Bradycardia during hypotension following release of a tourniquet in orthopaedic surgery

Heart rate (HR) and mean arterial blood pressure (MBP) were followed in 39 consecutive patients during orthopaedic surgery with the leg exsanguinated by an inflatable tourniquet around the thigh. The circulation was stable in all patients until release of the tourniquet. Following release of the tourniquet MBP decreased from 94 +/- 5 (s.e. mean) to 45 +/- 12 mmHg (12.5 +/- 0.7 to 6.0 +/- 1.6 kPa) (P less than 0.005) in 10 patients, while it remained stable in the others. At the same time the hypotensive group showed a decrease in HR from 83 +/- 6 to 67 +/- 3 beats min-1 (P less than 0.005) while no significant change in HR was seen in the normotensive group. The hypotensive group was older (57 +/- 8 versus 50 +/- 4 years (P less than 0.05)), had a larger blood loss during surgery (2.9 +/- 1.2 versus 0.7 +/- 0.3 ml kg-1 (P less than 0.005)), and the duration of the operation was longer in this group (120 +/- 14 versus 60 +/- 27 min (P less than 0.001). It is suggested that the characteristic deviation of HR in conjunction with hypotension following release of a tourniquet is bradycardia.     

Oxygen consumption and carbon dioxide elimination after release of unilateral lower limb pneumatic tourniquets.

Oxygen consumption (VO2), carbon dioxide elimination (VCO2), and respiratory exchange ratio (RQ) were continuously measured in 15 male and 15 female adults during knee surgery, with the leg exsanguinated by an inflatable tourniquet around the thigh. Arterial blood was also intermittently sampled for blood gas analysis, electrolytes, and lactate content before and after tourniquet deflation. There was a significant increase in VO2 and VCO2 after tourniquet deflation, which was more pronounced in the male (aged 29.5 +/- 14.8 yr, mean +/- SD) than the female (aged 56.9 +/- 15.6 yr) patients, both in terms of maximal increase (P less than 0.001) and percent of increase from values before deflation (P less than 0.001 and P = 0.01). The body weights and tourniquet inflation times were not significantly different between the male and female patients. Excess VO2 (O2 debt) and excess VCO2 over 12 min after deflation of the tourniquet were also significantly higher for male (593.5 +/- 222.9 mL and 714.9 +/- 463.8 mL, respectively) than for female patients (302 +/- 73.3 mL and 196 +/- 162.22 mL, respectively; P less than 0.01). There was no correlation between the duration of tourniquet inflation time and peak increase in VO2, peak increase in VCO2, and O2 debt over 12 min after deflation of the tourniquet; however, tourniquet time was weakly correlated with excess VCO2 over 12 min after tourniquet deflation (r = 0.55, P = 0.002). There was a significant decrease in pHa (P less than 0.001) from release of PaCO2 and lactate after tourniquet deflation. Plasma potassium levels also increased significantly after tourniquet release (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Using the Boazul cuff to reduce blood loss in varicose vein surgery.

OBJECTIVE: this study was designed to assess if the use of a sterile exsanguination tourniquet (Boazul cuff) reduced blood loss from the groin and avulsion wounds during varicose vein surgery, (saphenofemoral disconnection, stripping to knee and multiple avulsions). DESIGN: prospective, parallel cohort study. MATERIALS: thirty-eight patients undergoing primary varicose vein surgery. METHODS: the blood loss and number of avulsion wounds were recorded for each patient. RESULTS: the tourniquet was used on 21 legs and there were 24 legs in the non-tourniquet group. In the tourniquet group, the median blood loss from the groin was 15 ml, (range 5-70 ml), and from the leg was 5 ml, (range 0-120 ml). The corresponding figures for the group without the tourniquet were a median of 17.5 ml, (range 5-105 ml), and a median of 95 ml, (range 10-505 ml). The mean number of avulsions in the tourniquet group was 25 (range 9-38), and in the non-tourniquet group was 15, (range 5-40). There was significantly less blood loss from the leg in the tourniquet group (p<0.0001) despite the fact that there were more avulsions in the tourniquet group (p<0.001). CONCLUSIONS: use of the Boazul cuff significantly decreases the blood loss from the avulsion sites during routine varicose vein surgery, and may encourage the surgeon to perform more avulsions.     

