Klein, J.

Implications of the law on video recording in clinical practice (Article)

2012-10-01T00:00:00Z

Background: Technological developments allow for a variety of applications of video recording in health care, including endoscopic procedures. Although the value of video registration is recognized, medicolegal concerns regarding the privacy of patients and professionals are growing. A clear understanding of the legal framework is lacking. Therefore, this research aims to provide insight into the juridical position of patients and professionals regarding video recording in health care practice. Methods: Jurisprudence was searched to exemplify legislation on video recording in health care. In addition, legislation was translated for different applications of video in health care found in the literature. Results: Three principles in Western law are relevant for video recording in health care practice: (1) regulations on privacy regarding personal data, which apply to the gathering and processing of video data in health care settings; (2) the patient record, in which video data can be stored; and (3) professional secrecy, which protects the privacy of patients including video data. Practical implementation of these principles in video recording in health care does not exist. Conclusion: Practical regulations on video recording in health care for different specifically defined purposes are needed. Innovations in video capture technology that enable video data to be made anonymous automatically can contribute to protection for the privacy of all the people involved.

Reprinted Article "a combination of statins and beta-blockers is independently associated with a reduction in the incidence of perioperative mortality and nonfatal myocardial infarction in patients undergoing abdominal aortic aneurysm surgery" (Article)

2011-09-01T00:00:00Z

Objective: To investigate the combined beneficial effect of statin and beta-blocker use on perioperative mortality and myocardial infarction (MI) in patients undergoing abdominal aortic aneurysm surgery (AAA). Background: Patients undergoing elective AAA-surgery identified by clinical risk factors and dobutamine stress echocardiography (DSE) as being at high-risk often have considerable cardiac complication rate despite the use of beta-blockers. Methods: We studied 570 patients (mean age 69 ±9 years, 486 males) who underwent AAA-surgery between 1991 and 2001 at the Erasmus MC. Patients were evaluated for clinical risk factors (age>70 years, histories of MI, angina, diabetes mellitus, stroke, renal failure, heart failure and pulmonary disease), DSE, statin and beta-blocker use. The main outcome was a composite of perioperative mortality and MI within 30 days of surgery. Results: Perioperative mortality or MI occurred in 51 (8.9%) patients. The incidence of the composite endpoint was significantly lower in statin users compared to nonusers (3.7% vs. 11.0%; crude odds ratio (OR): 0.31, 95% confidence interval (CI): 0.13-0.74; p = 0.01). After correcting for other covariates, the association between statin use and reduced incidence of the composite endpoint remained unchanged (OR: 0.24,95% CI: 0.10-0.70; p = 0.01). Beta-blocker use was also associated with a significant reduction in the composite endpoint (OR: 0.24, 95% CI: 0.11-0.54). Patients using a combination of statins and beta-blockers appeared to be at lower risk for the composite endpoint across multiple cardiac risk strata; particularly patients with 3 or more risk factors experienced significantly lower perioperative events. Conclusions: A combination of statin and beta-blocker use in patients with AAA-surgery is associated with a reduced incidence of perioperative mortality and nonfatal MI particularly in patients at the highest risk.

Perioperative care of the older patient (Article)

2011-06-01T00:00:00Z

Nearly 60% of the Dutch population undergoing surgery is aged 65 years and over. Older patients are at increased risk of developing perioperative complications (e.g., myocardial infarction, pneumonia, or delirium), which may lead to a prolonged hospital stay or death. Preoperative risk stratification calculates a patient's risk by evaluating the presence and extent of frailty, pathophysiological risk factors, type of surgery, and the results of (additional) testing. Type of anesthesia, fluid management, and pain management affect outcome of surgery. Recent developments focus on multimodal perioperative care of the older patient, using minimally invasive surgery, postoperative anesthesiology rounds, and early geriatric consultation.

Exercise ankle brachial index adds important prognostic information on long-term out-come only in patients with a normal resting ankle brachial index (Article)

2011-06-01T00:00:00Z

Background: The clinical value of exercise ankle brachial index (ABI) is still unclear, especially in patients with normal resting ABI. Method: 2164 patients performed a single-stage treadmill exercise test to diagnose or evaluate PAD. The population was divided into two groups: a normal resting ABI (resting ABI ≥ 0.90) and PAD (resting ABI < 0.90). Patients with a normal resting ABI were divided into 4 exercise ABI groups: exercise ABI < 0.90, 0.90-0.99, 1.00-1.09 and 1.10-1.29 (reference). Results: Mean follow-up was 5. years. Exercise ABI added significant prognostic information on all cause long-term mortality only in patients with normal resting ABI (p-value 0.014, HR 0.99 95% CI (0.98-0.99)), not in patients with PAD. Fifty years or older (OR 2.93 95% CI (1.65-5.20)) and resting systolic blood pressure > 140. mmHg (OR 2.18 95% CI (1.35-3.55)) were associated with an abnormal exercise ABI in patients with a normal resting ABI. Mortality rate increased when the exercise ABI became worse (p trend 0.0001) with a 2.5-fold increase mortality risk in patients with a normal resting ABI but exercise ABI <0.90 (HR 2.56, 95% CI (1.11-5.91)). Conclusion: In patients with a normal resting ABI, treadmill exercise ABI added important prognostic information on long-term mortality. Based on our results we recommend that at least all patients suspected for PAD, with a resting ABI ≥ 0.90, who are 50. years or older and having hypertension should undergo treadmill exercise testing.

