Uncalibrated arterial pressure waveform analysis for less-invasive cardiac output determination in obese patients undergoing cardiac surgery.

BACKGROUND: Uncalibrated arterial waveform analysis (FloTrac/Vigileo) uses standard arterial access to determine cardiac output (CO). Calculations are based on arterial waveform characteristics in combination with patient characteristic data to estimate individual arterial compliance. It has been shown that obesity is associated with altered arterial compliance independently of other risk factors. We conducted this study to assess the validity of measuring CO by the FloTrac/Vigileo device in obese patients undergoing cardiac surgery in comparison with bolus thermodilution technique. METHODS: Fifteen obese patients with a BMI of > or = 30 and 23 non-obese patients (BMI 18-25) undergoing coronary artery bypass grafting (CABG) were included. Simultaneous CO measurements by bolus thermodilution and the FloTrac/Vigileo device (software version 1.10) were obtained intraoperatively after induction of anaesthesia, before cardiopulmonary bypass (CPB), after CPB, and after sternal closure. Measurements in the intensive care unit (ICU) were performed upon arrival in the ICU, after 4, 8, and 24 h after surgery. CO was indexed to the body surface area (cardiac index, CI). RESULTS: The analysis of 262 data pairs revealed a bias and precision of 0.19 and +/-0.66 litre min(-1) m(-2), resulting in a percentage error of 26.6%. Thermodilution CI values ranged from 1.1 to 4.2 litre min(-1) m(-2) [mean 2.4 (0.52) litre min(-1) m(-2)]. Subgroup analysis resulted in a percentage error of 29.8% in obese patients and 24.4% in patients with normal BMI. CONCLUSIONS: The semi-invasive FloTrac/Vigileo device was found to adequately agree with bolus pulmonary artery thermodilution in both obese and non-obese patients undergoing CABG.

Influence of continuous perioperative beta-blockade in combination with phosphodiesterase inhibition on haemodynamics and myocardial ischaemia in high-risk vascular surgery patients.

BACKGROUND: We sought to assess the intra- and postoperative haemodynamic effects of continuous perioperative beta-adrenergic blockade combined with phosphodiesterase (PDE) III inhibition and its potential benefits in limiting perioperative myocardial ischaemia in high-risk vascular surgery patients. METHODS: Seventy-five patients were randomly assigned to receive tight heart rate (HR) control by a continuous infusion of: esmolol in combination with the PDE III inhibitor enoximone (esmolol+enoximone group), esmolol infusion alone (esmolol group), or standard therapy (control group) for a period of 48 h. Myocardial ischaemia and dysfunction were detected by serial plasma Troponin T (TnT) and B-type natriuretic peptide (BNP) measurements. RESULTS: Cardiac index (CI) increased significantly only in esmolol+enoximone-treated patients [CI: from 2.4 (0.2) litre min(-1) m(-2) at baseline to 3.2 (0.2) litre min(-1) m(-2) at 24 h after surgery; P=0.001] and was significantly higher than in the esmolol [CI: from 2.5 (0.2) litre min(-1) m(-2) at baseline to 2.6 (0.2) litre min(-1) m(-2) at 24 h; P=0.18] and the control groups [CI: from 2.4 (0.2) litre min(-1) m(-2) at baseline to 2.7 (0.2) litre min(-1) m(-2) at 24 h; P=0.13]. A significant postoperative release of TnT was detected only in control patients. Plasma BNP levels increased towards the end of surgery in all patients. Peak plasma BNP concentrations were significantly higher in control patients [293 (98) pg ml(-1)] than in esmolol [118 (71) pg ml(-1)] and in esmolol+enoximone-treated patients [78 (21) pg ml(-1)]. CONCLUSIONS: Inotropic therapy with the PDE III inhibitor enoximone combined with tight HR control by a continuous infusion of esmolol improved cardiac function and reduced myocardial ischaemia in high-risk vascular surgery patients. CLINICAL TRIAL REGISTRATION INFORMATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT00348101.

Influence on coagulation of a potato-derived hydroxethylstarch (HES 130/0.42) and a maize-derived hydroxethylstarch (HES 130/0.4) in patients undergoing cardiac surgery.

