Developed Extrapotine Myelinolysis after Hysteroscopic Myomectomy: A case report / 대한마취과학회지

Transcervical resection of endometrium is under-utilized in the treatment of dysfunctional uterine bleeding, uterine myoma and menorrhagia. The procedure is similar to transurethral resection of prostate in men with a possibility of substantial absorption of irrigation fluid. Absorption of a large volume of fluid can cause excessive intravascular volume, hyponatremia, cerebral edema and death. Severe hyponatremia leading to extrapontine myelinolysis is an extremely rare complication of this procedure. So, We report a case of developed extrapontine myelinolysis after hysteroscopic myomectomy which, however, showed complete recovery.

Hydrohemothorax and Subclavian Artery Laceration during Internal Jugular Vein Cannulation: A case report / 대한마취과학회지

Central venous cannulation via an internal jugular vein has become a common procedure in the management and monitoring of severely ill patients. Although complications such as carotid artery puncture or pneumothorax have been reported, hemothorax is relatively uncommon. We describe a case of hydrohemothorax and subclavian artery laceration which occurred during right internal jugular vein cannulation. A 44-year-old female patient was admitted for laparoscopic adrenalectomy under general anesthesia. For central venous pressure monitoring, central venous cannulation performed. However, dilator overinsertion injured the right subclavian artery. This led to a massive ipsilateral hydrohemothorax requiring thoracotomy for subclavian artery repair. This case suggests that central venous cannulation should be done carefully and improves awareness of the potential for dilator induced injury.

Change of Blood Pressure Variability before and during Sevoflurane Anesthesia / 대한마취과학회지

BACKGROUND: Relatively little is known about the effects of general anesthesia on blood pressure variability (BPV). This study was designed to evaluate the changes of high frequency (HF) and low frequency (LF) of BPV before and during general anesthesia with sevoflurane. METHODS: Beat-to-beat blood pressure was recorded at conscious baseline and during general anesthesia at 2% end-tidal sevoflurane in 17 healthy living-liver transplantation donors. BPV estimated by power spectra of systolic (SBP) and mean blood pressure (MBP) was calculated. RESULTS: Both LF power of SBP and MBP were diminished to 96.2% and 97.1% during sevoflurane anesthesia (5.5 +/- 2.8 to 0.2 +/- 0.2 mmHg2, 6.6 +/- 3.7 to 0.2 +/- 0.2 mmHg2, P < 0.001 for both). However, there were no significant changes of HF power of SBP and MBP during sevoflurane anesthesia. CONCLUSION: Sevoflurane anesthesia reduced noticeably LF power, which was associated with sympathetic vasomotor activity, but not HF power, which represents mostly the mechanical effect of respiration on blood pressure, of BPV.

Assessment of Autonomic Response before and after Total Spinal Anesthesia in Rats: Power Spectral Analysis / 대한마취과학회지

BACKGROUND: Total spinal anesthesia (TSA) after injections of local anesthetics into the intrathecal space during epidural anesthesia is not rare. TSA anesthetizes cranial nerves and peripheral nerves, causes specific circulatory disturbances related to autonomic imbalance. Spectral analysis of heart rate variability (HRV) and blood pressure variability (BPV) provide a dynamic assessment of sympathetic and parasympathetic tone. Cross-spectral analysis has been used to emphasize this dynamic baroreflex control of HR as a frequency-dependent phenomenon and allows an assessment of baroreflex function. To examine the effects of TSA on the autonomic nervous system, we used spectral and cross-spectral analytic METHODS. METHODS: We investigated 14 rats before and after TSA. Power spectral densities of blood pressure (BP) and heart rate (HR) were estimated by fast Fourier transform. To evaluate the effect of TSA on baroreflex function, the cross spectral gain, phase, and coherence between beat-to-beat BP and HR signals were calculated by using transfer function analysis. RESULTS: With the onset of TSA, BP and HR significantly decreased. TSA significantly decreased the low frequency (LF) and high frequency (HF) components of HRV and BPV. Baroreflex sensitivity (BRS) obtained from transfer function gain between these variables was significantly decreased. CONCLUSIONS: TSA reduces the LF and HF components of HRV and BPV. These suggest that TSA in rats decreases both parasympathetic and sympathetic drive. Moreover, the decrease in BRS suggests impairment of cardiac baroreflex buffering function during TSA.

