Wolfgang H. Maleck

Nefopam and clonidine in the prevention of postanaesthetic shivering.

Postanaesthetic shivering affects up to 70% of patients after general anaesthesia, and may be very distressing. Various drugs have been used to treat or prevent postanaesthetic shivering, but the ideal one has not yet been found. Sixty patients undergoing elective abdominal or orthopaedic surgery under general anaesthesia were included in a randomised, double‐blind study. Patients received clonidine (3 μg.kg−1), nefopam (0.15 mg.kg−1) or saline 0.9% as a placebo at the end of surgery, prior to extubation. Nefopam and clonidine significantly reduced the incidence and severity of shivering in comparison with the placebo. The recovery time, between the end of anaesthesia and extubation, was significantly longer in the clonidine‐treated patients [13.6 (5.2) min] than in either the nefopam [9.6 (2.8) min] or the placebo [10.0 (5.4) min] groups. Mean arterial blood pressure and heart rate were significantly lower in the clonidine group compared with both other groups. Our results suggest that nefopam and clonidine are effective in the prevention of postanaesthetic shivering. However, following clonidine administration the recovery time was prolonged and hypotension was significantly greater than after nefopam.

The effect of In vitro hemodilution with gelatin, dextran, hydroxyethyl starch, or Ringer's solution on Thrombelastograph.

To determine the effects of progressive in vitro hemodilution with various plasma substitutes on whole blood coagulation, blood was obtained from six healthy volunteers. The Thrombelastograph® (TEG; Haemoscope Corp., Morton Grove, IL) variables of reaction time, coagulation time, maximum amplitude, and growth angle were determined. The following plasma substitutes were tested: two gelatin solutions (4% gelatin polysuccinate and 5.5% oxypolygelatin); two dextrans (10% dextran 40 and 6% dextran 60); and five hydroxyethyl starch (HES) preparations (6% HES 70/0.5–0.55, 3% HES 200/0.5, 6% HES 200/0.5, 10% HES 200/0.5, and 6% HES 450/0.7). Ringer’s solution was also tested to assist analyzing the intrinsic effect of colloid molecules on blood coagulation. The dilution ratios of citrated blood volume to plasma substitute volume were 10:2, 10:4, and 10:10. Blood coagulation was affected by plasma substitutes when the dilution ratios of citrated blood volume to colloid solution volume were 10:4 and 10:10. TEG variables did not change significantly after in vitro hemodilution with lactated Ringer’s solution. The tested gelatin solutions showed less intrinsic effect on blood coagulation than other plasma substitutes. All HES preparations showed similar intrinsic effects as 6% dextran 60. The plasma substitute of 10% dextran 40 had the strongest effect on coagulation. Coagulation time was the most markedly affected TEG variable. Blood coagulation may be compromised when the dilution ratio of blood volume to colloid solution volume is >10:4. Whereas gelatin solutions have less intrinsic effect on blood coagulation, 10% dextran 40 has the strongest effect on coagulation. Implications: Blood coagulation may be compromised when the dilution ratio of blood volume to colloid solution volume is >10:4. Whereas gelatin solutions have less intrinsic effect on blood coagulation than hydroxyethyl starch or dextran, 10% dextran 40 has the strongest effect on coagulation.

Unexpected return of spontaneous circulation after cessation of resuscitation (Lazarus phenomenon)

Since 1982, more than 20 patients with return of spontaneous circulation after cessation of cardiopulmonary resuscitation (Lazarus phenomenon) have been published. We report on another case here. Such cases are probably underreported due to medicolegal concerns. After cessation of resuscitation, each patient should be further monitored for at least 10 min to detect a possible Lazarus phenomenon.

Diltiazem may preserve renal tubular integrity after cardiac surgery.

