Hee-Pyoung Park

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.

Albumin Therapy Improves Local Vascular Dynamics in a Rat Model of Primary Microvascular Thrombosis: A Two-Photon Laser-Scanning Microscopy Study

Background and Purpose— High-dose human albumin is robustly neuroprotective in preclinical ischemia models and is currently in phase III clinical trial for acute ischemic stroke. To explore the hypothesis that albumin’s protective effect is mediated in part by salutary intravascular mechanisms, we assessed microvascular hemodynamics in a model of laser-induced cortical arteriolar thrombosis. Methods— The cortical microcirculation of anesthetized, physiologically monitored Sprague-Dawley rats was studied in vivo via a frontoparietal cranial window (intact dura) by two-photon laser-scanning microscopy after plasma-labeling with fluorescein-dextran. Focal thrombosis was produced in 30- to 50-&mgr;m cortical arterioles by laser irradiation. Arteriolar flow velocity was measured repeatedly by line-scanning. At 30 minutes post-thrombosis, animals were treated with either human albumin, 2 g/kg, or with saline control. Results— Baseline arteriolar flow velocity averaged 3.5±1.8 mm/s and was reduced to 10% to 13% of control values by laser-induced thrombosis, which also led to focal vasodilatation (mean, 49% above baseline diameter). Saline treatment at 30 minutes post-thrombosis failed to influence arteriolar flow velocity, which remained depressed at 10% to 22% of control throughout the subsequent 60- to 90-minute observation period. By contrast, albumin treatment induced a prompt rise in median flow velocity to 38% of control by 10 minutes post-treatment, and to 61% to 67% of control by 50 to 60 minutes. Conclusions— High-dose albumin therapy induces a prompt, sustained improvement in microvascular hemodynamics distal to a cortical arteriolar thrombosis; these data support an important intravascular component to albumin’s protective effect in acute cerebral ischemia.

Albumin Therapy Augments the Effect of Thrombolysis on Local Vascular Dynamics in a Rat Model of Arteriolar Thrombosis. A Two-Photon Laser-Scanning Microscopy Study

Background and Purpose— Results of our recent pilot clinical trial suggest that the efficacy of thrombolytic therapy in acute ischemic stroke may be enhanced by the coadministration of high-dose albumin. Here, we explored the microvascular hemodynamic effects of this combined therapy in a laboratory model of cortical arteriolar thrombosis. Methods— We studied the cortical microcirculation of physiologically monitored rats in vivo by two-photon laser-scanning microscopy after plasma-labeling with fluorescein-dextran. We induced focal thrombosis in 30- to 50-&mgr;m cortical arterioles by laser irradiation and measured arteriolar flow velocity by repeated line-scanning. At 30 minutes post-thrombosis, we treated animals with the thrombolytic agent, reteplase, which was coadministered with either human albumin, 2 g/kg, or with saline control. Results— Baseline arteriolar flow velocity averaged 3.8±0.7 mm/s, was immediately reduced by thrombosis to 22% to 25% of control values, and remained unchanged before treatment. Subthrombolytic doses of reteplase combined with saline led to a median increase in flow velocity to 37% of control distal to the thrombus (P=nonsignificant versus pretreatment). By contrast, reteplase combined with albumin therapy resulted in a prompt, highly significant increase of median flow velocity to 58% of control levels (P=0.013 versus reteplase+saline), which remained significantly higher than the reteplase+saline group at multiple time-points over the subsequent hour. Conclusions— The beneficial effect of subthrombolytic doses of reteplase on microvascular hemodynamics distal to a cortical arteriolar thrombosis is markedly enhanced by the coadministration of high-dose albumin therapy; these results have important clinical implications for the management of patients with acute ischemic stroke.

The effect of the lateral decubitus position on the intraocular pressure in anesthetized patients undergoing lung surgery

Background:  Changing the body position alters the intraocular pressure (IOP). The aim of this study was to investigate the alteration in IOP of the eyes after a positional change from a supine position to a lateral decubitus position in anesthetized patients, in order to detect differences in IOP between the two eyes, possibly due to a gravity effect, in the lateral decubitus position.

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.

Efficacy of butylscopolamine for the treatment of catheter-related bladder discomfort: a prospective, randomized, placebo-controlled, double-blind study

BACKGROUND Catheter-related bladder discomfort (CRBD) secondary to intraoperative catheterization of urinary bladder is one of the most distressing symptoms during recovery from anaesthesia. Butylscopolamine, a peripheral antimuscarinic agent, is effective for relieving the pain, which is because of smooth muscle contraction. The aim of this study was to assess the efficacy and safety profiles of butylscopolamine in treating CRBD after urological surgeries. METHODS Adult male patients undergoing urological surgery requiring urinary bladder catheterization intraoperatively were enrolled. Induction and maintenance of anaesthesia were standardized. Patients were randomized into two groups after complaining of CRBD in the post-anaesthesia care unit. The control group (n=29) received normal saline and the butylscopolamine group (n=28) was administered butylscopolamine 20 mg i.v. The severity of CRBD, postoperative pain, and adverse effects were assessed at baseline, 20 min, 1, 2, and 6 h after administration of the study drug. RESULTS The severity of CRBD observed in the butylscopolamine group was significantly lower than that of the control group at 1, 2, and 6 h after administration of the study drug [59 (12), 50 (16), 40 (21) in the control group vs 41 (22), 32 (25), 23 (18) in the butylscopolamine group, P<0.01]. Rescue analgesics were required less in the butylscopolamine group than in the control group (P=0.001). Adverse events were comparable between the two groups. CONCLUSION Butylscopolamine 20 mg administered i.v. after complaining CRBD during recovery reduced both the severity of CRBD and the need for rescue analgesics without adverse effects in patients undergoing urologic surgeries.

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.

Sevoflurane post-conditioning increases nuclear factor erythroid 2-related factor and haemoxygenase-1 expression via protein kinase C pathway in a rat model of transient global cerebral ischaemia

BACKGROUND The antioxidant mechanism of sevoflurane post-conditioning-induced neuroprotection remains unclear. We determined whether sevoflurane post-conditioning induces nuclear factor erythroid 2-related factor (Nrf2, a master transcription factor regulating antioxidant defence genes) and haemoxygenase-1 (HO-1, an antioxidant enzyme) expression, and whether protein kinase C (PKC) is involved in Nrf2 activation, in a rat model of transient global cerebral ischaemia/reperfusion (I/R) injury. METHODS Eighty-six rats were assigned to five groups: sham (n=6), control (n=20), sevoflurane post-conditioning (two cycles with 2 vol% sevoflurane inhalation for 10 min, n=20), chelerythrine (a PKC inhibitor; 5 mg kg(-1) i.v. administration, n=20), and sevoflurane post-conditioning plus chelerythrine (n=20). The levels of nuclear Nrf2 and cytoplasmic HO-1 were assessed 1 or 7 days after ischaemia (n=10 each, apart from the sham group, n=3). RESULTS On day 1 but not day 7 post-ischaemia, Nrf2 and HO-1 expression were significantly higher in the sevoflurane post-conditioning group than in the control group. Chelerythrine administration reduced the elevated Nrf2 and HO-1 expression induced by sevoflurane post-conditioning. CONCLUSIONS Sevoflurane post-conditioning increased Nrf2/HO-1 expression via PKC signalling in the early phase after transient global cerebral I/R injury, suggesting that activation of antioxidant enzymes may be responsible for sevoflurane post-conditioning-induced neuroprotection in the early phase after cerebral I/R injury.

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.