Reperfusion of ischemic lower limbs increases pulmonary microvascular permeability

Lower torso ischemia and reperfusion has been shown to stimulate the generation of thromboxane (Tx)A2, leading to transient pulmonary hypertension and later to polymorphonuclear leukocyte accumulations in the lungs. This study investigated whether hind limb ischemia leads to increased pulmonary microvascular permeability. Anesthetized sheep (n = 6) previously prepared with a lung lymph fistula underwent 2 hr of tourniquet ischemia of both lower limbs. One minute following tourniquet release mean pulmonary arterial pressure (MPAP) rose from 14 +/- 1 to 36 +/- 4 mm Hg (p less than 0.05) and returned to baseline within 30 min. The pulmonary arterial wedge pressure of 4 +/- 1 mm Hg was unchanged. Plasma TxB2 levels rose from 211 +/- 21 to 304 +/- 52 pg/ml (p less than 0.05) 10 min after tourniquet release and were back to baseline at 30 min. Lymph flow (QL) rose from 4.3 +/- 0.6 ml/30 min to 8.3 +/- 1.8 ml/30 min (p less than 0.05); the lymph/plasma (L/P) protein ratio rose slightly but not significantly. In three sheep, inflation of a left atrial balloon increased left atrial pressure from 3 to 16 mm Hg. MPAP rose from 14 to 24 mm Hg. There was an increase in QL from 3.6 to 17 ml/30 min; the L/P protein ratio declined from 0.63 to 0.41. These results indicate that reperfusion following 2 hr of bilateral hind limb ischemia results in increased pulmonary microvascular permeability.     

Clean up varicose vein surgery--use a tourniquet

A controlled randomised trial has been carried out to ascertain if there are tangible benefits from using a tourniquet when avulsing varicose veins during routine varicose vein surgery. Twenty-six patients have been studied. Twenty limbs were operated on with a tourniquet and 20 limbs without a tourniquet. The mean weight of varices excised was 2.76 g (range 0.51-8.79 g) with a tourniquet and 2.68 g (0.77-11.27 g) without a tourniquet (NS, Wilcoxon's rank sum test). Mean blood loss was 16 ml (0-136 ml) with a tourniquet and 107 ml (16-581 ml) without a tourniquet (P less than 0.01, Wilcoxon's rank sum test). The mean time to complete avulsions was 38 min with a tourniquet and 35 min without a tourniquet (NS, Student's t test). The tangible benefits of a tourniquet are limited to the saving of blood which can amount to 500 ml per leg. Losses could amount to 1 litre in bilateral cases operated upon without tourniquet. The method is simple, provides a clean operating field and should be more widely used.     

A prospective randomised trial of tourniquet in varicose vein surgery

A prospective randomised trial of 50 patients was carried out to assess the autoclavable Lofquist cuff (Boazal, Sweden) as a tourniquet in varicose vein surgery and determine the effect on bleeding, bruising, cosmesis and patient pain and activity. Patients undergoing unilateral long saphenous vein ligation, stripping and avulsions were randomised to tourniquet or no tourniquet. Lofquist cuffs were applied after inflation to 120 mmHg to the upper thigh for the duration of the surgery. Varicose vein grade, duration of surgery, blood loss, extent of bruising at 7 days, pain and activity scores over the first week, and wound complications and cosmetic result at 6 weeks were recorded. Patients' age, sex, and varicose vein grade were similar in the two groups. Peroperative blood loss (median, range) was significantly reduced in the tourniquet group (0 ml, 0-20 ml) compared to the no tourniquet group (125 ml, 20-300; P < 0.01). Operative time and thigh bruising (median, range) were also reduced in the tourniquet group (30 min, 11-47 min; 72 cm2, 30-429 cm2), respectively, compared to the no tourniquet group (37 min, 18-50 min; 179 cm2, 24-669 cm2) both (P < 0.01). There was no difference in pain and activity scores in the two groups and cosmetic results were also similar. The use of the Lofquist cuff tourniquet during varicose vein surgery reduces peroperative blood loss, operative time and postoperative bruising without any obvious drawbacks.     

