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H Wulf

Publications and source records attributed to H Wulf.

At least 55 records · Page 3Linked to original sources
PubMed2003

[Anesthesia in the breast feeding period. Excretion of anesthetic agents and adjuvants into breast milk and potential pharmacological side-effects on the suckling infant].

Whenever an anesthetic is needed during the breast feeding period, potential pharmacological side-effects imposed on the infant by any kind of anesthetic agent used during both general and regional anesthesia are in contrast to the potential beneficial effects of breast feeding for the infant and the mother. Despite an increasing knowledge and understanding of the mechanisms of excretion of drugs and their metabolites through breast milk, information about most anesthetic drugs are still either inconclusive or contradictory. Often it is impossible to decide whether a certain substance that is potentially excreted through breast milk might be harmless or harmful for the breast-fed infant. In addition to that only few anesthetic agents and drugs used in conjunction with an anesthetic are officially approved for use during pregnancy and the period of breast feeding and for medico-legal reasons pharmaceutical companies generally advise against the use of any of those drugs during this period. However, based on the knowledge of pharmacological properties of commonly used anesthetic agents it is reasonable to assume that continuing breast feeding in the immediate postoperative period after a single anesthetic can be considered safe for the infant since no adverse effects caused by or secondary to the single use of those drugs can be expected. Provided there is a careful choice of anesthetic drugs, there is no need to consider that a single general or regional anesthetic is an indication to stop breast feeding. Even planned elective surgical procedures do not need to be postponed. No scientifically based interval between surgery under general or regional anesthesia and resumption of breast feeding can be recommended. Instead current opinion is that breast feeding can be resumed as soon as the mother feels physically and mentally capable to do so.

Adjuvants, Anesthesia↗
PubMed2003

[Prediction of postoperative nausea and vomiting using an artificial neural network].

OBJECTIVE: Postoperative nausea and vomiting (PONV) are still frequent side-effects after general anaesthesia. These unpleasant symptoms for the patients can be sufficiently reduced using a multimodal antiemetic approach. However, these efforts should be restricted to risk patients for PONV. Thus, predictive models are required to identify these patients before surgery. So far all risk scores to predict PONV are based on results of logistic regression analysis. Artificial neural networks (ANN) can also be used for prediction since they can take into account complex and non-linear relationships between predictive variables and the dependent item. This study presents the development of an ANN to predict PONV and compares its performance with two established simplified risk scores (Apfel's and Koivuranta's scores). METHODS: The development of the ANN was based on data from 1,764 patients undergoing elective surgical procedures under balanced anaesthesia. The ANN was trained with 1,364 datasets and a further 400 were used for supervising the learning process. One of the 49 ANNs showing the best predictive performance was compared with the established risk scores with respect to practicability, discrimination (by means of the area under a receiver operating characteristics curve) and calibration properties (by means of a weighted linear regression between the predicted and the actual incidences of PONV). RESULTS: The ANN tested showed a statistically significant ( p<0.0001) and clinically relevant higher discriminating power (0.74; 95% confidence interval: 0.70-0.78) than the Apfel score (0.66; 95% CI: 0.61-0.71) or Koivuranta's score (0.69; 95% CI: 0.65-0.74). Furthermore, the agreement between the actual incidences of PONV and those predicted by the ANN was also better and near to an ideal fit, represented by the equation y=1.0x+0. The equations for the calibration curves were: KNN y=1.11x+0, Apfel y=0.71x+1, Koivuranta 0.86x-5. CONCLUSION: The improved predictive accuracy achieved by the ANN is clinically relevant. However, the disadvantages of this system prevail because a computer is required for risk calculation. Thus, we still recommend the use of one of the simplified risk scores for clinical practice.

Artificial Intelligence↗
PubMed2003

[Artificial neural networks. Theory and applications in anesthesia, intensive care and emergency medicine].

