurane and remifentanil. In both groups, postoperative pain was controlled using fentanyl-based intravenous patient controlled analgesia, and ramosetron 0.3 mg was administered at the end of surgery. The incidence of PONV, severity of nausea and pain, and requirements of rescue antiemetics and analgesics were recorded. Results The incidence of nausea in the post-anesthetic care unit was 22.6% in the Des group and 6.5% in the TIVA (p=0.001) group. The incidence of nausea at postoperative 1-6 hours was 54.8% in the Des group and 16.1% in the TIVA group (p=0.001). At postoperative 6-48 hours, there were no significant differences in the incidence of nausea between groups. Conclusion In order to prevent PONV after RLRP in the early postoperative period, anesthesia using TIVA with propofol is required regardless of patient-related risk factors.

The Intraocular Pressure under Deep versus Moderate Neuromuscular Blockade during Low-Pressure Robot Assisted Laparoscopic Radical Prostatectomy in a Randomized Trial.

Background This study aimed to determine whether continuous deep neuromuscular blockade (NMB) improves the surgical conditions and facilitates robotic-assisted laparoscopic radical prostatectomy (RALRP) under low intra-abdominal pressure (IAP) to attenuate the increase in intraocular pressure (IOP) during CO2 pneumoperitoneum in the steep Trendelenburg (ST) position. Methods Sixty-seven patients undergoing RALRP were randomly assigned to a moderate NMB group (Group M), including patients who received atracurium infusion until the end of the ST position, maintaining a train of four count of 1–2; and the deep NMB group (Group D), including patients who received rocuronium infusion, maintaining a post-tetanic count of 1–2. IOP was measured in all patients at nine separate time points. All RALRPs were performed by one surgeon, who rated the overall and worst surgical conditions at the end of the ST position. Results The highest IOP value was observed at T4 (60 min after the ST position) in both Group M (23.3 ± 2.7 mmHg) and Group D (19.8 ± 2.1 mmHg). RALRP was accomplished at an IAP of 8 mmHg in 88% Group D patients and 25% Group M patients. The overall surgical condition grade was 4.0 (3.0–5.0) in Group D and 3.0 (2.0–5.0) in Group M (P < 0.001). Conclusion The current study demonstrated that continuous deep NMB may improve surgical conditions and facilitate RALRP at a low IAP, resulting in significant attenuation of the increase on IOP. Moreover, low-pressure pneumoperitoneum, facilitated by deep NMB still provided acceptable surgical conditions. Trial Registration ClinicalTrials.gov NCT02109133

Assessing the stability and safety of procedure during endoscopic submucosal dissection according to sedation methods: a randomized trial.

Background Although endoscopic submucosal dissection (ESD) is routinely performed under sedation, the difference in ESD performance according to sedation method is not well known. This study attempted to prospectively assess and compare the satisfaction of the endoscopists and patient stability during ESD between two sedation methods. Methods One hundred and fifty-four adult patients scheduled for ESD were sedated by either the IMIE (intermittent midazolam/propofol injection by endoscopist) or CPIA (continuous propofol infusion by anesthesiologist) method. The primary endpoint of this study was to compare the level of satisfaction of the endoscopists between the two groups. The secondary endpoints included level of satisfaction of the patients, patient’s pain scores, events interfering with the procedure, incidence of unintended deep sedation, hemodynamic and respiratory events, and ESD outcomes and complications. Results Level of satisfaction of the endoscopists was significantly higher in the CPIA Group compared to the IMIE group (IMIE vs. CPIA; high satisfaction score; 63.2% vs. 87.2%, P=0.001). The incidence of unintended deep sedation was significantly higher in the IMIE Group compared to the CPIA Group (IMIE vs. CPIA; 17.1% vs. 5.1%, P=0.018) as well as the number of patients showing spontaneous movement or those requiring physical restraint (IMIE vs. CPIA; spontaneous movement; 60.5% vs. 42.3%, P=0.024, physical restraint; 27.6% vs. 10.3%, P=0.006, respectively). In contrast, level of satisfaction of the patients were found to be significantly higher in the IMIE Group (IMIE vs. CPIA; high satisfaction score; 85.5% vs. 67.9%, P=0.027). Pain scores of the patients, hemodynamic and respiratory events, and ESD outcomes and complications were not different between the two groups. Conclusion Continuous propofol and remifentanil infusion by an anesthesiologist during ESD can increase the satisfaction levels of the endoscopists by providing a more stable state of sedation. Trial Registration ClinicalTrials.gov NCT01806753

