BACKGREOUND: Cerebral damage caused by hemorrhagic shock presents an important challenge for critical care medicine. The type of fluid to resuscitate hemorrhagic shock is important for the outcome of such patients. Pentastarch is low-molecular-weight hydroxyethyl starch, which increases cerebral blood flow (CBF) by plasma volume expansion and compensatory vasodilation, and improves the microcirculation in the ischemic brain area by reducing the blood viscosity. METHODS: The authors continuously determined CBF and CMRO2 in 10 mongrel dogs weighing 20.1 +/- 0.8 kg with posterior sagittal sinus outflow method. Dogs were subjected to the 20 minute-period of hemorrhagic shock to a mean arterial pressure of 40 mmHg. The shock phase was followed by resuscitation with the same volume of 10% pentastarch as blood loss. The authors assessed the changes of CBF, CMRO2, and CBF/CMRO2 ratio immediately and 30, 60, 90, 120 minutes after pentastarch infusion. Brain water content was assessed by the wet-dry weight method. RESULTS: CBF was increased above the control level, immediately and 30 minutes after 10% pentastarch infusion (p<0.05), and approximated to the control level for the remaining time. CMRO2 was increased, immediately and 30, 60, 90 minutes after 10% pentastarch infusion (p<0.05), and approximated to the control level at 120 minutes. CBF/CMRO2 ratio was recovered to the control level after 10% pentastarch infusion. Brain water content was not significantly different from the normal value of dogs. CONCLUSION: 10% pentastarch may be used with safety to resuscitate hemorrhagic shock because it recovers the balance between the cerebral oxygen supply and demand, and does not cause cerebral edema.
Animals ; Arterial Pressure ; Blood Viscosity ; Brain ; Brain Edema ; Critical Care ; Dogs ; Humans ; Hydroxyethyl Starch Derivatives* ; Microcirculation ; Oxygen* ; Plasma Volume ; Reference Values ; Resuscitation ; Shock ; Shock, Hemorrhagic* ; Starch ; Vasodilation

BACKGROUND: If general anesthesia is used for cesarean section, important considerations include minimizing the duration of general anesthesia. One may think that skin incision should be started immediately after endotracheal intubation. If so, intra-operative awareness and perception of pain may occur due to light anesthesia. Allowing skin incision to be started 5 min after intubaton while administering 50% nitrous oxide and isoflurane 0.75%, we investigated the changes of BIS (bispectral index), and Apgar scores. METHODS: The investigation was carried out on 33 full-term ASA 1 or 2 patients underwent elective cesarean section under general anesthesia. If any fetal abnormalities were found, we excluded those cases. Premedication was omitted. After rapid sequence induction with sodium thiopental 4 mg/kg, succinylcholine 1 mg/kg, we made skin incision immediately after intubation in control group (n = 18) and 5 min after intubation in experimental group while administering 50% nitrous oxide and isoflurane 0.75%. Muscle relaxation was maintained with intravenous administration of atracurium 0.5 mg/kg. We measured BIS, mean arterial pressure (MAP), heart rate in 1 min interval from preinduction period to delivery and recorded Apgar scores 1 and 5 min after delivery, skin incision to delivery time and uterine incision to delivery time. And we counted the number of patients whose BIS values had been below 60 and 70 from skin incision to delivery in each group. RESULT: Apgar scores recorded 1 and 5 min after delivery did not show significant differences between control and experimental group. During the periods of abdominal wall traction, uterine incision and delivery, BIS values of experimental group were significantly lower than control group and moreover, tended to remain below 60 while those of control group during the same periods tended to be above 60 (P < 0.05). The number of patients of experimental group, whose BIS values had been below 60 from skin incision to delivery, was twice as much as that of control group (P < 0.05), but in case of BIS value below 70, there was no significant difference between control and experimental group. During the periods of skin incision and abdominal wall traction, the MAP's of experimental group were significantly lower than control group (P < 0.05). In cases of heart rate, skin incision to delivery time and uterine incision to delivery time, there were no significant differences between control and experimental group. CONCLUSION: Allowing the skin incision to be started 5 min after intubation while administering 50% nitrous oxide and isoflurane 0.75%, BIS values remained below 60 from abdominal wall traction to delivery, and anesthetics-induced fetal depression did not occur.
Abdominal Wall ; Administration, Intravenous ; Anesthesia ; Anesthesia, General ; Arterial Pressure ; Atracurium ; Cesarean Section* ; Depression ; Female ; Heart Rate ; Humans ; Intubation* ; Intubation, Intratracheal ; Isoflurane ; Muscle Relaxation ; Nitrous Oxide ; Pregnancy ; Premedication ; Skin ; Sodium ; Succinylcholine ; Thiopental ; Traction

