The effect of injection speed on remifentanil-induced cough in children / 대한마취과학회지

BACKGROUND: Remifentanil sometimes elicits cough during induction of anesthesia, as with the use of other fentanyl congeners. We designed this study to investigate the incidence of remifentanil-induced cough (RIC) in children and to evaluate the effect of injection speed on RIC. METHODS: One hundred twenty ASA physical status I-II patients, aged 3-12 yr, undergoing general anesthesia were enrolled in the study. Patients were randomly assigned to one of the three groups. Patients in Group R30 received remifentanil 1.5 microg/kg at a constant rate over 30 s. Patients in Group R45 received remifentanil 1.5 microg/kg over 45 s, and patients in Group R60 received remifentanil 1.5 microg/kg over 60 s, respectively. Episodes of cough were recorded and graded as mild (1-2), moderate (3-4), or severe (5 or more). Mean arterial pressure (MAP), heart rate (HR), and SpO2 were recorded on arrival in the operating room (baseline) and 1 min after remifentanil infusion. RESULTS: The incidence of RIC was 33.3% in Group R30 (13 of 39 patients), 17.9% in Group R45 (7 of 39 patients), and 5.0% in Group R60 (2 of 40 patients). Patients in Group R60 had a significantly lower incidence of RIC than those in Group R30 (P = 0.001). The MAP, HR, and SpO2 values were not significantly different between groups. CONCLUSIONS: When intravenous remifentanil 1.5 microg/kg was administered in pediatric patients, the incidence of RIC decreased from 33 to 5% by increasing the injection time from 30 to 60 s. Remifentanil should be administered slowly over 60 s in children to suppress cough during anesthesia induction.

Arrangements of the intravenous parallel infusions with anti-reflux valves decreasing occlusion alarm delay / 대한마취과학회지

BACKGROUND: The methods of arrangement of combined intravenous parallel infusions using anti-reflux valve (ARV), with and without anti-syphon valve (ASV) that could decrease occlusion alarm delay were investigated. METHODS: Occlusion challenge tests were mainly performed as bench experiments of four kinds of multiple parallel infusions (10 ml/h and 50 ml/h infusions), which were connected at the proximal or distal portion of ARV, with or without ASV. Alarm threshold was set to 1000 mmHg. Occlusion alarm delays and the compliances of the infusion systems were compared among groups. RESULTS: Without ASV, compared to 10 ml/h infusion alone distal to anti-reflux valve, 50 ml/h infusion distal to anti-reflux valve reduced the mean alarm delay from 416 +/- 7 s to 81 +/- 3 s (P < 0.001). Compared to 50 ml/h infusion alone, combined 10 ml/h and 50 ml/h infusion distal to ARV prolonged the alarm delay from 81 +/- 3 s to 133 +/- 6 s (P < 0.001). However, combined infusions distal to ARV with ASV significantly reduced the alarm delay from 133 +/- 6 s to 74 +/- 5 s (P < 0.001), and also reduced the compliance of the infusion system from 2.31 +/- 0.12 to 1.20 +/- 0.08 microl/mmHg (P < 0.001). CONCLUSIONS: The infusion setup of faster infusion rate, lower compliant system using ASV could effectively decrease occlusion alarm delay during multiple intravenous parallel infusions using ARV.

Spontaneous intracranial epidural hematoma following aortic valve replacement: A case report

Epidural hematomas are usually traumatic in origin. Non-traumatic spontaneous epidural hematoma is rare and its incidence is not known. It can occur in the presence of coagulopathy and hypotension. We report a case of spontaneous intracranial epidural hematoma following the aortic valve replacement, possibly arising from excessive anticoagulation and hypotension during ventricular fibrillation.