PURPOSE To evaluate the influence of dopamine and diltiazem on renal function and markers for acute renal failure, including urinary alpha-glutathion s-transferase (alpha-GST), alpha-1-microglobulin (alpha(1)-MG) and N-acetyl-ss-glucosaminidase (ss-NAG) after extracorporeal circulation. METHODS In a randomized, placebo-controlled, double-blind trial we evaluated the efficacy of dopamine (2.5 micro g x kg(-1) x min(-1)), diltiazem (2 micro g x kg(-1) x min(-1)) or placebo administered over 48 hr postoperatively to maintain renal tubular integrity in 60 elective cardiac surgery patients. alpha-GST, alpha(1)-MG, ss-NAG, and creatinine clearance were measured from urine collected during surgery (T0), the first four hours (T1), 24 hr (T2) and 48 hr (T3) postoperatively. RESULTS Cumulative urine output in the diltiazem group (9.0 +/- 2.8 L) increased significantly compared with placebo (7.0 +/- 1.6 L), but not compared with dopamine (7.8 +/- 1.8 L). Creatinine clearance showed no significant intergroup differences. In all groups alpha(1)-MG increased from T0 to T3, but we found no significant intergroup differences. alpha-GST increased significantly from T0 to T3 in the placebo (2.1 +/- 1.8 to 11.4 +/- 8.6 micro g x L(-1)) and in the dopamine groups (2.7 +/- 1.8 to 13.6 +/- 14.9 micro g x L(-1)), but not in the diltiazem group (1.8 +/- 1.4 to 3.2 +/- 3.2 micro g x L(-1)). Forty-eight hours postoperatively alpha-GST was significantly lower in the diltiazem group than in both other groups. CONCLUSIONS Diltiazem stimulates urine output, reduces excretion of alpha-GST and ss-NAG and may be useful to maintain tubular integrity after cardiac surgery.

A comparison of urapidil, clonidine, meperidine and placebo in preventing postanesthetic Shivering

UNLABELLED This placebo-controlled study was performed to evaluate the efficacy of urapidil compared with clonidine and meperidine in preventing postanesthetic shivering, which is common after anesthesia administration and may be very distressing. We studied 120 patients undergoing elective abdominal or orthopedic surgery under standardized general anesthesia. After surgery, patients were randomly assigned to one of four groups (each group n = 30) using a double-blinded protocol: Group A received 0.2 mg/kg urapidil; Group B, 3 microg/kg clonidine; Group C, 0.4 mg/kg meperidine; and Group D, saline 0.9% as placebo. Postanesthetic shivering was scored by using a five-point scale. Clonidine and meperidine significantly reduced the incidence and the severity of shivering in comparison with placebo, whereas there were no significant differences between the urapidil and placebo groups. Both clonidine and meperidine caused a significantly prolonged emergence time (13.4 +/- 5.8 and 13. 3 +/- 5.0 min, respectively) compared with placebo (10.4 +/- 5.3 min) and urapidil (11.4 +/- 2.9 min). We confirmed that both clonidine and meperidine are effective in preventing postanesthetic shivering, whereas urapidil, in our setting and dosage, was not effective. Patients who received clonidine or meperidine had a prolonged emergence time. In the dosage used, urapidil seems to be unable to prevent postanesthetic shivering. IMPLICATIONS Shivering (irregular muscle activity) is common after surgery and anesthesia. This study compared urapidil (an antihypertensive drug) as a prophylaxis with two established antishivering drugs (meperidine and clonidine) and placebo. In the dosage used, we were unable to show a significant benefit of urapidil.

Hepatocellular integrity after parenteral nutrition: comparison of a fish-oil-containing lipid emulsion with an olive-soybean oil-based lipid emulsion

Background and objective Parenteral nutrition including lipids might be associated with liver disease. The cause leading to parenteral nutrition-related liver dysfunction remains largely unknown but is likely to be multifactorial. The study was performed to assess the effects of a lipid emulsion based on soybean oil, medium-chain triglycerides, olive and fish oil (SMOFlipid20%) compared with a lipid emulsion based on olive and soybean oil on hepatic integrity. Methods In a prospective, randomized, double-blinded trial, 44 postoperative patients with an indication for parenteral nutrition were allocated to one of two regimens: group A (n = 22) received SMOFlipid, group B (n = 22) a lipid emulsion based on olive and soybean oil for 5 days. Aspartate aminotransferase, alanin-aminotransferase, and serum alpha-glutathion S-transferase were measured before the start of parenteral nutrition (d0), at day 2 (d2), and day 5 (d5) after the start of parenteral nutrition. The significance level was defined at a P value of less than 0.05. Results There was no significant difference at d0, but at d2 and d5, significantly lower aspartate aminotransferase (d2: group A: 27 ± 13 vs. group B: 47 ± 36 U l−1; d5: A: 31 ± 14 vs. B: 56 ± 45 U l−1), alanin-aminotransferase (d2: A: 20 ± 12 vs. B: 42 ± 39 U l−1; d5: A: 26 ± 15 vs. B: 49 ± 44 U l−1), and α-glutathion S-transferase levels (d2: A: 5 ± 6 vs. B: 17 ± 21 U l−1; d5: A: 6 ± 7 vs. B: 24 ± 27 μg l−1) were found in soybean oil, medium-chain triglycerides, olive and fish oil group compared with the control group. Conclusion Hepatic integrity was well retained with the administration of SMOFlipid whereas in patients receiving a lipid emulsion based on olive and soybean oil liver enzymes were elevated indicating a lower liver tolerability.