BACKGROUND: Direct laryngoscope may be less useful under conditions of limited visualization. Light wand is a lighted stylet to transilluminate neck tissues allowing intubation without visualization. Thus, difficult intubation due to anatomy can be overcome. For comparison of light wand and direct laryngoscope, we checked time to intubation (TTI), success rate, relation of TTI and thyromental distance (TMD), and change of blood pressure and heart rate after intubation. METHODS: We selected and randomly allocated sixty adults to direct layngoscope group (D) and light wand group (L). Without premedication, propofol and vecuronium were injected for intubation. Time to intubation was measured from the time of grasping direct laryngoscope or light wand until the time of inserting endotracheal tube into trachea. We checked the change of blood pressure and heart rate after intubation, and studied the correlation of TTI and TMD. RESULTS: TTI was 16.5 sec (6.53~115.3 sec) for group D and 11.8 sec (4.31~36.0 sec) for group L. There was no significant difference between the groups. The rise of blood pressure and heart rate was less with light wand. There was a correlation of [TTI]=1248- 388[TMD]-30[TMD]2 in group L patients whose TMD is less than 7 cm. CONCLUSION: Compared with direct laryngoscope, light wand is as easy to use and can be more effective especially for patients whose anatomy may make intubation difficult or whose cardiovascular system is unstable.
Adult ; Blood Pressure* ; Cardiovascular System ; Hand Strength ; Heart Rate* ; Heart* ; Humans ; Intubation* ; Laryngoscopes* ; Neck ; Premedication ; Propofol ; Trachea ; Vecuronium Bromide

BACKGROUND: Direct laryngoscope may be less useful under conditions of limited visualization. Light wand is a lighted stylet to transilluminate neck tissues allowing intubation without visualization. Thus, difficult intubation due to anatomy can be overcome. For comparison of light wand and direct laryngoscope, we checked time to intubation (TTI), success rate, relation of TTI and thyromental distance (TMD), and change of blood pressure and heart rate after intubation. METHODS: We selected and randomly allocated sixty adults to direct layngoscope group (D) and light wand group (L). Without premedication, propofol and vecuronium were injected for intubation. Time to intubation was measured from the time of grasping direct laryngoscope or light wand until the time of inserting endotracheal tube into trachea. We checked the change of blood pressure and heart rate after intubation, and studied the correlation of TTI and TMD. RESULTS: TTI was 16.5 sec (6.53~115.3 sec) for group D and 11.8 sec (4.31~36.0 sec) for group L. There was no significant difference between the groups. The rise of blood pressure and heart rate was less with light wand. There was a correlation of [TTI]=1248- 388[TMD]-30[TMD]2 in group L patients whose TMD is less than 7 cm. CONCLUSION: Compared with direct laryngoscope, light wand is as easy to use and can be more effective especially for patients whose anatomy may make intubation difficult or whose cardiovascular system is unstable.
Adult ; Blood Pressure* ; Cardiovascular System ; Hand Strength ; Heart Rate* ; Heart* ; Humans ; Intubation* ; Laryngoscopes* ; Neck ; Premedication ; Propofol ; Trachea ; Vecuronium Bromide

BACKGROUND: Explicit recall in a cesarean section under general anaesthesia can be a terrifying experience and may cause psychological sequelae. Administering low doses of midazolam, we investigated the changes of the bispectral index (BIS) and the occurrence of explicit recall of specific events after fetal expulsion in a cesarean section under general anesthesia. METHODS: The investigation was carried out on 30 ASA 1 or 2 parturients who underwent a cesarean section under general anesthesia. Anesthesia was maintained with 50% N2O in oxygen and 0.75% of isflurane. We randomly allocated parturients into a control group (n = 10), group A (n = 10), and B (n = 10). Neither midazolam nor any other drugs except oxytocin were administered in the control group. In the group A and B, midazolam 0.02 and 0.03 mg/kg respectively, were injected immediately after umbilical cord clamping. An isolated forearm test were done to all the parturients at 5, 10, and 20 minutes after fetal expulsion. We assessed the changes of the BIS at 1, 2, 3, 4, 5, 10, 15, and 20 minutes after fetal expulsion, at discontinuance of isoflurane administration and extubation. The wav file, "clench your left or right hand" was binaurally played, simultaneously with the isolated forearm test. The wav file, "one, two, three, four, five" was also binaurally played 15 minutes after fetal expulsion. We interviewed all the parturients the next day and assessed the occurrence of explicit recall. RESULTS: The BIS values after fetal expulsion in the control group and group A was maintanied above 60 and group B, below 60 (P < 0.05). The lowest median BIS value was 54.5 in the group A, 36.4 in the group B (P < 0.05). There were two parturients in the control group and in the group A, respectively, who showed explicit recall. The results of the isolated forearm test were negative for all groups. The extubation times and PAR scores failed to show significant differences among the three groups. CONCLUSIONS: The authors confirmed the occurrence of explicit recall for specific events after fetal expulsion. The BIS values after fetal expulsion could be maintained below 60 until the end of surgery,and explicit recall could be prevented when we injected midazolam 0.03 mg/kg immediately after fetal expulsion.
Anesthesia ; Anesthesia, General* ; Cesarean Section* ; Constriction ; Female ; Forearm ; Isoflurane ; Midazolam* ; Oxygen ; Oxytocin ; Pregnancy ; Umbilical Cord