BACKGROUND: This study compared the effects of a potato-based hydroxyethyl starch (HES) with those of a maize-derived HES preparation on coagulation in cardiac surgery patients. METHODS: Sixty patients undergoing elective cardiac surgery with cardiopulmonary bypass were allocated randomly to receive either a potato-derived HES (6% HES 130/0.42) (n=30) or a waxy-maize-derived HES (6% HES 130/0.4) (n=30) given to keep pulmonary capillary wedge pressure/central venous pressure between 12 and 14 mm Hg until the second postoperative day (POD). A four-channel thrombelastography analyzer was used to measure rotation thrombelastometry (ROTEM) and whole blood aggregometry was used to assess the effects on platelet function. RESULTS: Potato HES 2990 (340) ml and maize HES 2890 (350) ml were given on the second POD. Standard coagulation (e.g. fibrinogen and antithrombin III) did not differ between the groups. Blood loss and need for transfusion of blood/blood products did not differ. Coagulation time (intrinsic/extrinsic CT) and clot formation time (intrinsic/extrinsic CFT) increased similarly after surgery and after 5 h, but recovered completely by the first and second POD. Clot firmness was similar in both groups. Platelet function induced by three inductors decreased significantly after surgery, but without significant differences between the two groups. Platelet function had recovered fully by the first POD. CONCLUSIONS: Both HES preparations showed similar effects on thrombelastometry and platelet function. As blood loss and need for the use of blood products were also similar, both potato- and maize-derived HES preparations can be safely used in cardiac surgery with regard to haemostasis.

Is albumin administration in hypoalbuminemic elderly cardiac surgery patients of benefit with regard to inflammation, endothelial activation, and long-term kidney function?

BACKGROUND: Because patients with low albumin levels may benefit from human albumin (HA) administration, we studied correction of hypovolemia with HA in hypoalbuminic elderly cardiac surgery patients. METHODS: In a prospective, randomized study, 50 patients aged >80 yr undergoing cardiac surgery using cardiopulmonary bypass with a preoperative serum albumin concentration of <3.5 mg/dL, received either 5% HA (n = 25) or hydroxyethyl starch (6% HES 130/0.4) (n = 25). Volume was added to the priming (500 mL) and given until the morning of the second postoperative day to keep pulmonary capillary wedge pressure or central venous pressure between 12 and 14 mm Hg. RESULTS: Inflammatory response (interleukins-6, -10), endothelial activation (intercellular adhesion molecule-1), and kidney function (including glutathione transferase-alpha and neutrophil gelatinase-associated lipocalin) were measured after induction of anesthesia, 5 h after surgery, and the first and second postoperative day. A follow-up, approximately 60 days after discharge from the hospital, was done. Two thousand nine hundred eighty +/- 430 mL of HA and 3060 +/- 680 mL of HES 130/0.4 were given. Serum albumin concentration was significantly increased by HA (to 4.5 +/- 0.3 mg/dL). Serum creatinine, glomerular filtration rate, and urinary levels of alpha-glutathione transferase and neutrophil gelatinase-associated lipocalin were not different in the HA-compared to the HES-treated patients. The inflammatory response was similar in both groups, whereas endothelial activation was less in the HES group. None of the patients developed renal failure requiring renal replacement therapy. CONCLUSION: Use of HA in hypoalbuminemic cardiac surgery patients aged >80 yr was without benefit with regard to inflammatory response, endothelial activation, and renal function compared to 6% HES 130/0.4.

Association of N-terminal pro-brain natriuretic peptide and cardiac troponin T with in-hospital cardiac events in elderly patients undergoing coronary artery surgery.

BACKGROUND AND OBJECTIVES: Despite evidence of their prognostic power for non-surgical patients, the value of perioperative natriuretic peptides and cardiac troponins as markers of cardiac events is incompletely defined. This study sought to examine whether perioperative N-terminal pro-brain natriuretic peptide (NT-proBNP) and cardiac troponin T (cTnT) levels could be used for the prediction of in-hospital cardiac events in elderly patients undergoing elective coronary artery bypass grafting. METHODS: Ninety-eight elderly patients (>75 yr) undergoing elective coronary artery bypass grafting with cardiopulmonary bypass were enrolled and followed up for 121 and 0.66 1 for NT-proBNP and cTnT (sensitivity, specificity, positive predictive value and negative predictive value of 84.3%, 89.4%, 78.9% and 92.4%, and 93.7%, 74.2%, 63.8% and 96.1%, respectively) at 24 h after surgery to be associated with in-hospital cardiac events. An elevation of both biomarkers above these threshold values was independently associated with individual postoperative complications (odds ratio, 18.9; 95%, CI, 2.3-106.1). CONCLUSIONS: In elderly patients undergoing elective coronary artery bypass grafting surgery, high values of NT-proBNP and cTnT measured 24 h after the end of surgery were independently associated with in-hospital cardiac events.