Finding the 'Ideal' Regimen for Fentanyl-Based Intravenous Patient-Controlled Analgesia: How to Give and What to Mix?

Purpose This analysis was done to investigate the optimal regimen for fentanyl-based intravenous patient-controlled analgesia (IV-PCA) by finding a safe and effective background infusion rate and assessing the effect of adding adjuvant drugs to the PCA regimen. Materials and Methods Background infusion rate of fentanyl, type of adjuvant analgesic and/or antiemetic that was added to the IV-PCA, and patients that required rescue analgesics and/or antiemetics were retrospectively reviewed in 1827 patients who underwent laparoscopic abdominal surgery at a single tertiary hospital. Results Upon multivariate analysis, lower background infusion rates, younger age, and IV-PCA without adjuvant analgesics were identified as independent risk factors of rescue analgesic administration. Higher background infusion rates, female gender, and IV-PCA without additional 5HT3 receptor blockers were identified as risk factors of rescue antiemetics administration. A background infusion rate of 0.38 µg/kg/hr [area under the curve (AUC) 0.638] or lower required rescue analgesics in general, whereas, addition of adjuvant analgesics decreased the rate to 0.37 µg/kg/hr (AUC 0.712) or lower. A background infusion rate of 0.36 µg/kg/hr (AUC 0.638) or higher was found to require rescue antiemetics in general, whereas, mixing antiemetics with IV-PCA increased the rate to 0.37 µg/kg/hr (AUC 0.651) or higher. Conclusion Background infusion rates of fentanyl between 0.12 and 0.67 µg/kg/hr may safely be used without any serious side effects for IV-PCA. In order to approach the most reasonable background infusion rate for effective analgesia without increasing postoperative nausea and vomiting, adding an adjuvant analgesic and an antiemetic should always be considered.

Effects of Dexmedetomidine on Changes in Heart Rate Variability and Hemodynamics During Tracheal Intubation.

Sympathetic hyperactivation during tracheal intubation prolongs the QT interval and increases the risk of arrhythmias. We investigated if dexmedetomidine pretreatment affected autonomic nervous system balance and QT intervals during intubation. Sixty-six patients were randomized to receive 1.0 &mgr;g/kg fentanyl (group F, n = 22), 0.5 &mgr;g/kg dexmedetomidine (group D0.5, n = 22), or 1.0 &mgr;g/kg dexmedetomidine (group D1.0, n = 22) before induction. Autonomic nervous system balance was assessed by the ratio of low-frequency/high-frequency (LF/HF) power for heart rate variability at baseline (T0), before intubation (T1), and after intubation (T2). QT intervals were corrected by the Bazetts formula (QTc) and compared at baseline, before intubation, and 1, 2, and 3 minutes after intubation. The LF/HF ratio was higher after intubation compared with that at T0 in group F (P < 0.001). There were no significant changes in groups D0.5 and D1.0. The LF/HF ratio was significantly higher in group F compared with those in groups D0.5 and D1.0 after intubation (7.9 vs. 2.1 and 2.5; P < 0.001). The heart rate was increased for 3 minutes after intubation in group F, whereas only for 1 minute after intubation in groups D0.5 and D1.0, compared with that at baseline. More patients in group F had QTc greater than 440 ms compared with that in group D0.5 or D1.0 (8 vs. 1 and 2; P = 0.005) at 1 minute after intubation. In contrast to 1.0 &mgr;g/kg fentanyl, pretreatment with 0.5 or 1.0 &mgr;g/kg dexmedetomidine suppressed sympathetic hyperactivity and attenuated QTc prolongation during intubation.