Artificial neural networks (ANN) are constructed to simulate processes of the central nervous system of higher creatures. An ANN consists of a set of processing units (nodes) which simulate neurons and are interconnected via a set of "weights" (analogous to synaptic connections in the nervous system) in a way which allows signals to travel through the network in parallel. The nodes (neurons) are simple computing elements. They accumulate input from other neurons by means of a weighted sum. If a certain threshold is reached the neuron sends information to all other connected neurons otherwise it remains quiescent. One major difference compared with traditional statistical or rule-based systems is the learning aptitude of an ANN. At the very beginning of a training process an ANN contains no explicit information. Then a large number of cases with a known outcome are presented to the system and the weights of the inter-neuronal connections are changed by a training algorithm designed to minimise the total error of the system. A trained network has extracted rules that are represented by the matrix of the weights between the neurons. This feature is called generalisation and allows the ANN to predict cases that have never been presented to the system before. Artificial neural networks have shown to be useful predicting various events. Especially complex, non-linear, and time depending relationships can be modelled and forecasted. Furthermore an ANN can be used when the influencing variables on a certain event are not exactly known as it is the case in financial or weather forecasts. This article aims to give a short overview on the function of ANN and their previous use and possible future applications in anaesthesia, intensive care, and emergency medicine.

Anesthesiology↗
PubMed2003

Neuromuscular block and relative concentrations of mivacurium isomers under isoflurane versus propofol anaesthesia.

BACKGROUND AND OBJECTIVE: The augmentation of the effect of neuromuscular blocking drugs with volatile anaesthetics is well documented, but the mechanism remains unclear. The pharmacological interaction and relative plasma concentrations of mivacurium isomers were investigated during either propofol- or isoflurane-maintained anaesthesia. METHODS: Forty-four patients were randomly assigned to one of two groups: isoflurane or propofol. All patients received an initial dose of mivacurium 0.1 mg kg(-1). After recovery of the first twitch (T1) response measured by acceleromyography to 5%, a T1 depression of 90-99% was maintained by infusion. After a steady state was reached, blood samples were taken after 10 and 30 min for analysis of mivacurium isomers. Recovery times for T1 to 251/50/75/90% (TW25-90), train-of-four ratio 25/70% and recovery index (time TW25-75) were recorded after stop of infusion. RESULTS: In the isoflurane group, lower infusion rates were needed (3.0 +/- 1.6 versus 3.6 +/- 1.6 microg kg(-1) min(-1)) and there was a slower recovery (significant for train-of-four ratio 70%: 21.9 versus 17.9 min). The plasma concentrations of mivacurium and its trans-trans isomer (in percentage of the total) were significantly higher in the isoflurane group (10 min: 52.6 versus 25.8%; 30 min: 49.6 versus 23.2%). CONCLUSIONS: For mivacurium, the phenomenon of 'potentiation' of the effect of muscle relaxants by volatile anaesthetics could be due to an increase in the plasma concentration of the potent trans-trans isomer.

Adult↗
PubMed2002

[Plasma cholinesterase variations as a result of prolonged neuromuscular blockade. Review and problems encountered in two cases of prolonged neuromuscular blockade after muscle relaxation with succinylcholine as compared to mivacurium].

Succinylcholine and mivacurium are degraded more slowly in patients with a qualitatively or quantitatively reduced plasma cholinesterase and are therefore known for inducing a prolonged postoperative apnea. Perioperative laboratory screening even including plasma cholinesterase activity testing will not prevent this due to a possible aberration only in the qualitative cholinesterase activity. This is illustrated by introducing two cases reports of prolonged apnea after administration of mivacurium or succinylcholine. The pathophysiology of plasma cholinesterase is reviewed including genetically determined variants and the degradation pathways of mivacurium and succinylcholine. Only extensive laboratory chemical tests are sufficient to prevent this possible complication. Due to the rare incidence there is no evidence for recommending these laboratory investigations in all patients. Once prolonged apnea occurs following the administration of mivacurium or succinylcholine the best choice is ongoing ventilation combined with a sufficient sedation.

Apnea↗
PubMed2002

[Postoperative pain therapy in minimally invasive direct coronary arterial bypass surgery. I.v. opioid patient-controlled analgesia versus intercostal block].