Which countries publish in important anesthesia and critical care journals

UNLABELLED Using a MEDLINE-based analysis, we studied the national origin of articles published in important anesthesia, pain, critical care, and emergency medicine journals. All journals in English listed in the Science Citation Index (SCI) of Journal Citation Reports under the subheadings Anesthesiology (n = 17) and Emergency Medicine & Critical Care (n = 13) were analyzed with the help of MEDLINE. Issues from 1996 and 1997 were included and summarized. Letters, abstracts, editorials, meeting reports, and news were not included. MEDLINE printouts were studied, and we classified the country of origin of the first author. The following subsets were defined: Anesthesia, Regional Anesthesia and Pain, Clinical Monitoring and Computing, Intensive Care Medicine and Resuscitation, and Emergency Medicine and Trauma. A total of 10,643 publications in 30 journals were published during 1996 and 1997. Of the 30 journals, 17 originate in the United States (US) and 8 from United Kingdom (UK). In 14 of the 17 US journals, >50% of the publications came from the US. The US was the most active nation, with a total of 4,283 articles (40.2% of all contributions), followed by the UK with 1,418 articles (13.3%). When looking at the number of publications with regard to inhabitants or impact factor per million inhabitants, small highly industrialized nations (Finland 35.41 and Sweden 33.9 articles/million inhabitants) were significantly more active than large highly industrialized countries (US 16.2, Germany 6.1, Japan 4.5 articles/million inhabitants). It is presumed that indicators of productivity in medical research are the number of articles published and the cumulative impact factor. During 1996 and 1997, the US was the most active nation with regard to publications in important journals in the areas of anesthesia, pain, critical care, and emergency medicine. Small highly industrialized nations, however, had a higher activity rate than larger countries. IMPLICATIONS In a MEDLINE-based analysis, we examined the number of publications in important anesthesia, pain, critical care, and emergency medicine journals (n = 30) for the years 1996 and 1997 and analyzed these with regard to national origin. The United States was by far the most active nation in this medical area (4283 articles [40.2%]), followed by the United Kingdom (13.3%). With regard to publications per million inhabitants, small highly industrialized nations contributed overproportionally to publications in this area.

Meconium and amniotic fluid embolism: effects on coagulation in pregnant mini-pigs.

OBJECTIVE A hallmark of amniotic fluid embolism is the induction of coagulation defects. Little is known about the nature of these defects or the causative agent or agents. The purpose of this study was to assess the effects of meconium containing (native) meconium-amniotic-fluid infusion (MAFI) and meconium-free (centrifuged) amniotic-fluid infusion (AFI) on the coagulation system in the mini-pig model. DESIGN Laboratory study. SETTING University institute animal laboratory. SUBJECTS Near-term pregnant Göttingen bred mini-pigs in three groups (control, MAFI, AFI) of six animals each. INTERVENTIONS After induction of anesthesia, amniotic fluid was collected by cesarean section in all animals. Depending on the group, animals received either Ringers solution (control), native amniotic fluid (MAFI), or centrifuged amniotic fluid (AFI) via an ear vein. MEASUREMENTS AND MAIN RESULTS Blood samples were taken from a central vein before infusion (baseline), immediately after infusion, every 10 mins until 90 mins after infusion, and finally, every 20 mins until 150 mins after infusion. The following parameters were measured: Platelets, partial thromboplastin time, prothrombin time, fibrinogen, factors V, VII, VIII, antithrombin III, and protein C. The values relative to baseline in the MAFI and AFI groups were compared with control by rank order test. A p<.05 was considered statistically significant. Compared with the control group, platelets were lower in the MAFI group (p<.005), PTT was prolonged in both the MAFI and AFI groups (p<.005), fibrinogen was lower in both the MAFI and AFI groups (p<.05), prothrombin index was lower (i.e., prothrombin time was prolonged) in the MAFI group (p<.05), and protein C was lower in the MAFI group (p<.005). CONCLUSIONS Both MAFI and, to a much lesser extent, AFI cause an activation of coagulation in mini-pigs. The changes induced by meconium-free AFI are probably not sufficient to explain the high mortality of the condition.