BACKGROUND: In some cases of one-lung ventilation (OLV), hypoxemia may occur secondarily to the obligatory right to left transpulmonary shunt through the collapsed lung. We investigated the efficacy of high frequency jet ventilation (HFJV) to the non-dependent lung which rendered to be manually collapsed by surgeon and not to be reinflated, in improving systemic oxygenation and ventilation during OLV while ventilating the dependent lung with intermittent positive pressure ventilation. METHODS: Investigation was carried out on 20 ASA 2 or 3 patients who underwent thoracotomy in lateral decubitus position. The patients were randomly allocated into HFJV group (n = 11) or CPAP group (n = 9). In HFJV group, 20 minutes after OLV began, HFJV with driving pressure 1.0 bar, Ti 30%, and frequency 150 cycles/min, was applied to the non-dependent lung. In CPAP group, 5 cmH2O of CPAP was applied to the non-dependent lung without re-inflation. We compared the changes of PaO2, PaCO2, AaDO2 and pulmonary shunt, before and after HFJV or CPAP was applied to the non-dependent lung during OLV. RESULTS: AaDO2 and pulmonary shunt were decreased significantly and therefore, PaO2 was increased significantly when HFJV was applied to the non-dependent lung (P < 0.05, respectively). PaO2, AaDO2 and pulmonary shunt were not improved after 5 cmH2O of CPAP was applied to the non-dependent lung without re-inflation. In HFJV group, PaCO2 measured after HFJV was not decreased significantly compared with that before HFJV. CONCLUSIONS: HFJV to the non-dependent lung during OLV improved systemic oxygenation, even after the non-dependent lung collapsed completely but did not enhance CO2 elimination. 5 cmH2O of CPAP to the non-dependent lung, which was completely collapsed and not re-inflated, did not improve systemic oxygenation.
Anoxia ; High-Frequency Jet Ventilation* ; Humans ; Intermittent Positive-Pressure Ventilation ; Lung* ; One-Lung Ventilation* ; Oxygen* ; Thoracotomy ; Ventilation

BACKGROUND: As the clinical-end point is not clear-cut in conscious sedation, there are no objective and feedback-providing methods to assess the depth of sedation within the levels appropriate for conscious sedation. METHODS: The investigation was carried out on 19 ASA PS 1 patients. The authors developed a system to measure the reaction time to visual (red colored flash, 40 lux for 30 msec) and auditory (beep, 1,000 Hz, 67.5 dB for 30 msec) stimulations. The authors confirmed the beeps to be audible to all the patients before the test began. When they perceived a visual or auditory stimulation, the authors instructed the patients to signal by pushing a button as soon as possible. The reaction time was defined as the time from the beginning of stimulation to the push of a button. The patients were gradually sedated with propofol TCI. The authors measured the visual and auditory reaction time and BIS after every 0.1 microgram/ml increment of the effect site concentration of propofol. RESULTS: As the effect site concentration of propofol increased, the reaction time to visual and auditory stimulations tended to be prolonged (P < 0.0001, respectively). The estimate was 409 and 498, respectively, which means the slope a in y = ax; x means unit change of the effect site concentration of propofol; y means the estimated values of the reaction time. The BIS values at loss of response to visual and auditory stimulations were 86 +/- 7 and 78 +/- 7 (mean +/- SD). CONCLUSIONS: The responses to visual and auditory stimulations were prolonged and ultimately abolished as the effect site concentration of propofol increased. The loss of response to visual stimulations preceded the loss of response to auditory stimulations. The BIS values at loss of responses to visual and auditory stimulations suggested light and moderate sedation, respectively.
Acoustic Stimulation ; Conscious Sedation* ; Humans ; Photic Stimulation ; Propofol* ; Reaction Time*