The effect of a thigh tourniquet on the pharmacokinetics of midazolam

Although the general pharmacokinetics of midazolam (M) are well documented, little is known about the possible effects of a thigh tourniquet on the distribution and elimination of this drug. METHOD. Institutional approval for the study and individual informed consent were obtained. We studied 30 patients (ASA-I) without premedication who electively underwent a surgical procedure of the lower limb. Patients were divided into three groups of 10. The procedure was done in groups I and II with and in group III without tourniquet use. Anesthesia was induced in groups I and II with 0.1 mg/kg M, fentanyl 5 micrograms/kg, alcuronium-dichloride 0.15 mg/kg and etomidate 0.1-0.2 mg/kg i.v. and maintained with enflurane 0.3-1.0 vol.-%. About 20 min after midazolam injection and after exsanguination the tourniquet was applied on the proximal thigh in group I. In group II anesthesia was induced with etomidate 0.2 mg/kg and alcuronium-dichloride 0.15 mg/kg i.v., and maintained about 20 min with enflurane 1.0-1.5 vol.-% until exsanguination and tourniquet application. After this, these patients also received 0.1 mg/kg M and 5 micrograms/kg fentanyl i.v. Through an indwelling arterial line, blood samples were obtained prior to and 2, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165 and 180 min after M injection. Plasma M levels were measured by high-performance liquid chromatography with UV detection. These concentrations were fitted to a two-compartment open model. Comparison between groups was performed using the Kruskal-Wallis test and p less than 0.05 was considered to indicate significance. RESULTS. The groups were all comparable in age and weight, and groups I and II also in duration of thigh ischemia. Midazolam elimination half-time (t beta 1/2) was significantly shorter in group II than in groups III and I (52 min vs 126 min and 139 min; p less than 0.05). Of the calculated distribution volumes (volume of the central compartment, volume in the steady state and volume in the elimination phase), only the volume in the steady state was significantly smaller in group II than in groups III and I (p less than 0.05). Groups III and I did not differ significantly in the computed parameters. The measured initial midazolam mean concentrations in group II were twice those in groups III and I (655 ng/ml vs 323 ng/ml and 332 ng/ml). Since clearance was not significantly different between any two groups, the shorter t beta 1/2 in group II was probably due to the reduced distribution volume. CONCLUSION. These data demonstrate that in the presence of a thigh tourniquet the timing of the injection - before or after application of the tourniquet is of decisive importance. Injection after the application of a tourniquet leads to an higher plasma level and shortens the elimination half-life.     

Cardiovascular effects of two different regional anaesthetic techniques for unilateral leg surgery

Background : Cardiovascular function was assessed in 20 ASA I-II patients, scheduled for elective orthopaedic surgery with tourniquet in order to compare the haemodynamic changes induced by unilateral spinal anaesthesia and combined sciaticofemoral nerve block.
Methods : After baseline measurement of cardiovascular parameters, patients were randomized to receive unilateral spinal anaesthesia or combined sciatico-femoral nerve block. Spinal anaesthesia was obtained by 8 mg of hyperbaric bupivacaine 0.5% slowly injected (speed=0.02 ml s-¹) through a 25-G Whitacre spinal needle with the bevel orientated towards the dependent side and patients lying on their operated side for 15 min (group S, n=10). Combined sciatico-femoral nerve block was obtained by 7 mg kg-¹ of mepivacaine 2% (group NB, n = 10). Haemodynamic variables were recorded 5, 10, 15, and 30 min after anaesthetic injection before surgery was started.
Results : Anthropometric data, duration of surgery and acceptability of anaesthetic techniques were similar in the 2 groups. In 8 patients of group S, spinal block was restricted to the operated side (pinprick test and Bromage scale), while the other 2 patients developed bilateral spinal block after being turned supine. NB patients showed no haemodynamic changes during the study, whereas patients in group S showed a small but significant decrease of mean arterial blood pressure (P<0.002 vs baseline and P<0.04 vs NB), cardiac index (P<0.01 vs baseline and P0.01 vs NB), and stroke volume index (P<0.01 vs baseline and P<0.01 vs NB).
Conclusion : Both sciatico-femoral and unilateral spinal blockade provide adequate anaesthesia for unilateral leg surgery with tourniquet. The former technique affects cardiovascular performance less than the latter one.     