OBJECTIVE: Lately introduced cardiosurgical procedures such as MIDCAB enable an early extubation immediately after surgery. This also requires an adequate anesthesia regime and especially a sufficient postoperative analgesia. Patient controlled analgesia (PCA) and intercostal nerve blockade (ICB) were evaluated for their suitability for postoperative pain relief in patients undergoing a MIDCAB procedure. MATERIAL AND METHODS: After approval by the local ethic committee and obtaining written informed consent 43 patients were included in this study. Anesthesia was induced and maintained in a total intravenous standardised manner with propofol, remifentanil, cisatracurium and additionally glyceroltrinitrate, clonidine and esmolol were given as needed. After revascularisation patients were randomly assigned to one of two groups receiving either 7.5 mg piritramid i.v. before extubation and continuing a PCA with 2 mg boli and a 10 min lockout, or an ICB with ropivacaine 1% (4 times 5 ml). Additionally all patients received 1 g paracetamol rectally before induction of anesthesia and 1 g metamizol i.v. at the end of surgery. A rescue medication of 3.75 mg piritramid i.v. was allowed. A pain score (NRS 0-10), the Aldrete score (AS 0-12) and oxygen saturation were obtained 1, 4, and 8 h after extubation. RESULTS: The ICB group showed a significantly greater pain reduction in the first (5.8 +/- 1.8 vs. 7.3 +/- 1.9; P < 0.02) and fourth h (3.6 +/- 1.3 vs. 4.6 +/- 1.4; P < 0.02), respectively. Transfer to an intermediate care ward one hr after extubation was achieved more often in the ICB group according to the AS (ICB 9.6 +/- 1.5 vs. PCA 8.9 +/- 1.2; P < 0.05), too. There was no difference with respect to the oxygen saturation. The additional piritramid demand was 9.3 mg in the ICP group and 5 mg in the PCA group in the first 8 hours postoperative. CONCLUSION: ICB gives a better pain relief in the early postoperative phase after MIDCAB procedures compared to a PCA. Both regimes are adequate in order to provide a sufficient pain relief and help to avoid prolonged postoperative mechanical ventilation. These will enable an early transfer of patients to an intermediate care station and save ICU capacity.

Adult↗
PubMed2002

[Placental passage of anesthetics and adjuvants].

In obstetric anaesthesia almost all anaesthetic agents are capable of traversing the fetomaternal blood barrier. They all carry potential side-effects putting the unborn or newborn child at risk. Of major relevance is their potential for embryotoxicity, teratogenicity, postpartal cardiorespiratory or neuromuscular depression and the disturbance of thermoregulation. This can possibly lead to fetal malformation, asphyxia or floppy infant syndrome. Furthermore compromisation of uterine blood flow or contractility of the mature uterus plays an important role for the incidence of intrauterine asphyxia and premature labour or birth. Considering the physiological and pathophysiological alterations during pregnancy regarding all organ systems, the overall goal is to find an ideal choice of anaesthetic drugs and techniques in order to minimise an increased anaesthetic risk during pregnancy.

Adjuvants, Anesthesia↗
PubMed2002

[Patient evaluation of postoperative recovery. An evaluation of the QoR scores in 577 patients].

BACKGROUND: In 1999 Myles and co-workers presented their quality of recovery score (QoR score) as a tool to evaluate postoperative recovery and to measure patient satisfaction. It was developed according to predefined psychological standards and its reliability and validity had been proven in large clinical trials. The aim of this study was to evaluate a German version of the QoR in a heterogeneous group of surgical patients. METHODS: A total of 577 unselected patients completed a modified questionnaire. The response rate and time spent on completing the test were recorded. A stepwise multivariate regression analysis identified factors with significant impact on the QoR score. Other analyses were performed descriptively. RESULTS: Of the patients 83% completed the questionnaire in a median time of 9 h after surgery without assistance. For 75% of these it took 2 min or less. The median QoR score was 15 (10(th)/90(th) percentile: 11/18). Cronbach's p (=0.63) and mean corrected item correlation (=0.32) were used as measures of internal reliability. Factors with impact on the QoR score were: period of time after surgery when performing the test, severity of surgery, sex, general vs local anaesthesia, duration of anaesthesia, and age. CONCLUSIONS: The German translation of the QoR score is easily applicable to a heterogeneous surgical population and thus can be used as a valuable measure of quality of anaesthesia care and patient satisfaction.

Adult↗
PubMed2002

[Pharmacoeconomical model for cost calculation using a study on prophylaxis of nausea and vomiting in the postoperative phase as an example. Cost effectiveness analysis of a tropisetron supplemented desflurane anaesthesia in comparison to a propofol total intravenous anaesthesia (TIVA)].