Elderly Patients Require Higher Doses of Sugammadex for Rapid Recovery from Deep Neuromuscular Block

This study compared the doses of sugammadex needed for rapid recovery from deep neuromuscular blockade (NMB) between young and elderly adults. Twenty‐two young (20–40 yrs) and 22 elderly (≥70 yrs) adults were enrolled, and deep NMB of 1–2 post‐tetanic counts was maintained with rocuronium intraoperatively. Predetermined doses of sugammadex were given at the end of surgery starting at 4.0 mg/kg for the first patient of each group. Doses were decreased or increased in following patients by 0.5 mg/kg, depending on the ‘success’ or ‘failure’ of rapid recovery in the preceding patient. ‘Success’ was defined as adequate recovery (train‐of‐four ratio 0.9) within 2 min. after sugammadex administration. The median (range) of ages was 29 (20–40) and 73 (70–84) yrs for the young and elderly adults, respectively. Doses of sugammadex facilitating adequate recovery from deep NMB within 2 min. in each patient population with 50% and 95% probability were defined as ED50 and ED95, respectively. The ED50 estimated by the Dixons method was significantly higher in the elderly compared to young adults [4.2 ± 0.4 mg/kg versus 3.3 ± 0.3 mg/kg, p < 0.001]. The ED50 (83% CI) estimated by isotonic regression was 4.5 (4.2–5.0) mg/kg in elderly adults and 3.3 (3.2–3.4) mg/kg in young adults. The ED95 (95% CI) estimated by isotonic regression was 5.4 (4.9–5.5) mg/kg and 4.4 (3.9–4.5) mg/kg in the elderly and young adults, respectively. In conclusion, dose adjustments of sugammadex should be considered when rapid recovery from deep NMB is needed in elderly adults.

Efficacy of Palonosetron vs. Ramosetron for the Prevention of Postoperative Nausea and Vomiting: A Meta-Analysis of Randomized Controlled Trials

Purpose This study was designed as a meta-analysis of randomized controlled trials (RCTs) that included the comparison of palonosetron and ramosetron for postoperative nausea and vomiting (PONV) prophylaxis. Materials and Methods A systematic search was conducted for the PubMed, EMBASE, Web of Science, CENTRAL, KoreaMed, and Google Scholar databases (PROSPERO protocol number CRD42015026009). Primary outcomes were the incidences of postoperative nausea (PON) and postoperative vomiting (POV) during the first 48 hrs after surgery. The total 48-hr period was further analyzed in time epochs of 0–6 hrs (early), 6–24 hrs (late), and 24–48 hrs (delayed). Subgroup analyses according to number of risk factors, sex, and type of surgery were also performed. Results Eleven studies including 1373 patients were analyzed. There was no difference in PON or POV between the two drugs for the total 48-hr period after surgery. However, palonosetron was more effective in preventing POV during the delayed period overall [relative risk (RR), 0.59; 95% confidence interval (CI), 0.39 to 0.89; p=0.013], as well as after subgroup analyses for females and laparoscopies (RR, 0.56; 95% CI, 0.36 to 0.86; p=0.009 and RR, 0.46; 95% CI, 0.23 to 0.94; p=0.033). Subgroup analysis for spine surgery showed that ramosetron was more effective in reducing POV during the total 48-hr (RR, 3.34; 95% CI, 1.46 to 7.63; p=0.004) and early periods (RR, 8.47; 95% CI, 1.57 to 45.72; p=0.013). Conclusion This meta-analysis discovered no definite difference in PONV prevention between the two drugs. The significant findings that were seen in different time epochs and subgroup analyses should be confirmed in future RCTs.

