Monitored anesthesia care with dexmedetomidine in transfemoral percutaneous trans-catheter aortic valve implantation: two cases report / 대한마취과학회지

Percutaneous trans-catheter aortic valve implantation (TAVI) is recommended for inoperable patients with severe aortic stenosis at high risk for conventional aortic valve replacement. Originally, TAVI was mostly performed under general anesthesia. Here we describe two cases of transfemoral TAVI performed under monitored anesthesia care (MAC) with dexmedetomidine. Dexmedetomidine provides sedation, analgesia with minimal respiratory depression. Although MAC during transfemoral TAVI has limitations, such as unexpected patient movement and difficulty in intra-procedural use of transesophageal echocardiography, MAC with dexmedetomidine is feasible with close monitoring, fluoroscopic guidance and the participation of experienced anesthesiologists.

Severe acute respiratory failure after aortic valve replacement in a patient with nonspecific interstitial pneumonia: A case report

A 57-year-old female patient with suspicious interstitial lung disease underwent aortic valvular replacement for aortic stenosis. She complained of severe dyspnea, and her preoperative chest X-ray and computed tomography findings showed multiple ground glass opacity causing interstitial lung disease. After aortic valvular replacement, and as part of the weaning process after cardiopulmonary bypass, she was placed on a ventilator. Nonetheless, the peak airway pressure was higher than 40 mmHg with a less than 50 ml tidal volume, and there was no visible end-tidal CO2 curve. Repeated suction, expansion, and intravenous corticosteroid injection with aminophylline loading were performed to improve the patient's condition. Extracorporeal membrane oxygenation began after cardiopulmonary bypass and was sustained for 5 days. This case demonstrated the fragility of lungs with interstitial disease, and the need to exercise more precaution against acute respiratory failure after cardiopulmonary bypass.

Effect of remote ischemic preconditioning on cognitive function after off-pump coronary artery bypass graft: a pilot study / 대한마취과학회지

BACKGROUND: Several studies have shown in animal models that remote ischemic preconditioning (rIPC) has a neuroprotective effect. However, a randomized controlled trial in human subjects to investigate the neuroprotective effect of rIPC after cardiac surgery has not yet been reported. Therefore, we performed this pilot study to determine whether rIPC reduced the occurrence of postoperative cognitive dysfunction in patients who underwent off-pump coronary artery bypass graft (OPCAB) surgery. METHODS: Seventy patients who underwent OPCAB surgery were assigned to either the control or the rIPC group using a computer-generated randomization table. The application of rIPC consisted of four cycles of 5 min ischemia and 5 min reperfusion on an upper limb using a blood pressure cuff inflating 200 mmHg before coronary artery anastomosis. The cognitive function tests were performed one day before surgery and again on postoperative day 7. We defined postoperative cognitive dysfunction as decreased postoperative test values more than 20% of the baseline values in more than two of the six cognitive function tests that were performed. RESULTS: In the cognitive function tests, there were no significant differences in the results obtained during the preoperative and postoperative periods for all tests and there were no mean differences observed in the preoperative and postoperative scores. The incidences of postoperative cognitive dysfunction in the control and rIPC groups were 28.6% (10 patients) and 31.4% (11 patients), respectively. CONCLUSIONS: rIPC did not reduce the incidence of postoperative cognitive dysfunction after OPCAB surgery during the immediate postoperative period.

Transcatheter Aortic Valve Implantation: Early Experience in Korea

BACKGROUND AND OBJECTIVES: Transcatheter aortic valve implantation (TAVI) was recently introduced in Korea. The present report describes the experience of early TAVI cases. SUBJECTS AND METHODS: Between March, 2010 and October, 2011, 48 patients with severe symptomatic aortic stenosis (AS) were screened at the Asan Medical Center to determine their suitability for surgical intervention. Of these, 23 were considered unsuitable and underwent TAVI. Procedural success rates, procedure-related complications, and clinical outcomes were evaluated in the TAVI patients. RESULTS: Transfemoral (n=20) or transapical (n=3) TAVI was performed. The mean age of patients was 75.9+/-5.4 years and 57% were females. The mean logistic European System for Cardiac Operative Risk Evaluation was 25.6+/-5.1%. Implantation was successful in 22 patients (19 transfemoral, three transapical). After successful implantation, the mean aortic valve area increased from 0.68+/-0.14 cm2 to 1.45+/-0.33 cm2. There were no procedure-related complications or mortality. The patients showed no paravalvular aortic regurgitation with > or = moderate degree and remained stable without progression during follow-up. During follow-up (interquartile range, 1.1-12.9), all patients were alive without any occurrence of valve failure. CONCLUSION: TAVI procedure is feasible in patients with inoperative symptomatic AS leading to hemodynamic and clinical improvement. With accumulation of experience, proper patient selection and development of device technologies, TAVI should decrease adverse events and expand the indications in the near future.

