Update PONV – Was gibt es Neues bei der Prophylaxe und Therapie von postoperativer Übelkeit und postoperativem Erbrechen?

Die Anaesthesiologie - Auch wenn für Anästhesiologen über Jahrzehnte die Prophylaxe und Therapie postoperativer Schmerzen im Rahmen des postoperativen Patientenkomforts an vorderster...     

Albumin Adsorption and Retention on C18-Alkyl-Derivatized Polyurethane Vascular Grafts

The short-term albumin affinity and thrombo-resistance of a polyether polyurethane vascular graft have been improved. The method is based on the C18 alkylation of the polymer. Thrombus formation by a planimetric technique and albumin retention on wire-reinforced polyurethane tubes, both C18 alkylated and untreated, were measured in short-term (4-h) exposure at femoral arterial sites in the dog. 125I-Albumin was preabsorbed on tubes and then exposed to blood for successive 2-h periods. Albumin uptake on alkylated tubes prior to blood exposure and retention following 2 h of blood exposure were significantly greater than on controls. Following a fast desorption phase in blood, the remaining albumin was more slowly desorbed from alkylated than from control tubes. Reincubation with albumin and blood reexposure produced a similar tendency, suggesting blood conditioning does not reduce the albumin affinity-enhancing property of C18 alkylation in the short term. Blood-preconditioning experiments suggested endogenous albumin has a high affinity for the C18-alkylated surface. Scanning electron microscopic examination showed thrombus and platelet densities were higher on control than on alkylated surfaces. These results suggest in vivo albumin affinity is increased for C18-alkylated polyurethane, which may be linked to decreased thrombus formation on these surfaces.     

Retinal degeneration associated with RDH12 mutations results from decreased 11-cis retinal synthesis due to disruption of the visual cycle

Human Molecular Genetics     

hTERT gene amplification and increased mRNA expression in central nervous system embryonal tumors

High-level gains at 5p15, a chromosomal region including the human telomerase catalytic protein subunit (hTERT) gene, have been documented in several medulloblastomas. We therefore analyzed hTERT gene dosage in a group of medulloblastomas and other embryonal brain tumors using differential PCR. Amplification of the hTERT locus was detected in 15 of 36 (42%) tumors examined. To correlate gene amplification with message level, we used real-time quantitative PCR to measure hTERT mRNA in 50 embryonal brain tumors. hTERT mRNA was detected in all but one of these cases, and mRNA level correlated significantly with gene dosage (r = 0.82). Log-rank analysis of survival data revealed a trend toward poor clinical outcomes in patients with medulloblastomas containing high hTERT mRNA levels, but clinical follow-up was relatively short and the association was not statistically significant (P = 0.078). Comparative genomic hybridization was used to further analyze the tumor with the greatest hTERT gene dosage and mRNA level, a recurrent medulloepithelioma. hTERT was amplified in the recurrent tumor but not in the primary lesion, suggesting this locus can be involved in tumor progression. Our data indicate that hTERT gene amplification is relatively common in embryonal brain tumors, and that increased expression of hTERT mRNA may be associated with biologically aggressive tumor behavior.     

Pre-treatment with ozonized oxygen (O3) aggravates inflammation in septic rats

Objective and design:Ozone is produced by neutrophils during bacterial killing. Its application was found to be beneficial in peritonitis patients. Therefore, we measured survival and cytokines after ozone pre-treatment in septic rats. Subjects and treatment:With approval, 40 male Wistar-rats were allocated to 1) ozone pre-treatment for five days before intra-abdominal sepsis, or 2) no pre-treatment. Methods:The primary endpoint was mortality at 120 h. Secondary endpoints were plasma cytokine levels. Results:In the control group mortality was 50% (10/20 rats). After ozone pre-treatment, survival was only 35% (7/20 rats, Log-Rank test: P = 0.10). Ozone increased TNF-α and MIP-2 after infection: 127±23 pg/ml and 94±19 pg/ml (control group: 398 pg/ml and 369 pg/ml; P < 0.002 and P < 0.01). IL-6 levels were similar in both groups. Conclusions:Ozone pre-treatment was pro-inflammatory in sepsis with a trend to reduced survival. Therefore, its effects in sepsis should be further evaluated in animal trials.     