Impact of priming the infusion system on the performance of target-controlled infusion of remifentanil / 대한마취과학회지

BACKGROUND: The start-up behavior of syringe and syringe pump is known to be one of the causes of inaccurate intravenous infusion. This study evaluated the method of priming the infusion system (PRIMING), and its impact on the target-controlled infusion (TCI) of two remifentanil diluents. METHODS: PRIMING was performed using an evacuation of 2.0 ml to the atmosphere prior to TCI. Forty-eight TCI, using 50 microg/ml (Remi50) or 20 microg/ml (Remi20) of diluents, were performed targeting 4.0 ng/ml of effect-site concentration (Ceff), with PRIMING or not. The gravimetrical measurements of the delivered infusates reproduced actual Ceff. The bolus amount and time to reach 95% target were compared. RESULTS: Without PRIMING, Remi50 infused less bolus (43 +/- 23 %) than Remi20 (19 +/- 9 %) (P = 0.003), and showed more delayed increase of Ceff (11.2 +/- 4.0 min) than Remi20 (7.4 +/- 0.4 min) (P = 0.028). However, PRIMING significantly decreased the deficit of the bolus (2 +/- 1%), as well as the delay of the increase of Ceff in Remi50 (1.2 +/- 0.2 min) (both P < 0.001). In addition, with PRIMING, the start-up bolus showed minimal difference to the nominal bolus (1 and 2%), and Ceff were increased to 4.0 +/- 0.1 ng/ml at the expected time of peak effect, irrespective of the diluents. CONCLUSIONS: Proper operation of the syringe pump used in the priming of the syringe may be helpful in reduction of the inaccuracy of TCI, particularly during the early phase of infusion, or the infusion of a more concentrated diluent.

False selection of syringe-brand compatibility and the method of correction during target-controlled infusion of propofol / 대한마취과학회지

BACKGROUND: We evaluated volumetric differences of syringe brand compatibilities, and investigated the impact of false brand settings on target-controlled infusion (TCI) and their methods of correction. METHODS: Gravimetric measurement of 10 ml bolus infusions was performed using BD Plastipak (BDP) and Terumo compatible syringes, while setting to 7 different kinds of brand compatibilities (BDP, Sherwood Monoject, BD Perfusion, Braun Perfusor, Braun Omnifix, Fresenius Injectomat, and Terumo). To investigate the performance of TCI using BDP with a false setting to Terumo (BDPTERUMO) and Terumo to BDP (TERUMOBDP), 24 TCI targeting 4.0 microg/ml of effect-site concentration (Ceff) of propofol were performed. Subsequently, another 24 TCI were evaluated for simple corrections of false settings at 30 min. We also investigated 24 TCI using active corrections (fill-up for BDPTERUMO, evacuation for TERUMOBDP) based on the pharmacokinetics of propofol. The Ceff at 30 min of TCI and time to normalize to +/- 5% of target concentration (T+/-5%target) were compared. RESULTS: The Ceff of BDPTERUMO showed negative bias and 17.2% inaccuracy, and the Ceff of TERUMOBDP showed positive bias and 19.5% inaccuracy. The Ceff at 30 min showed no difference between the methods of correction in BDPTERUMO or TERUMOBDP. The T+/-5%target in both the active corrections was significantly shorter than that of each simple corrections (P < 0.001). CONCLUSIONS: False brand setting of syringe proportionally maintained different predicted concentrations as much as the volumetric differences of syringe brand. Based on the results, it is proposed that correction methods based on pharmacokinetics could effectively normalize the differences, without giving up the wrong TCI.

Cross-simulation between two pharmacokinetic models for the target-controlled infusion of propofol / 대한마취과학회지

BACKGROUND: We investigated how one pharmacokinetic (PK) model differed in prediction of plasma (Cp) and effect-site concentration (Ceff) using a reproducing simulation of target-controlled infusion (TCI) with another PK model of propofol. METHODS: Sixty female patients were randomly assigned to TCI using Marsh PK (Group M) and TCI using Schnider PK (Group S) targeting 6.0 microg/ml of Cp of propofol for induction of anesthesia, and loss of responsiveness (LOR) was evaluated. Total and separate cross-simulation were investigated using the 2 hr TCI data (Marsh TCI and Schnider TCI), and we investigated the reproduced predicted concentrations (MARSHSCH and SCHNIDERMAR) using the other model. The correlation of the difference with covariates, and the influence of the PK parameters on the difference of prediction were investigated. RESULTS: Group M had a shorter time to LOR compared to Group S (P < 0.001), but Ceff at LOR was not different between groups. Reproduced simulations showed different time courses of Cp. MARSHSCH predicted a higher concentration during the early phase, whereas SCHNIDERMAR was maintained at a higher concentration. Volume and clearance of the central compartment were relevant to the difference of prediction, respectively. Body weight correlated well with differences in prediction between models (Rsqr = 0.9821, P < 0.001). CONCLUSIONS: We compared two PK models to determine the different infusion behaviors during TCI, which resulted from the different parameter sets for each PK model.