AIM OF THE STUDY: Postoperative nausea and vomiting (PONV) are among the most frequent complications after general anaesthesia. Avoiding these symptoms is of utmost importance for most patients; PONV is not only a major source of discomfort for patients but also a cause of additional costs for the patients and the health care provider. The economical impact of PONV will become even more important in the near future because the number of surgical procedures performed on an ambulatory basis is increasing. The following article gives a short overview of the terminology and measures used in pharmacoeconomical studies concerning PONV. Furthermore the economical aspects of a low-flow anaesthesia supplemented with the 5-HT(3)-antagonist tropisetron compared with a total intravenous anaesthesia (TIVA) using propofol are described. METHODS: For this comparison a decision analysis was performed using data of a randomised control trial on 150 female patients undergoing major gynaecological surgery. The patients were randomised to receive a total intravenous anaesthesia with propofol-alfentanil or a balanced anaesthesia with desfluran (fresh gas flow 1 l.min(-1)) supplemented by 2 mg tropisetron at the end of surgery. RESULTS: Indirect costs associated with anaesthesia using desflurane-tropisetron (4.94 Euro) are not different from that of propofol-TIVA (4.81 Euro) because of a similar incidence of PONV in the PACU. Furthermore, the total cost for 100 min general anaesthesia is higher in the desflurane-tropisetron group (30.94 Euro) compared with the TIVA group (24.55 Euro) due to the decreasing acquisition costs of propofol in the last 2 years. CONCLUSION: Total intravenous anaesthesia with propofol is more cost-efficient than balanced anaesthesia with desflurane and additional tropisetron as a prophylactic antiemetic.

Adult↗
PubMed2002

[Transient neurologic symptoms after spinal anesthesia. A quantitative systematic overview (meta-analysis) of randomized controlled studies].

BACKGROUND: Transient neurologic symptoms (TNS) after spinal anesthesia (SPA) is defined as back pain with radiation or dysesthesia in the buttocks, thighs, hips and calves, occurring within 24 h after recovery from otherwise uneventful SPA. The symptoms last for about 1-3 days but neurophysiologic evaluation does not show pathologic findings. The type and the preparation of the local anesthetic drug (baricity, concentration, additives or preservatives) are most often discussed as the underlying cause of TNS. METHODS: Randomized controlled comparative studies reporting the incidence of TNS were systematically searched. Descriptive statistics are presented summarizing the identified trials and the pooled relative risk (RR), the number-needed-to-harm (NNH) with their 95% confidence intervals (95%-CI) were calculated using a random effects model. RESULTS: A total of 29 studies with a 2,813 patients fulfilled the inclusion criteria. Summarizing all patients in these trials without further adjustment, the incidence of TNS was 16.9% after lidocaine, 19.1% after mepivacaine, but only 1.1% after bupivacaine and 1.7% after prilocaine. For tetracaine, procaine, and ropivacaine there were too few studies to draw meaningful conclusions. Using meta-analysis techniques these data were confirmed: the pooled relative risk (RR) for suffering from TNS was 6.7-fold higher after lidocaine (95%-CI: 2.5-18) than after SPA with bupivacaine and 5.5-fold higher (95%-CI: 2-15) than after prilocaine. Furthermore, data show that baricity, concentration of the local anesthetic, and addition of vasoconstrictors have no significant influence on the occurrence of TNS. CONCLUSION: Prilocaine and bupivacaine for SPA are associated with less TNS than lidocaine and mepivacaine. For the other local anesthetics there were not enough comparative trials to give conclusive recommendations.

Adjuvants, Anesthesia↗
PubMed2002

Impact of a multimodal anti-emetic prophylaxis on patient satisfaction in high-risk patients for postoperative nausea and vomiting.

Postoperative nausea and vomiting (PONV) are frequent and unpleasant symptoms. This prospective study aimed to assess the efficacy of a multimodal approach to prevent PONV, and patient satisfaction using the willingness-to-pay method. Two validated risk scores were applied to forecast the individual risk for PONV in 900 consecutive patients of whom 108 were identified as high-risk patients (predicted risk: 79-87%). High-risk patients received multimodal anti-emetic prophylaxis: total intravenous anaesthesia with propofol, high fractional inspired oxygen (80%), omission of nitrous oxide, dexamethasone 8 mg, haloperidol 10 microg.kg(-1), and tropisetron 2 mg. Of the remaining patients with low or moderate risk for PONV, a random sample of 71 females received balanced propofol-desflurane anaesthesia without prophylactic anti-emetics. All patients were interviewed 2 and 24 h after surgery for occurrence of nausea and vomiting. Patient satisfaction was measured using the willingness-to-pay method. The incidence of PONV (95%-confidence interval) in the control-group was 41% (29-51%), slightly lower than predicted by the risk scores (53-57%). The multimodal anti-emetic approach reduced the predicted risk (79-87%) in the high risk-group to 7% (3-14%). This was associated with a high willingness-to-pay median (25th/75th percentile) of 84 UK pounds (33-184 UK pounds) in the multimodal anti-emetic group compared to 14 UK pounds (4-30 UK pounds) in the control group. A multimodal anti-emetic approach can considerably reduce the incidence of PONV in high-risk patients and is associated with a high patient satisfaction as measured by the willingness-to-pay method.

