C. J. Kalkman

Effects of the introduction of the WHO "Surgical Safety Checklist" on in-hospital mortality: a cohort study.

Objective:To evaluate the effect of implementation of the WHOs Surgical Safety Checklist on mortality and to determine to what extent the potential effect was related to checklist compliance. Background:Marked reductions in postoperative complications after implementation of a surgical checklist have been reported. As compliance to the checklists was reported to be incomplete, it remains unclear whether the benefits obtained were through actual completion of a checklist or from an increase in overall awareness of patient safety issues. Methods:This retrospective cohort study included 25,513 adult patients undergoing non-day case surgery in a tertiary university hospital. Hospital administrative data and electronic patient records were used to obtain data. In-hospital mortality within 30 days after surgery was the main outcome and effect estimates were adjusted for patient characteristics, surgical specialty and comorbidity. Results:After checklist implementation, crude mortality decreased from 3.13% to 2.85% (P = 0.19). After adjustment for baseline differences, mortality was significantly decreased after checklist implementation (odds ratio [OR] 0.85; 95% CI, 0.73–0.98). This effect was strongly related to checklist compliance: the OR for the association between full checklist completion and outcome was 0.44 (95% CI, 0.28–0.70), compared to 1.09 (95% CI, 0.78–1.52) and 1.16 (95% CI, 0.86–1.56) for partial or noncompliance, respectively. Conclusions:Implementation of the WHO Surgical Checklist reduced in-hospital 30-day mortality. Although the impact on outcome was smaller than previously reported, the effect depended crucially upon checklist compliance.

Preoperative prediction of severe postoperative pain

&NA; We developed and validated a prediction rule for the occurrence of early postoperative severe pain in surgical inpatients, using predictors that can be easily documented in a preoperative setting. A cohort of surgical inpatients (n=1416) undergoing various procedures except cardiac surgery and intracranial neurosurgery in a University Hospital were studied. Preoperatively the following predictors were collected: age, gender, type of scheduled surgery, expected incision size, blood pressure, heart rate, Quetelet index, the presence and severity of preoperative pain, health‐related quality of life the (SF‐36), Spielbergers State–Trait Anxiety Inventory (STAI) and the Amsterdam Preoperative Anxiety and Information Scale (APAIS). The outcome was the presence of severe postoperative pain (defined as Numeric Rating Scale ≥8) within the first hour postoperatively. Multivariate logistic regression in combination with bootstrapping techniques (as a method for internal validation) was used to derive a stable prediction model. Independent predictors of severe postoperative pain were younger age, female gender, level of preoperative pain, incision size and type of surgery. The area under the receiver operator characteristic (ROC) curve was 0.71 (95% CI: 0.68–0.74). Adding APAIS scores (measures of preoperative anxiety and need for information), but not STAI, provided a slightly better model (ROC area 0.73). The reliability of this extended model was good (Hosmer and Lemeshow test p‐value 0.78). We have demonstrated that severe postoperative pain early after awakening from general anesthesia can be predicted with a scoring rule, using a small set of variables that can be easily obtained from all patients at the preoperative visit. Before this internally validated preoperative prediction rule can be applied in clinical practice to support anticipatory pain management, external validation in other clinical settings is necessary.

Long-term propofol infusion and cardiac failure in adult head-injured patients

Five adult patients with head injuries inexplicably had fatal cardiac arrests In our neurosurgical intensive-care unit after the introduction of a sedation formulation containing an increased concentration of propofol. To examine the possible relation further, we did a retrospective cohort analysis of head-injured adults admitted to our unit between 1996 and 1999 who were sedated and mechanically ventilated. 67 patients met the inclusion criteria, of whom seven were judged to have died from propofol-infusion syndrome. The odds ratio for the occurrence of the syndrome was 1.93 (95% CI 1.12-3.32, p=0.018) for every mg/kg per h increase in mean propofol dose above 5 mg/kg per h. We suggest that propofol infusion at rates higher than 5 mg/kg per h should be discouraged for long-term sedation in the intensive-care unit.

The effect of outpatient preoperative evaluation of hospital inpatients on cancellation of surgery and length of hospital stay.

To evaluate the possible effects of outpatient preoperative evaluation (OPE) for new surgical patients who will be inpatients, we conducted an observational study at a university hospital in The Netherlands. Various outcomes before and after the introduction of an OPE clinic were compared. The study population comprised all 21,553 elective adult inpatients operated on between January 1, 1997 and December 31, 1999. Cardiac surgery, obstetric and pediatric patients, and patients operated on in same-day surgery were excluded. The main outcome measures were surgical cases canceled for medical reasons, rate of same-day admissions (who were expected to increase), and length of hospital stay. After introduction of OPE, the rate of cancellations for medical reasons decreased from 2.0% to 0.9% (adjusted odds ratio 0.7, 95% CI, 0.5–0.9). The rate of same-day admissions increased from 5.3% before to 7.7% after OPE introduction (adjusted odds ratio 1.2, 95% CI, 1.01–1.39), and the total hospital length of stay (in days) significantly decreased by a factor of 0.92 (0.90–0.94), which was partly the result of a reduction in preoperative admission time. We concluded that, although smaller than anticipated, the use of OPE for potential inpatients leads to a significant reduction of cancelled cases and of length of admission. Further increase of these benefits from OPE requires changes in institutional policy, such as forcing surgical departments to increase their number of same-day admissions.