Development of a contralateral acute subdural hematoma during awake craniotomy for glial tumor in a 12-year-old boy: A case report

Contralateral acute subdural hematomas that occur during removal of brain tumors under general anesthesia are extremely rare, and there are no reports of this developing during awake craniotomy for brain tumors. We report a case of a 12-year-old boy who complained of sudden and severe headache and nausea around the completion of removal of a glial tumor of the frontal lobe under awake anesthesia. Postoperative computerized tomography scan revealed the presence of contralateral acute minimal subdural hematoma. We suggest that during craniotomy with awake anesthesia for brain tumors, contralateral acute subdural hematoma may occur, even in the absence of brain bulging or changes in vital signs. Sudden intra-operative headache and nausea should be investigated by immediate postoperative computerized tomography scans to ascertain diagnosis.

Development of a contralateral acute subdural hematoma during awake craniotomy for glial tumor in a 12-year-old boy: A case report

Contralateral acute subdural hematomas that occur during removal of brain tumors under general anesthesia are extremely rare, and there are no reports of this developing during awake craniotomy for brain tumors. We report a case of a 12-year-old boy who complained of sudden and severe headache and nausea around the completion of removal of a glial tumor of the frontal lobe under awake anesthesia. Postoperative computerized tomography scan revealed the presence of contralateral acute minimal subdural hematoma. We suggest that during craniotomy with awake anesthesia for brain tumors, contralateral acute subdural hematoma may occur, even in the absence of brain bulging or changes in vital signs. Sudden intra-operative headache and nausea should be investigated by immediate postoperative computerized tomography scans to ascertain diagnosis.

The effect of airway obstruction on systolic arterial and central venous pressure during sedation in patients undergoing total knee replacement / 대한마취과학회지

BACKGROUND: Severe respiratory variations of systolic arterial and central venous pressure (CVP) may increase the risk of embolic event in orthopedic patient. As airway obstruction during sedation can cause this respiratory variation, we evaluated the degree of variations of systolic blood (SBP) and CVP during airway obstruction period. METHODS: Fifteen females who had obstructed airway during total knee replacement (TKR) were included for the study. After regional anesthesia were established, SBP and CVP variations were analyzed according to the three periods; baseline, obstruction, and airway, respectively. Calculated CVP variables were similar to SBP variables as below: DeltaSBP = Expmax (maximal value at expiration) - Inspnadir (minimal value at inspiration), %DeltaSBP = (DeltaSBP/ Exp(max)) x 100. The frequencies of pulsus paradoxus (PP) and negative inspiratory CVP (NIC) were also measured. RESULTS: At obstruction period, DeltaSBP was 21.7 mmHg and 93.3% of patient had PP. Also, DeltaCVP was 19.3 mmHg and 100% of patient showed NIC. %DeltaCVP (140%) was larger than %DeltaSBP (16%). And DeltaCVP was inversely correlated with baseline and obstruction SBP and %DeltaCVP was also inversely correlated with baseline CVP at obstruction period. CONCLUSIONS: During airway obstruction in sedated TKR patients, variations of CVP are larger than those of SBP. So we have to monitor CVP continuously as well as SBP so as not to increase the possible risk of respiratory of variation.