Preoperative oral dextromethorphan attenuated tourniquet-induced arterial blood pressure and heart rate increases in knee cruciate ligament reconstruction patients under general anesthesia

The precise mechanism of tourniquet-induced arterial blood pressure increase is unknown. We determined the effect of preoperative oral dextromethorphan (DM) on arterial blood pressure and heart rate changes during tourniquet inflation in knee cruciate ligament reconstruction patients under general anesthesia. Patients in the DM group (n = 38) received oral DM 30 mg, and patients in the control group (n = 38) received oral placebo 2 h before the induction of anesthesia. Anesthesia was maintained with sevoflurane 2.0% and N(2)O in 33% oxygen, and the trachea was intubated until the end of surgery. Arterial blood pressure and heart rate were measured at 0, 30, and 60 min after the start of tourniquet inflation. Systolic arterial blood pressure and heart rate at 60 min in the control group were significantly more than those in the DM group (131.1 +/- 15.8 mm Hg versus 123.6 +/- 15.9 mm Hg [P < 0.05] and 74.1 +/- 11.3 bpm versus 67.8 +/- 8.5 bpm [P < 0.01], respectively). The percentage increase in systolic arterial blood pressure and heart rate in the DM group was also attenuated when compared with that in the control group (P < 0.05). In conclusion, preoperative oral DM 30 mg significantly attenuated arterial blood pressure and heart rate increases during tourniquet inflation under general anesthesia. IMPLICATIONS: We demonstrated that preoperative oral dextromethorphan 30 mg significantly attenuated arterial blood pressure and heart rate increases at 60 min during tourniquet inflation in patients undergoing knee cruciate ligament reconstruction under general anesthesia.     

Results of open heart surgery in patients with impaired renal function as creatinine clearance below 30 ml/min. The effects of pulsatile perfusion

Twelve patients (pts) with coronary and/or valvular heart disease and preoperative creatinine clearance (Ccr) below 30 ml/min underwent cardiac surgery using cardiopulmonary bypass (CPB) with pulsatile (P:n = 7) and nonpulsatile (NP:n = 5) perfusion. Preoperative Ccr was 15.8 +/- 4.4 ml/min in the P group and 26.5 +/- 4.7 ml/min in the NP group. After surgery, the NP group showed significant increases in BUN and serum creatinine within a week, but the P group showed significant increase in BUN only. The NP group had a significant decrease in Ccr on the 7th postoperative day, but there was no significant change in the P group. Three patients, 2 from the NP group and one from the P group, died from complications (operative mortality: 14 vs 40%). These data suggested that P-CPB appeared to be advantageous in patients with preoperatively impaired renal function with low Ccr although many other factors might influence the outcome.     

Tranexamic acid given intraoperatively reduces blood loss after total knee replacement: a randomized,controlled study

BACKGROUND: Extensive blood loss in total knee replacement (TKR) surgery is well known and is associated with a high transfusion rate of allogenic blood. Tranexamic acid (TXA) has been shown to reduce blood loss by 50% in this patient group, but only in cases with a perioperative loss of 1400-1800 ml. This study was performed to see if TXA offers any advantages in knee replacement surgery with blood loss at 800 ml. METHODS: Thirty consecutive patients scheduled for TKR in spinal anesthesia with the use of a tourniquet, were randomized to TXA or non-TXA. Tranexamic acid 10 mg kg-1 was given at conclusion of surgery and again 3 h later. Blood loss was registered. RESULTS: Total blood loss was at all times significantly lower in the TXA group compared to the non-TXA group (409.7+/-174.9 ml vs. 761.7+/-313.1 ml; P<0.001). There were no differences in coagulation parameters. No patients in the TXA group had a blood transfusion vs. 13% in the non-TXA group (NS). No complications were registered in the two groups. CONCLUSION: We conclude that TXA significantly reduces blood loss after total knee replacement surgery.     

Tourniquet-induced limb ischemia: a neurophysiologic animal model

A rat model of tourniquet-induced ischemia was created to observe the changes in sciatic afferent neuronal activity associated with prolonged tourniquet inflation on the hind leg. The sciatic nerve was divided in the proximal thigh and a two-electrode microfilament recording technique and signal averaging computer were used to survey afferent neuronal activity prior to and after tourniquet inflation. This method was able to determine both firing rate and conduction velocity of spontaneously active or mechanically sensitive nerve fibers. In 14 rats observed prior to tourniquet inflation there was much spontaneous activity. These fibers all had rapid conduction velocities (30 +/- 6.9 m/s) (mean +/- SD) and firing rates (16.3 +/- 1.9 H). All fibers could be stimulated by movement of distal joints or by probing the skin of the leg. After tourniquet inflation, a pressure-induced conduction block occurred stopping all spontaneous and mechanically induced activity. After a short interval, (55 +/- 16 min) a different group of spontaneously active fibers were observed that had both slow conduction (2.04 +/- 0.77 m/s) firing rates (0.54 +/- 0.9 H). These fibers did not respond to mechanical stimulation of the limb distal to the tourniquet, or local anesthetic or cold block of the nerve distal to the tourniquet. Blockade of the sciatic nerve just proximal to the tourniquet and deflation of the tourniquet did abolish activity in these fibers. In ten separate rats in which tourniquets were placed but no surgical incision made, mean arterial blood pressure rose significantly after tourniquet inflation. With tourniquet deflation, blood pressure fell significantly from levels observed during tourniquet inflation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Ketamine sedation during spinal anesthesia for arthroscopic knee surgery reduced the ischemia-reperfusion injury markers

