Jung-Won Hwang

Comparison of alfetanil and ketamine in combination with propofol for patient-controlled sedation during fiberoptic bronchoscopy.

Background:  During fiberoptic bronchoscopy, propofol, ketamine, benzodiazepines, and opiates are most commonly used, alone or in combination for sedation. The aim of this study was to compare the clinical efficacy of propofol/ketamine with propofol/alfentanil for patient‐controlled sedation (PCS) during fiberoptic bronchoscopy.

Isoflurane preconditioning protects motor neurons from spinal cord ischemia: Its dose-response effects and activation of mitochondrial adenosine triphosphate-dependent potassium channel

We examined in a rabbit model of transient spinal cord ischemia (SCI) whether isoflurane (Iso) preconditioning induces ischemic tolerance to SCI in a dose-response manner, and whether this effect is dependent on mitochondrial adenosine triphosphate-dependent potassium (K(ATP)) channel. Eighty-six rabbits were randomly assigned to 10 groups: Control group (n=8) received no pretreatment. Ischemic preconditioning (IPC) group (n=8) received 5 min of IPC 30 min before SCI. The Iso 1, Iso 2 and Iso 3 groups (n=10, 9, 8) underwent 30 min of 1.05, 2.1 and 3.15% Iso inhalation commencing 45 min before SCI. The Iso 1HD, Iso 2HD and Iso 3HD groups (n=9, 9, 8) each received a specific mitochondrial K(ATP) channel blocker, 5-hydroxydecanoic acid (5HD, 20mg/kg), 5 min before each respective Iso inhalation. The 5HD group (n=8) received 5HD without Iso inhalation. The sham group (n=9) had no SCI. SCI was produced by infra-renal aortic occlusion via the inflated balloon of a Swan-Ganz catheter for 20 min. The Iso 1, Iso 2 and Iso 3 groups showed a better neurologic outcome and more viable motor nerve cells (VMNCs) in the anterior spinal cord 72 h after reperfusion than the control group (p<0.05). Iso 3 group showed a better neurologic outcome and more VMNCs than Iso 1 group (p<0.05). And, the Iso 1, Iso 2 and Iso 3 groups showed a better neurologic outcome and higher VMNC numbers than the corresponding Iso 1HD, Iso 2HD and Iso 3HD groups (p<0.05). This study demonstrates that Iso preconditioning protects the spinal cord against neuronal damage due to SCI in a dose-response manner via the activation of mitochondrial K(ATP) channels.

Comparison of two insertion techniques of ProSeal laryngeal mask airway: standard versus 90-degree rotation.

Background:This study compared two insertion techniques of ProSeal™ laryngeal mask airway. Methods:A total of 160 female patients (American Society of Anesthesiologists physical status I or II; age 18–80 yrs) undergoing gynecologic surgery were randomly allocated to the standard or rotational technique groups. In the standard technique group (n = 80), ProSeal™ laryngeal mask airway insertion was performed by a single experienced user using digital manipulation. In the rotational technique group (n = 80), the ProSeal™ laryngeal mask airway was rotated counter clockwise through 90 degrees in the mouth and advanced until the resistance of the hypopharynx was felt, and then straightened out in the hypopharynx (n = 80). The ease of insertion was assessed by the success rate at the first attempt. Heart rate and mean blood pressure were recorded 1 min before and 1 min after insertion. Postoperative complications were noted. Results:The success rate of insertion at the first attempt was higher for the rotational technique (100% vs. 85%, P < 0.001). The overall success rate, i.e., successful insertion within three attempts, was 94% for the standard technique versus 100% for the rotational technique. There was no significant change in heart rate, but mean blood pressure increased significantly with the standard technique (P = 0.001). The incidence of blood staining (9% vs. 36%, P < 0.001) and sore throat (8% vs. 25%, P = 0.005) was lower with the rotational technique. Conclusion:The rotational technique is more successful than the standard technique and is associated with less pharyngeal mucosal trauma, as evidenced by a lower incidence of sore throat and mucosal bleeding.

Positional blood pressure change and the risk of hypotension during spinal anesthesia for cesarean delivery: an observational study.

BACKGROUND: We investigated whether preoperative positional arterial blood pressure change predicted hypotension and ephedrine requirement during spinal anesthesia for cesarean delivery. METHODS: Arterial blood pressure was measured in 66 women undergoing cesarean delivery in the supine and the right lateral positions. Positional blood pressure change was defined as the difference between mean blood pressure in the right lateral and supine positions. Hypotension (<80% baseline) was recorded, and severe hypotension (<70% baseline) was treated with ephedrine. RESULTS: The mean (range) positional blood pressure change was 11 (3–29) mm Hg, and the incidence of hypotension was 41%. Positional blood pressure change and heart rate correlated with hypotension (P < 0.001 for both) and ephedrine requirement (P = 0.004). Positional blood pressure change in those who developed hypotension was higher than for those without hypotension (mean (SD), 17 (6) vs. 7 (2) mm Hg, P < 0.001). CONCLUSIONS: A preoperative increase in blood pressure after position change may be a good variable to predict hypotension during spinal anesthesia for cesarean delivery.