Hemodynamic Changes after Endotracheal Intubation in Patients with Cerebral Aneurysm

BACKGROUND: Tracheal intubation with a lightwand intubating device (Trachlight) attenuates the hemodynamic stress response to tracheal intubation compared with a direct laryngoscope approach. We compared the effects of the direct laryngoscope (Macintosh blade) and lightwand for intubation in patients with cerebral aneurysm. METHODS: Twenty-four patients undergoing cerebral aneurysm clipping surgery were randomly divided to either the lightwand (Group 1, n = 12) or the laryngoscope (Group 2, n = 12) Group. All patients received fentanyl (2-3microg/kg), midazolam (0.1 mg/kg), and thiopental sodium (2-3microg/kg) followed by vecuronium (0.1- 0.15microg/kg). The lungs were ventilated with 3-4% isoflurane in oxygen, with 1% lidocaine (1-1.5microg/kg) administered before intubation with either the lightwand or the laryngoscope. Systolic, diastolic and mean blood pressures and heart rate were recorded continuously before and for 5 min after intubation. RESULTS: Systolic and mean arterial blood pressure increased significantly (P < 0.05) 1 minute after intubation, but then returned to normal within the next minute. There were no differences in hemodynamic changes between the two groups, and no complications. CONCLUSIONS: Intubation technique did not affect hemodynamic changes in patients with cerebral aneurysm. In patients with aneurysms, appropriate anesthetic levels and pharmacologic manipulation will attenuate the hemodynamic stress response associated with tracheal intubation.

The effects of propofol on neurotoxicity induced by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid in rat mixed cortical cultures / 대한마취과학회지

BACKGROUND: The pattern of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-mediated neurotoxicity (necrosis vs apoptosis) and the neuroprotective effect of propofol on AMPA-mediated neurotoxicity are still unclear. METHODS: Thirteen-day-old primary rat mixed cortical cultures were used. To measure the neuroprotective effect of propofol, AMPA (50micrometer), AMPA (50micrometer) plus propofol (0.1, 1, 25, 50micrometer), AMPA (50micrometer) plus DMSO, propofol (50micrometer) and DMSO were administered (n = 45). Seventy-two h later, surviving cells were counted using trypan blue staining and were converted to cell death rate (CDR). To measure the effect of propofol (50micrometer) on AMPA (50micrometer)-induced apoptosis, a triple stain was done. In a fixed field (x400), the number of neuronal cells stained by neuronal nuclei (NeuN) and Hoechst staining and apoptotic cells stained by terminal deoxynucleotidyl transferase mediated dUTP nick-end-labeling (TUNEL) assays were counted. Apoptotic cell rates (ACR) were also calculated. Statistical analyses were performed using one way-analysis of variance followed by Bonferroni's test. P < 0.05 was considered statistically significant. RESULTS: AMPA (50micrometer) stimulation demonstrated 49.3% CDR, and adding propofol 50micrometer decreased CDR to 29.4% (P < 0.05). In the TUNEL assay, cells with no drug treatment demonstrated 12.3% ACR and 50micrometer AMPA increased ACR to 28% (P < 0.05). Adding 50micrometer propofol to AMPA decreased the ACR to 20.1% (P < 0.05). CONCLUSIONS: Propofol (50micrometer) had neuroprotective effects against AMPA (50micrometer)-induced cell death by reducing apoptosis.

The effects of propofol on neurotoxicity induced by alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid in rat mixed cortical cultures / 대한마취과학회지

BACKGROUND: The pattern of alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-mediated neurotoxicity (necrosis vs apoptosis) and the neuroprotective effect of propofol on AMPA-mediated neurotoxicity are still unclear. METHODS: Thirteen-day-old primary rat mixed cortical cultures were used. To measure the neuroprotective effect of propofol, AMPA (50micrometer), AMPA (50micrometer) plus propofol (0.1, 1, 25, 50micrometer), AMPA (50micrometer) plus DMSO, propofol (50micrometer) and DMSO were administered (n = 45). Seventy-two h later, surviving cells were counted using trypan blue staining and were converted to cell death rate (CDR). To measure the effect of propofol (50micrometer) on AMPA (50micrometer)-induced apoptosis, a triple stain was done. In a fixed field (x400), the number of neuronal cells stained by neuronal nuclei (NeuN) and Hoechst staining and apoptotic cells stained by terminal deoxynucleotidyl transferase mediated dUTP nick-end-labeling (TUNEL) assays were counted. Apoptotic cell rates (ACR) were also calculated. Statistical analyses were performed using one way-analysis of variance followed by Bonferroni's test. P < 0.05 was considered statistically significant. RESULTS: AMPA (50micrometer) stimulation demonstrated 49.3% CDR, and adding propofol 50micrometer decreased CDR to 29.4% (P < 0.05). In the TUNEL assay, cells with no drug treatment demonstrated 12.3% ACR and 50micrometer AMPA increased ACR to 28% (P < 0.05). Adding 50micrometer propofol to AMPA decreased the ACR to 20.1% (P < 0.05). CONCLUSIONS: Propofol (50micrometer) had neuroprotective effects against AMPA (50micrometer)-induced cell death by reducing apoptosis.