Adult↗
PubMed2002

[Prophylaxis of Postoperative Nausea and Vomiting FollowingGynaecological Laparoscopy].

OBJECTIVE: Compared to other procedures, gynaecological laparoscopies are followed rather frequently by postoperative nausea and vomiting (PONV). Therefore, we investigated the prophylactic antiemetic efficacy of metoclopramide and droperidol under general anaesthesia with isoflurane (part 1). Given the rather unsatisfying results of this monoprophylaxis we examined the effects of a quintuple prophylaxis in this setting (part 2). METHODS: Part 1: Following ethical committee approval and written informed consent 120 patients scheduled for elective gynaecological laparoscopy were allocated prospectively, randomly and observer-blinded to the following groups: group P (placebo): 2 ml NaCl 0.9 %, group D: 2.5 mg droperidol, group M: 10 mg metoclopramide. Part 2: Subsequently 50 patients scheduled for elective gynaecological laparoscopy and bearing a minimum risk of 25 % to experience postoperative vomiting were allocated prospectively and blinded to the observers to a quintuple prophylaxis group: group X: 10 mg metoclopramide, 2.5 mg droperidol, 12.5 mg dolasetron, 62.5 mg dimenhydrinate, 8mg dexamethasone. Part 1 and 2: Anaesthesia was induced with fentanyl, etomidate and succinycholine and maintained with isoflurane/N2O, fentanyl and cisatracurium. The antiemetics were applied intravenously 20 min prior to end of surgery. RESULTS: Within the first 24 h postoperatively vomiting occurred more frequently in group P (44 %) compared to group D (21 %, p = 0.046) and group M (33 %, n. s.). Nausea also occurred more frequently in group P (61 %) compared to group D (24 %, p = 0.003) and group M (48 %, n. s.). Intensity of nausea was reduced both in group D and group M compared to group P (p = 0.03). Likewise the requirements for antiemetics as a rescue medication were reduced in group D (p = 0.02) and group M (p = 0.047) compared to group P. In group X no patient suffered from postoperative vomiting, no patient required a rescue antiemetic. CONCLUSIONS: Whereas droperidol provides a reliable antiemetic effect, the prophylactic effect of metoclopramide is rather uncertain. Therefore, further studies regarding a dose response-relationship for metoclopramide are deemed necessary. Since a monoprophylaxis with droperidol or metoclopramide failed to attain a satisfying PONV-prophylaxis in patients at high risk for PONV, the quintuple antiemetic combination might be an effective and safe solution.

Adolescent↗
PubMed2002

[Motor function during patient-controlled analgesia via a lumbar epidural catheter after major abdominal surgery. Ropivacaine-sufentanil vs. bupivacaine-sufentanil].

INTRODUCTION: The aim of the present study was to investigate postoperative motoric impairment during patient-controlled analgesia after major abdominal surgery with ropivacaine-sufentanil and bupivacaine-sufentanil via a lumbar epidural catheter. METHODS: After approval of the local ethics committee, 40 patients scheduled for major lower abdominal surgery were randomly allocated to receive bupivacaine 0.25 % or ropivacaine 0.2 %, both with sufentanil 2 microgram/ml in a double blind manner. General anaesthesia (midazolam, etomidate, fentanyl, vecuronium, and desflurane in N2O/O2) and postoperative management of the patients were standardised. Postoperatively, the motoric function and ability for active early mobilisation was examined clinically (application of the Bromage scale, ability to leave the bed and ability to walk). Reduction of muscular force of the legs was measured postoperatively using a scale and compared with preoperative baseline values. To ensure a similar level of analgesia, a 10-cm visual analogue scale was applied at rest and while coughing. RESULTS: The two groups did not differ with respect to the demographic data and postoperative levels of analgesia. Less reduction of motoric function at rest was observed in the ropivacaine group (p = 0,044). However, this did not lead to an increased ability to get up from bed (p = 0,57) or to walk around (p = 0,17). A high number of patients did not meet the requirements for early ambulation. Almost half of the patients of both groups were unable to leave their beds in the morning of the first postoperative day. On the second postoperative day about 25 - 30 % of the patients could not walk even when support was applied. Furthermore, median reduction (10th/90th percentile) of muscular strength was reduced to 50 % (37 %/76 %) in the ropivacaine group and to 48 % (31 %/61 %) in the bupivacaine group compared with preoperative values. DISCUSSION: While quality of analgesia was similar, mobility of the legs at rest is better preserved with ropivacaine 0.2 % than with bupivacaine 0.25 %. However, despite the fact that high dose sufentanil was added to both local anaesthetics, there was marked motoric impairment in both groups probably due to the lumbar site of the epidural catheter. This was associated with an unacceptable high incidence of patients unsuitable for early postoperative mobilisation.