We studied the effect of ketamine sedation on oxidative stress during arthroscopic knee surgery with tourniquet application by determining blood and tissue malonyldialdehyde (MDA) and hypoxanthine (HPX) levels. Thirty ASA I-II patients undergoing arthroscopic knee surgery with tourniquet were randomly divided into two groups. Spinal anesthesia induced with 12.5 mg bupivacaine was administered to all patients. In the ketamine group, after IV administration of 0.01 mg/kg midazolam, a continuous infusion of ketamine (0.5 mg . kg(-1) . h(-1)) was used until the end of surgery whereas the placebo group received a volume-equivalent placebo infusion. Ramsey Sedation Scale (RSS) was used for assessing the sedation level. Venous blood and synovial membrane tissue samples were obtained before ketamine infusion, at 30 min of tourniquet ischemia, and at 5 min after tourniquet deflation for MDA and HPX measurements. Tissue MDA and HPX levels were significantly less in the ketamine group than the control group after reperfusion. RSS scores were higher in the ketamine group without any adverse effect. We conclude that ketamine sedation attenuates lipid peroxidation markers in arthroscopic knee surgery with tourniquet application.     

Intra-articular tenoxicam improves postoperative analgesia in knee arthroscopy

PURPOSE: Non Steroidal Anti-inflammatory drugs have a well documented benefit in the relief of postoperative pain. This study was designed to compare the analgesic effect of intra-articular tenoxicam 20 mg with intravenous tenoxicam on postoperative pain in 88 patients undergoing day case knee arthroscopy. METHODS: A prospective, double blind, randomized trial was performed. All patients received a standard general anesthetic. Patients in group A received 20 mg tenoxicam made up to 40 ml with normal saline intra-articularly (ia) and 2 ml normal saline i.v. Patients in group B received 40 ml normal saline intra-articularly and 2 ml, 20 mg of tenoxicam, i.v. RESULTS: Both groups of patients were similar with respect to age, weight, sex and tourniquet inflation time. Patients receiving ia tenoxicam had lower pain scores (at rest and upon movement) at 30, 60, 120 and 180 min postoperatively (0.8+/-0.2 vs. 2.5+/-0.2 at rest and 1.24+/-0.2 vs. 3.4+/-0.2 at movement at 60 min; P< 0.0001). Fewer patients required additional analgesia in the first four hours postoperatively (33% vs. 84%; P<0.00001) and the time to first analgesia (23.7+/-11.2 vs. 9.4+/-0.6; P<0.02) was longer in those receiving ia tenoxicam. CONCLUSION: Intra-articular tenoxicam provides superior postoperative analgesia and reduces postoperative analgesic requirements compared with i.v. tenoxicam in patients undergoing day case knee arthroscopy.     

The analgesic effect of nitroglycerin added to lidocaine on intravenous regional anesthesia

We evaluated the analgesic effect of nitroglycerine (NTG) when added to lidocaine in IV regional anesthesia. Thirty patients undergoing hand surgery were randomly assigned to two groups. The control group (group C, n = 15) received a total dose of 40 mL with 3 mg/kg of lidocaine diluted with saline, and the NTG group (group NTG, n = 15) received an additional 200 mug NTG. Hemodynamic variables, tourniquet pain measured before and 1, 5, 10, 20, and 30 min after tourniquet inflation, and analgesic requirements were recorded during the operation. After the tourniquet deflation, at 1 and 30 min and 2 and 4 h, visual analog scale (VAS) score, time to first analgesic requirement, total analgesic consumption in the first 24 h after operation, and side effects were noted. Shortened sensory and motor block onset time (3.2 +/- 1.1 versus 4.5 +/- 1.2 min; P = 0.01 and 3.3 +/- 1.6 versus 5.2 +/- 1.8; P = 0.009 in group NTG and group C, respectively), prolonged sensory and motor block recovery times (6.8 +/- 1.6 versus 3.1 +/- 1.2 min P < 0.0001 and 7.3 +/- 1.3 versus 3.6 +/- 0.8 P < 0.0001 in group NTG and group C, respectively), shortened VAS scores of tourniquet pain (P = 0.023), and improved quality of anesthesia were found in group NTG (P < 0.05). VAS scores were lower in group NTG after tourniquet release and in the postoperative period (P = 0.001). First analgesic requirement time was longer in group NTG (225 +/- 74 min versus 39 +/- 33 min) than in group C (P < 0.0001). Postoperative analgesic requirements were significantly smaller in group NTG (P < 0.0001) but the side effects were similar in both groups. We conclude that the addition of NTG to lidocaine for IV regional anesthesia improves sensory and motor block, tourniquet pain, and postoperative analgesia without side effects.     