Determination of moderate-to-severe postoperative pain on the numeric rating scale: a cut-off point analysis applying four different methods

BACKGROUND Cut-off points (CPs) of the numeric rating scale (NRS 0-10) are regularly used in postoperative pain treatment. However, there is insufficient evidence to identify the optimal CP between mild and moderate pain. METHODS A total of 435 patients undergoing general, trauma, or oral and maxillofacial surgery were studied. To determine the optimal CP for pain treatment, four approaches were used: first, patients estimated their tolerable postoperative pain intensity before operation; secondly, 24 h after surgery, they indicated if they would have preferred to receive more analgesics; thirdly, satisfaction with pain treatment was analysed, and fourthly, multivariate analysis was used to calculate the optimal CP for pain intensities in relation to pain-related interference with movement, breathing, sleep, and mood. RESULTS The estimated tolerable postoperative pain before operation was median (range) NRS 4.0 (0-10). Patients who would have liked more analgesics reported significantly higher average pain since surgery [median NRS 5.0 (0-9)] compared with those without this request [NRS 3.0 (0-8)]. Patients satisfied with pain treatment reported an average pain intensity of median NRS 3.0 (0-8) compared with less satisfied patients with NRS 5.0 (2-9). Analysis of average postoperative pain in relation to pain-related interference with mood and activity indicated pain categories of NRS 0-2, mild; 3-4, moderate; and 5-10, severe pain. CONCLUSIONS Three of the four methods identified a treatment threshold of average pain of NRS≥4. This was considered to identify patients with pain of moderate-to-severe intensity. This cut-off was indentified as the tolerable pain threshold.

The PINE study of epidural steroids and local anaesthetics to prevent postherpetic neuralgia: a randomised controlled trial

BACKGROUND Postherpetic neuralgia is the most frequent complication of herpes zoster. Treatment of this neuropathic pain syndrome is difficult and often disappointing. We assessed the effectiveness of a single epidural injection of steroids and local anaesthetics for prevention of postherpetic neuralgia in older patients with herpes zoster. METHODS We randomly assigned 598 patients older than 50 years, with acute herpes zoster (rash <7 days) below dermatome C6, to receive either standard therapy (oral antivirals and analgesics) or standard therapy with one additional epidural injection of 80 mg methylprednisolone acetate and 10 mg bupivacaine. The primary endpoint was the proportion of patients with zoster-associated pain 1 month after inclusion. Analyses were by intention-to-treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN32866390. FINDINGS At 1 month, 137 (48%) patients in the epidural group reported pain compared with 164 (58%) in the control group (relative risk [RR] 0.83, 95% CI 0.71-0.97, p=0.02). After 3 months these values were 58 (21%) and 63 (24%) respectively (0.89, 0.65-1.21, p=0.47) and, at 6 months, 39 (15%) and 44 (17%; 0.85, 0.57-1.13, p=0.43). We detected no subgroups in which the relative risk for pain 1 month after inclusion substantially differed from the overall estimate. No patient had major adverse events related to epidural injection. INTERPRETATION A single epidural injection of steroids and local anaesthetics in the acute phase of herpes zoster has a modest effect in reducing zoster-associated pain for 1 month. This treatment is not effective for prevention of long-term postherpetic neuralgia.

Meta-analysis of Thoracic Epidural Anesthesia versus General Anesthesia for Cardiac Surgery

Background:A combination of general anesthesia (GA) with thoracic epidural anesthesia (TEA) may have a beneficial effect on clinical outcomes after cardiac surgery. We have performed a meta-analysis to compare mortality and cardiac, respiratory, and neurologic complications in patients undergoing cardiac surgery with GA alone or a combination of GA with TEA. Methods:Randomized studies comparing outcomes in patients undergoing cardiac surgery with either GA alone or GA in combination with TEA were retrieved from PubMed, Science Citation index, EMBASE, CINHAL, and Central Cochrane Controlled Trial Register databases. Results:The search strategy yielded 1,390 studies; 28 studies that included 2,731 patients met the selection criteria. Compared with GA alone, the combined risk ratio for patients receiving GA with TEA was 0.81 (95% CI: 0.40–1.64) for mortality, 0.80 (95% CI: 0.52–1.24) for myocardial infarction, and 0.59 (95% CI: 0.24–1.46) for stroke. The risk ratios for the respiratory complications and supraventricular arrhythmias were 0.53 (95% CI: 0.40–0.69) and 0.68 (95% CI: 0.50–0.93), respectively. Conclusions:This meta-analysis showed that the use of TEA in patients undergoing cardiac surgery reduces the risk of postoperative supraventricular arrhythmias and respiratory complications. The sparsity of events precludes conclusions about mortality, myocardial infarction, and stroke, but the estimates suggest a reduced risk after TEA. The risk of side effects of TEA, including epidural hematoma, could not be assessed with the current dataset, and therefore TEA should be used with caution until its benefit-harm profile is further elucidated.