The postoperative C-reactive protein level can be a useful prognostic factor for poor outcome and symptomatic vasospasm in patients with aneurysmal subarachnoid hemorrhage.

Background: Ninety-three patients undergoing surgical or endovascular operation secondary to aneurysmal subarachnoid hemorrhage (SAH) were retrospectively analyzed to determine the influence of the different time points of C-reactive protein (CRP) measurement on the prediction of vasospasm and clinical outcome. Methods: Laboratory data such as the CRP level and the white blood cell count, preoperative demographic and clinical data, intraoperative and postoperative data, and complications such as intracerebral hemorrhage, hydrocephalus, vasospasm, and surgical decompression were collected at hospital discharge or symptomatic vasospasm and used as predictable factors for poor outcome (Modified Rankin Scale score 4 to 6). Results: Twenty-three and 28 patients showed poor outcome and symptomatic vasospasm after SAH, respectively. Both preoperative and postoperative CRP levels were significantly higher in patients with a poor outcome compared with patients with a good outcome (P<0.05). The area under the receiver operating characteristic curve of CRP measured on postoperative day 1 or 2 (CRP POD1-2) for predicting a poor clinical outcome was 0.870, and its cutoff point of 4 mg/dL had a sensitivity of 0.826 and a specificity of 0.843. A high CRP level after aneurysm treatment was associated with severe neurological deterioration on admission, cerebral infarction, intracerebral hemorrhage, and surgical decompression (P<0.05). CRP POD1-2, and not the preoperative CRP, was an independent factor in predicting symptomatic vasospasm (P<0.05). In patients with symptomatic vasospasm, an increase in the postoperative CRP was associated with the time profile of developing symptomatic vasospasm. Conclusion: Postoperative CRP, especially CRP POD1-2, can be a useful prognostic factor for both poor outcome and symptomatic vasospasm in patients with aneurysmal SAH.

Dexmedetomidine is effective for monitored anesthesia care in outpatients undergoing cataract surgery

Background Dexmedetomidine has a sedative analgesic property without respiratory depression. This study evaluated the efficacy of dexmedetomidine as an appropriate sedative drug for monitored anesthesia care (MAC) in outpatients undergoing cataract surgery on both eyes compared with combination of propofol and alfentanil. Methods Thirty-one eligible patients were randomly divided into two groups on the first operation day. Dexmedetomidine was administered in group D at 0.6 µg/kg/h, and propofol and alfentanil was infused concomitantly in group P at a rate of 2 mg/kg/h and 20 µg/kg/h, respectively. Sedation was titrated at Ramsay sedation score 3. Iowa satisfaction with anesthesia scale (ISAS) of the patients was evaluated postoperatively. Systolic blood pressure (SBP), heart rate (HR), respiration rate (RR), and peripheral oxygen saturation (SpO2) were recorded throughout the surgery. For the second operation, the group assignments were exchanged. Results Postoperative ISAS was 50.3 (6.2) in group D and 42.7 (8.7) in group P, which was statistically significant (P < 0.001). SBP was significantly lower in group D compared with group P from the beginning of the operation. HR, RR, and SpO2 were comparable between the two groups. There were 8 cases (25.8%) of hypertension in group P, and 1 case (3.2%) in group D (P < 0.05). In contrast, 1 case (3.2%) of hypotension and 1 case (3.2%) of bradycardia occurred in group D. Conclusions Compared with the combined use of propofol and alfentanil, dexmedetomidine could be used appropriately for MAC in cataract surgery with better satisfaction from the patients and a more stable cardiovascular state.

Clevudine for chronic hepatitis B: antiviral response, predictors of response, and development of myopathy

Summary.  Clevudine has been approved for the treatment of chronic hepatitis B (CHB) in South Korea. However, its long‐term antiviral effect and safety awaits more study. The aim of this study was to evaluate antiviral efficacy, predictors of virologic response, and development of myopathy after clevudine therapy for CHB. The study included 102 nucleoside naïve CHB patients who had received clevudine for more than 6 months with good compliance. The median duration of clevudine treatment was 53 weeks (range, 25–90 weeks). A retrospective analysis of data retrieved from medical records was performed. The cumulative rate of virologic response [hepatitis B virus (HBV) DNA level <2000 copies/mL] at 48 weeks of clevudine therapy was 81%, and cumulative rate of clevudine resistance was 11% at 60 weeks of treatment. Independent predictors of virologic response to clevudine therapy were hepatitis B e antigen (HBeAg) negativity and rapid decrease of viral load during the early phase of treatment. The clevudine‐related myopathy developed in 3.9% of patients, and was reversible after discontinuation of clevudine. Clevudine showed a potent antiviral response, and its effect was higher in HBeAg‐negative patients, with rapid viral load reduction after therapy. However, long‐term therapy for more than 1 year resulted in the development of considerable resistance and myopathy. Therefore, we should consider alternative antiviral agents if clevudine resistance or clevudine‐induced myopathy is developed in patients on clevudine for the treatment of CHB.

