Changes in hepatocellular integrity during and after desflurane or isoflurane anaesthesia in patients undergoing breast surgery

We have assessed hepatocellular integrity in patients anaesthetized with desflurane or isoflurane using glutathione transferase Alpha (GSTA) as a sensitive indicator. Volatile anaesthetic was administered to 72 women at 0.7 MAC for 25 min and thereafter at 1.0 MAC. GSTA was measured with a time-resolved immunofluorometric assay in serum samples. Mild or moderate increases in GSTA were found in approximately 40% of patients immediately after anaesthesia. In the desflurane group (n = 30) the increase in GSTA concentration was from a baseline value of the geometric mean of 1.3 microgram litre-1 (95% confidence interval 0.9-1.9 microgram litre-1) to a peak of 2.6 (1.8-3.8) micrograms litre-1. The corresponding increase in the isoflurane group (n = 31) was from 1.3 (0.9-1.9) microgram litre-1 to 3.0 (2.2-4.2) micrograms litre-1. The change in GSTA concentration was significant in both groups but not between groups. No predictive factors for the increase in GSTA concentrations were found. Increased GSTA concentrations were not accompanied by increases in amino-transferases. We conclude that desflurane and isoflurane anaesthesia were associated with a mild subclinical disturbance of hepatocellular integrity.

Comparison of respiratory effects of tramadol and pethidine

Tramadol is a centrally acting opioid with a low affinity for mu-opioid receptors, which has been claimed not to depress respiration as do the classic opioids. The respiratory effects of intravenous (i.v.) pethidine (0.6 mg kg-1) and tramadol (0.6 mg kg-1) were compared in 36 ASA Grade I-II patients in a placebo-controlled double-blind study. After induction of anaesthesia with propofol followed by suxamethonium-facilitated endotracheal intubation, the patients spontaneously breathed halothane in 70% nitrous oxide and oxygen via a non-rebreathing valve. Inspiratory and expiratory oxygen, and end-tidal carbon dioxide concentrations (PETCO2), tidal volume (VT), minute volume of ventilation (MV) and respiratory rate were monitored by a side-stream spirometry at an end-tidal halothane of 0.3%. The recordings were collected before surgery. Pethidine caused significant respiratory depression seen as an increase in fractional inspiratory-expiratory oxygen difference and PETCO2 and as a decrease in MV and respiratory rate. However, the effects of tramadol were similar to those of a placebo. Tidal volume was not affected by any study drug. In conclusion, tramadol 0.6 mg kg-1 was shown not to be associated with respiratory depression, unlike equipotent dose of pethidine in this setting.

Comparison of intrathecal morphine and continuous femoral 3-in-1 block for pain after major knee surgery under spinal anaesthesia

Major knee surgery is associated with moderate or severe post-operative pain. Intrathecal morphine and continuous femoral 3-in-1 block were compared prospectively in 40 patients for pain after major knee surgery under spinal anaesthesia, with 4 mL isobaric 0.5% bupivacaine. In a random order, 20 patients received preservative free morphine 0.3 mg mixed with spinal bupivacaine. In 20 patients, following spinal anaesthesia with only bupivacaine, femoral 3-in-1 block was performed post-operatively with 0.5% bupivacaine 2 mg kg-1. The block was continued via a catheter with 0.25% bupivacaine 0.1 mL h-1 kg-1 until the next morning (24 h after induction of spinal anaesthesia). Intramuscular oxycodone was given as a rescue analgesic in all patients. Two patients from the femoral group were excluded due to technical failure. Three patients in the morphine group and one patient in the femoral group did not need any additional oxycodone. In the morphine group on average 2.8 (range 0-7) and in the femoral group 3.2 (0-5) additional doses of oxycodone were needed during the 24 h observation period. The mean pain scores were significantly lower in the morphine group at 9 and 12 h into the 24-h trial. Itching was seen only in the morphine group (40% of the patients). Other side effects were similar in the two groups. All patients were satisfied with their pain therapy. Both intrathecal morphine and femoral 3-in-1 block alone were insufficient for the treatment of severe pain after major knee surgery.

