Summary

Background and objective: Patients undergoing total abdominal hysterectomy under general anaesthesia have a high risk of developing postoperative nausea and vomiting (PONV). The aim of this study was to evaluate the incidence of PONV in patients undergoing total abdominal hysterectomy under spinal anaesthesia with intravenous patient-controlled analgesia (PCA) using morphine and to compare its incidence with and without antiemetic prophylaxis. Methods: Thirty-four patients undergoing total abdominal hysterectomy under spinal anaesthesia with i.v. PCA morphine postoperatively were divided into two groups. The first (n = 17) received ondansetron prophylaxis near the end of surgery while the second (n = 17) received no prophylaxis. Morphine consumption, emetic episodes (on a 3-point scale), patient satisfaction (visual analogue score), sedation and pruritus were evaluated 2, 4, 6, 9, 12, 18 and 24 h postoperatively. Results: Patient characteristics, postoperative morphine consumption (43.3 ± 7.6 vs. 40.3 ± 12.3 mg) and peristaltic recovery time (16.9 ± 5 vs. 18.4 ± 5.2 h) were similar in both groups. Overall nausea and vomiting were significantly lower in the ondansetron prophylaxis group than in the group without prophylaxis (52.9% vs. 88.2%, P < 0.05). Though nausea alone was higher in the prophylaxis group (41.2% vs. 29.4%), nausea with vomiting was significantly lower in the prophylaxis group (11.8% vs. 58.8%, P < 0.01). Patients' satisfaction scores were higher in the ondansetron group at all times and the difference was significant (P < 0.05) 4 h postoperatively. Conclusions: The incidence of PONV in patients undergoing total abdominal hysterectomy under spinal anaesthesia with i.v. PCA morphine is very high (88.2%). Antiemetic prophylaxis with ondansetron is highly recommended in this patients group resulting in a lower incidence of nausea and vomiting, and significantly improves patient' satisfaction and life quality in the early postoperative period.

We have compared the efficacy of granisetron with perphenazine in the prevention of vomiting after tonsillectomy with or without adenoidectomy in children. In a prospective, randomized, double-blind study, 90 paediatric patients, ASA I, aged 4–10 years, received granisetron 40 mg kg−1 or perphenazine 70 mg kg−1 (n=45 each) intravenously immediately after an inhalation induction of anaesthesia. A standard general anaesthetic technique was employed throughout. A complete response, defined as no emesis with no need for another rescue antiemetic, during the first 3 h (0–3 h) after anaesthesia was 87% with granisetron and 78% with perphenazine (P=0.204). The corresponding incidence during the next 21 h (3–24 h) after anaesthesia was 87% and 62% (P=0.007). No clinically serious adverse events were observed in any of the groups. We conclude that granisetron is a better anti-emetic than perphenazine for the long-term prevention of post-operative vomiting in children undergoing general anaesthesia for tonsillectomy.

Summary:

Background and objective: Several new techniques and agents (e.g. ropivacaine) have been introduced in regional anaesthesia to improve patients outcome and safety. The beneficial effects on patient outcome are clear with these techniques, however, no information is available about their pattern and frequency of use in clinical practice. This study presents data concerning the current practice of regional anaesthesia in Germany. Methods: A questionnaire was sent to every German anaesthesia department (n = 1381). Questions focused on the frequency and range of regional anaesthetic procedures employed, with attention also to the organizational structural of the individual institution. Results: Six hundred and sixty-seven questionnaires were returned anonymously, representing a return rate of 48.3%. In hospitals with less than 200 beds, the number of regional anaesthetics was markedly higher compared to large hospitals with more than 400 beds. In contrast, small hospitals tended to provide only basic techniques of regional anaesthesia, whereas larger hospitals implemented more advanced techniques. Bupivacaine remains the most commonly used long-lasting local anaesthetic. Staff structure was also different in small departments – patient care was performed by board certified anaesthesiologists while residents were responsible for the patients in larger departments. Conclusions: In small hospitals a majority of board certified anaesthesiologists rely on basic regional anaesthesia techniques. In large departments some consultants provide the entire spectrum of regional anaesthesia, with the majority of cases transferred to the residents responsibility. These results indicate the strong need to improve residency programs with regard to regional anaesthesia.