An evaluation of the analgesic efficacy of intravenous regional anesthesia with lidocaine and ketorolac using a forearm versus upper arm tourniquet

Intravenous regional anesthesia (IVRA) using a forearm tourniquet may be a potentially safer technique compared with using an upper arm tourniquet. Ketorolac is a useful adjuvant to lidocaine for IVRA. In this study, we assessed the analgesic efficacy of administering IVRA lidocaine and ketorolac with either a forearm or upper arm tourniquet for outpatient hand surgery. Upper arm IVRA was established using 40 mL of a solution containing 200 mg of lidocaine and ketorolac 20 mg (0.5 mg/mL). Forearm IVRA was established using 20 mL of a solution containing 100 mg of lidocaine and ketorolac 10 mg (0.5 mg/mL). Onset and duration of sensory block as well as postoperative pain and analgesic use were recorded. The patients who received forearm IVRA had a significantly longer period during which they required no analgesics (701 +/- 133 min) compared with 624 +/- 80 min for the upper arm IVRA ketorolac patients (P = 0.032). Onset of sensory block was similar between the two groups; however, recovery of sensation was significantly longer in the Forearm IVRA (22 +/- 5 min) group compared with the Upper Arm IVRA (13 +/- 3 min) group (P < 0.05). There were no differences in postoperative analgesic use or pain scores between the two groups. We conclude that forearm IVRA with lidocaine and ketorolac provides safe and effective perioperative analgesia for patients undergoing ambulatory hand surgery. This technique results in a longer duration of sensory block and prolonged postoperative analgesia compared with upper arm IVRA while using one-half the doses of both lidocaine and ketorolac. IMPLICATIONS: Forearm tourniquet intravenous regional anesthesia (IVRA) with 50% less lidocaine and ketorolac provides for both a longer duration of sensory block and prolonged postoperative analgesia compared with upper arm IVRA.     

High dose aprotinin to reduce blood loss in patients undergoing redo open heart surgery.

Recently, aprotinin has been demonstrated to be effective in reducing post-operative bleeding after open heart surgery. The aim of this study was to evaluate the effectiveness of high dose aprotinin in patients undergoing redo open heart surgery in whom perioperative bleeding is generally increased. Fifty-eight patients, mean age 55 years, underwent a second open heart surgery for single valve replacement in 37 patients (mitral or aortic), for double valve replacement in 16 patients and for coronary artery by-pass grafting in 4 patients. In 30 of the 58 patients (Group A) aprotinin was infused with the following scheme: 2 million KIU in 30 minutes during induction of anesthesia, 2 million KIU in the priming volume of extracorporeal circulation and 500,000 KIU every hour until the end of the surgical procedure. The remaining 28 patients served as control group (Group B). No adverse reactions to aprotinin were observed. There was no significant difference in cardiopulmonary by-pass time and minimum temperature achieved between the two groups of patients. During the operative day blood loss was significantly lower in group A than in group B (492 +/- 336 ml vs. 628 +/- 273 ml) (p < 0.01). This difference was not significant during the following days. However 3 days after the operation a still significant difference was reported in total blood loss between group A and group B (816 +/- 507 ml vs. 1018 +/- 373 ml) (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Bupivacaine use after knee arthroscopy: pharmacokinetics and pain control study

