Perineural injection to nerve root and radicular blood flow: a clinical study during spinal surgery.

BACKGROUND AND OBJECTIVE: To investigate the effects of the perineural injection of lidocaine or corticosteroids on radicular blood flow during spinal surgery. METHODS: After lumbar discectomy, a probe for laser Doppler flowmetry was placed directly on the 4th or 5th lumbar nerve root. Thirty patients undergoing lumbar discectomy were randomly assigned to one of three groups. Each group received one of three protocols for a perineural injection to the nerve root: 1.0 mL 0.9% saline in group A, 1.0 mL 1% lidocaine in group B or 1.0 mL dexamethasone (4 mg) in group C. Measurements included radicular blood flow, mean arterial pressure, haemoglobin concentration, percutaneous oxygen saturation and end-tidal carbon dioxide tension. Radicular blood flow was measured by laser Doppler flowmetry before the injection and 15 min after these injections. The three groups were similar with respect to mean arterial pressure, haemoglobin concentration, percutaneous oxygen saturation and end-tidal carbon dioxide tension. RESULTS: Radicular blood flow did not change after the injection in any of the groups. CONCLUSIONS: The results suggest that the perineural injection of 1% lidocaine or dexamethasone does not affect radicular blood flow during lumbar discectomy.

[Effects of dopamine and dobutamine on renal function and urinary excretion of prostaglandin E2 in elderly postoperative patients].

Effects of dopamine and dobutamine on renal function and urinary excretion of prostaglandin E2 (UPGE) were studied in 21 elderly patients who underwent abdominal surgery. Fractional sodium excretion (FeNa), creatinine clearance (Ccr), urinary volume (UV, ml.kg-1.min-1) and UPGE were measured on the first and second postoperative day. These patients were divided into three groups: i.e. C (control), DA (dopamine) and DB (dobutamine) groups. Group DA received dopamine 2 mcg.kg-1.min-1 beginning at six o'clock on the first postoperative day. Group DB received dobutamine 2 mcg.kg-1.min-1. There were no significant differences in UV and UPGE among these three groups. Ccr was significantly higher on the second postoperative day than that on the first postoperative day in DA group. FeNa in DA group was higher than in C group on the second postoperative day. The relationship between UPGE and UV was not determined. These results suggest that DA improve renal functions in the elderly.

[The effect of calories of preoperative oral intake on the glucose metabolic response in children].

We performed prospective study to determine whether the increase of calories with preoperative oral intake will prevent ketosis due to preoperative starvation in children receiving afternoon surgery. Twenty five children (aged 3 to 9 years) for elective minor surgery under general anesthesia with sevoflurane and nitrous oxide were divided into morning surgery group and afternoon surgery group, and the latter was divided into 2 groups according to calories contained in the clear fluid. The calorie of the clear fluid in the afternoon group P was 0.24 kcal.ml-1, and that in the afternoon group A was 0.48 kcal.ml-1. The calorie of the clear fluid in the morning group was 0.48 kcal. ml-1. The levels of blood glucose, blood ketone body, plasma free fatty acids (NEFA), insulin, glucagon and cortisol were measured before and during intravenous infusion in three groups. The urinary catecholamine excretion was measured in the urine collected from 18:00 on the day before operation day until the start of anesthesia. There were no significant differences in the levels of blood glucose, NEFA, insulin, glucagon, cortisol and urinary catecholamine excretion. But the level of blood ketone body only in the afternoon group P was significantly higher than that in the morning group. But the levels of NEFA before infusion were higher than average in 40-60 percent of patients of each group. These data suggest that the increasing preoperative calories with oral intake will prevent ketosis due to preoperative starvation in the afternoon group as well as in the morning group. But the short duration of starvation only can not prevent lipolysis completely.

Effects of controlled hypotension with sevoflurane anaesthesia on hepatic function of surgical patients.

The effects of controlled hypotension induced with trimethaphan (TMP), nitroglycerin (TNG) or prostaglandin E1 (PGE1) during sevoflurane anaesthesia on hepatic function were studied in 28 patients undergoing spinal fusion surgery. Patients were randomly divided into three groups to receive TMP (group A, n = 10), TNG (group B, n = 10) or PGE1 (group C, n = 8). Anaesthesia was maintained with N2O and sevoflurane. The mean arterial blood pressure was maintained at 60 mmHg for 90 min. Measurements included arterial ketone body ratio (AKBR-acetoacetate/3-hydroxybutyrate), SGOT, SGPT, LDH, blood glucose and blood gases were made. Measurements were taken before hypotension, 60 min and 90 min after starting hypotension, 60 min after recovery from hypotension and on the post-operative day. AKBR showed no significant change. SGOT, SGPT and LDH were within normal limits. Controlled hypotension induced with TMP, TNG or PGE1 under sevoflurane anaesthesia in surgical patients did not cause hepatocellular damage.

Acute haemodilution and prostaglandin E1-induced hypotension: effects on the coagulation-fibrinolysis system.