Protective Effect of Isoflurane on Noise-induced Hearing Loss in Mice / 대한마취과학회지

BACKGROUND: It is well known that the loud noise exposure can lead to noise-induced hearing loss (NIHL). Drilling during mastoid surgery may result in NIHL. The noise level produced by drilling of the mastoid bone can exceed 125 dB HL (hearing level); therefore, mastoid surgery itself is associated with a lower incidence of NIHL than expected. The aim of this study was to analyze the effects of isoflurane on NIHL and hair cell morphological changes. METHODS: BALB/c mice were divided into 2 groups; a control group (n = 20) and an isoflurane group (n = 20). The mice of both groups were exposed to 120 dB SPL (sound pressure level) broadband white noise for 3 hours per day, for 3 consecutive days. The mice in the isoflurane group were anesthetized with isoflurane while exposed to the noise. The auditory brainstem response (ABR) thresholds were determined 1 day before and after the noise-exposure and then again after 7 days. Both cochlea were removed and stained using fluorescent isothiocyanate (FITC) phalloidin. RESULTS: 1 day prior to noise-exposure, the ABR thresholds were those of a normal hearing level in both the control and isoflurane groups. In the control group, the mean hearing threshold was 78.0+/-2.6 dB HL after 1 day of noise-exposure and 81.5+/-3.4 dB HL after 1 week; in the isoflurane group, the mean hearing threshold was 49+/-11.7 dB HL after 1 day and 30.5+/-9.3 dB HL after 1 week. The hearing thresholds after noise exposure in the control were significantly higher than those in the isoflurane group (P<0.05). CONCLUSIONS: The occurrence of NIHL decreased and the hair cell damage suppressed in the mice exposed to intense noise while anesthetized by isoflurane.

The Effect of Low-dose Atropine on Baroreflex Sensitivity Assessed by Transfer Function Analysis / 대한마취과학회지

BACKGROUND: The arterial baroreflex is a key mechanism for maintaining blood pressure homeostasis. Low-dose atropine (LDA) causes bradycardia, either by acting on the sinoatrial node or due to its effect on central muscarinic receptors, which increases vagal activity. We evaluated the effect of LDA on baroreflex sensitivity (BRS) in healthy awake subjects. METHODS: We assessed changes in RR interval (RRI) and systolic blood pressure (SBP), power spectral densities of heart rate variability (HRV) and systolic blood pressure variability (SBPV), and spontaneous BRS by using transfer function analysis before and after LDA (2microgram/kg) in 17 healthy volunteers. RESULTS: LDA induced not only bradycardia but also increased of the high-frequency (HF) component of HRV, RMSSD (root mean squared successive difference interval), and pNN50 (percentage of sinus cycles differing from the preceding cycle by > 50 ms). The HF and LF components of SBPV remained unchanged. Spontaneous BRS determined by transfer function analysis increased significantly (P < 0.05), and changes in BRS were significantly associated with changes in the HF component of HRV (P < 0.05). CONCLUSIONS: LDA increased vagal cardiac function and arterial baroreflex in awake subjects. This result suggests that increased vagal cardiac function by LDA application is related to baroreflex increase.