Assessing the applicability of scoring systems for predicting postoperative nausea and vomiting

We have validated two scoring systems for predicting postoperative nausea and vomiting, derived by Apfel et al. and Koivuranta et al. from 1388 adult inpatients undergoing a wide range of surgical procedures. The predictive accuracy of the scoring systems was evaluated in terms of the ability to discriminate between patients with and without postoperative nausea and vomiting (discrimination) and agreement between observed and predicted outcomes (calibration). Discrimination and calibration were less than expected based on previous reports, with both scoring systems providing risk predictions that were too extreme. The area under the ROC curve was 0.63 for Apfel et al.s scoring system and 0.66 for Koivuranta et al.s scoring system. Neither of the scoring systems provided a risk threshold for administering anti‐emetic prophylaxis that yielded satisfying results in terms of predictive values, sensitivity and specificity. Hence, in their original forms, the scoring systems do not guarantee accurate prediction of the risk of postoperative nausea and vomiting in other patient populations. Koivuranta et al.s scoring system appears to be more robust across different populations.

Predicting postherpetic neuralgia in elderly primary care patients with herpes zoster: prospective prognostic study.

Abstract Postherpetic neuralgia (PHN) is the most frequent complication of herpes zoster (HZ) and difficult to treat. Timely identification of high‐risk HZ‐patients enables physicians to focus on PHN prevention. To assess which simple to measure factors are independent predictors of PHN, and whether psychosocial and serological/virological parameters have additional predictive value, a prospective cohort study in primary care was conducted. We included 598 elderly (>50 years) consecutive patients with acute HZ (rash <7 days) below sixth cervical dermatome. At baseline demographic, clinical (e.g., duration and severity of pain and rash), psychological (Pain Cognition List [PCL] and Spielberger’s Anxiety Inventory), serological (VZV‐antibodies) and virological (viremia presence) variables were measured. Blood tests were performed in a random subset of 218 patients. Primary outcome was significant pain (VAS >30 on 0–100 scale) after three months. The final prediction model obtained from multivariable logistic regression was (internally) validated using bootstrapping techniques, and adjusted for optimism. Forty‐six (7.7%) patients developed PHN. Independent predictors were age (odds ratio [OR] = 1.08 per year), acute pain severity (OR = 1.02 per unit), presence of severe rash (OR = 2.31), and rash duration before consultation (OR = 0.78 per day): area under receiver‐operating‐characteristic curve [ROC area] = 0.77 (95% CI: 0.71–0.82). Of the five PCL scores, only factor V (‘trust in healthcare’) was an additional predictor (OR = 1.01 per unit), though it increased the ROC area with only 0.01 to 0.78. The Spielberger’s anxiety scores and serological and virological variables were no additional predictors. Thus, four simple variables can help physicians to timely identify elderly HZ‐patients at risk of PHN.

Effect of chronic nonmalignant pain on highway driving performance

Abstract Most pain patients are treated in an outpatient setting and are engaged in daily activities including driving. Since several studies showed that cognitive functioning may be impaired in chronic nonmalignant pain, the question arises whether or not chronic nonmalignant pain affects driving performance. Therefore, the objective of the present study was to determine the effects of chronic nonmalignant pain on actual highway driving performance during normal traffic. Fourteen patients with chronic nonmalignant pain and 14 healthy controls, matched on age, educational level, and driving experience, participated in the study. Participants performed a standardized on‐the‐road driving test during normal traffic, on a primary highway. The primary parameter of the driving test is the Standard Deviation of Lateral Position (SDLP). In addition, driving‐related skills (tracking, divided attention, and memory) were examined in the laboratory. Subjective assessments, such as pain intensity, and subjective driving quality, were rated on visual analogue scales. The results demonstrated that a subset of chronic nonmalignant pain patients had SDLPs that were higher than the matched healthy controls, indicating worse highway driving performance. Overall, there was a statistically significant difference in highway driving performance between the groups. Further, chronic nonmalignant pain patients rated their subjective driving quality to be normal, although their ratings were significantly lower than those of the healthy controls. No significant effects were found on the laboratory tests.