The association between psychological factors and the development of complex regional pain syndrome type 1 (CRPS1) - A prospective multicenter study (Article)

2011-04-04T00:00:00Z

The objective of this study was to investigate the association between psychological factors and complex regional pain syndrome type 1 (CRPS1). A prospective multicenter cohort study was performed involving the emergency room of three hospitals, and patients age 18 years or older, with a single fracture, were included in the study. At baseline (T0), participants completed a questionnaire covering demographic, psychological (Symptom Checklist-90), and medical variables. At plaster removal (T1) and at T2, the participants completed a questionnaire addressing symptoms of CRPS1. Psychological factors that were analysed were agoraphobia, depression, somatization, insufficiency, (interpersonal) sensitivity, insomnia, and life events. In total, 596 consecutive patients were included in the study, and 7.0% were diagnosed with CRPS1. None of the psychological factors predicted the development of CRPS1. The scores on the Symptom Checklist-90 subscales fell into the range of the general population and were, in most cases, average or below average when compared with those of pain patients or psychiatric patients. No empirical evidence supports a diagnosis of CRPS1 patients as psychologically different, and the current results indicate that there is no association between psychological factors and CRPS1.

Discrepant perceptions of communication, teamwork and situation awareness among surgical team members (Article)

2011-04-01T00:00:00Z

Objective: To assess surgical team members' differences in perception of non-technical skills. Design: Questionnaire design. Setting: Operating theatres (OTs) at one university hospital, three teaching hospitals and one general hospital in the Netherlands. Participants: Sixty-six surgeons, 97 OT nurses, 18 anaesthetists and 40 nurse anaesthetists. Methods: All surgical team members, of five hospitals, were asked to complete a questionnaire and state their opinion on the current state of communication, teamwork and situation awareness at the OT. Results: Ratings for 'communication' were significantly different, particularly between surgeons and all other team members (P ≤ 0.001). The ratings for 'teamwork' differed significantly between all team members (P ≤ 0.005). Within 'situation awareness' significant differences were mainly observed for 'gathering information' between surgeons and other team members (P<0.001). Finally, 72-90% of anaesthetists, OT nurses and nurse anaesthetists rated routine team briefings and debriefings as inadequate. Conclusions: This study shows discrepancies on many aspects in perception between surgeons and other surgical team members concerning communication, teamwork and situation awareness. Future research needs to ascertain whether these discrepancies are linked to greater risk of adverse events or to process as well as systems failures. Establishing this link would support implementation and use of complex team interventions that intervene at multiple levels of the healthcare system.

Tussen de modder van de praktijk en de schone wetenschap (Inaugural Lecture)

2010-11-26T00:00:00Z

Rede, uitgesproken bij de aanvaarding van het ambt van bijzonder hoogleraar ‘Veiligheid in de zorg’ aan het instituut Beleid & Management Gezondheidszorg van de Faculteit der Geneeskunde en Gezondheidswetenschappen, Erasmus Universiteit Rotterdam, vanwege de Vereniging Trustfonds EUR, op 26 november 2010. ‘Tussen de modder van de praktijk en de schone wetenschap’ gaat in op het grote contrast tussen de successen van bio - medisch onderzoek en het haperen van de uitvoering van zorg. Veiligheid in de zorg staat nu bijna een decennium hoog op de nationale en internationale agenda. Hoewel er vele initiatieven ontplooid zijn om de veiligheid te verhogen, is onduidelijk of de veiligheid van de patiënt beter is dan daarvoor. Klein schetst de enorme uitdaging waar de zorg voor staat. Om deze uitdaging tot een succes te brengen zal ook de uitvoering van zorg een wetenschap - pelijke basis moeten krijgen.

Outbreak of severe sepsis due to contaminated propofol: Lessons to learn (Article)

2010-11-01T00:00:00Z

Nosocomial infections are a frequent concern in healthcare. Despite the available knowledge on nosocomial infections and preventive measures, outbreaks of infections continue to occur. An outbreak of severe sepsis in patients who underwent minor procedures in an operating theatre during two consecutive days is described and analysed in this study. We performed a retrospective cohort study using epidemiological data in order to investigate the source of infection together with microbiological and on-site investigations and interviews. Seven patients met the case definition of postoperative systemic inflammatory response syndrome (SIRS). All other patients operated on over the same period served as controls. Of the risk factors investigated, general anaesthesia and propofol were statistically significant (P=0.003). Klebsiella pneumoniae and Serratia marcescens were cultured from opened vials of propofol, propofol-related devices and from blood cultures from two of the patients. These strains were genotypically indistinguishable. Lapses in aseptic preparation, handling and storage of the propofol were observed, and were the most probable cause of the extrinsic contamination. The daily procedure of handling propofol was not performed according to the manufacturer's recommendations, the main departure being the use of a single-use vial for multiple patients. This study documents the risk of infection due to contaminated propofol and the importance of having written guidelines for its handling.

A decline in walking distance predicts long-term outcome in patients with known or suspected peripheral artery disease (Article)

2010-06-01T00:00:00Z

AIM: To assess the predictive value of a decline in total walking distance and ankle brachial index (ABI) on all-cause mortality and cardiac death in patients with known or suspected peripheral artery disease. METHODS: Two hundred and sixty-one patients, who performed single-stage treadmill walking test twice to evaluate their peripheral artery disease, were enrolled in an observational study. Patients who underwent surgery during follow-up were excluded. Delta total walking distance and delta resting and exercise ABI consisted of the difference between the first and the second test. All three variables were categorized into two groups: stable/improvement or a decline. RESULTS: The mean follow-up period was 6 years. At both 5 years and total follow-up, a decline in total walking distance was independent and highly associated with an increased mortality risk and cardiac death [hazard ratio: 2.31 (95% confidence interval 1.35-3.96); hazard ratio: 3.55 (95% confidence interval: 1.53-8.21), respectively]. A decline in resting or exercise ABI after adjustment for delta walking distance was not significantly associated with all-cause mortality or cardiac death. CONCLUSION: A decline in total walking distance in single-stage treadmill exercise tests is a strong prognostic predictor of all-cause mortality and cardiac death in the short term and long term.