A comparison of nefopam and clonidine for the prevention of postanaesthetic shivering: a comparative, double-blind and placebo-controlled dose-ranging study.

Postanaesthetic shivering is a frequent complication following general anaesthesia. The aim of this study was to compare the effectiveness of three doses of nefopam with clonidine and placebo in the prevention of postanaesthetic shivering. We studied 371 patients undergoing abdominal or orthopaedic surgery. Patients were allocated to one of five groups: Group A (n = 73) received 0.2 mg.kg−1 nefopam, Group B (n = 75) 0.1 mg.kg−1 nefopam, Group C (n = 76) 0.05 mg.kg−1 nefopam, Group D (n = 73) 1.5 μg.kg−1 clonidine, and Group E (n = 74) saline 0.9% as placebo. We found a significant reduction in the incidence of shivering in Group A compared to Group C and clonidine as well as to the placebo group. All active treatments reduced the incidence and the severity of shivering compared to placebo. At 5 min postoperatively clonidine‐treated patients showed a significant decrease in MAP and a significantly lower Aldrete score compared to all other groups. No haemodynamic or sedative adverse events were observed in the nefopam‐treated patients. The results of our study indicate that nefopam (0.2 mg.kg−1) is superior to clonidine (1.5 μg.kg−1) in the prophylaxis of postanaesthetic shivering and not accompanied by sedative or haemodynamic side‐effects.

RETRACTED ARTICLE: Diltiazem may preserve renal tubular integrity after cardiac surgery

PURPOSE To evaluate the influence of dopamine and diltiazem on renal function and markers for acute renal failure, including urinary alpha-glutathion s-transferase (alpha-GST), alpha-1-microglobulin (alpha(1)-MG) and N-acetyl-ss-glucosaminidase (ss-NAG) after extracorporeal circulation. METHODS In a randomized, placebo-controlled, double-blind trial we evaluated the efficacy of dopamine (2.5 micro g x kg(-1) x min(-1)), diltiazem (2 micro g x kg(-1) x min(-1)) or placebo administered over 48 hr postoperatively to maintain renal tubular integrity in 60 elective cardiac surgery patients. alpha-GST, alpha(1)-MG, ss-NAG, and creatinine clearance were measured from urine collected during surgery (T0), the first four hours (T1), 24 hr (T2) and 48 hr (T3) postoperatively. RESULTS Cumulative urine output in the diltiazem group (9.0 +/- 2.8 L) increased significantly compared with placebo (7.0 +/- 1.6 L), but not compared with dopamine (7.8 +/- 1.8 L). Creatinine clearance showed no significant intergroup differences. In all groups alpha(1)-MG increased from T0 to T3, but we found no significant intergroup differences. alpha-GST increased significantly from T0 to T3 in the placebo (2.1 +/- 1.8 to 11.4 +/- 8.6 micro g x L(-1)) and in the dopamine groups (2.7 +/- 1.8 to 13.6 +/- 14.9 micro g x L(-1)), but not in the diltiazem group (1.8 +/- 1.4 to 3.2 +/- 3.2 micro g x L(-1)). Forty-eight hours postoperatively alpha-GST was significantly lower in the diltiazem group than in both other groups. CONCLUSIONS Diltiazem stimulates urine output, reduces excretion of alpha-GST and ss-NAG and may be useful to maintain tubular integrity after cardiac surgery.