BACKGROUND: In inducing anesthesia for burn patients, nondepolarizing muscle relaxant (NDMR) is usually used, because succinylcholine, a widely used muscle relaxant may cause hyperkalemia. It is well known that because burn patients show resistance to NDMR, a high dose of NDMR is needed for them. In this study, we wanted to know whether there is significant difference of the relaxation effect between 0.1 mg/Kg and 0.15 mg/Kg dose's of vecuronium, and between burn and unburn patients. METHODS: Subjects are 40 male patients having 1 or 2 ASA physical status (20 are burn patients and the other 20 are unburn patients). We divided them into 4 groups; 1) Group BI (burn patients, vecuronium 0.1 mg/Kg) 2) Group BII (burn Pts, vecuronium 0.15 mg/Kg) 3) Group UBI (unburn Pts, vecuronium 0.1 mg/Kg) 4) Group UBII (unburn Pts, vecuronium 0.15 mg/Kg). Average onset times (time from injection of vecuronium to zero first twitch height (T1)) were measured and intubating condition were scored on 0 to 4 scale. RESULTS: The onset time of vecuronium and distribution of intubation scores didn't show statistical differences among 4 groups. CONCLUSION: The onset time of vecuronium and intubating condition in burn patients dosen't show a difference from unburn patient.
Anesthesia ; Burns ; Burns, Electric* ; Humans ; Hyperkalemia ; Intubation ; Intubation, Intratracheal* ; Male ; Neuromuscular Blockade* ; Neuromuscular Monitoring ; Relaxation ; Succinylcholine ; Vecuronium Bromide*

High frequency ventilation considerably reduces the risk of barotrauma due to low peak airway pressure compared to conventional mechanical ventilation. This risk, however, is also preaent with high frequency jet ventilation (HFJV) if excessive driving preasure are used and, above all if expiration is impeded. We investigated the effects of outflow resistance, which was varied by connecting different size of tube (ID 8.0, 7.5, 7.0, 6.5, 5.5, 5.0, 4.5, 4.0 mm), which was cut in 10 cm length, to the proximal site of endotracheal tube (ID 8.0 mm), which was inserted into the trachea of anesthetized dogs with a attached airway pressure monitoring catheter externally, in different driving pressure (2 kg/cm2, 1 kg/cm2) and frequency (100beats/min, 200beats/min) on the intra-airway preesure during HFJV. HFJV was performed with a catheter (diameter 2.5 mm) which was inaerted through endotracheal tube and located 1 cm proximal to the tip of endotracheal tube. Intra-airway pressure was acutely increased with the tube size of smaller than 5.5 mm in driving pressure 2 kg/cm2 and 5.0 mm in driving pressure 1 kg/cm2 compared to previous size of tube. 2 kg/cm2 of driving pressure showed significant higher airway pressure compared to 1 kg/cm in any size of tube. There was no difference in airway pressure by varing of frequency with same driving preasure. In summary, pulmonary barotrauma due to higher airway pressure may be occur if HFJV catheter occupied more than 25% of outflow tract area especially in higher driving pressure.
Airway Resistance ; Animals ; Barotrauma ; Catheters ; Dogs ; High-Frequency Jet Ventilation* ; High-Frequency Ventilation ; Respiration, Artificial ; Trachea ; Ventilation

Simultaneous intraoperative measurements of eardiac output were obtained in twenty one patients with thoracic electric bioimpedance(TEB) and transesophageal Doppler, two patients with transesophageal Doppler and thermodilution, one patient with TEB and thermodilution, and three patients with TEB, transesophageal Doppler and thermodilution techniques to evaluate the utility of noninvasive methods. Pairs of measurments were obtained 6S times with TEB and thermodilution, 109 times with transesophageal Doppler and thermodilution, and 373 times with TEB and transesophageal Doppler techniques. Correlation of the measurements was poor, with r=0.39 for TEB and thermodilution, r=0.44 for transesophageal Doppler and thermodilution, and r=0.39 for TEB and transesophageal Doppler. The mean difference between TEB and thermodilution, transesophageal Doppler and thermodilution, and TEB and transesophageal Doppler values was -2.41+/-1.79 L/min(mean+/-SD), -0.98+/-1.70 L/min, and -0.69+/-1.01 L/min, respectively. The scattergrams with confidence band lines showed that 22.0% of the scattergram points fell within +/-20% band and 51.5% within +/-40% band in TEB and thermodilution, 55.0% of the scattergram points fell within +/-20% band and 77.9% within +/-40% band in transesophageal Doppler and thermodilution, and 63.6% of the scattergram points fell within +/-20% band and 90.9 within +/-40% band in TEB and transesophageal Doppler. Therefore, it is concluded that neither noninvasive technique reliably estimated cardiac output as determined by thermodilution.
Cardiac Output* ; Humans ; Thermodilution*