Anesthetic considerations during heart-lung transplantation in a patient with an unresectable pulmonary artery sarcoma / 대한마취과학회지

No abstract available.

Temporary bilateral sensorineural hearing loss following cardiopulmonary bypass: A case report / 대한마취과학회지

Sudden sensorineural hearing loss has been reported to occur following anesthesia and various non-otologic surgeries, mostly after procedures involving cardiopulmonary bypass. Unilateral sensorineural hearing loss resulting from microembolism is an infrequent complication of cardiopulmonary bypass surgery that has long been acknowledged. Moreover, there are few reports on the occurrence of bilateral sensorineural hearing loss without other neurologic deficits and its etiology has also not been determined. We describe here a rare case of bilateral hearing loss without other neurologic deficits in an otherwise healthy 27-year-old woman who underwent cardiopulmonary bypass surgery for repair of severe mitral valve stenosis. The patient suffered from profound sensorineural hearing loss in both ears that was recognized immediately upon extubation, and audiometry tests confirmed the diagnosis. Without any treatment, her hearing recovered almost completely by the time of her discharge one week after surgery.

The prophylactic use of recombinant factor VIIa in a patient with DeBakey type III aortic dissection: A case report / 대한마취과학회지

Little is known about the prophylactic use of recombinant factor VIIa (rFVIIa) in patients undergoing surgery for a bleeding aorta employing cardiopulmonary bypass. We report the successful use of rFVIIa in a patient undergoing hypothermic circulatory arrest and prolonged cardiopulmonary bypass for repair of a DeBakey type III aortic dissection.

Anesthetic considerations of percutaneous transcatheter aortic valve implantation: first attempt in Korea: A report of 2 cases / 대한마취과학회지

Conventional aortic valve replacement for severe aortic stenosis is associated with a high operative mortality in the elderly patients with significant comorbidities, including severe respiratory dysfunction, renal insufficiency, and compromised cardiac function. Human transcatheter aortic valve implantation was first reported in 2002 and has become a valid alternative in selected high-risk patients in Europe and North America. This article describes the first attempt of transfemoral transcatheter aortic valve implantation in Korea. The procedure was applied in two consecutive patients with severe aortic stenosis. Despite several intra-operative complications during procedure, the post-operative outcomes were good for both patients. At post-operative 30 days there was satisfactory prosthetic valve function and hemodynamic stability.

Comparison of the Clinical Outcomes of Red Blood Cell Transfusion in Cardiac Surgical Patients according to the Hematocrit / 대한수혈학회지

BACKGROUND: Recent studies have shown that blood transfusions, and especially red blood cells, are associated with potential adverse outcomes. This study was designed to investigate the effects of red blood cell transfusion according to the hematocrit on the clinical outcomes after cardiac surgery. METHODS: The 433 patients who were undergoing cardiac surgery were randomized to two groups. One group was transfused red blood cells with a hematocrit of 20%, and the other group was transfused red blood cells with a hematocrit of 20~25%. The amounts of intraoperative and postoperative transfusion and various parameters of the clinical outcomes were checked. RESULTS: In the hematocrit 20% group, and the postoperative hemoglobin and hematocrit were lower than that of the hematocrit >20% group. But there were no differences of the amounts of intraoperative and postoperative transfusion, the use of inotropics, the platelet count, the prothrombin time (PT), the activated partial thromboplastin time (aPTT), the levels of aspartate aminotransferase (AST), the levels of alanine aminotransferase (ALT), blood urea nitrogen (BUN), serum creatinine (Cr), brain natriuretic peptide (BNP) and creatine kinase MB (CK-MB), the extubation time and the ICU stay time between the two groups. CONCLUSION: A hematocrit lower than 20% was tolerated by the cardiac surgical patients and it was not related to the postoperative morbidity and outcomes.