Extracorporeal immunoadsorption compared to avidin chase: enhancement of tumor-to-normal tissue ratio for biotinylated rhenium-188-chimeric BR96

Based on the biodistribution and kinetics of biotinylated 188Re-chimeric BR96 (chiBR96), the enhancement of the tumor-to-normal tissue (T/N) radioactivity ratio using extracorporeal immunoadsorption (ECIA) was evaluated and compared with that of avidin "chase" in colon carcinoma-isografted Brown Norwegian rats.

METHODS

Extracorporeal immunoadsorption (ECIA) was performed 6 or 12 hr after intravenous administration of biotinylated 188Re-chiBR96. Radioactivity redistribution was investigated just after ECIA [8 or 14 hr postinjection of the antibody] and 40 or 34 hr after ECIA performance (48 hr postinjection). Avidin was administered intraperitoneally at 6 hr postinjection. Tumor radioactivity uptake and T/N activity ratios of biotinylated 188Re-chiBR96 were compared using ECIA and avidin chase and were also compared with controls.

RESULTS

Both ECIA and avidin chase can rapidly increase the radioactivity tumor-to-blood ratio without significantly interfering with the tumor uptake. ECIA at 8 hr postinjection increased the T/N ratios in blood-rich tissues, such as liver and bone marrow, from 6 and 8 to 10 and 18, respectively. Corresponding T/N ratios at 14 hr increased from 9 and 10 to 24 and 36. In contrast, when avidin chase was used, there were no T/N improvements, except in blood. Moreover, avidin chase caused a significant accumulation of radioactivity in the liver.

CONCLUSION

The ECIA approach, with direct removal of unbound circulating biotinylated 188Re-chiBR96, thus can rapidly improve and maintain T/N ratios without overloading the liver with radioactivity, in contrast to avidin chase.

Comparison of respiratory effects of tramadol and oxycodone

STUDY OBJECTIVE

To compare the respiratory effects of tramadol and oxycodone.

DESIGN

Placebo-controlled, double-blind randomized study.

SETTING

IV Department of Surgery, Helsinki University Central Hospital.

PATIENTS

36 ASA physical status I and II patients undergoing minor surgery with general anesthesia.

INTERVENTIONS

The respiratory effects of intravenous (i.v.) tramadol 0.6 mg/kg and oxycodone 0.04 mg/kg were compared after induction of anesthesia with propofol and succinylcholine-facilitated endotracheal intubation. Patients spontaneously breathed halothane in 70% nitrous oxide and oxygen via a nonrebreathing valve. The trial drugs or placebo were given after recovery from neuromuscular block.

MEASUREMENTS AND MAIN RESULTS

Inspiratory and expiratory oxygen and end-tidal carbon dioxide concentrations (ETCO2), tidal volume (VT) minute volume of ventilation (VE), and respiratory rate (RR) were recorded by side-stream spirometry with end-tidal halothane of 0.3% for 30 minutes before surgery. Oxycodone caused a significant respiratory depression seen as an increase in the inspiratory-expiratory oxygen difference and ETCO2 and as a decrease in VE and RR. On the contrary, the effect of tramadol were similar to those of placebo. VT was not affected by any study drug.

CONCLUSION

Tramadol was not associated with respiratory depression in the present setting.

Splanchnic and renal deterioration during and after laparoscopic cholecystectomy: a comparison of the carbon dioxide pneumoperitoneum and the abdominal wall lift method