Hemodynamic Response to a Rapid Fluid Challenge in End-Stage Liver Disease / 대한마취과학회지

BACKGROUND: Patients with end-stage liver disease have a hyperdynamic circulatory state complicated by a high right ventricular end-diastolic volume index (RVEDVI) and a low ventricular performance. These changes often make if difficult to evaluate volume status and preload. In this study, we analyzed hemodynamic profiles after a rapid fluid challenge in the recipients of a liver transplant. METHODS: Hemodynamic responses were evaluated before and after 200 ml of a 5% albumin challenge in forty patients, recipients of a liver transplant with a Swan-Ganz right-heart ejection fraction oximetry thermodilution cathether. Patients were divided into two groups, group A (responders, n=12, >or= 10% increase in stroke volume index (SVI) after fluid challenge) and group B (non-responders, n = 28, decrease or < 10% increase in SVI after fluid challenge). We analyzed hemodynamic data obtained from the two groups before and after the fluid challenge. RESULTS: Group B had a lower baseline right ventricular ejection fraction (REF) (49.9+/-5.9% vs 42.8+/-5.7%), a higher RVEDVI (120.8+/-19.4 ml/m2 vs 143.6+/-26.3 ml/m2), and a higher right ventricular end-systolic volume index (RVESVI) (60.8+/-14.0 ml/m2 vs 82.8+/-20.5 ml/m2) than group A. In group B, the cardic index (CI) and right ventricular stroke work index (RVSWI) were not increased after the fluid challenge. There was a mild decrease in the mean arterial pressure (MAP) in group B after the fluid challenge. There was a moderate negative correlation between the fluid-induced change in SVI and the baseline RVEDVI in all patients (r =-0.40, P<0.05). CONCLUSIONS: Our study suggests that there is no improvement of hemodynamic profiles after a rapid fluid challenge in many patients with end-stage liver disease, especially those with a high RVEDVI.

Cardiac Tamponade Recognized after Reperfusion during an Orthotopic Liver Transplantation / 대한마취과학회지

Cardiac tamponade is a life-threatening predicament which demands early recognition and immediate treatment. We report a case of iatrogenic intraoperative cardiac tamponade during an orthotopic liver transplantation. A 55 year-old man was scheduled for an orthotopic liver transplantation due to hepatocellular carcinoma. During the anhepatic period, the patient's vital signs remained stable, but the central venous pressure and pulmonary artery diastolic pressure were increased. However, immediately after reperfusion, sudden hypotension and tachycardia developed. Fluid volume resuscitation and epinephrine injection led only to a transient improvement of the blood pressure. It took approximately 30 minutes to realize the possibility of the cause of hypotension might be due to cardiac tamponade rather than post-reperfusion syndrome. After an emergent transdiaphragmatic pericardiocentesis, we found that the cause of the cardiac tamponade was tearing of an epicardial coronary vein. Evacuation of a massive hematoma resulted in a rapid improvement in the patient's cardiovascular status. The patient has made an uneventful recovery.

Measurement of Auto-PEEP in Anesthetized Patients Using a Laser-Flex Endotracheal Tube with Changes in Respiratory Rates and Tidal Volume / 대한마취과학회지

BACKGROUND: The aim of the present study was to detect and quantify auto-positive end-expiratory pressure (auto-PEEP) in anesthetized patients using a Laser-Flex endotracheal tube (Mallincrodt, ID, 6.0 mm), by comparing the effects of changes in tidal volume and respiratory rate. METHODS: All patients (n = 30) undergoing elective surgery were anesthetized, paralyzed and intubated with a ID 8.0 mm endotracheal tube (n = 10, control), ID 6.0 mm endotracheal tube (n = 10, group S), or ID 6.0 mm Laser-Flex endotracheal tube (n = 10, group L), respectively. After anesthetic induction, ventilator settings using a Siemens Servo 900C were changed for a tidal volume of 8, 10 ml/kg, respiratory rates of 10, 12 or 14 breaths/min. Peak airway pressure was measured and auto-PEEP was quantified using an end-expiratory occlusion method. Data recorded on the Bicore CP-100 pulmonary monitor was transfered to a PC and analyzed by processing software (ANADAT). RESULTS: In group S and L, peak airway pressure and auto-PEEP were higher than control group and increased during an increase in tidal volume (P < 0.05). But they were increased significantly during an increase of respiratory rate, only when the tidal volume was 10 ml/kg (P < 0.05). CONCLUSIONS: There was an increase of auto-PEEP in anesthetized patients using a Laser-Flex endotracheal tube during incremental changes of tidal volume and respiratory rates.