Amides↗
PubMed2002

[Head and neck cancer surgery in the elderly].

BACKGROUND: The literature on management of advanced head and neck cancer in the elderly is limited. Diagnostic and treatment decisions may be implicated by advanced age itself. METHOD: Treatment outcomes of head and neck cancer in elderly patients were reviewed in the literature. The results should serve as a basis for an individualized treatment strategy. RESULTS: A comparison of data shows that chronologic age alone should not be a contraindication to adequate oncologic surgery. An aggressive approach to head and neck cancer management with curative intention can be also considered in high aged patients with advanced cancer. Surgical therapy of head and neck cancer can be as effective in elderly patients as in younger patients without a significant increase in mortality and complications. CONCLUSIONS: Head and neck cancer patients of all age groups should have a treatment of equal quality regardless of whether the expected outcome is cure or palliation.

Aged↗
PubMed2002

Plasma concentration of ropivacaine after intercostal blocks for video-assisted thoracic surgery.

BACKGROUND: Absorption of local anaesthetics following intercostal blocks is rapid. Therefore, plasma concentrations of ropivacaine during intercostal blocks with ropivacaine 2, 5, 7.5 and 10 mg ml-1 (ropivacaine 5 ml injected into each of four intercostal spaces) in patients undergoing video-assisted thoracic surgery were determined. METHODS: After informed consent and ethics committee approval, 64 patients were randomly allocated to four groups for intercostal nerve block (ropivacaine 2, 5, 7.5 or 10 mg ml-1 at the end of surgery). Central (mixed) venous and arterial plasma samples were collected before the start of intercostal application, and 2, 5, 10, 15, 20, 30, 45, 60 and 90 min afterwards. Plasma concentrations of ropivacaine were measured by high performance liquid chromatography. RESULTS: Maximum venous plasma concentrations occurred after the mean times of 10.7 (range, 5-15), 10.8 (5-20), 11.3 (5-20) and 12.2 (5-45) min, respectively for each group. The groups had mean concentrations of 1.3 (SD, 0.6; range, 0.3-2.3), 2.1 (1.0; 0.5-4.5), 2.4 (1.0; 1.2-5.1) and 2.5 (0.9; 1.7-5.6) micrograms ml-1, respectively. Maximum arterial plasma concentration following 1.0% ropivacaine occurred after 16 (5-45) min with a mean of 2.3 (0.6; 1.5-3.6) micrograms ml-1. No signs of central nervous system or cardiac toxicity were observed. CONCLUSIONS: After intercostal blocks the absorption of ropivacaine is rapid compared with other techniques for regional anaesthesia and results in relatively high venous and arterial plasma concentrations, especially if a dose of 100 mg or more is used.

Adult↗
PubMed2002

Patient preferences for immediate postoperative recovery.

BACKGROUND: Several attempts have been made to evaluate patients' concerns with respect to postoperative recovery. To identify aspects of postoperative recovery relevant to patients, several methodological and statistical approaches have been used. One of the first to provide useful information was Fredrick Orkin who used conjoint analysis. This methodology is usually performed by market researchers to learn about the relative importance of product attributes. We used conjoint analysis in the present study. METHODS: A total of 220 patients undergoing preoperative anaesthetic examination before impending surgery under general anaesthesia were asked to rate nine scenarios during immediate postoperative recovery based on four factors (alertness, pain, postoperative nausea and vomiting (PONV), and extra costs) each with three levels. Using conjoint analysis the relative impact of each factor on ranking the scenarios was assessed. RESULTS: The relative importance of the four factors (as a percentage of the preference decision) was PONV (49%), pain (27%), alertness (13%), and additional costs (11%). CONCLUSION: Avoidance of PONV is a major concern for patients before surgery.

Adolescent↗