Growth suppression of four cancer cells by hyperbaric nitrous oxide and methotrexate / 대한마취과학회지

BACKGROUND: Nitrous oxide concentration is easily controlled by respiratory ventilation. It suppresses bone marrow via the inhibition of thymidylate synthesis. The aim of this work was to determine the optimal pressure and exposure duration of nitrous oxide, as well as methotrexate concentration that maximizes the suppression of 4 cancer cells: CCRF-CEM, K562, A549 and MDA-MB-231. METHODS: Each cancer cell was cultured in a hyperbaric chamber at 1, 2 and 3 atmosphere of 74% nitrous oxide for 24, 48, and 72 hours at 0, 0.3, 0.7, 1, 2, 5 and 10 microM methotrexate (MTX), respectively. The results were expressed in the ratio of the number of cancer cells cultured under specific conditions (S cells) to that under normal conditions (N cells). RESULTS: The S/N ratio of CCRF-CEM cells was 87.4% in 24-hour culture, 95.0% in 48-hour culture and 115.9% in 72-hour culture (P 0.05). However, the S/N ratio of MDA-MB 231 cells was 66.9% in 24-hour culture, 83.1% in 48 hour culture and 87.8% in 72-hour culture (P < 0.05). CONCLUSIONS: Only the growth of the MDA-MB-231 cells was significantly reduced after a longer exposure time to nitrous oxide, but those of the other cells were not.

Nitric oxide and pulmonary hypertension / 대한마취과학회지

Pulmonary hypertension is a serious complication of a number of lung and heart diseases that is characterized by peripheral vascular structural remodeling and loss of vascular tone. Nitric oxide can modulate vascular injury and interrupt elevation of pulmonary vascular resistance selectively; however, it can also produce cytotoxic oxygen radicals and exert cytotoxic and antiplatelet effects. The balance between the protective and adverse effects of nitric oxide is determined by the relative amount of nitric oxide and reactive radicals. Nitric oxide has been shown to be clinically effective in the treatment of congenital heart disease, mitrial valvular disease combined with pulmonary hypertension and in orthotropic cardiac transplantation patients. Additionally, new therapeutic modalities for the treatment of pulmonary hypertension, phosphodiesterase inhibitors, natriuretic peptides and aqueous nitric oxide are also effective for treatment of elevated pulmonary vascular resistance.

The effects of gabapentin pretreatment on brain injury induced by focal cerebral ischemia/reperfusion in the rat / 대한마취과학회지

BACKGROUND: Experimental studies have shown that gabapentin can reduce neuronal injury in the setting of cerebral ischemia, but the mechanisms have not yet been clearly determined. This study was conducted to determine whether gabapentin pretreatment altered expression levels of heat shock protein 70 and reduced acute phase neuronal injury in rats subjected to transient focal cerebral ischemia/reperfusion. METHODS: Forty male Sprague-Dawley rats (260-300 g) were randomly assigned to one of four groups (saline-treated, or 0.1, 0.5, or 5 mg/kg gabapentin group). In all animals, focal cerebral ischemia was induced by intraluminal middle cerebral artery occlusion for 1 hour. The animals of the gabapentin groups were pretreated with a single intravenous administration of gabapentin 20 minutes before ischemic insults. The infarct volume, brain edema and motor behavior deficits were analyzed 24 hours after ischemic insult. Caspase-3-reactive cells and cells showing Hsp70 activity were counted in the caudoputamen and fronto-parietal cortex. RESULTS: The infarction ratio was significantly decreased in the 5 mg/kg gabapentin group (P < 0.05) and brain edema ratios were significantly reduced in the 0.1 mg/kg, 0.5 mg/kg, and 5 mg/kg gabapentin groups 24 hours after ischemia/reperfusion injury (P < 0.05). There were more Hsp70-reactive cells in the 5 mg/kg gabapentin group than in the saline group in both the caudoputamen and fronto-parietal cortex (P < 0.05). CONCLUSIONS: These results indicate that gabapentin may have a neuroprotective effect and can reduce early neuronal injury caused by focal cerebral ischemia/reperfusion; this may be mediated by expression of Hsp70. However, gabapentin pretreatment did not prevent caspase-dependent apoptosis.