Carbon dioxide (CO2) pneumoperitoneum together with an increased intraabdominal pressure (IAP) induces a hemodynamic stress response, diminishes urine output, and may compromise splanchnic perfusion. A new retractor method may be less traumatic. Accordingly, 30 ASA physical status I or II patients undergoing laparoscopic cholecystectomy were randomly allocated to a CO2 pneumoperitoneum (IAP 12-13 mm Hg) (control) or to a gasless abdominal wall lift method (retractor) group. Anesthesia and intravascular fluids were standardized. Direct mean arterial pressure (MAP), urine output, urine-N-acetyl-beta-D-glucosaminidase (U-NAG), arterial blood gases, gastric mucosal PCO2, and intramucosal pH (pHi) were measured. Normoventilation was instituted in all patients. MAP increased (P < 0.001) only with CO2 pneumoperitoneum. Minute volume of ventilation had to be increased by 35% with CO2 insufflation. PaCO2 was significantly higher (P < 0.05) for 3 h postoperatively in the control group. Diuresis was less (P < 0.01) and U-NAG levels (P < 0.01) higher in the control group. The pHi decreased after induction of pneumoperitoneum up to three hours postoperatively and remained intact in the retractor group. We conclude that the retractor method for laparoscopic cholecystectomy ensures stable hemodynamics, prevents respiratory acidosis, and provides protection against biochemical effects, which reveal the renal and splanchic ischemia caused by CO2 insufflation.

IMPLICATIONS

A mechanical retractor method (gasless) was compared with conventional CO2 pneumoperitoneum for laparoscopic cholestectomy. The gasless method ensured stable hemodynamics, prevented respiratory acidosis, and provided protection against the renal and splanchnic ischemia seen with CO2 pneumoperitoneum.

Pharmacokinetics and ventilatory effects of oxycodone before and after liver transplantation

The pharmacokinetics and ventilatory effects of oxycodone were studied in six volunteer patients with end-stage liver cirrhosis before and after orthotopic liver transplantation. Plasma samples and urine were collected for 24 hours after intravenous administration of 0.05 mg/kg oxycodone hydrochloride. Concentrations of oxycodone and its metabolites, noroxycodone and oxymorphone, were measured in plasma and urine. THe median elimination half-life of oxycodone was 13.9 hours (range, 4.6 to 24.4 hours) in patients with cirrhosis before transplantation and 3.4 hours (range, 2.6 to 5.1 hours) after transplantation (p < 0.05). Correspondingly, oxycodone clearance increased from 0.26 L/min (range, 0.15 to 0.73 L/min) before transplantation to 1.13 L/min (range, 0.71 to 3.98 L/min) after transplantation (p < 0.05). Oxycodone depressed ventilation more strongly before transplantation than after transplantation (p < 0.05). Care should be exercised when oxycodone is used in patients with end-stage disease.

Effects of dietary sodium and magnesium on cyclosporin A-induced hypertension and nephrotoxicity in spontaneously hypertensive rats

Arterial hypertension, nephrotoxicity, and magnesium loss are common side effects of the immunosuppressive agent cyclosporin A (CsA). In the present study, the effects of dietary sodium and magnesium on CsA toxicity were examined in spontaneously hypertensive rats. A 6-week treatment with CsA during a moderately low-sodium diet (Na 0.3%, Mg 0.2% of the dry weight of the chow) raised blood pressure only slightly, without evidence of nephrotoxicity. By contrast, CsA during a high-sodium diet (Na 2.6%) produced a pronounced rise in blood pressure as well as marked nephrotoxicity, comprising decreased creatinine clearance, increased levels of serum creatinine and urea, and increased urinary protein excretion. During the high-sodium diet, CsA decreased myocardial and bone magnesium concentration and increased myocardial and renal calcium concentration. Magnesium supplementation (Mg 0.6%) protected against the CsA-induced hypertension and nephrotoxicity during the high-sodium diet. Magnesium supplementation also completely prevented the CsA-induced myocardial magnesium depletion and calcium accumulation in the heart and kidney during the high-sodium diet. Our findings indicate a detrimental interaction between increased sodium intake and CsA treatment and a marked protection by concomitant oral magnesium supplementation.

Comparison of epidural morphine and oxycodone for pain after abdominal surgery

STUDY OBJECTIVE

To compare the efficacy and side effects of epidural morphine and oxycodone for pain following major abdominal surgery.

DESIGN

Randomized, double-blind study.

SETTING

4th Department of Surgery, Helsinki University Central Hospital.

PATIENTS

44 adult ASA physical status I, II, and III patients scheduled for elective major abdominal surgery.