Predicted Effect-site Concentration of Remifentanil for Facilitating Laryngeal Mask Airway Insertion with Propofol Target-Controlled Infusion / 대한마취과학회지

BACKGROUND: The addition of remifentanil during the propofol induced anesthesia facilitates the insertion of laryngeal mask airway (LMA) with minimal adverse hemodynamic disturbances. This study predicted the optimal effect-site concentration of remifentanil for LMA insertion with propofol target-controlled infusion (TCI). METHODS: In 25 adults patients, aged 18-60 years, anesthesia was induced with propofol TCI at the effect-site concentration of 4microgram/ml. Two minutes later, the predetermined effect-site concentration of remifentanil was started. The remifentanil concentration was determined using modified Dixon's up-and-down method (0.5 ng/ml as a step size). The first patient was tested at 2.0 ng/ml remifentanil. The insertion of LMA was attempted 3 min after remifentanil TCI began. The response of the patients to the insertion of LMA was classified as either 'movement' or 'no movement'. RESULTS: The remifentanil concentration at which there was a 50% probability of successful LMA insertion (EC50) was 3.18 +/- 0.53 ng/ml. From probit analysis, the EC50 of remifentanil was 3.10 ng/ml (95% confidence limits, 2.55-4.11 ng/ml), and the EC95 was 4.31 ng/ml (95% confidence limits, 3.64-11.11 ng/ml). CONCLUSIONS: The predicted effect-site concentration of remifentanil for facilitating LMA insertion was 3.18 ng/ml in 50% of adults during propofol TCI at an effect-site concentration of 4microgram/ml without premedication.

Therapeutic Hypothermia in Patients with Traumatic Head Injury

No abstract available.

The Effect of Nitrous Oxide on Cerebral Entropy during Isoflurane Inhalational Anesthesia / 대한마취과학회지

BACKGROUND: The bispectral index has limitations in describing the exact depth of anesthesia during nitrous oxide inhalation. This study examined the effect of nitrous oxide on the cerebral entropy measured using an entropy module (M-ENTROPY Module S/5(R), Datex-Ohmeda division, Instrumentarium Corporation, Helsinki, Finland) during the stable anesthetic period with isoflurane inhalation. METHODS: Sixty ASA 1 or 2 adult patients were randomly allocated to three groups. During the stable maintenance period after the skin incision, the baseline entropy values (response entropy, RE; state entropy, SE) were recorded at 2.5 minutes intervals over a 20 minute period on a single frontal channel at 0.9% end-tidal isoflurane. After this, medical air was used continuously (group C) or replaced with nitrous oxide at 40% (group L) or 60% (group H) with continuous hemodynamic and entropy values monitoring. Each of the variables was recorded and analyzed at 2.5 minutes intervals over a 20 minute period. RESULTS: Average values (mean +/-SD) of the RE and SE during experimental period were lower in group H (29.2 +/-12.3 and 28.5 +/-11.7, respectively) than group L (33.9 +/-7.3 and 33.0 +/-7.3, respectively) and the averaged values were lower in group L than in group C (46.6 +/-14.8 and 45.5 +/-14.2, respectively). The percent reduction was larger in group H (42.1 +/-14.2 and 38.7 +/-16.5, respectively) than in group L (25.3 +/-15.1 and 24.4 +/-14.9, respectively) and the percent reduction was larger in group L than in group C (P < 0.01). Conclusions: Added nitrous oxide during the anesthetic maintenance period with isoflurane decreases the level of cerebral entropy.