Background and objective Efficacy and side–effects of piritramide (pirinitramide) and morphine, given intravenously for postoperative analgesia after hysterectomy, were compared in a randomized controlled double-blind trial in 92 ASA class I–III patients.

Methods Administration was investigator–controlled during the first 90 min and subsequently via a patientcontrolled device. Visual analogue scales for pain intensity and verbal rating scales for side-effects were taken repeatedly.

Results Median visual analogue scores for pain intensity on a 100-mm scale 4, 8 and 24 h after surgery were 10, 8.5 and 5mm in the piritramide group and 18, 10 and 8.5mm in the morphine group. These differences are neither statistically nor clinically significant. Median values for nausea on a verbal rating scale from 0 to 3 were zero for both groups at all times with similar ranges. There was no difference in number of episodes of vomiting and retching and usage of antiemetics. The mean amount of piritramide used for initial titration was 15.2 mg; the respective amount of morphine was 15.4 mg.

Conclusions In this setting the two agents are equally effective and show a similar profile of sideeffects.

Summary

Background and objective: Following the discovery of the feasibility of assessing the adequacy of the splanchnic perfusion by means of gastrotonometry, this technique became extensively used in clinical practice and in research. At present, high-technology instruments are available for the purpose. However, there is still a need for a simple, cheap tool that is easily applicable for patients of all ages. The present article describes such a tool and presents the results of in vitro and in vivo validation measurements with it. Methods: Balloon-free tonometric probes consisting of silicone rubber tubes were developed. In vitro measurements of the uptake of CO2 inside the probes and for comparison in a conventional ballooned intestinal tonometer were made in a closed container maintained at 37°C. In in vivo studies in anaesthetized dogs, the tonometric PCO2 values were determined with a tonometric probe and catheter introduced simultaneously into the ileum of the animals and the results were analysed by the Bland–Altman method. Results: The in vitro equilibration studies revealed that the filling media inside the probes equilibrated rapidly with the PCO2 content of the chamber. The data obtained from the in vivo investigations with the two different methods demonstrated a statistically significant linear association (correlation coefficient: 0.778, significance: P < 0.001). Conclusion: The new simple tonometric probe described appears to be a reliable tool with certain advantages for gastric tonometry. However, further studies are warranted before its general clinical use.

The anaesthetic management of a 25-year-old parturient with juvenile rheumatoid arthritis (Still's disease) and a difficult airway presenting for elective Caesarean section is described. Inadequate block after epidural anaesthesia necessitated general anaesthesia. This was safely accomplished by securing the airway with awake oral fibreoptic intubation before general anaesthesia was induced. The problems of performing an awake fibreoptic intubation in a pregnant patient are discussed and a simple method for performing the technique is described.

Doppler cardiac output (CO) determination is discussed as a non-invasive alternative to CO estimation by thermodilution. This study was designed to compare the accuracy of a new transoesophageal Doppler device with the thermodilution technique. In 24 patients undergoing coronary artery bypass surgery, CO was determined simultaneously by the oesophageal Doppler (OD) and thermodilution (TD) method in triplicate for three sample episodes: after induction of anaesthesia during clinical steady-state conditions (A), after start of surgery (B), and after sternotomy (C). The agreement between ODCO and TDCO estimations was assessed by analysing the mean difference, indicating the systematic error, and analysing the distribution of differences between the two methods. The bias between ODCO and TDCO estimations was 0.38 (−0.06 to +0.81) L min−1 (mean and 95% confidence interval) for sample episode A, 0.48 (−0.11 to +1.1) L min−1 for sample episode B, and 0.69 (+0.08 to +1.3) L min−1 (P < 0.05 vs. zero) for sample episode C. Bias analysis of the log-transformed data revealed that 95% of the ODCO values differed from TDCO values by 43% below to 50% above for sample episode A, by 39% below to 95% above for sample episode B, and by 32% below to 96% above for sample episode C. Analysis of the changes in CO from sample episode A to B and from sample episode B to C, expressed as percentage values, showed a non-significant bias between the methods, but the 2 SD limits were ±44% and ±36% respectively. Our findings suggest that CO estimation by OD cannot replace estimation by the TD method.