INTERVENTIONS

Thirty-three patients were allocated randomly to one of two epidural groups and 11 patients received oxycodone intravenously (IV). The two epidural groups received either morphine (bolus 0.015 mg/kg followed by an infusion 0.003 mg/kg/hr) or oxycodone (bolus 0.15 mg/kg followed by an infusion 0.03 mg/kg/hr) before induction of standardized anesthesia and for 24 hours thereafter. A third group of patients was given the same dose of IV oxycodone as in the epidural group, serving as an open control group for epidural oxycodone.

MEASUREMENTS AND MAIN RESULTS

Blood samples were drawn for plasma opioid concentrations. Postoperatively, pain (at rest and during coughing), nausea, pruritus, sedation, respiratory rate, and hemodynamics were recorded until the end of the infusions. The epidural dose ratio between morphine and oxycodone was 1:8.4 to 9.8 to provide similar analgesia. Side effects occurred similarly in the three groups. Mild respiratory depression was seen in all groups, especially in the IV oxycodone group. In all groups, hemodynamic variables remained within normal limits.

CONCLUSIONS

In the dosages reported, oxycodone can be used epidurally for acute post-operative pain. The analgesic effect was as good as that of epidural morphine.

Third ventricle colloid cysts: a consecutive 12-year series

A continuous follow-up review of colloid cysts including aspects of natural history and evaluation of treatment options is necessary to optimize individual treatment. Thirty-seven consecutive patients with colloid cyst of the third ventricle seen at Karolinska Hospital between 1984 and 1995 were reviewed. Five patients were admitted in a comatose state, and two died despite emergency ventriculostomy. Three had recurrent cysts following previous aspiration procedure. During the study period, patients underwent a total of 10 ventriculostomies, 10 aspirations, 26 microsurgical operations, and two shunt operations. Twenty-four of 26 microsurgical operations were transcallosal and two were transcortical. Twenty-four operations (22 transcallosal and two transfrontal approaches) without permanent morbidity were performed by four surgeons. Transient memory deficit from forniceal traction was noted in 26%. The remaining two transcallosal operations, which led to permanent morbidity or mortality, were performed by two different surgeons. Aspiration of cysts performed by four different surgeons carried a 40% risk of transient memory deficit (10% permanent) and an 80% recurrence rate. One patient was found to be cured on radiological studies obtained at the 5-year follow-up review. Seven cysts were followed by means of radiological studies with no treatment for 6 to 37 months. Five of these cysts grew, indicating that younger patients with colloid cysts will probably need surgical treatment. The main causes of unfavorable results were: 1) failure to investigate symptoms that proved fatal; 2) subtotal resection; and 3) surgical complications. Transcallosal microsurgery produced excellent results when performed by experienced surgeons. A colloid cyst of the foramen of Monro is a disease that should be detected before permanent neurological damage has occurred. Permanent morbidity or mortality should not be accepted in modern series of third ventricle colloid cysts.

Postoperative drowsiness and emetic sequelae correlate to total amount of carbon dioxide used during laparoscopic cholecystectomy

BACKGROUND

After laparoscopy with carbon dioxide (CO2) insufflation early postoperative recovery is often complicated with drowsiness and postoperative nausea and vomiting (PONV).

METHODS

25 ASA I-II patients undergoing elective laparoscopic cholecystectomy under standardized anaesthesia were studied in a randomized, prospective study. The conventional CO2 pneumoperitoneum was compared with the mechanical abdominal wall lift (AWL) method with minimal CO2 insufflation with special reference to postoperative recovery.

RESULTS

Postoperative drowsiness was of a significantly longer duration with the conventional method (p < 0.001) compared with the AWL technique. There was a positive correlation with the total amount of CO2 used and the duration of drowsiness (r = 0.75, p < 0.01). PONV was seen significantly more often in patients with CO2 insufflation of more than 121 (p < 0.05).

CONCLUSIONS

Avoiding excessive CO2 is beneficial for smoother and more uneventful recovery after laparoscopic cholecystectomy.

