Co-administration of midazolam decreases propofol dose during anesthesia in endoscopic laryngeal microsurgery.

BACKGROUND: Propofol is commonly used in total intravenous anesthesia (TIVA) for brief surgical procedures because it offers rapid recovery and has fewer side effects. However, concomittent use of other adjuvant agents has been considered so that the same anesthetic effects can be achieved at lower doses of propofol which is more expensive without compromising rapid recovery and increasing the adverse effects. This study was therefore designed to evaluate the co-administration of midazolam and propofol during anesthesia for endoscopic microsurgery and test its influences on the consumption of propofol and the quality of anesthesia. METHODS: Forty-two patients receiving selective endoscopic microsurgery were enrolled in this study. All patients received high frequency jet ventilation (HFJV) under TIVA. The control group (n = 21) received propofol (20 mg/5 s) during induction and 10 mg/kg/h as maintenance. The study group (n = 21) received midazolam (0.06 mg/kg) and propofol (20 mg/5 s) for induction with propofol 8 mg/kg/hr for maintenance. Doses of propofol, vital signs, recovery time, post-anesthetic high cortical function, and adverse events were evaluated and compared. RESULTS: Co-administration of midazolam and propofol in TIVA could reduce the induction dose and the total dose of propofol by 51% and 26% respectively but still achieve the same anesthetic effects. Vital signs and recovery were not influenced, and incidence of adverse effects did not increase. CONCLUSIONS: Our result suggests that co-administration of midazolam and propofol in TIVA appears to be safe, effective, and economic alternative to that with propofol alone. The effects were synergic but side effects were not.

An urgent technique of applying high frequency jet ventilation in patients with extreme periglottic stenosis.

Applying high frequency jet ventilation (HFJV) to patients with extreme periglottic stenosis (EPS) carries high risk of barotrauma or severe circulatory depression, since the stenotic airway will result in inadequate outflow tract obstructing the passage of the expired gas. We encountered with emergent obstruction of the outflow tract in 13 patients with EPS during HFJV in endolaryngeal microsurgery (ELM) procedures. The phenomenon of progressive gas trapping occurred within seconds in all patients. Barotrauma and disastrous circulatory depression would occur if we had not recognized them and then taken some measures immediately. We surmounted these potentially lethal events without interrupting the surgical procedures and found neither hypoxia nor barotrauma in all these patients. This may attribute to an urgent technique, i.e., intermittent disconnecting the jet conduit at the junction of the proximal end of the insufflation catheter and the distal end of the patient connecting tube of jet ventilator during HFJV.

Will epidural with light general anesthesia increase the incidence of awareness with recall or dream postoperatively.

BACKGROUND: The incidence of awareness with recall during general combined with epidural anesthesia has not been previously reported. The purpose of this study was to quantify the incidence. MATERIALS & METHODS: One hundred patients were divided into two groups. Group 1 (N = 50) received general anesthesia (GA), Group 2 (N = 50) received GA and epidural anesthesia (EA) intraoperatively. No premedication was given. These patients were induced with thiopentol (5 mg/kg) or propofol (2.0 mg/kg) and anectine (1.2 mg/kg) for smooth tracheal intubation and maintained with N2O:O2 = 1.5:1.5, and isoflurane and muscle relaxant of either pavulon or atracurium. No sedatives was given. Before anesthesia, we introduced an epidural catheter into the group 2 patients. After induction, headphones with soft music were given to the patients, in both groups, throughout the operation. 20-36 hours after operation or when the patients were fully awake, we asked the patients if they had heard anything or dreamed intraoperatively. RESULTS: We found that not one of the one hundred patients heard anything or dreamed intraoperatively.

Observation of coagulation change during induced hypotensive anesthesia and autologous plasma transfusion.

Coagulation change was studied in 16 adult female patients undergoing radical hysterectomy with BPLND surgery. None had preoperative alterations in coagulation or liver function and was receiving anticoagulant or antiplatelet medication. Sixteen ASA class I-II were divided into 2 groups randomly with eight patients in each group. One group accepted autologous plasma transfusion near the end of surgery, the other group did not. Autologous plasma was retrieved by plasma saver post induction of anesthesia. Every patient received induced hypotensive anesthesia during the operation. Whole blood coagulation status was quantitated by using thromboelastography (TEG). Blood samples for TEG were obtained before induction of anesthesia, after closure of peritoneum, and 2 hours post autologous plasma transfusion or 2 hours post peritoneum closure. Most parameters measured by TEG showed improved coagulation status in autologous plasma transfusion group. We concluded that coagulation change was minimal during induced hypotension, and improved coagulation was obtained 2 hours post autologous plasma transfusion during radical hysterectomy with BPLND surgery.