A combination of sevoflurane postconditioning and albumin increases Bcl-2 expression after transient global cerebral ischemia compared with either sevoflurane postconditioning or albumin alone.

Background: The aim of this study was to determine whether a combination of sevoflurane postconditioning and albumin provides additive neuroprotective effects after transient global cerebral ischemia in rats. Methods: Forty-three rats were assigned to 4 groups: the control group (group C; n=13; 3 died) received no treatment. The albumin group (group A; n=10) received 2 g/kg of albumin for 5 minutes after ischemia. The sevoflurane postconditioning group (group P; n=10) underwent 2 sevoflurane inhalations after ischemia. Each inhalation consisted of 5 minutes of 2.5% sevoflurane and a subsequent washout time of 5 minutes. The sevoflurane postconditioning plus albumin group (group PA; n=10) received additional albumin during sevoflurane postconditioning after ischemia. In all groups, ischemia was induced by a bilateral common carotid artery occlusion along with hemorrhagic hypotension and was maintained for 10 minutes. Histologic and neurobehavioral outcomes were measured 7 days after ischemia in CA1 pyramidal cells of the rat hippocampus. Results: Groups A, P, and PA showed an improved neurological outcome and contained more viable cells in the hippocampal CA1 area compared with group C (P<0.05). The number of apoptotic cells was significantly reduced in group PA compared with group C (P<0.01). There was a significant difference in the Bcl-2, an antiapoptotic protein, expression between group C and other groups (P<0.01) and between group A or P and group PA (P<0.05). Conclusions: A combination of sevoflurane postconditioning and albumin increased the level of Bcl-2 expression compared with sevoflurane postconditioning or albumin alone, suggesting their combination might provide additional neuroprotection by decreasing apoptosis.

Effect of tracheostomy timing on clinical outcome in neurosurgical patients: early versus late tracheostomy.

Background: The optimal timing of tracheostomy in neurosurgical patients is not well established. This retrospective study was conducted to determine the effect of the timing of tracheostomy on clinical outcome in mechanically ventilated neurosurgical patients admitted to the surgical intensive care unit (ICU). Methods: A total of 125 neurosurgical patients, who underwent tracheostomy and had total mechanical ventilation (MV) duration of ≥7 days from October 2007 to December 2011, were enrolled. Patients were divided into 2 groups based on the timing of tracheostomy. Tracheostomy was performed within 10 days of MV in the early group (group E, n=39), whereas in the late group, it was performed after 10 days of MV (group L, n=86). The ICU and in-hospital mortality rates, total duration of MV, length of stay (LOS) in the ICU, hospital LOS, and incidence of ventilator-associated pneumonia (VAP) were compared between both the groups. Results: The total MV duration and ICU LOS were significantly longer in group L than E (21.5±15.5 vs. 11.4±5.6 d, P<0.001; 31.1±18.2 vs. 19.9±10.6 d, P<0.001). The incidence of VAP before tracheostomy was higher in group L than group E (44 vs. 23%, P<0.05). No significant difference was found in the ICU and in-hospital mortality rates and hospital LOS between the groups. Conclusions: Early tracheostomy reduced the MV duration, ICU LOS, and incidence of VAP in critically ill neurosurgical patients. However, early tracheostomy did not reduce either the ICU or hospital mortality.

Postanaesthetic emergence agitation in adult patients after general anaesthesia for urological surgery

Objective To investigate the incidence and risk factors for emergence agitation in the postanaesthetic care unit (PACU), in adult patients undergoing urological surgery. Methods Medical records were retrospectively reviewed. Preoperative, intraoperative and postoperative variables were evaluated. Emergence agitation was defined as a Riker sedation–agitation score ≥5. Logistic regression analysis was used to determine independent risk factors for emergence agitation. Results Emergence agitation was observed in 48/488 (9.8%) patients. Chronic lung disease (odds ratio [OR] 2.72, 95% confidence interval [CI] 1.03, 7.17), duration of surgery (OR 1.01, 95% CI 1.00, 1.01), history of social drinking (OR 2.48, 95% CI 1.25, 4.93), postoperative pain score (OR 1.32, 95% CI 1.14, 1.53), voiding urgency (OR 2.20, 95% CI 1.01, 4.77) and presence of gastric tube (OR 2.85, 95% CI 1.07, 7.54) were independent risk factors for emergence agitation. Conclusions Adequate postoperative pain management and prevention of catheter-related bladder discomfort may be helpful in reducing the incidence of emergence agitation in urology patients.