The Effect of Remifentanil on the Loss of Consciousness during Propofol Infusion / 대한마취과학회지

BACKGROUND: General anesthesia is a balance between hypnosis and analgesia. Remifentanil is often combined with propofol to both induce and maintain total intravenous anesthesia. This study evaluated the effect of remifentanil on the propofol requirements for a loss of consciousness. METHODS: Forty adult patients with ASA 1 or 2 were enrolled in this study. The patients were randomly given either saline or remifentanil before the induction of anesthesia with an infusion of propofol, 15 mg/kg/h. In the remifentanil group, all the patients received a computer controlled infusion of remifentanil with a effect site concentration of 4 ng/ml. The times required for the patient to lose consciousness, the propofol requirements and the bispectral index at the loss of consciousness to verbal commands were recorded. RESULTS: In the remifentanil group, loss of consciousness was attained significantly faster and with lower propofol doses than in the saline group. The bispectral indices were significantly higher at loss of consciousness in the remifentanil group. CONCLUSIONS: A remifentanil infusion before the induction of propofol anesthesia significantly reduces the propofol requirements for the loss of consciousness. Remifentanil enhances the hypnotic effect of propofol.

The Effect of Low-dose Ketamine on the Incidence of Emergence Agitation in Preschool Children Receiving Sevoflurane Anesthesia: Comparison with Ketorolac / 대한마취과학회지

BACKGROUND: Emergence agitation is a common side effect of sevoflurane anesthesia in preschool children. Low-dose ketamine is defined as a bolus dose of less than 1 mg/kg when administered via the intravenous route, and produces potent analgesia without respiratory depression or other side effects. In this study, we examined the effect of low-dose ketamine on the incidence of emergence agitation in preschool children receiving sevoflurane anesthesia and compared this with the effect of ketorolac. METHODS: Sixty eight preschool children receiving sevoflurane anesthesia were randomized to receive either ketorolac 1 mg/kg or ketamine 0.2 mg/kg intravenously before the end of surgery. Emergence agitation was assessed using a 3-point scale (1 = asleep, calm, or mildly agitated but easily consolable; 2 = moderately agitated or restless but inconsolable; and 3 = hysterical, crying inconsolably, or thrashing) during transfer and at 10 minutes after arrival at our postanesthesia care unit. RESULTS: We observed that the incidences of emergence agitation were 30.0%, 45.0% in the ketamine group, and 60.7%, 78.6% in the ketorolac group (P < 0.05) during transfer and at 10 minutes after arrival at the postanesthesia care unit, respectively. No significant difference was observed between the two groups with respect to discharge time from the postanethesia care unit. CONCLUSIONS: Emergence agitation after sevoflurane anesthesia in preschool children was significantly reduced by low-dose ketamine as compared with ketorolac without delaying recovery.

Effect of Combined Hyperventilation and Mannitol on Cerebral Blood Flow and Cerebral O2 Metabolism during a Craniectomy / 대한마취과학회지

BACKGROUND: There are therapies to lower intracranial pressure (ICP) including head elevation, hyperventilation, diuretics injection, intravenous mannitol, hypothermia, cerebrospinal fluid drainage, and cerebral resection in neurosurgical patients. However in recent reports, hyperventilation followed by mannitol administration may lead to cerebral ischemia. Therefore, we investigated the effect of 0.5-1.0 g/kg mannitol administration on jugular venous oxygen saturation (SjVO2) and cerebral arterial- jugular venous oxygen content difference (AVDO2) at PaCO2 25-30 mmHg and 35-40 mmHg in patients undergoing neurosurgery. METHODS: We studied 17 patients undergoing neurosurgery in the Ajou University Hospital. Anesthesia was induced with fentanyl, midazolam, thiopental, and vecuronium, and maintained with O2-Air-Isoflorane, a continuous infusion of fentanyl, and vecuronium. Patients were divided into two groups. Group 1 (n = 10) which is PaCO2 25-30 mmHg and Group 2 (n = 7) which is PaCO2 35-40 mmHg by controlling ventilator. Measurements of SjVO2 and AVDO2 in following time intervals: I = preinjection of mannitol, II = postinjection 20 minutes of mannitol, III = postinjection 40 minutes of mannitol were obtained for each group. 0.5-1.0 g/kg mannitol was administered intravenously just at duramater opening. RESULTS: Hemodynamics and hematologics were not significantly different among the two groups. SjVO2 of each group are as follows; Group 1; I (70.3+/-8.1%), II (66.3+/-6.9%), III (69.1+/-7.9%) and Group 2; I (78.6+/-7.4%), II (75.1+/-8.1%), III (76.0+/-11.2%). Hyperventilation significantly decreased SjVO2. AVDO2 was not significantly different but SjVO2 in II was significantly decreased compared with I and III in Group 1 (20% patients). CONCLUSIONS: Mannitol produced a change of SjVO2 and AVDO2 during hyperventilation. Therefore, intravenous mannitol during hyperventilation should be given cautiously according to the patients status because it may cause cerebral ischemia in critical patients.