The effects of acute haemodilution, during prostaglandin E1 (PGE1)-induced hypotension, on the blood coagulation-fibrinolysis system were studied in 40 patients undergoing hip surgery. The patients were randomly divided into four groups of 10 patients each; Group A (control) received no induced hypotension or haemodilution, group B received hypotension alone, group C received haemodilution alone and group D received the combination of induced hypotension and haemodilution. Haemodilution in groups C and D was produced by drawing approximately 1000 mL of blood and replacing it with the same amount of 6% hydroxyethyl starch. Induced hypotension in groups B and D was conducted with PGE1 and mean blood pressure was maintained at 55 mmHg. The mean dosage of PGE1 was 648 micrograms in group B and 661 micrograms in group D. In the control and PGE1-induced hypotension groups there was no significant change in platelet count (PLT), prothrombin time (PT), activated partial thromoplastin time (aPTT), fibrinogen (FIB), antithrombin-III (AT-III) or plasminogen (PLG). Haemodilution alone caused significant decreases in PLT (-43%), PT (+21%), FIB (-33%), AT-III (-21%) and PLG (-27%), and a significant increase in aPTT (+26%), whereas the combination of PGE1-induced hypotension did not cause any further change in these parameters. Serum-fibrin degradation products (FDP) significantly increased (+300%) and PLG significantly decreased (-30%) after surgery in all groups. It can be concluded that acute haemodilution to a haematocrit value of 22 +/- 2% causes a slight coagulopathy, which is not enhanced when combined with PGE1-induced hypotension.

[Comparison between cultures of urine sediment and of the vagina for detection of carriers of group B Streptococcus (GBS) among pregnant women].

An attempt was made to detect carriers of group B Streptococcus (GBS) among pregnant women by vaginal culture. Reported carrier rates have varied from 3% to 15% and one study has reported that cultures of urine sediment showed a very high positivity rate of 30% among non-pregnant women. In this study, we cultured urine sediment from 110 non-pregnant and 415 pregnant women. Among non-pregnant women, 26% were found to be GBS carriers by culture of urine sediment. Among pregnant women, the carrier rate was 3% by vaginal culture and 15% by culture of urine sediment. The serotypes of cases positive by vaginal vulture were identical with those positive by urine sediment culture. For detection of GBS carriers among pregnant women, culture of urine sediment is easy and reduces the rate of false negativity.

[Blood flow in the operating field during controlled hypotension by nitroglycerin, trimetaphan and prostaglandin E1].

We used the laser flowmeter to measure and compare the effect of nitroglycerin (TNG), trimetaphan (TMP) and prostaglandin E1 (PGE1) on the blood flow of operating field during hypotension induced by each drug. The study was done in 33 patients (TNG:13, TMP:13 and PGE1:7) anesthetized with modified NLA who underwent radical mastectomy. We put the probe of the laser flowmeter on the skin of the opposite breast to the operating field and measured the skin blood flow change. Measurements were made before and during hypotension induced by each drug. TMP-induced hypotension decreased blood flow significantly (P less than 0.05), but TNG and PGE1 had no significant effect. Intraoperative blood losses of TNG and PGE1 group were not significantly larger than that of TMP group. From this study we conclude that TNG, TMP and PGE1 can dry the operating field and decrease intraoperative blood loss similarly. Therefore we should choose the drugs to induce hypotension considering the effect of the drug on blood flow of the important organs and each patient's complications.

Comparison of the effects of amrinone and dobutamine on hemodynamics and myocardial oxygen balance in dogs with experimental left ventricular failure.

The purpose of the present study was to induce left ventricular failure in anesthetized dogs by repeated ventricular fibrillation and then to determine if amrinone is effective in circulatory support by comparing the effects of amrinone and dobutamine. After the repetitive ventricular fibrillation, mean arterial pressure and stroke volume index decreased, pulmonary capillary wedge pressure (PCWP) increased, and acute left ventricular failure occurred. Thereafter, dogs were divided into the following four groups. In Group C (n = 6), normal saline was administered; in Group D (n = 6), dobutamine was administered at 7 micrograms/kg/min; and in Groups A40 (n = 6) and A80 (n = 7), amrinone was administered at 40 micrograms/kg/min and 80 micrograms/kg/min, respectively. Stroke volume index increased by 78% in Group D and 46% in both Groups A40 and A80. Pulmonary capillary wedge pressure decreased by 44% in Group A40 and 38% in Group A80, but remained unchanged in Group D. Similarly, total peripheral resistance decreased by 32% in Group A40, 29% in Group A80, but remained unchanged in Group D. These results suggest that amrinone increased cardiac output and decreased both preload and afterload. In the coronary circulation, both drugs caused direct coronary vasodilation since they increased myocardial oxygen supply in excess of the increase in myocardial oxygen demand. Neither drug produced signs of myocardial ischemia, as indicated by myocardial lactate metabolism. Amrinone should be a useful drug after open heart surgery, especially in cases where significant adverse effects of catecholamines occur or where a low-output state with increased preload and afterload exists.