Individual titration of propofol plasma target improves anaesthetic stability in patients undergoing major abdominal surgery: a comparison with manually controlled infusion.

BACKGROUND AND OBJECTIVE: The impact of anaesthesia using target-controlled infusion with propofol on intraoperative stability, recovery and cost compared to manually controlled infusion has been evaluated with inconsistent results. We studied a new device that allows more individual titration of propofol target-controlled infusion by using the effect-site concentration at the loss of eyelash reflex to predict the maintenance infusion rate (FM-TCI). METHODS: Fifty-six patients undergoing major abdominal surgery lasting >2 h were randomly assigned to receive either FM-TCI (n = 28) or MCI-controlled (n = 28) anaesthesia. Both groups were Bispectral Index-monitored and thoracic epidural analgesia was established. Anaesthetic stability, incidence of haemodynamic abnormalities, time to extubation, propofol consumption and patient satisfaction were assessed. RESULTS: In the FM-TCI group, a significantly improved anaesthetic stability was achieved (0.43 +/- 0.44 vs. 1.31 +/- 0.78 adjustments of propofol infusion per patient per hour, P = 0.003) and time to extubation was significantly shorter (9.6 +/- 2.1 vs. 15.7 +/- 9.6 min P = 0.011). With FM-TCI, propofol consumption was significantly lower. Haemodynamic stability and patient satisfaction did not differ between the groups. CONCLUSION: FM-TCI helps to provide more stable anaesthesia conditions requiring less-frequent adjustments of the propofol infusion compared to manually controlled infusion in patients undergoing major abdominal surgery.

Hepatocellular integrity in patients requiring parenteral nutrition: comparison of structured MCT/LCT vs. a standard MCT/LCT emulsion and a LCT emulsion.

BACKGROUND AND OBJECTIVE: The aetiology of parenteral nutrition-associated hepatic injury remains unresolved. The aim of the study was to evaluate the effects of structured triglycerides in parenteral nutrition compared either to a physical medium-chain triglycerides (MCT)/long-chain triglcerides (LCT) mixture or to a LCT emulsion on hepatic integrity. METHODS: In a randomized, double-blinded trial, we studied 45 patients undergoing abdominal surgery, who were expected to receive parenteral nutrition for 5 days. Patients were allocated to one of three nutrition regimens: Group A (n = 15) received structured triglycerides, Group B (n = 15) a MCT/LCT and Group C (n = 15) a LCT lipid emulsion. Before the start of parenteral nutrition (T0), 24 h (T1), 48 h (T2), 72 h (T3) and 120 h (T4) after start of infusion the following parameters were measured: Alpha-glutathione S-transferase (alpha-GST), alanine aminotransferase (ALT), aspartate aminotransferase (AST), glucose and serum triglycerides. RESULTS: At T3 and T4, alpha-GST levels were significantly higher in Group B (T3: 9.4 +/- 9.9; T4: 14.6 +/- 19.5 microg L-1) and Group C (T3: 14.2 +/- 20.8; T4: 22.4 +/- 39.3 microg L-1) compared with the patients receiving structured triglycerides (T3: 1.9 +/- 1.8; T4: 3.2 +/- 2.7 microg L-1). Whereas the mean alpha-GST-levels in structured triglycerides group always remained in the normal range, this was not the case in both other groups at T3 and T4. There were no significant differences concerning ALT, AST and glucose levels. At T3 and T4, triglyceride levels were significantly lower in Group A than in Groups B and C. CONCLUSIONS: Hepatic integrity was well retained with the administration of structured triglycerides, whereas both MCT/LCT emulsion and LCT emulsion caused subclinical hepatic injury.