The effects of gabapentin pretreatment on brain injury induced by focal cerebral ischemia/reperfusion in the rat / 대한마취과학회지

BACKGROUND: Experimental studies have shown that gabapentin can reduce neuronal injury in the setting of cerebral ischemia, but the mechanisms have not yet been clearly determined. This study was conducted to determine whether gabapentin pretreatment altered expression levels of heat shock protein 70 and reduced acute phase neuronal injury in rats subjected to transient focal cerebral ischemia/reperfusion. METHODS: Forty male Sprague-Dawley rats (260-300 g) were randomly assigned to one of four groups (saline-treated, or 0.1, 0.5, or 5 mg/kg gabapentin group). In all animals, focal cerebral ischemia was induced by intraluminal middle cerebral artery occlusion for 1 hour. The animals of the gabapentin groups were pretreated with a single intravenous administration of gabapentin 20 minutes before ischemic insults. The infarct volume, brain edema and motor behavior deficits were analyzed 24 hours after ischemic insult. Caspase-3-reactive cells and cells showing Hsp70 activity were counted in the caudoputamen and fronto-parietal cortex. RESULTS: The infarction ratio was significantly decreased in the 5 mg/kg gabapentin group (P < 0.05) and brain edema ratios were significantly reduced in the 0.1 mg/kg, 0.5 mg/kg, and 5 mg/kg gabapentin groups 24 hours after ischemia/reperfusion injury (P < 0.05). There were more Hsp70-reactive cells in the 5 mg/kg gabapentin group than in the saline group in both the caudoputamen and fronto-parietal cortex (P < 0.05). CONCLUSIONS: These results indicate that gabapentin may have a neuroprotective effect and can reduce early neuronal injury caused by focal cerebral ischemia/reperfusion; this may be mediated by expression of Hsp70. However, gabapentin pretreatment did not prevent caspase-dependent apoptosis.

Erratum: Growth suppression of four cancer cells by hyperbaric nitrous oxide and methotrexate (Korean J Anesthesiol 2010; 58(1): 61-69) / 대한마취과학회지

No abstract available.

Assessment of successful epidural steroid injection using photoplethysmogram

BACKGROUND:One of effective treatment methods for back pain and radiculopathy is epidural steroid injection (ESI). However, its effectiveness is hard to judge.So, it is strongly urged to develop a method to evaluate the proper injection of ESI. Photoplethysmogram (PPG) is known as a technique to measure blood oxygen saturation. We were intended to study the PPG for the evaluation of the ESI instantaneously. METHODS:All patients were explained for the study protocol to get informed consent.Twenty volunteers were recruited for this study and four of them were allocated in one of 5 ESI levels; L2-3, L3-4, L4-5, L5-S1 and caudal.They were in the lateral position with 4 PPG probes in their both 2nd fingers and 2nd toes.The PPG signals were collected to a device and converted digitally.PPG signal has two components, total absorbance (TA) and oscillating pulse component (OPC).We compared the both toe PPG signals before and after ESI based on the finger PPG. RESULTS:TA changed in 60% of ESI volunteers and L4-L5 and L5-S1 groups had high change rate compared to L2-L3 group.Also, the symptom relief rate of TA and OPC change volunteers of L4-L5 and L5-S1 were 100% but other level had variable relief rate. CONCLUSIONS:It is possible to use the PPG signal to predict ESI success based appropriate signal change.It is also needed to develop other level signal detection method and to modify appropriate guideline for the decision of change of PPG.

The Mechanism of R-PIA Induced Mechanical Antiallodynia in a Peripheral Neuropathic Rat / 대한마취과학회지

BACKGROUND: The injury by a nerve ligation produces a mechanical allodynia. The antiallodynic effect resulted from intrathecal administration of the adenosine analogues has been well known. ATP-sensitive potassium channel blockers have been known to reverse the effect of some antinociceptive drugs in animal and human studies. Therefore, the present study is to assess the relationship between antiallodynic effect of N6-(R)-phenylisopropyl adenosine (R-PIA) and mitochondrial ATP-sensitive potassium (mKATP) channel in a neuropathic pain model. METHODS: Allodynia was induced in male Sprague Dawley rats by the tight ligation of the left lumbar 5th and 6th spinal nerves. We tested the mechanical allodynia by pricking von Frey filaments to the left hind paw and assessed withdrawal thresholds of paw with up-down method. For the estimation of the antiallodynic effect of R-PIA, R-PIA (0.5, 1 and 2microgram) or saline were administered intrathecally.To investigate the reversal effect on antiallodynic effect of R-PIA, variable amounts of 5-hydroxydecanoate (5-HD, 20, 30 and 40 mg), mKATP channel blocker were administered intraperitoneally at 5 min prior to the intrathecal injection of 2microgram of R-PIA, and the degree of allodynia was assessed. RESULTS: The paw withdrawal threshold was gradually increased with increased dose of R-PIA and reached the maximum level with 2microgram R-PIA (P < 0.05). The increase of paw withdrawal threshold with 2microgram R-PIA was significantly reversed dose-dependently by intraperitoneal pretreatment of 20, 30 and 40 mg/kg 5-HD (P < 0.05). CONCLUSIONS: In our results, intraperitoneal injection of 5-HD before intrathecal injection of R-PIA had reversed the antiallodynic effect of R-PIA. This results suggest that the mechanism of mechanical antiallodynia induced by intrathecal injection of R-PIA may relate with the mK(ATP) channel in a rat model of nerve ligation injury.