The Prognostic Value of Impaired Walking Distance on Long-term Outcome in Patients with Known or Suspected Peripheral Arterial Disease (Article)

2009-10-01T00:00:00Z

Objectives: To assess the predictive value of walking distance after an exercise test on long-term outcome in patients with normal and impaired ankle-brachial index (ABI). Design: A total of 2191 patients with known or suspected peripheral arterial disease (PAD), who were referred for a single-stage treadmill exercise test to diagnose or evaluate their PAD, were enrolled in an observational study between 1993 and 2006. Materials and methods: They were divided into two groups: normal ABI (≥0.90) and impaired ABI (<0.90). Walking distance was divided into quartiles (no (reference), mild, moderate or severe impairment). Results: In patients with normal ABI, severe walking distance was, after adjustment, associated with higher mortality risk (hazard ratio (HR): 2.60 (range: 1.16-5.78)). In patients with impaired ABI, all walking distance impairment quartiles were associated with higher mortality (mild HR: 1.26 (range: 0.95-1.67), moderate HR: 1.52 (range: 1.13-2.05) and severe HR: 1.69 (range: 1.26-2.27)). Furthermore, comparable associations were observed between all walking distance quartiles, cardiac death or major adverse cerebrovascular and cardiac events. Conclusions: Our study illustrated that walking impairment is a strong prognostic indicator of long-term outcome in patients with impaired and normal ABI, which should be a warning sign to physicians to monitor these patients carefully and to provide them optimal treatment.

Is there an association between psychological factors and the Complex Regional Pain Syndrome type 1 (CRPS1) in adults? A systematic review (Article)

2009-09-01T00:00:00Z

Complex Regional Pain Syndrome type 1 (CRPS1) is a complication after trauma or surgery. Its pathophysiology is still a matter of debate, and psychological factors have been suggested to play a role, although their influence is unclear. The aim of this study was to investigate the evidence for the influence of psychological factors on the onset and maintenance of CRPS1 in adults. In a systematic review, articles were selected using Cochrane, Pubmed/Medline, Psychinfo, and Cinahl since 1980. Only original articles and empirical studies were included. Based on these selection criteria, 31 articles were identified. Studies were evaluated and weighted using a quality assessment instrument. The few prospective studies do not report a relationship between CRPS1 and depression, anxiety, neuroticism, or anger. The results of the retrospective/cross-sectional studies yield contradictory results regarding psychological problems in patients with CRPS1. A majority show no association, and studies with a higher methodological quality lean to a conclusion of no relationship between psychological factors and CRPS1. The majority of included studies (N = 24; 77%) had only a poor to moderate methodological quality. Although many patients with CRPS1 are stigmatized as being psychologically different, this literature review identified no relationship between CRPS1 and several psychological factors. Only life events seemed to be associated with CRPS1: patients who experienced more life events appeared to have a greater chance of developing CRPS1. More studies with greater methodological quality and more participants should be performed on the association between psychological factors and the development and course of CRPS1.

Awake craniotomy induces fewer changes in the plasma amino acid profile than craniotomy under general anesthesia (Article)

2009-08-01T00:00:00Z

In this prospective, observational, 2-armed study, we compared the plasma amino acid profiles of patients undergoing awake craniotomy to those undergoing craniotomy under general anesthesia. Both experimental groups were also compared with a healthy, age-matched and sex-matched reference group not undergoing surgery. It is our intention to investigate whether plasma amino acid levels provide information about physical and emotional stress, as well as pain during awake craniotomy versus craniotomy under general anesthesia. Both experimental groups received preoperative, perioperative, and postoperative dexamethasone. The plasma levels of 20 amino acids were determined preoperative, perioperative, and postoperatively in all groups and were correlated with subjective markers for pain, stress, and anxiety. In both craniotomy groups, preoperative levels of tryptophan and valine were significantly decreased whereas glutamate, alanine, and arginine were significantly increased relative to the reference group. Throughout time, tryptophan levels were significantly lower in the general anesthesia group versus the awake craniotomy group. The general anesthesia group had a significantly higher phenylalanine/tyrosine ratio, which may suggest higher oxidative stress, than the awake group throughout time. Between experimental groups, a significant increase in large neutral amino acids was found postoperatively in awake craniotomy patients, pain was also less and recovery was faster. A significant difference in mean hospitalization time was also found, with awake craniotomy patients leaving after 4.53+/-2.12 days and general anesthesia patients after 6.17+/-1.62 days; P=0.012. This study demonstrates that awake craniotomy is likely to be physically and emotionally less stressful than general anesthesia and that amino acid profiling holds promise for monitoring postoperative pain and recovery.

Inflammatory profile of awake function-controlled craniotomy and craniotomy under general anesthesia (Article)

2009-07-27T00:00:00Z

Background. Surgical stress triggers an inflammatory response and releases mediators into human plasma such as interleukins (ILs). Awake craniotomy and craniotomy performed under general anesthesia may be associated with different levels of stress. Our aim was to investigate whether those procedures cause different inflammatory responses. Methods. Twenty patients undergoing craniotomy under general anesthesia and 20 patients undergoing awake function-controlled craniotomy were included in this prospective, observational, two-armed study. Circulating levels of IL-6, IL-8, and IL-10 were determined pre-, peri-, and postoperatively in both patient groups. VAS scores for pain, anxiety, and stress were taken at four moments pre- and postoperatively to evaluate physical pain and mental duress. Results. Plasma IL-6 level significantly increased with time similarly in both groups. No significant plasma IL-8 and IL-10 change was observed in both experimental groups. The VAS pain score was significantly lower in the awake group compared to the anesthesia group at 12 hours postoperative. Postoperative anxiety and stress declined similarly in both groups. Conclusion. This study suggests that awake function-controlled craniotomy does not cause a significantly different inflammatory response than craniotomy performed under general anesthesia. It is also likely that function-controlled craniotomy does not cause a greater emotional challenge than tumor resection under general anesthesia. Copyright