[Continuous beta-block with esmolol in combination with enoximone: influence on cardiac function in high risk patients undergoing vascular surgery]. / Kontinuierliche beta-Blockade mit Esmolol in Kombination mit Enoximon-Gabe : Einfluss auf die kardiale Funktion bei gefässchirurgischen Risikopatienten.

BACKGROUND: The aim of this study was to assess cardiac function in vascular surgery patients with known coronary artery disease (CAD) who received continuous perioperative beta blocker therapy with esmolol alone versus esmolol in combination with the phosphodiesterase (PDE) III inhibitor enoximone. PATIENTS AND METHODS: Over a period of 24 h, 28 patients were assigned to receive heart rate (HR) control by continuous infusion of esmolol in combination with the PDE III inhibitor enoximone (Esmolol+Enoximone group) or esmolol alone (Esmolol group; n=14). Cardiac function was assessed by the use of a pulmonary artery catheter and serial measurements of plasma troponin T (TnT) und B-type natriuretic peptide (BNP). RESULTS: The heart rate significantly decreased to the target rate of 50-60 min(-1) in both groups over the observation period. Cardiac index increased significantly only in Esmolol+Enoximone-treated patients (from 2.4+/-0.2 lxmin(-1)xm(-2) to 3.1+/-0.1 lxmin(-1)xm(-2)) and was significantly higher than in the esmolol alone group (from 2.5+/-0.2 lxmin(-1)xm(-2) to 2.4+/-0.1 lxmin(-1)xm(-2)). No patient had detectable levels of cTnT perioperatively. Peak plasma BNP concentrations were significantly increased in both groups but the highest values were measured in the esmolol alone group. CONCLUSION: Inotropic therapy with the PDE III inhibitor enoximone improves cardiac function in high risk patients with known CAD undergoing vascular surgery and also when receiving systematic heart rate control by continuous infusion of esmolol.

Prevention of atrial fibrillation after coronary artery bypass graft surgery using a potassium-magnesium-aspartate solution (Inzolen).

BACKGROUND: Atrial fibrillation (AFIB) following cardiac surgery is a frequent complication. The purpose of this study was to evaluate the efficacy of a potassium-magnesium-aspartate solution (Inzolen) for the prevention of AFIB. METHODS: In a randomised, prospective, double-blinded study, we studied 88 patients undergoing elective coronary artery bypass graft surgery (CABG). After surgery, patients were allocated randomly to one of two groups. Group A (n = 43) received a potassium-magnesium-aspartate solution (Inzolen), group B (n = 45) received potassium chloride; both solutions were administered continuously for 48 hours to keep the potassium serum levels between 4.5 and 5.5 mmol/l. Patients were observed for 5 days postoperatively and the incidence of atrial fibrillation was noted. At the end of surgery (T0), 4 h (T1), 24 h (T2), 48 h (T3), and 120 h (T4) postoperatively, magnesium and potassium serum levels were measured. RESULTS: The two groups did not differ significantly with regard to demographics and perioperative data. No significant difference in the incidence of postoperative atrial fibrillation was seen (group A: 41.9 % vs. group B 31.1 %; P = 0.53). In group A, the magnesium serum levels were significantly higher at T1 (1.15 +/- 0.18 vs. 0.87 +/- 0.11 mmol/l), T2 (1.24 +/- 0.22 vs. 0.82 +/- 0.10 mmol/l) and T3 (1.15 +/- 0.18 vs. 0.81 +/- 0.20 mmol/l) compared to group B, whereas potassium levels were similar in the two groups throughout the study period. CONCLUSIONS: The use of a potassium-magnesium-aspartate solution (Inzolen) showed no significant difference in potassium chloride for the prophylaxis of postoperative atrial fibrillation secondary to CABG.

Influence of controlled hypotension using esmolol and sodium nitroprusside on natriuretic peptides in patients undergoing endonasal sinus surgery.