The influence of position and PEEP on arterial blood gas during operation.

From December, 1990 to December, 1991, we studied the influence of PEEP and positional change to arterial blood gas in 60 ASA class II or III, aged 20 to 65 years, non-obese patients. The patients were assigned randomly into six groups. Group 1: head down position without PEEP. Group 2: head down position with PEEP 5 cmH2O. Group 3: lithotomy position without PEEP. Group 4: lithotomy position with PEEP 5 cmH2O. Group 5: supine position without PEEP. Group 6: supine position with PEEP 5 cmH2O. Blood gas analysis were performed at 5, 15, 30, 60, 120, and 180 minutes after positional change in group 1-4 and after anesthesia in group 5 and 6. The ventilator settings were: tidal volume -10 ml x 25 x (height in meters)2, rate 8/min. The results of significant difference inter-grouply were: PaO2 at 15 minutes; PaCO2 at 5 minutes; pH at 60, 120, and 180 minutes; base excess (BE) at 120 and 180 minutes. As the time progressed, PaO2 decreased in group 1, 2, and 3; PaCO2 decreased in group 3 and 5; pH decreased in group 3; BE decreased in all groups. PaCO2 were between 30-40 mmHg and no hypocarbia produced in all groups. In conclusion, ventilation of the non-obese patient based on 10 ml x 25 x (height in meters)2 x 8/min produce normocarbia and PaO2 more than 80 mmHg with 50% oxygen. No significant difference of PaO2 were found whether there were position change or PEEP 5 cmH2O.

Effects of opioid agonists and opioid antagonists in endotoxic shock in rats.

Endotoxic shock is presented with a complex pathophysiology and is associated with high mortality. Recently, it has been reported that endogenous opioids play an important role in endotoxic shock. Pressor effect of naloxone in shock may be mediated through antagonism of endogenous opioid inhibition of the sympatho-adrenal catecholaminergic system. In endotoxemic animal, circulating catecholamine levels were not elevated by naloxone. It is possible that naloxone acts upon opiate receptors to enhance catecholamine actions at the receptor level or post-receptor level. We investigated endotoxic shock using a rat model. The animals anesthetized with phenobarbital were infused with E. coli LPS for 30 minutes. They were divided into 5 groups. After an endotoxin i.v. infusion of 15 mg/kg (LD 60), a significant fall in mean arterial pressure (MAP), heart rate and pH occurred in all groups. Treatment with naloxone or buprenorphine or naloxone + epinephrine resulted in significant improvement in MAP, pH and base excess. Treatment with morphine resulted in a decrease in MAP and an increase in heart rate. The pressor response to epinephrine 10, 30, 60 microgram/kg i.v. caused an increase of 62%, 48% and 17% of control values respectively in endotoxic treated rats. The duration of the pressor response to epinephrine was significantly increased by naloxone, although no significant effects on survival were seen at 4 hours after the start of treatment. These findings suggest that the buprenorphine may prove to be an alternative to naloxone, the co-administration of naloxone and epinephrine may be of benefit in the management of septic shock.

Comparison of antiemetic effect among ephedrine, droperidol and metoclopramide in pediatric inguinal hernioplasty.

Prevention and treatment of postoperative nausea and vomiting with ephedrine, droperidol and metoclopramide have been reported to be effective. To further investigate their efficacy, 100 pediatric patients scheduled to undergo inguinal hernioplasty on ambulatory basis were divided into five groups, namely, group 1: normal saline (iv) control; group 2: ephedrine 0.5 mg/kg, (im); group 3: droperidol 50 micrograms/kg. (iv); group 4: ephedrine 1 mg/kg. (im); group 5: metoclopramide 0.15 mg/kg. (iv). At the end of surgery, each patient received the drug treatment according to the specified group to which he was randomly assigned. The occurrence of postoperative nausea and vomiting was recorded in the recovery room and inquired at home by telephone within 24 h following surgery by a blinded observer. The authors found that there were no significant differences between the control group and ephedrine groups with whichever dose that was used in the prevention of postoperative nausea and vomiting. Droperidol and metoclopramide were effective in dealing with problem in comparison with control group (p less than 0.05). However, metoclopramide was more suitable than droperidol for pediatric outpatient based on duration of somnolence, return of orientation, and time of discharge.

[Burns caused by electrocautery during surgery].