Elderly patients undergoing major vascular surgery: Risk factors and medication associated with risk reduction (Article)

2009-01-01T00:00:00Z

This study assesses risk factors in elderly vascular surgery patients and to evaluate whether perioperative cardiac medication can reduce postoperative mortality rate. In a cohort study, 1693 consecutive patients ≥65 years undergoing major non-cardiac vascular surgery were preoperatively screened for cardiac risk factors and medication. During follow-up (median: 8.2 years), mortality was noted. Hospital mortality occurred in 8.1% and long-term mortality in 28.5%. In multivariate analysis, age, coronary artery disease, heart failure, cerebrovascular disease, renal failure and diabetes were significantly associated with increased hospital and long-term mortality. Perioperative aspirin (OR: 0.53, 95% confidence interval: 0.34-0.83), β-blockers (OR: 0.32, 95% CI: 0.19-0.54) and statins (OR: 0.35, 95% CI: 0.18-0.68) were significantly associated with reduced hospital mortality. In addition, aspirin (HR: 0.65, 95% CI: 0.53-0.81), angiotensin-converting enzyme (ACE)-inhibitors (HR: 0.74, 95% CI: 0.59-0.92), β-blockers (HR: 0.61, 95% CI: 0.48-0.76) and statins (HR: 0.65, 95% CI: 0.49-0.87) were significantly associated with reduced long-term mortality. Heterogeneity tests revealed a gradient decrease of mortality risk in patients from low to high age using statins (p = 0.03). In conclusion, age is an independent predictor of hospital and long-term mortality in elderly patients undergoing major vascular surgery. Aspirin, ACE-inhibitors, β-blockers and statins reduce long-term mortality risk. Especially the very elderly may benefit from statin therapy.

Intraoperative awareness during paediatric anaesthesia (Article)

2009-01-01T00:00:00Z

Background. Previous studies indicate a higher incidence of awareness during anaesthesia in children than in adults, that is, around 1% vs 0.2%. In this prospective cohort study, we determined the incidence of intraoperative awareness in children undergoing elective or emergency surgery at a university children's hospital. Methods. Data from 928 consecutive paediatric patients, aged 5-18 yr, were collected prospectively over a 12 month period. Interviews using a structured questionnaire were scheduled at three time points: within 24 h after the operation, and 3-7 and 30 days after operation. Reports of suspected awareness were sent to four independent adjudicators. If they all agreed, the case was classified as a true awareness case. Results. The interviews generated 26 cases of suspected awareness. Six cases were judged to be true awareness, equalling a 0.6% incidence (95% confidence interval 0.03-1.40%). Auditory and sensory perceptions were the sensations most reported by these six children. Pain, anxiety, and paralysis were less often mentioned. The children in general did not report awareness as stressful. Conclusions. The incidence of awareness in this study, in children undergoing general anaesthesia, is comparable with recent reports from other countries, and appears to be higher than that reported in adults.

Prognostic value of hypotensive blood pressure response during single-stage exercise test on long-term outcome in patients with known or suspected peripheral arterial disease (Article)

2008-12-01T00:00:00Z

Objective: A decline in systolic blood pressure during exercise is thought to be a sign of severe coronary artery disease. However, no studies have yet examined this effect in patients with known or suspected peripheral arterial disease. Therefore, we investigated the prognostic value of hypotensive blood pressure response after single-stage exercise test on long-term mortality, major adverse cerebrovascular and cardiac events (MACCE) and the effects of statin, β-blocker and aspirin use in patients with known or suspected peripheral arterial disease. Methods: A total of 2022 patients were enroled in an observational study with a mean follow-up of 5 years. Hypotensive blood pressure response, 4.6% of the total population, was defined as a drop in exercise systolic blood pressure below resting systolic blood pressure. Results: Our study showed that hypotensive blood pressure response was associated with an increased risk of all-cause mortality [hazard ratio (HR): 1.74, 95% confidence interval (CI): 1.10-2.73] and MACCE (HR: 1.85, 95% CI: 1.14-3.00), independent of other clinical variables. Additionally, after adjustments for clinical risk factors and propensity score, baseline statin use was associated with a reduced risk of all-cause mortality (HR: 0.60, 95% CI: 0.44-0.80). Besides, statin and aspirin use were both also associated with a reduced risk of MACCE (HR: 0.65, 95% CI: 0.47-0.89 and HR: 0.69, 95% CI: 0.53-0.88, respectively). Conclusion: Hypotensive blood pressure response after single-stage treadmill exercise tests in patients with known or suspected peripheral arterial disease was associated with a higher risk for all-cause long-term mortality and MACCE, which might be reduced by statin and aspirin use.