[A study of post-traumatic stress reactions among war refugees based on medical records. A standard model may support the treatment]

A special project designed to aid Bosnian refugees in Stockholm County was initiated and funded by the County Council in February 1994. The present study, a joint endeavour involving the Bosnian Project, the Centre for Trauma and Torture Diagnostics, and the Red Cross Centre for torture victims, was designed to fulfil the following aims: To characterise the patient population in terms of social situation, trauma history, symptoms and treatment; To review accumulated experience at the three centres; To outline and discuss the treatment; and To suggest new avenues for further research concerning refugees and trauma. To obtain comparable material for this retrospective review of case records at the three centres, a special case chart format was adopted, covering pre-war and pre-treatment information on general background, social situation, health status and medication, as well as trauma history, symptoms and treatment. Most patients reported good pre-war health, but at the time of the study exhibited manifest effects of trauma history; 95 per cent reported mental problems, and 39 per cent medical disease or physical disorders. These refugees were thus characterised by manifest post-traumatic stress symptoms and need of treatment. Despite their relatively short time in Sweden, almost all had permanent residence permits and fixed addresses. The absence of a comparable control group precluded comparison with other refugee or normal populations. The findings suggest the need of co-ordination and co-operation between the special facilities available to refugees, and of a standardised format for case records.

Randomized comparison of the neuroendocrine response to laparoscopic cholecystectomy using either conventional or abdominal wall lift techniques

Increase in plasma renin activity and noradrenaline concentration occur in response to carbon dioxide insufflation during laparoscopic cholecystectomy. In a randomized study the conventional carbon dioxide pneumoperitoneum was compared with the abdominal wall lift method for laparoscopic cholecystectomy, with special reference to neuroendocrine changes and renal function. The total mean(s.d.) volume of carbon dioxide insufflated was 42(23) litres with the conventional method and 9(7) litres with abdominal wall lift (P < 0.001). Mean(s.d.) intra-abdominal pressure after 15 min of insufflation was 11(2) and 3(9) mmHg respectively (P < 0.01). In the conventional group mean(s.d.) plasma renin activity increased slightly from 5.5(2.1) to 6.1(2.0) ng ml-1 during the first 55 min of laparoscopic cholecystectomy. In the abdominal wall lift group plasma renin activity decreased from 5.3(2.7) to 3.8(0.9) ng ml (P < 0.01 between the groups). Plasma antidiuretic hormone concentration increased similarly in both groups. Diuresis was significantly less with conventional pneumoperitoneum during the first 35 min of the operation compared with the abdominal wall lift method (P < 0.001). There were significant increases in plasma noradrenaline concentration in both groups (P < 0.001), but the increase was slightly higher in the conventional group during the first 15 min of insufflation. The abdominal wall lift method with minimal carbon dioxide insufflation was associated with smaller neuroendocrine responses and better preservation of renal function compared with conventional carbon dioxide pneumoperitoneum.

Gasless laparoscopic cholecystectomy: comparison of postoperative recovery with conventional technique

We have compared, in a randomized study in 26 patients, immediate and late postoperative recovery after elective laparoscopic cholecystectomy using the gasless, mechanical abdominal wall lift method with conventional carbon dioxide pneumoperitoneum. After the gasless method, tracheal extubation was performed significantly earlier than after the conventional method (P < 0.01). End-tidal carbon dioxide concentrations were significantly higher after pneumoperitoneum for 30 min after operation (P < 0.01). In the conventional group, deviation in Maddox-Wing recordings from preoperative values remained at a significantly higher level during the 3-h recovery room period (P < 0.01). There was a positive correlation between the total amount of carbon dioxide used and duration of drowsiness (r = 0.61, P < 0.001) and the Maddox-Wing deviation (r = 0.62, P < 0.001). Postoperative nausea and vomiting, and right shoulder pain occurred less often after the gasless method (P < 0.05). Late recovery criteria (ability to drink, void and walk) in patients in the gasless group were fulfilled approximately 7 h earlier than in those in the pneumoperitoneum group (P < 0.01). Gasless laparoscopic cholecystectomy resulted in more uneventful and faster immediate and late postoperative recovery than conventional carbon dioxide pneumoperitoneum.