Cerebral Ischemia Detected by the Bispectral Index during Cardiopulmonary Bypass: A case report / 대한마취과학회지

The bispectral index (BIS) has been developed as a measure for monitoring the hypnotic drug effect. EEG processing results in a BIS scale from 0 to 100, where 100 represents an awake and responsive patient, and the scale decreases when hypnotics are administered. Here we describe two patients in whom the BIS decreased to nearly 0 during cardiac surgery. Postoperatively both patients showed hypoxic brain injury. There are several possible causes for a decrease in the BIS during surgery, including deep anesthesia, hypothermia and cerebral ischemia. In the present cases, cerebral hypoperfusion was the likely cause. During cardiac surgery, hemodynamic changes such as acute hypotension and cardiac arrest can cause cerebral ischemia. Cerebral ischemia develops most commonly during cardiopulmonary bypass (CPB). Therefore, the BIS may be useful for detecting severe cerebral ischemia during CPB, although it has some limitations as a cerebral monitor.

The Hemodynamic Effects of Remifentanil as an Induction Agent in Cardiac Surgery

BACKGROUND: Remifentanil may be advantageous during induction of anesthesia in patient with heart disease because of rapid onset and hemodynamic stability. Some study reported that remifentanil showed complications such as profound bradycardia, severe hypotension and rigidity. The purpose of this study is to investigate the hemodynamic changes and side effects of remifentanil by using the methods of bolus administration during induction of anesthesia in cardiac surgery. METHODS: Fifty eight patients of ASA physical status 2~3 undergoing cardiac surgery were enrolled into 3 groups. We administered no remifentanil in Group A, 5microg/kg of remifentanil in Group B and 10microg/kg of remifentanil in Group C. After bolus administration of remifentanil over 30 sec, we infused 0.2microg/kg/min of remifentanil continuously. All group received continuous infusion of 100microg/ kg/min of propofol. After loss of consciousness, 0.15 mg/kg of vecuronium was administered. After the Bispectral index (BIS) value became lower than 60, intubation was done. Mean arterial pressure, heart rate, the incidence of cough, jaw and chest wall rigidity, and BIS value were measured initially and 1, 2, 3, 4, 5 minutes before intubation and 1, 2, 3, 4, 5 minutes after intubation. RESULTS: Mean arterial pressures of group B and C were significantly lower than those of group A (P < 0.05). Heart rate was similar among the groups. Group C showed a greater incidence of jaw rigidity (77%) compared with group A (35%) and group B (35%) (P < 0.05). The incidence of chest wall rigidity (66%) in group C was greater than group A (5%) and group B (15%) (P < 0.05). CONCLUSIONS: Remifentanil used as an induction agent (5microg/kg or 10microg/kg) may cause hypotension and jaw, chest wall rigidity with improper ventilation.

Three blood pressure measurement methods and comparison of measured data / 대한마취과학회지

No abstract available.

Abnormal BIS and Cerebral Oxygen Saturation during Mitral Valvuloplasty following Reversible Visual Loss in Postoperative Period: A case report / 대한마취과학회지

Cerebral complication after cardiac surgery with cardiopulmonary bypass varies widely focal neurologic deficit, stupor, coma, dementia, memory deficit, or seizures. The incidence of visual loss from ischemic optic neuropathy is from 0.06% to 0.113%. Visual loss is a rare but devastating complication of cardiac surgery. This report describes a patient who had reversible visual loss in postoperative period. She had undergone the decrease of bispectral index, cerebral oxygen saturation and the increase of suppression ratio during mitral valvuloplasty.