A simulation model for determining the optimal size of emergency teams on call in the operating room at night. (Article)

2008-11-01T00:00:00Z

BACKGROUND: Hospitals that perform emergency surgery during the night (e.g., from 11:00 pm to 7:30 am) face decisions on optimal operating room (OR) staffing. Emergency patients need to be operated on within a predefined safety window to decrease morbidity and improve their chances of full recovery. We developed a process to determine the optimal OR team composition during the night, such that staffing costs are minimized, while providing adequate resources to start surgery within the safety interval. METHODS: A discrete event simulation in combination with modeling of safety intervals was applied. Emergency surgery was allowed to be postponed safely. The model was tested using data from the main OR of Erasmus University Medical Center (Erasmus MC). Two outcome measures were calculated: violation of safety intervals and frequency with which OR and anesthesia nurses were called in from home. We used the following input data from Erasmus MC to estimate distributions of all relevant parameters in our model: arrival times of emergency patients, durations of surgical cases, length of stay in the postanesthesia care unit, and transportation times. In addition, surgeons and OR staff of Erasmus MC specified safety intervals. RESULTS: Reducing in-house team members from 9 to 5 increased the fraction of patients treated too late by 2.5% as compared to the baseline scenario. Substantially more OR and anesthesia nurses were called in from home when needed. CONCLUSION: The use of safety intervals benefits OR management during nights. Modeling of safety intervals substantially influences the number of emergency patients treated on time. Our case study showed that by modeling safety intervals and applying computer simulation, an OR can reduce its staff on call without jeopardizing patient safety.

A comparison in adolescents of composite auditory evoked potential index and bispectral index during propofol-remifentanil anesthesia for scoliosis surgery with intraoperative wake-up test (Article)

2008-11-01T00:00:00Z

BACKGROUND: The electroencephalogram-derived Bispectral Index (BIS), and the composite A-line ARX index (cAAI), derived from the electroencephalogram and auditory evoked potentials, have been promoted as anesthesia depth monitors. Using an intraoperative wake-up test, we compared the performance of both indices in distinguishing different hypnotic states, as evaluated by the University of Michigan Sedation Scale, in children and adolescents during propofol-remifentanil anesthesia for scoliosis surgery. Postoperative explicit recall was also evaluated. METHODS: Twenty patients (aged 10-20 yr) were enrolled. Prediction probabilities were calculated for induction, wake-up test, and emergence. BIS and cAAI were compared at the start of the wake-up test, at purposeful movement to command, and after the patient was reanesthetized. During the wake-up test, patients were instructed to remember a color, and were then interviewed for explicit recall. RESULTS: Prediction probabilities of BIS and cAAI for induction were 0.82 and 0.63 (P < 0.001), for the wake-up test, 0.78 and 0.79 (P < 0.001), and 0.74 and 0.78 for emergence (P < 0.001). During the wake-up test, a significant increase in mean BIS and cAAI (P < 0.05) was demonstrated at purposeful movement, followed by a significant decline after reintroduction of anesthesia. CONCLUSIONS: During induction, BIS performed better than cAAI. Although cAAI was statistically a better discriminator for the level of consciousness during the wake-up test and emergence, these differences do not appear to be clinically meaningful. Both indices increased during the wake-up test, indicating a higher level of consciousness. No explicit recall was demonstrated.

The obesity paradox in patients with peripheral arterial disease (Article)

2008-11-01T00:00:00Z

Background: Cardiac events are the predominant cause of late mortality in patients with peripheral arterial disease (PAD). In these patients, mortality decreases with increasing body mass index (BMI). COPD is identified as a cardiac risk factor, which preferentially affects underweight individuals. Whether or not COPD explains the obesity paradox in PAD patients is unknown. Methods: We studied 2,392 patients who underwent major vascular surgery at one teaching institution. Patients were classified according to COPD status and BMIs (ie, underweight, normal, overweight, and obese), and the relationship between these variables and all-cause mortality was determined using a Cox regression analysis. The median follow-up period was 4.37 years (interquartile range, 1.98 to 8.47 years). Results: The overall mortality rates among underweight, normal, overweight, and obese patients were 54%, 50%, 40%, and 31%, respectively (p < 0.001). The distribution of COPD severity classes showed an increased prevalence of moderate-to-severe COPD in underweight patients. In the entire population, BMI (continuous) was associated with increased mortality (hazard ratio [HR], 0.96; 95% confidence interval [CI], 0.94 to 0.98). In addition, patients who were classified as being underweight were at increased risk for mortality (HR, 1.42; 95% CI, 1.00 to 2.01). However, after adjusting for COPD severity the relationship was no longer significant (HR, 1.29; 95% CI, 0.91 to 1.93). Conclusions: The excess mortality among underweight patients was largely explained by the overrepresentation of individuals with moderate-to-severe COPD. COPD may in part explain the "obesity paradox" in the PAD population. Copyright

Usefulness of Hypertensive Blood Pressure Response During a Single-Stage Exercise Test to Predict Long-Term Outcome in Patients With Peripheral Arterial Disease (Article)

2008-10-01T00:00:00Z

The prognostic value of a hypertensive blood pressure (BP) response is still unclear. Therefore, the prognostic value of a hypertensive BP response in patients during single-stage exercise testing for peripheral arterial disease (PAD) on long-term mortality and major adverse cerebrovascular and cardiac events (MACCEs) was investigated. In addition, effects of statin, β-blocker, and aspirin use in patients with known or suspected PAD were studied. A total of 2,109 patients were enrolled in an observational prospective study from 1993 to 2005. Hypertensive BP response was defined as an increase in systolic BP ≥55 mm Hg (95thpercentile within our population) after a single-stage treadmill exercise test. The outcome was obtained by using the civil registries, and a questionnaire about cardiac events was sent to all survivals. Hypertensive BP response was associated with increased risk of long-term mortality (hazard ratio [HR] 1.42, 95% confidence interval [CI] 1.12 to 1.80) and MACCEs (HR 1.47, 95% CI 1.09 to 1.97). After adjustments for clinical risk factors and propensity score, baseline statin use was associated with reduced risk of long-term mortality (HR 0.59, 95% CI 0.44 to 0.79), and statin, β-blocker, and aspirin use were associated with reduced risk of MACCEs (HR 0.59, 95% CI 0.43 to 0.81; HR 0.75, 95% CI 0.60 to 0.95; HR 0.73, 95% CI, 0.57 to 0.92, respectively). In conclusion, hypertensive BP response at exercise in patients with known or suspected PAD is an important independent risk factor for all-cause long-term mortality and MACCEs, whereas statin, β-blocker, and aspirin use were associated with an improved outcome.