Einfluß verschiedener niedriger Droperidol-Dosierungen auf postoperative Angst, innere Anspannung, allgemeine Befindlichkeit und PONV

Background: Droperidol even in low doses such as 0,5?mg to 1,25?mg can increase postoperative anxiety and state of tension. The aim of this study was to determine whether these side effects occur frequently following low-dose droperidol and to see whether these are dose related. Methods: 184 female in- and outpatients ASA grade 1 and 2 undergoing gynaecological laparoscopy were recruited to this prospective, double-blind study. General anaesthesia was standardized (induction with thiopentone, fentanyl 2?µg/kg and vecuronium 0,1?mg/kg, tracheal intubation, maintainance with enflurane in N₂O/O₂). Patients were randomly allocated to receive saline (n=45), 0,625?mg (n=46), 1,25?mg (n=47) or 2,5?mg (n=46) droperidol i.v. 10 minutes before the end of surgery. 1, 3, 6, and 24 hours postoperatively, the patients’ anxiety, state of tension and overall mood was evaluated using two psychological questionnaires which had been tested for the perioperative period (Erlanger anxiety and tension-scale / BSKE-EWL-test). Sedation was evaluated by the staff of the recovery room. In addition, postoperative nausea and vomiting (PONV) was assessed using a 100?mm visual analogue scale and by counting the episodes of retching or vomiting. PONV was then rated over the whole observation period as none, mild, moderate or severe using a fixed scoring algorithm. Statistical analysis was performed using the ANOVA and the chi²-test. Results: The patients did not differ with regard to biometric data, duration of surgery and anaesthesia. The postoperative scores for anxiety, state of tension and overall mood were not different between the groups at any observation time (Fig.?1: anxiety and tension: P=0,5687; figure 2: overall mood: P=0,0647). Quality of sleep in the first night after surgery was the same in all groups (Table?2 and 3). Sedation was not significantly different (Table?4; P=0,0704). Furthermore, duration of stay in the recovery room did not differ (P=0,4353). On the other hand, three patients from the 2,5?mg droperidol group had to stay unexpectedly on the ward overnight, because they had been too much sedated to be discharged at home. This was not the case with any patient from the other groups. Compared to placebo, PONV over the whole 24?h observation period was significantly reduced by droperidol (Fig.?3; P=0,0338): completely free from PONV: placebo: 41,3%, 0,625?mg droperidol: 67,4%, 1,25?mg droperidol: 53,2%, 2,5?mg droperidol: 71,7%. Also the severity of PONV was reduced. Conclusion: In gynaecological laparoscopy under general anaesthesia with tracheal intubation, we recommend droperidol 0,625?mg in the prevention of PONV, as it reduces PONV as well as 2,5?mg with no severe sedation in this dosage. Psychological side effects did not occur more frequently after droperidol compared to placebo in any of the investigated dosages.     

Dexamethasone for prophylaxis of postoperative nausea and vomiting. A meta-analysis of randomized controlled studies