BACKGROUND AND OBJECTIVE: Atrial and brain natriuretic peptide, synthesized by cardiac myocytes, are mediators secreted secondary to cardiac volume expansion and increased filling pressure. The study was designed to assess serum concentration of atrial and brain natriuretic peptide in patients undergoing endonasal sinus surgery receiving controlled hypotension. METHODS: We studied 45 patients without cardiovascular history, scheduled for elective endonasal sinus surgery. Patients were allocated to one of three groups: controlled hypotension was induced either by using esmolol (n = 15) or sodium nitroprusside (n = 15) with a mean arterial pressure of 50-55 mmHg. In the control group (n = 15), mean arterial pressure was adjusted to 70-80 mmHg. Atrial and brain natriuretic peptides were measured preoperatively (T1), at the end of surgery (T2), 2 h (T3), 24 h (T4) and 48 h (T5) postoperatively. RESULTS: Preoperative atrial and brain natriuretic peptide plasma levels were within normal ranges and similar between all groups. Patients treated with esmolol (atrial natriuretic peptide: 2.46 +/- 0.75 microg mL(-1) brain natriuretic peptide: 4.34 +/- 3.06 microg mL(-1)) and sodium nitropusside (atrial natriuretic peptide: 2.48 +/- 0.92 microg mL(-1); brain natriuretic peptide: 4.49 +/- 3.21 microg mL(-1)) showed significantly lower concentrations of atrial and brain natriuretic peptide at T2 and T3 compared with controls (atrial natriuretic peptide: 5.31 +/- 2.32 microg mL(-1); brain natriuretic peptide: 13.26 +/- 8.98 microg mL(-1)) , P < 0.01) as well as a reduction in blood loss and duration of surgery. CONCLUSIONS: Controlled hypotension decreases the release of natriuretic peptides in cardiovascular healthy patients. This effect may be contributed to by changes in cardiac filling pressure due to lower systemic resistance and diminished perfusion pressure.

Semi-invasive monitoring of cardiac output by a new device using arterial pressure waveform analysis: a comparison with intermittent pulmonary artery thermodilution in patients undergoing cardiac surgery.

BACKGROUND: Thermodilution technique using a pulmonary artery catheter (PAC) is a widely used method to determine cardiac output (CO). It is increasingly criticized because of its invasiveness and its unclear risk-benefit ratio. Thus, less invasive techniques for measuring CO are highly desirable. We compared a new, semi-invasive device (FloTrac/Vigileo) using arterial pressure waveform analysis for CO measurement in patients undergoing cardiac surgery with bolus thermodilution measurements. METHODS: Forty patients undergoing coronary artery bypass grafting or valve repair were enrolled. A PAC was inserted and routine radial arterial access was used for semi-invasive determination of CO with the Vigileo. CO was measured simultaneously by bolus thermodilution and the Vigileo technique after induction of anaesthesia (T1), before cardiopulmonary bypass (CPB) (T2), after CPB (T3), after sternal closure (T4), on arrival in the intensive care unit (ICU) (T5), and 4 h (T6), 8 h (T7), and 24 h after surgery (T8). CO was indexed to the body surface area (cardiac index, CI). RESULTS: A total of 244 pairs of CI measurements were analysed. Bias and precision (1.96 sd of the bias) were 0.46 litre min(-1) m(-2) and +/- 1.15 litre min(-1) m(-2) (r = 0.53) resulting in an overall percentage error of 46%. Subgroup analysis revealed a percentage error of 51% for data pairs obtained intraoperatively (T1-T4), 42% in ICU (T5-T8), and 56% for values obtained during low CI (T1-T8). CONCLUSIONS: In cardiac surgery patients, CO measured by a new semi-invasive arterial pressure waveform analysis device showed only moderate agreement with intermittent pulmonary artery thermodilution measurement.

Inspired oxygen fraction of 0.8 compared with 0.4 does not further reduce postoperative nausea and vomiting in dolasetron-treated patients undergoing laparoscopic cholecystectomy.