Comparison of bispectral index and composite auditory evoked potential index for monitoring depth of hypnosis in children (Article)

2008-05-01T00:00:00Z

BACKGROUND: In pediatric patients, the Bispectral Index (BIS), derived from the electroencephalogram, and the composite A-Line autoregressive index (cAAI), derived from auditory evoked potentials and the electroencephalogram, have been used as measurements of depth of hypnosis during anesthesia. The performance and reliability of BIS and cAAI in distinguishing different hypnotic states in children, as evaluated with the University of Michigan Sedation Scale, were compared. METHODS: Thirty-nine children (aged 2-16 yr) scheduled to undergo elective inguinal hernia surgery were studied. For all patients, standardized anesthesia was used. Prediction probabilities of BIS and cAAI versus the University of Michigan Sedation Scale and sensitivity/specificity were calculated. RESULTS: Prediction probabilities for BIS and cAAI during induction were 0.84 for both and during emergence were 0.75 and 0.74, respectively. At loss of consciousness, the median BIS remained unaltered (94 to 90; not significant), whereas cAAI values decreased (60 to 43; P < 0.001). During emergence, median BIS and cAAI increased from 51 to 74 (P < 0.003) and from 46 to 58 (P < 0.001), respectively. With respect to indicate consciousness or unconsciousness, 100% sensitivity was reached at cutoff values of 17 for BIS and 12 for cAAI. One hundred percent specificity was associated with a BIS of 71 and a cAAI of 60. To ascertain consciousness, BIS values greater than 78 and cAAI values above 52 were required. CONCLUSIONS: BIS and cAAI were comparable indicators of depth of hypnosis in children. Both indices, however, showed considerable overlap for different clinical conditions.

Carotid artery stenting versus endarterectomy in relation to perioperative myocardial ischemia, troponin T release and major cardiac events (Article)

2007-09-01T00:00:00Z

BACKGROUND: Carotid artery stenting (CAS) is less invasive than endarterectomy. This study examined differences in perioperative myocardial ischemia, troponin T release and clinical cardiac events in patients undergoing CAS compared with endarterectomy. METHODS: In an observational study, CAS was performed in 24 and carotid endarterectomy in 44 patients. Before surgery, clinical risk factors were noted and dobutamine stress echocardiography was performed for cardiac risk assessment. Perioperative continuous 72-h 12-lead electrocardiographic monitoring was used for myocardial ischemia detection. Troponin T (>0.03 ng/ml) was measured on postoperative days 1, 3, 7 or before discharge. Cardiac events (cardiac death or Q-wave myocardial infarction) were noted during hospital stay and during follow-up (mean: 1.2 years). RESULTS: No significant differences were observed between patients with CAS and endarterectomy in terms of baseline clinical characteristics, dobutamine stress echocardiography results and cardiovascular medication. Perioperative myocardial ischemia was detected in nine patients (13%), perioperative troponin T release in seven patients (10%), early cardiac events in one patient (1%) and late cardiac events in three patients (4%). Significantly less perioperative myocardial ischemia was observed in patients with CAS compared with endarterectomy (0 versus 21%, P=0.02). Troponin T release was also significantly lower in CAS, compared with endarterectomy (0 versus 16%, P=0.04). Early (0 versus 2%, P=0.5) and late (0 versus 7%, P=0.2) cardiac events were lower after CAS, compared with endarterectomy, although these differences were not significant. CONCLUSION: CAS is associated with a lower incidence of perioperative myocardial ischemia and troponin T release, compared with endarterectomy.

A norm utilisation for scarce hospital resources: Evidence from operating rooms in a Dutch university hospital (Article)

2007-08-01T00:00:00Z

Background: Utilisation of operating rooms is high on the agenda of hospital managers and researchers. Many efforts in the area of maximising the utilisation have been focussed on finding the holy grail of 100% utilisation. The utilisation that can be realised, however, depends on the patient mix and the willingness to accept the risk of working in overtime. Materials and methods: This is a mathematical modelling study that investigates the association between the utilisation and the patient mix that is served and the risk of working in overtime. Prospectively, consecutively, and routinely collected data of an operating room department in a Dutch university hospital are used. Basic statistical principles are used to establish the relation between realistic utilisation rates, patient mixes, and accepted risk of overtime. Results: Accepting a low risk of overtime combined with a complex patient mix results a low utilisation rate. If the accepted risk of overtime is higher and the patient mix is less complex, the utilisation rate that can be reached is closer to 100%. Conclusion: Because of the inherent variability of health-care processes, the holy grail of 100% utilisation is unlikely to be found. The method proposed in this paper calculates a realistic benchmark utilisation that incorporates the patient mix characteristics and the willingness to accept risk of overtime.