To elucidate if an effect of propofol on endothelium-dependent relaxation could contribute to propofol-induced vasodilation, smooth muscle relaxation of isolated human omental artery and vein segments precontracted by endothelin-1 were measured. Substance P induced a concentration-dependent relaxation (mean ±SEM) in both artery (63 ± 8.4% of precontraction, n=9) and vein (60 ± 11%, n=7). The relaxation was enhanced by 10−6 M propofol (artery, 72 a 9.5%, n=9; vein, 81 ± 12%, n=7) but not affected by 10−7, 10−5 and 10−4 M propofol. In the presence of Nω-nitro-L-arginine methyl ester (nitric oxide synthase inhibitor), 10−6 M propofol still enhanced the substance P-induced relaxation in arteries but not veins, whereas 10−4 M propofol inhibited the relaxation in both arteries (rightward shift of the concentration-response curve) and veins (28 ± 7.5%, n=8). In the presence of potassium chloride (to prevent hyperpolarization), the enhancement of substance P-induced relaxation by 10−6 M propofol was abolished in both arteries and veins whereas 10−5 and 10−4 M propofol reduced the relaxation in arteries (38 ± 13% at 10−5 M, n=6; 30 ± 11% at 10−4 M, n=6) but not in veins. These results demonstrate that propofol, at lower, clinically relevant concentrations, promotes endothelium-dependent relaxation mediated via hyperpolarization in human omental arteries and via both nitric oxide and hyperpolarization in human omental veins.

Airway management is a major concern in Robin sequence, where micrognathia, glossoptosis and a cleft of the soft palate exist. The management of an infant with a potentially difficult airway is discussed where tracheal intubation was aided by the use of a 2.2-mm fibrescope mounted with a 3-mm endotracheal tube passed through a size 1 laryngeal mask airway.

The study compares responders and non-responders to post-operative patient-controlled analgesia (PCA) and evaluates factors that might differ between these two groups in order to identify non-responders during the early post-operative period. A prospective, randomized, double-blinded study design was used. Patients recovering from abdominal surgery were assigned to one of three treatment groups for a study period of 48 h. After titration of an individual loading dose, patients could self-administer 1 mL bolus doses(2 mg of morphine, 20 mg of tramadol or placebo) using a PCA device. Patients responding or not responding to the treatment were identified. In non-responders the escape medication was morphine.There were 96 responders and 65 non-responders. All responders showed similar pain scores, irrespective of the drug they received. Drug consumption of placebo responders was twice as high as that of opioid responders. Pain scores and analgesic consumption of non-responders were significantly higher compared with responders, although those patients received morphine. The loading dose correlated with subsequent analgesic consumption. Altogether, 89.2% of the non-responders were identified after the loading dose. Size of loading dose and pain scores during the first 30 min are useful for assessing the overall response to post-operative pain management. These factors may be valuable for predicting individual pain management.

Summary

Background and objective: Following strabismus surgery, immediate postoperative ophthalmic evaluation may be desired. Thus, an anaesthetic technique allowing rapid recovery of ocular motility is required. Saccadic eye movements is a biophysical monitor of ocular motility and may be used to assess recovery from anaesthesia. The aim of this study is to compare the time to the recovery of saccadic eye movements in patients, following one of two anaesthetic techniques: Propofol–remifentanil-based anaesthesia vs. sevoflurane–fentanyl-based anaesthesia. Methods: Fifty adult patients undergoing strabismus surgery were randomly assigned to one of two groups: patients in Group R received induction and maintenance of anaesthesia with propofol and remifentanil, while patients in Group S received induction of anaesthesia with propofol and fentanyl and maintenance of anaesthesia with sevoflurane. Recovery from anaesthesia was measured from the time all anaesthetics were turned off and was assessed every 2 min. Recovery time was attained when patients were able to generate brisk saccadic eye movements. At recovery time, the ophthalmic evaluation was started. Results: The mean recovery time of saccadic eye movements was significantly shorter in the Group R when compared to the Group S (12.1 ± 4.3 min vs. 21.5 ± 4.7 min, respectively, P < 0.0001). More patients in Group S experienced nausea and vomiting postoperatively as compared to Group R (9/25 vs. 2/25, respectively, P = 0.037). Conclusions: Propofol–remifentanil-based anaesthesia may be a useful technique in strabismus surgery when immediate postoperative ophthalmic evaluation is desired. When compared to sevoflurane maintenance of anaesthesia, it allows for a more rapid recovery from anaesthesia as judged by recovery of saccadic eye movements and a decreased incidence of postoperative nausea and vomiting.