Effect of Pneumoperitoneum on Oxidative Stress and Inflammation via the Arginase Pathway in Rats

Purpose Oxidative stress during CO2 pneumoperitoneum is reported to be associated with decreased bioactivity of nitric oxide (NO). However, the changes in endothelial nitric oxide synthase (eNOS), inducible nitric oxide synthase (iNOS), and arginase during CO2 pneumoperitoneum have not been elucidated. Materials and Methods Thirty male Sprague-Dawley rats were randomized into three groups. After anesthesia induction, the abdominal cavities of the rats of groups intra-abdominal pressure (IAP)-10 and IAP-20 were insufflated with CO2 at pressures of 10 mm Hg and 20 mm Hg, respectively, for 2 hours. The rats of group IAP-0 were not insufflated. After deflation, plasma NO was measured, while protein expression levels and activity of eNOS, iNOS, arginase (Arg) I, and Arg II were analyzed with aorta and lung tissue samples. Results Plasma nitrite concentration and eNOS expression were significantly suppressed in groups IAP-10 and IAP-20 compared to IAP-0. While expression of iNOS and Arg I were comparable between the three groups, Arg II expression was significantly greater in group IAP-20 than in group IAP-0. Activity of eNOS was significantly lower in groups IAP-10 and IAP-20 than in group IAP-0, while iNOS activity was significantly greater in group IAP-20 than in groups IAP-0 and IAP-10. Arginase activity was significantly greater in group IAP-20 than in groups IAP-0 and IAP-10. Conclusion The activity of eNOS decreases during CO2 pneumoperitoneum, while iNOS activity is significantly increased, a change that contributes to increased oxidative stress and inflammation. Moreover, arginase expression and activity is increased during CO2 pneumoperitoneum, which seems to act inversely to the NO system.

Effect of the Prolonged Inspiratory to Expiratory Ratio on Oxygenation and Respiratory Mechanics During Surgical Procedures

AbstractProlonged inspiratory to expiratory (I:E) ratio ventilation has been researched to reduce lung injury and improve oxygenation in surgical patients with one-lung ventilation (OLV) or carbon dioxide (CO2) pneumoperitoneum.We aimed to confirm the efficacy of the 1:1 equal ratio ventilation (ERV) compared with the 1:2 conventional ratio ventilation (CRV) during surgical procedures.Electronic databases, including PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Google Scholar were searched.Prospective interventional trials that assessed the effects of prolonged I:E ratio of 1:1 during surgical procedures.Adult patients undergoing OLV or CO2 pneumoperitoneum as specific interventions depending on surgical procedures.The included studies were examined with the Cochrane Collaborations tool. The data regarding intraoperative oxygenation and respiratory mechanics were extracted, and then pooled with standardized mean difference (SMD) using the method of Hedges.Seven trials (498 total patients, 274 with ERV) were included. From overall analysis, ERV did not improve oxygenation at 20 or 30 minutes after specific interventions (SMD 0.193, 95% confidence interval (CI): −0.094 to 0.481, P = 0.188). From subgroup analyses, ERV provided significantly improved oxygenation only with laparoscopy (SMD 0.425, 95% CI: 0.167–0.682, P = 0.001). At 60 minutes after the specific interventions, ERV improved oxygenation significantly in the overall analysis (SMD 0.447, 95% CI: 0.209–0.685, P < 0.001) as well as in the subgroup analyses with OLV (SMD 0.328, 95% CI: 0.011–0.644, P = 0.042) and laparoscopy (SMD 0.668, 95% CI: 0.052–1.285, P = 0.034). ERV provided lower peak airway pressure (Ppeak) and plateau airway pressure (Pplat) than CRV, regardless of the type of intervention.The relatively small number of the included articles and their heterogeneity could be the main limitations.ERV improved oxygenation at all of the assessment points during laparoscopy. In OLV, oxygenation improvement with ERV was observed 1 hour after application. ERV could be beneficial to reduce the Ppeak and Pplat.