Relation of Body Mass Index to Outcome in Patients With Known or Suspected Coronary Artery Disease (Article)

2007-06-01T00:00:00Z

Increased body mass index (BMI), a parameter of total body fat content, is associated with an increased mortality in the general population. However, recent studies have shown a paradoxic relation between BMI and mortality in specific patient populations. This study investigated the association of BMI with long-term mortality in patients with known or suspected coronary artery disease. In a retrospective cohort study of 5,950 patients (mean age 61 ± 13 years; 67% men), BMI, cardiovascular risk markers (age, gender, hypertension, diabetes, current smoking, angina pectoris, old myocardial infarction, heart failure, hypercholesterolemia, and previous coronary revascularization), and outcome were noted. The patient population was categorized as underweight, normal, overweight, and obese based on BMI according to the World Health Organization classification. Mean follow-up time was 6 ± 2.6 years. Incidences of long-term mortality in underweight, normal, overweight, and obese were 39%, 35%, 24%, and 20%, respectively. In a multivariate analysis model, the hazard ratio (HR) for mortality in underweight patients was 2.4 (95% confidence interval [CI] 1.7 to 3.7). Overweight and obese patients had a significantly lower mortality than patients with a normal BMI (HR 0.65, 95% CI 0.6 to 0.7, for overweight; HR 0.61, 95% CI 0.5 to 0.7, for obese patients). In conclusion, BMI is inversely related to long-term mortality in patients with known or suspected coronary artery disease. A lower BMI was an independent predictor of long-term mortality, whereas an improved outcome was observed in overweight and obese patients.

Reversal of rocuronium-induced (1.2 mg kg-1) profound neuromuscular block by accidental high dose of sugammadex (40 mg kg-1) (Article)

2007-05-01T00:00:00Z

Sugammadex is the first selective relaxant binding agent and reverses rocuronium-induced neuromuscular block. A case is reported in which a patient accidentally received a high dose of sugammadex (40 mg kg-1) to reverse a rocuronium-induced (1.2 mg kg-1) profound neuromuscular block. A fast and efficient recovery from profound neuromuscular block was achieved and no adverse events or other safety concerns were reported.

Multicenter randomized comparison of xenon and isoflurane on left ventricular function in patients undergoing elective surgery (Article)

2007-03-01T00:00:00Z

BACKGROUND: Volatile anesthetics are commonly used for general anesthesia. However, these can induce profound cardiovascular alterations. Xenon is a noble gas with potent anesthetic and analgesic properties. However, it is uncertain whether xenon alters myocardial function. The aim of this study was therefore to investigate left ventricular function during anesthesia with xenon compared with isoflurane. METHODS: The authors performed a randomized multicenter trial to compare xenon with isoflurane with respect to cardiovascular stability and adverse effects in patients without cardiac diseases scheduled for elective surgery. Two hundred fifty-nine patients were enrolled in this trial, of which 252 completed the study according to the protocol. Patients were anesthetized with xenon or isoflurane, respectively. Before administration of the study drugs and at four time points, the effects of both anesthetics on left ventricular function were investigated using transesophageal echocardiography. RESULTS: Global hemodynamic parameters were significantly altered using isoflurane (P < 0.05 vs. baseline), whereas xenon only decreased heart rate (P < 0.05 vs. baseline). In contrast to xenon, left ventricular end-systolic wall stress decreased significantly in the isoflurane group (P < 0.05 vs. baseline). Velocity of circumferential fiber shortening was decreased significantly in the xenon group but showed a more pronounced reduction during isoflurane administration (P < 0.05 vs. baseline). The contractile index (difference between expected and actually measured velocity of circumferential fiber shortening) as an independent parameter for left ventricular function was significantly decreased after isoflurane (P < 0.0001) but unchanged using xenon. CONCLUSIONS: Xenon did not reduce contractility, whereas isoflurane decreased the contractile index, indicating that xenon enables favorable cardiovascular stability in patients without cardiac diseases.

A randomized prospective study comparing the cobra perilaryngeal airway and laryngeal mask airway-classic during controlled ventilation for gynecological laparoscopy (Article)

2007-01-01T00:00:00Z

BACKGROUND: An increasing number of noninvasive, supraglottic airway devices are currently available. In this randomized single-blind study, we compared the Cobra Perilaryngeal Airway (CobraPLA) to the [Laryngeal Mask Airway (LMA)-Classic] during gynecological laparoscopy. METHODS: Forty patients received either an LMA-Classic or a CobraPLA. Insertion, ventilation and removal characteristics were noted, as well as any throat morbidity. RESULTS: Devices were similar for insertion characteristics, adverse events, and throat morbidity. Before pneumoperitoneum, peak airway pressures were 20.3 ± 4.9 cm H2O in the LMA-Classic group versus 25.5 ± 7.9 cm H2O in the CobraPLA group, P = 0.01. This difference was maintained during pneumoperitoneum; LMA-Classic (22.8 ± 6.1 cm H2O) and CobraPLA (28.1 ± 8.5 cm H2O), P = 0.04. Macroscopic blood occurred only on the CobraPLA, seen on 40% of the devices after removal, P = 0.001. CONCLUSION: During gynecological laparoscopy, the CobraPLA provides similar insertion characteristics, but higher airway sealing pressures than the LMA-Classic. The usefulness of this finding requires further investigation.

Increased preoperative glucose levels are associated with perioperative mortality in patients undergoing noncardiac, nonvascular surgery (Article)