Summary

Background and objective: We tested the hypothesis that disturbances of the visual pathway following sevoflurane general anaesthesia (a) exist and persist even after clinical discharge criteria have been met and (b) are associated with decreased contrast sensitivity.

Methods: We performed pattern and full-field flash electroretinograms (ERG) in 10 unpremedicated ASA I patients who underwent nitrous oxide/sevoflurane anaesthesia. ERG and contrast sensitivity were recorded preoperatively, immediately after discharge from the recovery room and 2 h after discontinuation of sevoflurane. The time at which the Post Anaesthesia Discharge Score first exceeded 9 was also noted. Data were analysed using paired, one-tailed t-tests and Pearson's correlation coefficient.

Results: On the full-field photopic ERG, b-wave latency was greater at each postoperative time point (31.6 ± 1.1 and 30.8 ± 1.1 ms) compared to preoperatively (30.1 ± 1.1 ms, P < 0.001 and P = 0.03, respectively). Oscillatory potential latencies were greater on discharge from the recovery room compared with pre-anaesthetic values (23.1 ± 3.1 vs. 22.4 ± 3.3 ms, P = 0.01) and returned to baseline by 2 h after emergence from anaesthesia. Also at 2 h after emergence from anaesthesia: (a) P50 latency on the pattern ERG was greater than at baseline (81.5 ± 17.9 vs. 51.15 ± 22.6 ms, P = 0.004); (b) N95 amplitude was less compared to pre-anaesthetic values (2.6 ± 0.5 vs. 3.3 ± 0.4 μV, P = 0.003) and (c) contrast sensitivity was less compared to baseline values (349 ± 153 vs. 404 ± 140, P = 0.048). A positive correlation was demonstrated between contrast sensitivity and both N95 amplitude and b-wave latency (r = 0.99 and r = −0.55 at significance levels of P < 0.005 and P < 0.05, respectively).

Conclusions: Postoperative ERG abnormalities and associated decreases in contrast sensitivity are consistently present in patients who have undergone nitrous oxide/sevoflurane anaesthesia. These abnormalities persist beyond the time at which standard clinical discharge criteria have been met.

Summary

The management of thyroid-associated eye disease is reviewed with particular reference to surgical management and its implications for anaesthetists. Experience from a unit undertaking such surgery is presented.