Clinical Use of Weaning Indices from Mechanical Ventilation in Surgical Intensive Care Unit Patients / 대한마취과학회지

BACKGROUND: A number of indices have been proposed as accurate predictors of weaning, but several studies have questioned the accuracy of these weaning indices in predicting the capability of independent breathing. The purpose of the study was to assess six standard bedside weaning indices and respiratory rate and tidal volume ratio (RRVT) of mechanically ventilated patients in the surgical intensive care unit (SICU). METHODS: The study was performed on 90 SICU patients who were mechanically ventilated. According to the outcome of weaning, they were divided into two groups, weaning success (n = 83) and weaning failure (n = 7). All subjects should have a PaO2 above 60 mmHg at an FiO2 of 0.4 and PEEP of 3 5 cmH2O and no PEEP in the extubated patients at the time of the weaning. Bedside weaning indices were respiratory rate (RR), tidal volume (VT), minute volume (VE), maximum inspiratory pressure (Pimax), vital capacity (VC), PaO2/FiO2 and RRVT. The predictive variables - sensitivity, specificity - of indices were calculated, and the data was also analysed with receiver-operating-characteristic (ROC) curves. RESULTS: Sensitivity was highest for VT (0.95), followed closely by the PaO2/FiO2 (0.94). Specificity was highest for Pimax (0.28). The VT was the best predictor of successful weaning, and Pimax was the best predictor of failure. The order of the area under the ROC curves was VC (0.761) followed by VE (0.636), VT (0.631), Pimax (0.546), PaO2/FiO2 (0.474), RR (0.457), and RRVT (0.339). CONCLUSIONS: Those weaning indices are good predictors of weaning success, but poor predictors of weaning failure. RRVT does not predict the weaning outcome.

Anesthesiology and Apoptosis / 대한마취과학회지

Necrosis is, in general, an unnatural cell death that rapidly occurs in response to severe insults such as poisons, anoxia, infections and trauma. Apoptosis or programmed cell death, unlike necrosis, is a physiological cell death that causes cell deletion without inflammation, release of cellular contents. In apoptosis, individual cells separate from their neighbors and begin a characteristic sequence of structural and biological changes. These changes include cell shrinkage, condensation of chromatin, DNA degradation, activation of caspase cascade. Finally, the cell itself fragments to form apoptotic bodies that engulfed by nearby phagocytes. Apoptosis is distinguished from necrosis in that gene activation is a prominent mechanism regulating cell survival. It is an essential physiological process that plays a critical role in development and tissue homeostasis and cell population control. However, apoptosis plays an important role in the pathogenesis of a number of disease. In the anesthesiology, apoptosis may contribute to major organ damage associated with ischemic/reperfusion injury, it has long been considered to represent necrosis. Apoptosis remains the important clinical consequence of ischemic/reperfusion injury. Free radicals, tumor necrosis factor-a (TNF-alpha), protein kinase c (PKC), caspases, P53, bcl-2 family and calcium have been suggested and frequently cited as important mediators for apoptosis. In this review, I will describe the known mediators and mechanism underlying apoptosis in major organ exposed to ischemic/reperfusion injury, because the usefulness and effectiveness of any therapeutic interventions for cell deaths after ischemic/reperfusion injury depends on a clear understanding of mechanism of apoptosis.