Bupivacaine (Marcaine) pharmacokinetics were determined in 11 patients receiving the drug intraarticularly after arthroscopic procedures performed on the knee with patients under general anesthesia. Forty milliliters of 0.25% bupivacaine (100 mg) were given as a bolus into the intraarticular space of the knee of each patient. The thigh tourniquet was released 2-3 min after injection and blood samples were obtained 5, 10, 15, 20, 30, 60, 120, 180, 250, and 300 min after tourniquet release. Pharmacokinetic parameters obtained were (mean +/- SD): Vd beta 206 +/- 88 L; Cle 0.816 +/- 0.378 L/min; t 1/2 beta 189 +/- 84 min; ka 9.92 +/- 6.79 x 10/min; Cpmax 0.48 +/- 0.20 micrograms/ml; and tmax 43.4 +/- 23.1 min. Correlations between higher peak plasma concentrations and longer tourniquet times (p = 0.02) and shorter intervals from injection to tourniquet deflation (p = 0.03) were found using multiple linear regression. Our results indicate that injections of 100 mg of bupivacaine intraarticularly after knee arthroscopy will produce peak blood levels within the 1st h after surgery and that these levels will be well below those noted to produce toxic reactions. Peak levels can be minimized with shorter tourniquet inflation times and with longer injection to tourniquet release intervals. Ninety healthy adult outpatient knee arthroscopy patients also were studied to evaluate the effectiveness of bupivacaine in relieving postoperative knee discomfort when injected immediately postoperatively. The subjects were randomized into four groups: (a) intraarticular injection of saline, (b) intraarticular injection of bupivacaine, (c) subcutaneous injection of bupivacaine at the portal sites, and (d) both intraarticular and subcutaneous injection of bupivacaine.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effects of propofol or sevoflurane on free radical production after tourniquet induced ischaemia-reperfusion injury during knee arthroplasty

BACKGROUND: We studied the effects of anesthesia with propofol or sevoflurane on the production of free oxygen radicals during total knee arthroplasty performed with the use of an ischemic tourniquet by measuring the levels of malondialdehyde (MDA). METHODS: We studied two groups of patients (20 patients in each group) who underwent total knee arthroplasty. To maintain anesthesia we delivered 66% nitrous oxide plus sevoflurane or propofol. Blood samples for the determination of the MDA levels were drawn before the application of the ischemic tourniquet and 5 and 30 minutes after its release. RESULTS: There were no differences between groups in regard to age, weight and duration of the tourniquet application. MDA levels decreased significantly in the propofol group 30 minutes after the release of the tourniquet (1.7 micromol litre(-1) vs 1.57 micromol litre(-1), Friedman's ANOVA, P = 0.007). In contrast, there was a small rise of the MDA levels in the sevoflurane group (1.82 micromol litre(-1) vs 1.96 micromol litre(-1), Friedman's ANOVA, P = 0.007). CONCLUSION: Propofol may have anti-oxidant properties in orthopaedic surgery requiring tourniquet application, but sevoflurane needs further study.     

Comparison of retroperitoneoscopic nephrectomy versus open approaches to nonfunctioning tuberculous kidneys: a report of 44 cases

PURPOSE: We retrospectively investigated the advantages of retroperitoneoscopic nephrectomy for nonfunctioning tuberculous kidneys by comparing its clinical results, operative methods and skills with those of open nephrectomy. MATERIALS AND METHODS: Clinical data on 22 patients with nonfunctioning tuberculous kidneys who underwent retroperitoneoscopic nephrectomy, including simple and subcapsular nephrectomy, were compared with those on 22 who underwent open nephrectomy for a similar indication during the same period. Results in the 2 groups were analyzed. RESULTS: There was no statistical difference between the retroperitoneoscopy and open surgery groups with regard to patient age, sex or mean operative time +/- SD (93.0 +/- 12.6 vs 92.6 +/- 35.5 minutes). Mean blood loss was significantly less in the retroperitoneoscopy group than in the open surgery group (78.3 +/- 60.6 vs 160 +/- 120.0 ml). Mean hospital stay after operation was notably shorter in the retroperitoneoscopy group compared with the open surgery group (3.3 +/- 0.9 vs 9.1 +/- 0.8 days). The mean analgesic requirement for opioids and diclofenac sodium was also lower in the retroperitoneoscopy group than in the open surgery group (0 vs 2.1 +/- 0.9 and 5.2 +/- 1.1 vs 5.8 +/- 1.3 doses, respectively). CONCLUSIONS: Retroperitoneoscopic nephrectomy for renal tuberculosis has several advantages over open nephrectomy, namely a smaller wound, less blood loss and more rapid recovery. It may provide a safe and reliable method for treating refractory renal tuberculosis clinically.