Summary

Background and objective: Inhalation anaesthetics given only during post-ischaemic reperfusion have some protective effect against reperfusion injury in the heart. Adenosine triphosphate-regulated mitochondrial potassium channels have been shown to be an important mediator of cardioprotection. Thus, we investigated whether 5-hydroxydecanoate, a putative mitochondrial potassium channel blocker, prevents the cardioprotective effect of volatile anaesthetics. Methods: Forty rats were randomly allocated to four groups of equal size: control group, 5-hydroxydecanoate group, 5-hydroxydecanoate + sevoflurane group and 5-hydroxydecanoate + isoflurane group. Seven minutes after the start of perfusion, normal saline (control group) or 5-hydroxydecanoate (the other groups) was administered. Ten minutes after the start of perfusion, the heart was rendered globally ischaemic for 10 min. One minute before the end of the ischaemic period, 2.7% sevoflurane or 1.4% isoflurane were administered in the 5-hydroxydecanoate + sevoflurane or 5-hydroxydecanoate + isoflurane groups respectively. The heart was reperfused for 10 min. Results: Adenosine triphosphate content at the end of reperfusion in the 5-hydroxydecanoate + sevoflurane group was significantly lower (P < 0.05) than those in the control and the 5-hydroxydecanoate + isoflurane groups (19.9 ± 8.7, 28.1 ± 3.4 and 30.4 ± 2.3 μmol g−1, respectively). In addition, the combination of inhalation anaesthetics and 5-hydroxydecanoate decreased the ratios of recovered hearts from ischaemia (5-hydroxydecanoate + sevoflurane group: 40%, 5-hydroxydecanoate + isoflurane group 50%). Conclusion: 5-hydroxydecanoate alone caused no significant changes in haemodynamics and myocardial metabolism. However, the combination of 5-hydroxydecanoate and volatile anaesthetics impaired the recovery from ischaemia. Although animal data cannot be extrapolated to human beings, we suggest that more attention be paid to patients on sulphonylurea drugs, which inhibit potassium channels, when they are anaesthetized with volatile anaesthetics.

Summary

Background and objective: It has been shown that racemic ketamine increases coronary blood flow and that this effect is at least in part due to a direct vasorelaxing effect of this substance. This study was designed to determine whether ketamine might stereoselectively relax isolated porcine coronary arteries.

Methods: Using the model of isolated vessels we studied the effects of S(+) ketamine, R(−) ketamine, and racemic ketamine (5–500 μg mL−1) on artery strips pre-contracted by either potassium chloride (KCl) or prostaglandin F2α (PGF2α). To elucidate possible mechanisms of action these experiments were repeated in the presence of one of the following compounds: Nω-nitro-l-arginine (l-NNA), indomethacin, glibenclamide, and tetraethylammonium (TEA) chloride, an inhibitor of the BKCa K+ channel.

Results: Both isoforms and racemic ketamine relaxed isolated coronary arteries in a concentration-dependent manner in concentrations beyond those used in clinical practice. S(+) ketamine exerted the strongest vasorelaxing effect, followed by racemic ketamine and R(−) ketamine. Pretreatment with l-NNA, indomethacin, or glibenclamide did not alter the vasodilating properties of ketamine, whereas TEA chloride significantly attenuated the vasorelaxing effects of all the three forms of ketamine.

Conclusions: Ketamine dilates coronary arteries in vitro when administered in high concentrations. There is a stereoselective difference with a stronger vasorelaxing effect of S(+) ketamine compared to racemic and R(−) ketamine. The impact of TEA chloride suggests that the activation of the BKCa channel may contribute to the vasodilating effect of ketamine.

Summary

Background and objective: To evaluate orotracheal intubation conditions after 1 min.

Patients and methods: A prospective randomized study with 376 adult American Society of Anesthesiologists (ASA) Grade I–III patients. Each patient received propofol, fentanyl and either suxamethonium (1 mg kg−1) or rocuronium. The intubating dose of rocuronium (2 × ED95) was preceded 4 min earlier by saline, or a 0.1 × ED95 priming dose of rocuronium, atracurium, cis-atracurium, vecuronium or mivacurium. Intubating conditions were graded as excellent, good or poor with respect to laryngoscopy, vocal cord position and movement and reaction to intubation and/or cuff inflation.

Results: There were significant differences (P < 0.05) in laryngoscopy between suxamethonium and rocuronium primed with saline, atracurium or cis-atracurium. With respect to vocal cord position and movement during intubation, rocuronium without priming differed significantly from all other groups and for reaction to insertion of tracheal tube and/or cuff inflation. Rocuronium without priming differed significantly from all other groups except for rocuronium primed with itself. The mivacurium group showed more signs of pre-curarization than other groups (P < 0.05). There were significant differences between rocuronium alone and the other groups when final intubating conditions were compared.

Conclusions: Priming rocuronium with 0.1 × ED95 of vecuronium, rocuronium, atracurium or cis-atracurium is a safe technique and did not increase risk of pre-curarization in healthy patients.