BACKGROUND: Postoperative nausea and vomiting (PONV) is one of the most frequent complications after general anaesthesia. Single-dose antiemetic prophylaxis has limited efficacy in high-risk patients. Adding a simple potential antiemetic approach, such as increasing the inspired oxygen fraction, to the antiemetic portfolio would preserve pharmacological interventions for treatment of symptoms in the postoperative period. However, the antiemetic effect of a high inspired oxygen fraction is still discussed controversially. The aim of the study was to evaluate whether an inspired oxygen fraction of 0.8 decreases PONV in patients receiving the 5-HT3-antagonist dolasetron. METHODS: In a randomized, placebo-controlled, double-blinded trial we studied 377 patients (ASA I-III) undergoing elective laparoscopic cholecystectomy. Induction of anaesthesia was standardized, including thiopental fentanyl and cis-atracurium. For all patients the individual risk for PONV was calculated using the Koivuranta score and all patients received 12.5 mg dolasetron i.v. before surgery. Patients were allocated randomly to one of three groups: Group A (n=125) received 80% oxygen in air, Group B (n=125) 40% oxygen in air and Group C (n=127) 40% oxygen in nitrous oxide. Postoperative nausea, postoperative vomiting (PV), or nausea, vomiting, or both (PONV) was assessed in the early (0-4 h) and overall postoperative period (0-24 h) by an anaesthesiologist unaware of patient allocation. RESULTS: There was a significantly lower incidence of PONV and PV in Groups A (PONV: 11.2%; PV: 3.2%) and B (PONV: 10.4%; PV: 3.2%) compared with Group C (PONV: 26.7%; PV: 13.3%), but there were no significant differences between Groups A and B. CONCLUSIONS: An inspired oxygen fraction of 0.8 does not further decrease PONV or vomiting in dolasetron-treated patients undergoing laparoscopic cholecystectomy. The lower incidence of PONV in Groups A and B compared with Group C is most likely caused by the omission of nitrous oxide.

Early recovery, cognitive function and costs of a desflurane inhalational vs. a total intravenous anaesthesia regimen in long-term surgery.

BACKGROUND: The purpose of the study was to compare time of recovery, return of cognitive function, post-anaesthetic care unit (PACU) stay and costs of a propofol/remifentanil (TIVA) with a desflurane/fentanyl-based anaesthesia (desflurane group) in surgical procedures lasting more than 150 min. METHODS: Forty-nine patients undergoing elective abdominal prostatectomy were allocated randomly to receive bispectal index (BIS)-controlled desflurane/fentanyl (n=24) or propofol/remifentanil (n=25). Awakening, clinical recovery, direct drug acquisition and post-operative pain treatment were documented. Cognitive skills were tested using the Mini-Mental Status (MMST) test. RESULTS: Extubation was significantly faster with desflurane (6.9+/-3.5 min) than with TIVA (11.2+/-4.0 min) as well as times for stating name and date of birth (desflurane: 6.1+/-3.9 and 6.6+/-4.0 min; TIVA: 12.4+/-11.5 min and 13.4+/-11.3 min). There were no significant differences in PACU discharge times or MMS scores between the groups. Significantly more patients suffered post-operative nausea and vomiting (PONV) in the desflurane (33% vs. 0%) than the TIVA group. Overall costs were significantly higher in the TIVA (58.8+/-11.6 euro) than in the desflurane group (35.0+/-5.7 euro). CONCLUSION: Patients undergoing prolonged surgical procedures showed a faster early recovery after desflurane/fentanyl than using TIVA, whereas stay in the PACU and recovery of cognitive function were similar in both groups. Costs of a TIVA regimen were significantly higher than using a desflurane-based anaesthesia technique.

Plasma substitutes.

Adequate restoration of intravascular volume remains an important therapeutic manoeuvre in managing the surgical, medical and the critically ill intensive care patient. Definition of the ideal volume replacement strategy still remains one of the burning problems. The choice between colloid and crystalloid solutions continues to generate controversy. The highly controversial crystalloid/colloid dispute has been enlarged to a colloid/colloid debate because aside of the natural colloid albumin several non-protein (synthetic) colloids are available as plasma substitutes (e.g. dextrans, gelatins, hydroxyethyl starch [HES] solutions). Due to their varying physico-chemical properties, these solutions widely differ with regard to their pharmacokinetic and pharmacodynamic properties as well as to their hemodynamic efficacy and side-effects. HES is the most intensively studied plasma substitute. The different HES preparations are defined by concentration, molar substitution (MS), mean molecular weight (MW), and the C2/C6 ratio of substitution. Two new HES specification, a third-generation HES with a lower Mw and a lower MS (6% HES 130/0.4) than all other HES preparation and a first-generation HES prepared in a balanced solution, may be promising by improving the therapy of the hypovolemic patient. Albumin cannot be recommended for correction of hypovolemia because of ist extreme costs and because it can easily be replaced by other no-protein colloids. Dextrans should also not be used any more due to the negative effects on coagulation and its high anaphylactic potency. The historical crystalloid/colloid controversy has been focused primarily on outcome. There is increasing evidence that outcome (mortality) is not the correct measure when assessing the ideal volume replacement strategy. New concepts about critical care such as organ perfusion and organ function, the role of inflammation, immunological aspects, and wound healing may change this point of view. Volume replacement has been hitherto often based on art, dogma and personal beliefs. Further well-performed studies in this area will help more to shed new light on the ideal volume replacement strategy of the hypovolemic patient than more meta-analyses that are pooling old-to-very old studies to solve this problem.