Cardiac evaluation of liver transplant recipients: QT dispersion in electrocardiogram

Increased QT dispersion, the interlead variability of the QT interval length in the 12-lead electrocardiogram, reflects uneven ventricular repolarization as a sign of cardiomyopathy. We analyzed QT dispersion in the preoperative electrocardiogram of 100 adult liver transplant recipients and 20 healthy control subjects. In 12% of the liver recipients, QT dispersion was increased above 65 ms (mean + 3SD). Six of these patients had a liver storage disease (haemochromatosis, Wilson's disease or amyloidosis). Five had a history of cardiac disease. Severe intraoperative cardiac complications occurred in three patients with markedly increased QT dispersion (> or = 99 ms). In conclusion, in liver storage diseases the heart may be affected, leading to increased risk of cardiac complications, which might be predicted from increased QT dispersion. Analysis of QT dispersion, a noninvasive inexpensive technique, can be recommended to be included in the cardiac screening of liver transplant candidates.

Heart rate variability in diabetic and non-diabetic renal transplant patients

BACKGROUND

Heart rate variability (HRV) has been used to investigate the autonomic modulation of heart rate. Diminished HRV has been observed in diabetic autonomic neuropathy, a condition associated with increased mortality. Uraemia is associated with impaired autonomic function, but reports on the effects of uraemia on HRV are scarce.

METHODS

HRV and its circadian variation were studied in 12 diabetic and 11 non-diabetic renal transplantation and in 12 control patients. HRV in time and frequency domains was determined from 24-hour ECG recordings.

RESULTS

In the diabetic group, all time domain and frequency domain measures of HRV were markedly reduced (P < 0.05), when compared with the control group, and the circadian variation of HRV was absent. The mean (SD) amplitudes (ms) in the frequency bands were: high frequency: 3 (1), 6 (3) and 15 (3); low frequency: 9 (7), 16 (10) and 25 (8); very low frequency: 14 (8), 23 (12) and 30 (11) in the diabetic and non-diabetic uraemic and in the control patients, respectively. In non-diabetic uraemic patients, a tendency to reduced HRV was observed, but no statistical differences in HRV measures were found when compared with the control group.

CONCLUSION

The severe impairment of HRV in patients with end-stage diabetic nephropathy is probably due to autonomic neuropathy and partly also to the co-existing heart diseases. It may be a contributing risk factor for ventricular arrhythmias and sudden death in these patients. Uraemia alone causes similar but less severe changes in HRV.

Respiratory compliance during orthotopic liver transplantation

After liver transplantation, respiratory complications are frequent. The purpose of this study was to assess if intraoperative monitoring of respiratory compliance is of clinical value in predicting such complications. Respiratory compliance was continuously monitored with a side-stream respiratory gas flow and pressure sensor (Datex, Helsinki, Finland) at the endotracheal tube in 18 adult patients undergoing orthotopic liver transplantation without veno-venous bypass. Respiratory compliance decreased along with blood volume expansion under anaesthesia before the start of surgery (P < 0.05). Compliance improved as ascites was removed at the beginning of laparotomy (P < 0.001). The highest compliance values were seen during liver surgery. In the patients without ascites preoperatively, compliance was lower at the end of surgery than at anaesthesia induction (P < 0.001). In the patients with ascites, compliance at the end of surgery was equally low as at anaesthesia induction. Compliance at the end of surgery was lower in the patients with bilateral than in those with right-sided or no pleural effusions in the postoperative chest X-rays (P < 0.001). In conclusion, intraoperative monitoring of respiratory compliance is one useful method for clinical use in predicting postoperative bilateral pleural effusions.

Transfusion-related acute lung injury (TRALI) after fresh frozen plasma in a patient with coagulopathy

BACKGROUND

Transfusion-related acute long injury (TRALI) is due to specific antigen-antibody reaction involving the donor's leucocyte or granulocyte antibodies towards the recipient's antigens. Aggregation in small pulmonary vessels occurs, leading to derangement of permeability.