OBJECTIVE: Randomised controlled trials investigating the efficacy of dexamethasone alone or in combination with other antiemetics to prevent postoperative nausea and vomiting (PONV) were included in a meta-analysis to estimate the relative efficacy of these treatments. METHODS: Studies were systematically searched using Medline, EMBASE, the Cochrane-Library, and by manual screening the reference lists and current issues of locally available anaesthesia journals. Studies identified were divided into four different groups. For each subgroup an independent analysis was performed: 1. Dexamethasone vs. placebo, 2. Dexamethasone + other antiemetic vs. other antiemetic alone, 3. Dexamethasone + other antiemetic vs. dexamethasone alone, 4. Dexamethasone vs. other antiemetics. The main end point in each study was defined as complete absence of nausea, retching, and vomiting after prophylactic antiemetic treatment. The pooled odds-ratios, the relative risk (RR) and the numbers-needed-to-treat (NNT) with their corresponding 95%-confidence intervals (given in parentheses) were calculated using a random effects model. RESULTS: A total of 26 studies with 2561 patients were analysed. 1. As a sole antiemetic agent dexamethasone is superior to placebo to prevent PONV (RR: 0.49 (0.15-0.42); NNT: 3.4 (2.5-5.3)). 2. When dexamethasone and an other antiemetic (e.g. a 5-HT3-antagonist) are combined this drug combination is significantly more effective than the single antiemetic without dexamethasone (RR: 0.60 (0.46-0.78); NNT: 7.3 (5.7-10.2)). 3. A similar result was obtained when the dexamethasone combination was compared with dexamethasone alone. The combination is statistically superior (RR: 0.16 (0.08-0.32); NNT: 3.2 (2.2-6.3)). 4. Dexamethasone was usually compared with 5-HT3-antagonist and to a less extends also with dopamine antagonists. Summarising these studies, there was no significant difference concerning effectiveness (RR: 1.35 (0.99-1.85); NNT: 10.6 (5.6-92.6)). CONCLUSION: Dexamethasone has antiemetics effects that are superior to placebo treatment and are comparable with conventional antiemetic agents (e.g. 5-HT3-antagonist, dopamine antagonists). The drug is especially useful in combination with other antiemetics and increases the efficacy of the antiemetic partner drug.     

Evaluation of three risk scores to predict postoperative nausea and vomiting

BACKGROUND: So far there are three different scores to predict postoperative vomiting (PV: Apfel et al., 1998) or postoperative nausea and vomiting (PONV: Koivuranta et al., 1997; Palazzo and Evans, 1993). All three scores used logistic regression analysis to identify and create weights for the risk factors for PV or PONV. In short, these were sex, age, history of previous PONV, motion sickness, duration of anaesthesia, and use of postoperative opioids. However, an external evaluation and a comparison of these scores has not been performed so far. METHODS: Patients undergoing a variety of surgical procedures under general anaesthesia were studied prospectively. Preoperatively, they completed a questionnaire concerning potential risk factors for the occurrence of PV or PONV implemented in the three risk scores. Balanced anaesthesia (induction agent, nondepolarising neuromuscular blocker, opioid, and inhalation agent in nitrous oxide/oxygen) was performed. No intravenous anaesthesia or any antiemetic prophylaxis was applied. Postoperatively, the patients were observed in the recovery room for the occurrence of PV and PONV and were visited twice on the ward within the 24-h observation period. Both the patients and the nursing staff were asked whether PV or PONV was present. The severity of PONV was categorised using a standardised scoring algorithm. A total of 1,444 patients was finally included into the analysis. Using information of the predicted risk for the individual patients and the actual occurrence of PV or PONV, Receiver Operator Characteristics (ROC-curves) were drawn. The area under each ROC-curve was calculated as a means of the predictive properties of each score and was compared for statistical differences. RESULTS: For prediction of PONV (any severity) the AUC-values (AUC=area under the curve) and the corresponding 95%-confidence intervals were: Apfel: 0.70 (0.67-0.72); Koivuranta: 0.71 (0.69-0.73); Palazzo: 0.68 (0.65-0.70). For prediction of PV: Apfel: 0.73 (0.71-0.75); Koivuranta: 0.73 (0.70-0.75); Palazzo: 0.68 (0.65-0.70). Thus, all three scores appeared to have a moderate accuracy as measured by the AUC. The score of Koivuranta predicts PONV (P=0.007) and also PV (P=0.002) significantly better than Palazzo's score. Furthermore, for predicting of PV the score of Apfel was also superior to Palazzo's score (P=0.005). All three scores predict PV with the same accuracy as PONV. CONCLUSION: The occurrence of PV and PONV in patients undergoing surgery under balanced anaesthesia can be predicted with moderate but acceptable accuracy using one of the available risk scores, regardless of local surgical or anaesthesiological circumstances. For clinical practice, we recommend the score published by Koivuranta, since its calculation is very simple.