Physostigmine for the prevention of postanaesthetic shivering following general anaesthesia - a placebo-controlled comparison with nefopam.

Physostigmine was studied for its efficacy in the prevention of postanaesthetic shivering compared to nefopam and placebo. We studied 89 patients undergoing abdominal and urological surgery. The study was randomised and double-blind, the patients received physostigmine 2 mg (n = 31), nefopam 10 mg (n = 30) or saline (n = 28). Haemodynamic parameters and temperature were measured at induction of anaesthesia (T0), and 5 min (T1), 15 min (T2), 30 min (T3) and 60 min (T4) after reaching the postanaesthetic care unit (PACU). Significantly less shivering occurred following administration of physostigmine and nefopam (9.7 and 3.3%) compared to placebo (53.6%). The degree of shivering was also significantly reduced following physostigmine and nefopam (p < 0.01). Extubation time, haemodynamic parameters and tympanic temperature were found to be similar in all groups. Aldrete score, duration of PACU stay and postoperative analgesic requirements did not differ between the groups. Only nefopam significantly (p < 0.01) reduced postoperative nausea and vomiting. Physostigmine is a safe alternative to nefopam, significantly reducing the incidence and severity of postanaesthetic shivering without affecting postanaesthetic recovery.

Insignificant effect of desflurane-fentanyl-thiopental on hepatocellular integrity--a comparison with total intravenous anaesthesia using propofol-remifentanil.

BACKGROUND AND OBJECTIVE: Inhalational anaesthetics have been associated with hepatotoxicity. Even desflurane, with its low solubility in blood and tissues, and its minimal hepatic biotransformation, is known to affect hepatic integrity. The effects of propofol on hepatic function are, however, a matter of controversy. Alpha-glutathione S-transferase (alpha-GST), a sensitive and specific biomarker for hepatic integrity, was measured to assess the influence of total intravenous anaesthesia (TIVA) with propofol vs. anaesthesia with desflurane. METHODS: Forty-two patients scheduled for elective prostatectomy were randomly allocated to receive either desflurane, fentanyl and thiopental (desflurane group) or propofol and remifentanil (TIVA group). Depth of anaesthesia was guided by bispectral index. Plasma concentrations of alpha-GST and aminotransferases were measured before induction of anaesthesia (TO), at the end of surgery (T1), as well as 2 h (T2) and 24 h (T3) postoperatively. Haemodynamic parameters and bispectral index values were documented. RESULTS: alpha-GST increased significantly in the desflurane group from TO (3.0 +/- 2.2 microg L(-1)) to T1 and T2 (5.5 +/- 4.3 and 5.6 +/- 3.7 microg L(-1), respectively), whereas no changes were seen in the TIVA group. alpha-GST values above the normal upper limit (> 7.5 microg L(-1)) were seen in 24% of the patients receiving desflurane. Aminotransferases remained unchanged in both groups throughout the study period. CONCLUSIONS: The use of propofol as part of a TIVA regimen seems to have no influence on hepatocellular function during and after surgery. In contrast, patients receiving desflurane showed a transient slight, but significant, increase of alpha-GST to above the normal upper limit after anaesthesia, although this was without further clinical relevance.

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 x kg(-1) nefopam, Group B (n = 75) 0.1 mg x kg(-1) nefopam, Group C (n = 76) 0.05 mg x kg(-1) nefopam, Group D (n = 73) 1.5 microg x 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 x kg(-1)) is superior to clonidine (1.5 microg x kg(-1)) in the prophylaxis of postanaesthetic shivering and not accompanied by sedative or haemodynamic side-effects.