CASE HISTORY

TRALI after transfusion of four units of fresh frozen plasma (FFP) for factor V deficiency prior to elective cholecystectomy is presented. Within a few minutes after the third unit of FFP a florid pulmonary oedema developed. Hypotension and hypoxia with SpO2 83-87% at FiO2 1.0 followed. Prompt monitoring of central haemodynamics revealed a normal cardiac index without pulmonary hypertension. The operation was then conducted as planned. The bilateral pulmonary oedema resolved after 72 hours with ventilatory support. The patient recovered without complications. When tested postoperatively, the second unit of FFP contained granulocyte antibodies and the third unit contained HLA antibodies. The crossmatch of the patient's granulocytes and lymphocytes towards the two donors of the two units of FFP was positive.

CONCLUSION

When TRALI is suspected the donor blood has to be tested against the recipient. Ventilatory support of the patient is continued until adequate oxygenation is reached.

Postoperative lumbar MR imaging with contrast enhancement. Comparison between symptomatic and asymptomatic patients

PURPOSE AND MATERIAL: Contrast-enhanced MR imaging of the spine after surgery for lumbar disk herniation almost always shows pathologic changes. To investigate to what extent these changes are correlated to patients' actual clinical symptoms, we compared the postoperative MR findings in 19 asymptomatic patients with 42 symptomatic patients (43 levels).

METHODS

The asymptomatic patients underwent MR examination one year after surgery. Twenty-six of the symptomatic patients underwent MR one year or less after surgery, and in 16 patients (17 levels) MR was performed more than one year after surgery.

RESULTS

Sixteen percent of the asymptomatic and 42% of the symptomatic patients had disk herniation at the level of previous surgery. Most of the herniated disks were found in the symptomatic patients less than one year after surgery. The amount of epidural scar tissue, displacement and thickening of nerve roots, and compression of the dural sac were also studied. Disk herniation as a probable cause of recurrent sciatica was a common finding among symptomatic patients examined one year or less after surgery. In comparing asymptomatic patients and symptomatic patients with more than one year between surgery and MR examination, no significant radiologic differences, including disk herniation, were found.

Cardiac failure aggravated by timolol eye drops: preoperative improvement by changing to pilocarpine

A 73-year-old woman with cardiac dysfunction had several episodes of severe bradycardia and pulmonary oedema when waiting for peripheral vascular surgery. She used timolol eye drops for primary open-angle glaucoma. The first episode of pulmonary oedema occurred two weeks prior to and the second on the day before the planned surgery. There were another two episodes of pulmonary oedema before she was transferred to the Department of Internal Medicine where she had a further two episodes of cardiac failure. After changing timolol to pilocarpine eye drops, the patient's condition was stabilized, and two weeks later surgery and postoperative recovery were uneventful.

The pharmacokinetics of oxycodone in uremic patients undergoing renal transplantation

STUDY OBJECTIVE

To determine the pharmacokinetics of oxycodone and the excretion of oxycodone and its metabolites noroxycodone and oxymorphone in uremic patients undergoing renal transplantation.

DESIGN

Open study of the pharmacokinetics and excretion of oxycodone.

SETTING

IV Department of Surgery, Helsinki University Central Hospital.

PATIENTS

10 uremic patients undergoing renal transplantation and 10 ASA status I patients undergoing general surgery.

INTERVENTIONS

Intravenous (IV) oxycodone chloride 0.07 mg/kg was administered 30 minutes before induction of standardized anesthesia. Sampling of blood and urine was conducted for 24 hours.

MEASUREMENTS AND MAIN RESULTS

The concentrations of oxycodone and noroxycodone in plasma and the 24 hour urine recoveries of the conjugated and unconjugated forms of oxycodone, noroxycodone, and oxymorphone were measured. Mean elimination half-life was prolonged in uremic patients due to increased volume of distribution and reduced clearance. Interindividual variation was very great. Plasma concentrations of noroxycodone were higher in uremic patients. Significantly smaller quantities of free oxycodone and noroxycodone and both free and conjugated oxymorphone were excreted in the urine in the uremic than in the control patients.

CONCLUSIONS

Elimination of oxycodone is impaired in end-stage renal failure.