2007-01-01T00:00:00Z

Objective: To determine the relationship between preoperative glucose levels and perioperative mortality in noncardiac, nonvascular surgery. Research design and methods: We performed a case-control study in a cohort of 108 593 patients who underwent noncardiac surgery at the Erasmus MC during 1991-2001. Cases were 989 patients who underwent elective noncardiac, nonvascular surgery and died within 30 days during hospital stay. From the remaining patients, 1879 matched controls (age, sex, calendar year, and type of surgery) were selected. Information was obtained regarding the presence of cardiac risk factors, medication, and preoperative laboratory results. Preoperative random glucose levels < 5.6 mmol/l (110 mg/dl) were normal. Impaired glucose levels in the range of 5.6-11.1 mmol/l were prediabetes. Glucose levels ≥ 11.1 mmol/l (200 mg/dl) were diabetes. Results: Preoperative glucose levels were available in 904 cases and 1247 controls. A cardiovascular complication was the primary cause of death in 207 (23%) cases. Prediabetes glucose levels were associated with a 1.7-fold increased mortality risk compared with normoglycernic levels (adjusted odds ratio (OR) 1.7 and 95% confidence interval (CI) 1.4-2.1; P<0.001). Diabetes glucose levels were associated with a 2.1-fold increased risk (adjusted OR 2.1 and 95% CI 1.3-3.5; P<0.001). In cases with cardiovascular death, prediabetes glucose levels had a threefold increased cardiovascular mortality risk (adjusted OR 3.0 and 95% CI 1.7-5.1) and diabetes glucose levels had a fourfold increased cardiovascular mortality risk (OR 4.0 and 95% CI 1.3-12). Conclusions: Preoperative hyperglycemia is associated with increased (cardiovascular) mortality in patients undergoing noncardiac, nonvascular surgery.

The open lung concept: effects on right ventricular afterload after cardiac surgery. (Article)

2004-09-01T00:00:00Z

BACKGROUND: The open lung concept (OLC) is a method of ventilation intended to maintain end-expiratory lung volume by increased airway pressure. Since this could increase right ventricular afterload, we studied the effect of this method on right ventricular afterload in patients after cardiac surgery. METHODS: We studied 24 stable patients after coronary artery surgery and/or valve surgery with cardiopulmonary bypass. Patients were randomly assigned to OLC or conventional mechanical ventilation (CMV). In the OLC group, recruitment manoeuvres were applied until Pa(o(2))/FI(O(2)) was greater than 50 kPa (reflecting an open lung). This value was maintained by sufficient positive airway pressure. In the CMV group, volume-controlled ventilation was used with a PEEP of 5 cm H(2)O. Cardiac index, right ventricular preload, contractility and afterload were measured with a pulmonary artery thermodilution catheter during the 3-h observation period. Blood gases were monitored continuously. RESULTS: To achieve Pa(O(2))/Fl(O(2)) > 50 kPa, 5.3 (3) (mean, SD) recruitment attempts were performed with a peak pressure of 45.5 (2) cm H(2)O. To keep the lung open, PEEP of 17.0 (3) cm H(2)O was required. Compared with baseline, pulmonary vascular resistance and right ventricular ejection fraction did not change significantly during the observation period in either group. CONCLUSION: No evidence was found that ventilation according to the OLC affects right ventricular afterload.

Statins are associated with a reduced incidence of perioperative mortality in patients undergoing major noncardiac vascular surgery. (Article)

2003-04-15T00:00:00Z

BACKGROUND: Patients undergoing major vascular surgery are at increased risk of perioperative mortality due to underlying coronary artery disease. Inhibitors of the 3-hydroxy-3-methylglutaryl coenzyme A (statins) may reduce perioperative mortality through the improvement of lipid profile, but also through the stabilization of coronary plaques on the vascular wall. METHODS AND RESULTS: To evaluate the association between statin use and perioperative mortality, we performed a case-controlled study among the 2816 patients who underwent major vascular surgery from 1991 to 2000 at the Erasmus Medical Center. Case subjects were all 160 (5.8%) patients who died during the hospital stay after surgery. From the remaining patients, 2 controls were selected for each case and were stratified according to calendar year and type of surgery. For cases and controls, information was obtained regarding statin use before surgery, the presence of cardiac risk factors, and the use of other cardiovascular medication. A vascular complication during the perioperative phase was the primary cause of death in 104 (65%) case subjects. Statin therapy was significantly less common in cases than in controls (8% versus 25%; P<0.001). The adjusted odds ratio for perioperative mortality among statin users as compared with nonusers was 0.22 (95% confidence interval 0.10 to 0.47). Similar results were obtained in subgroups of patients according to the use of cardiovascular therapy and the presence of cardiac risk factors. CONCLUSIONS: This case-controlled study provides evidence that statin use reduces perioperative mortality in patients undergoing major vascular surgery.

Een vitale kwestie: elke patient z'n lijfwacht (Inaugural Lecture)

2003-01-17T00:00:00Z

Auditory information processing during adequate propofol anesthesia monitored by electroencephalogram bispectral index (Article)

2001-01-01T00:00:00Z

Memory for intraoperative events may arise from inadequate anesthesia when the hypnotic state is not continuously monitored. Electroencephalogram bispectral index (BIS) enables monitoring of the hypnotic state and titration of anesthesia to an adequate level (BIS 40 to 60). At this level, preserved memory function has been observed in trauma patients. We investigated memory formation in elective surgical outpatients during target-controlled propofol anesthesia supplemented with alfentanil. While BIS remained between 40 and 60, patients listened to a tape with either familiar instances (exemplars) from two categories (Experimental [E] group, n = 41) or bird sounds (Control [C] group, n = 41). After recovery, memory was tested directly and indirectly. BIS during audio presentation was on average (+/- SD) 44 +/- 5 and 46 +/- 5 for Groups E and C, respectively. No patient consciously recalled the intraoperative period, nor were presented words recognized reliably (Group E, 0.9 +/- 0.8 hits; Group C, 0.8 +/- 0.8 hits) (P = 0.7). When asked to generate category exemplars, Group E named 2.10 +/- 1.0 hits versus 1.98 +/- 1.0 in Group C (P = 0.9). We found no explicit or implicit memory effect of familiar words presented during adequate propofol anesthesia at BIS levels between 40 and 60 in elective surgical patients. IMPLICATIONS: This study suggests that stable levels of adequate hypnosis may prevent information processing and memory formation during general anesthesia and supports the feasibility of electroencephalogram bispectral index as a monitor of adequate anesthesia.