A 19-year-old male suffering from crushed injury on the neck and anterior upper chest with suspected laceration of the trachea underwent emergent operation for surgical restoration of the trachea. First and second degrees of electric burns over the neck and upper back regions(4%) were accidentally caused by electrocautery during surgery. Short circuit due to over-wetting of the sheet and EKG leads may be responsible for this avoidable accident.

[Etiologies of unilateral block of epidural anesthesia: a case report].

We would like to present a patient, who was a 60 years old man, 160 cm tall, weighing 55 kg, which received debridement for his pressure sores under epidural anesthesia. While inserting the Touhy needle, there was obvious loss of resistance at the level of 9 cm below the skin. When the test dose was injected, the compliance was good. Later, the anesthesia behaved as unilateral block. After the operation, the computerized tomography revealed the epidural catheter was between the facia of right psoas major muscle. Form this case, there were some lesions: (1) The distance from the skin to the lumbar dura mater is seldom longer than 7 cm. (2) The obvious loss-of-resistance and good compliance of test dose are not the guarantee of epidural anesthesia. (3) The psoas block may be another cause of unilateral block of lumbar epidural anesthesia.

[pH-adjusted lidocaine HCl with or without epinephrine for epidural anesthesia].

Preparations of local anesthetics are prepared as acidic solutions of the salts to promote solubility and stability. In solution, these salts exist as both nonionized and ionized forms. The ratio depends on the pH of the solution, and it is only the non-ionized form that permeates the nerve membrane and sheath. This study of epidural analgesia was undertaken to determine the effect of increasing the pH of the lidocaine HCl by the addition of sodium bicarbonate. Parameters studied included the time of onset of analgesia (time between the completion of injection and the loss of scratch sensation at the left L1 dermatome), the spread of sensory blockade, the degree of motor block, and the blood pressure and heart rate. Eighty seven adult patients undergoing epidural anesthesia were divided into four groups. Group 1 patients were given 2% lidocaine HCl solution plus 1.5 mL normal saline per 10 mL of lidocaine (pH 5.55). Group 2 patients were given 2% lidocaine HCl solution plus 1.5 mL 7% sodium bicarbonate per 10 mL of lidocaine (pH 7.04). Group 3 received 2% lidocaine HCl solution with 1:200000 epinephrine plus 1.5 mL normal saline per 10 mL of lidocaine (pH 5.68). Group 4 received 2% lidocaine HCl solution with 1:200000 epinephrine plus 1.5 mL 7% sodium bicarbonate per 10 mL of lidocaine (pH 7.11). The time of onset of analgesia and the spread of sensory blockade were more rapid in groups 2 and 4. The degree of motor block was more pronounced in these two groups, as were the changes in blood pressure and heart rate.

[Spinal anesthesia with bupivacaine for transurethral resection of prostate: effects of specific gravity, volume and dose].

The investigation was carried out in 80 patients scheduled for transurethral resection of prostate (TUR-P). All patients were ASA I or II, and received no premedication. Before anesthesia, elastic bandages were applied to both lower extremities and 6 mL/kg of G/S (5% Glucose in 0.9% saline solution) was administered by intravenous infusion. The patient was placed in the lateral position and dural puncture was performed at the L3-4 interspace using a standard midline approach with a 23 gauge spinal needle. The patients were allocated randomly to four groups, each group consisting of 20 patients. Three mL of 0.5% Bupivacaine was administered in group A; 3 mL of 0.5% Bupivacaine with 1 mL 10% G/W (Glucose water) in group B; 2 mL of 0.5% Bupivacaine with 1 mL 10% G/W in group C and 3 mL of 0.5% Bupivacaine in 8% glucose in group D. Assessment of the sensory and motor blockade and measurement of arterial pressure and heart rate were performed after injection. All data were analyzed by ANOVA. A p value of less than 0.05 was considered statistically significant. The results showed that the duration of analgesia with plain Bupivacaine was shorter than with hyperbaric Bupivacaine (2.59 +/- 0.81 h vs 3.12 +/- 0.72 h, P less than 0.05). The maximum cephalad spread of analgesia was lower with plain Bupivacaine (T 9 +/- 2 vs T 7 +/- 2, P less than 0.05). Patients receiving either 3 mL or 4 mL of hyperbaric bupivacaine were similar in regard to duration and maximum cephalad spread of analgesia, but the effect on the cardiovascular system was more severe in the group receiving 4 mL.(ABSTRACT TRUNCATED AT 250 WORDS)