Objectives: This study identified characteristics of patients with moderate internal carotid arte... more Objectives: This study identified characteristics of patients with moderate internal carotid artery stenosis that are at increased risk for disease progression. Methods: Patients with asymptomatic moderate internal carotid disease (peak systolic velocity [PSV] Ͼ125cm/ sec and end diastolic velocity [EDV] Ͻ125cm/sec by duplex ultrasonography) correlating to 50-75% diameter reduction were followed for 3 years. Progression to greater than 75% diameter reduction (EDV Ͼ 125cm/sec) or presentation with focal neurological symptoms (stroke, amaurosis fugax, transient ischemic attack [TIA]) was documented. Co-morbidities, smoking status and medications were recorded. Log-rank testing, Wilcoxson models, and Kaplan-Meier plots provided statistical analysis. Results: During 3 year follow up, 26 (9%) of 288 patients (137 men, 151 women) developed symptoms [stroke: 9 (3.1%), TIA: 3 (1%), amaurosis fugax: 3 (1%)] or asymptomatic increase in diameter to Ͼ75% [11 (3.8%)]. All-cause mortality was 11% (33 patients). 17 patients (5.9%) underwent carotid endarterectomy and 5 (1.7%) had carotid stent placement. The event incidence was significantly higher for men (Pϭ.02), but survival was not different. The rate of disease progression and/or development of symptoms was 5.5% at 12 months and increased to 7.2% by 24 months. Co-morbidities with the highest associated event incidences were coronary artery disease [CAD] (8.1%), hyperlipidemia (7.3%), and hypertension [HTN] (6.7%). Medications associated with lower event incidences were insulin (2.8%) and angiotensin receptor blockers (1.9%). Conclusions: 9% of patients with asymptomatic moderate carotid stenosis progressed to severe stenosis or developed ipsilateral neurological symptoms at three year follow-up. The rate of asymptomatic disease progression or symptom development was to 7.2% by 24 months. Male patients with CAD, hyperlipidemia, and HTN are at increased risk and are candidates for frequent screening and/or early intervention.
European Journal of Vascular and Endovascular Surgery, 2012
WHAT THIS PAPER ADDS Cerebral hyperperfusion syndrome (CHS) after carotid endarterectomy (CEA) is... more WHAT THIS PAPER ADDS Cerebral hyperperfusion syndrome (CHS) after carotid endarterectomy (CEA) is potentially life threatening and therefore identification of patients at risk is essential. Intra-operative transcranial Doppler (TCD) monitoring is associated with both false positive and false negative results. In the present study we assessed the predictive values of an additional TCD measurement in the early postoperative phase. We found that postoperative TCD significantly increased both the positive and negative predictive values. Our adjusted monitoring strategy using perioperative TCD may contribute to the further reduction of adverse events after carotid revascularisation.
† Compared to propofol, isoflurane does not reduce myocardial injury in a trial of CABG patients.... more † Compared to propofol, isoflurane does not reduce myocardial injury in a trial of CABG patients. † No differences in shortand long-term morbidity and mortality were observed. † Cardioprotective properties of volatile anaesthetics seem to be dependent on the context of application. † Clinical relevance is questionable since significant volatile cardioprotection is only detected in very homogenous groups. Background. In experimental and clinical studies, volatile anaesthesia has proven to possess cardioprotective properties. However, no randomized controlled trials on the use of isoflurane during the entire cardiac surgical procedure are available. We therefore compared isofluranesufentanil vs propofol-sufentanil anaesthesia in patients undergoing coronary artery bypass grafting. Methods. One hundred patients were randomly assigned to receive isoflurane-sufentanil (I) (n ¼ 51) or propofol-sufentanil (P) (n ¼ 49) anaesthesia, aimed at the same hypnotic depth. Postoperative concentrations of cardiac troponin I (cTnI) were followed for 72 h. Secondary outcome variables were length of stay (LOS) in the intensive care unit (ICU) and in hospital, and 30 day and 1 yr mortality and morbidity, defined as acute myocardial infarction, arrhythmias, and cardiac dysfunction. Groups were compared by an on-treatment analysis, using linear mixed models for repeated measures. Results. Eighty-four patients completed the protocol (I: 41 vs P: 43). Postoperative cTnI concentrations increased to a maximum of I: 2.72 ng ml 21 (1.78-5.85) and P: 2.64 ng ml 21 (1.67-4.83), but did not differ between groups (P¼0.11). LOS in the ICU and in hospital was similar [ICU
Resolving the blind spot of transoesophageal echocardiography: a new diagnostic device for visual... more Resolving the blind spot of transoesophageal echocardiography: a new diagnostic device for visualizing the ascending aorta in
Assessment of stroke volume index with three different bioimpedance algorithms: lack of agreement... more Assessment of stroke volume index with three different bioimpedance algorithms: lack of agreement compared to thermodilution
Division of Perioperative Care and Emergency Medicine, University Medical Center Utrecht, Utrecht... more Division of Perioperative Care and Emergency Medicine, University Medical Center Utrecht, Utrecht, The Netherlands Background: Atherosclerosis of the ascending aorta (AA) and emboli-related complications after cardiac surgery are related. Knowledge on presence of AA-atherosclerosis before sternotomy allows changes in surgical strategy that avoid manipulation of the AA. The “Gold”-standard for assessment of AAatherosclerosis is epiaortic ultrasound scanning (EUS), but this can only be performed after sternotomy. Transesophageal echocardiography (TEE) is unable to detect atherosclerosis in distal AA due to the “blind” spot. A new method (A-View® method, an extension of TEE) enables assessment, preoperatively, of AA-atherosclerosis using a intra-tracheal fluid-filled balloon catheter. The aim of this diagnostic study was to evaluate if the A-View® method enables visualization of distal AA and safety of the diagnostic. Methods: In a cross-sectional diagnostic trial; patients undergoing ...
Background: Although several patient characteristic, clinical, and psychological risk factors for... more Background: Although several patient characteristic, clinical, and psychological risk factors for chronic postsurgical pain (CPSP) have been identified, genetic variants including single nucleotide polymorphisms have also become of interest as potential risk factors for the development of CPSP. The aim of this review is to summarize the current evidence on genetic polymorphisms associated with the prevalence and severity of CPSP in adult patients. Methods: A systematic review of the literature was performed, and additional literature was obtained by reference tracking. The primary outcome was CPSP, defined as pain at least 2 months after the surgery. Studies performed exclusively in animals were excluded. Results: Out of the 1001 identified studies, 14 studies were selected for inclusion. These studies described 5269 participants in 17 cohorts. A meta-analysis was not possible because of heterogeneity of data and data analysis. Associations with the prevalence or severity of CPSP were reported for genetic variants in the COMT gene, OPRM1, potassium channel genes, GCH1, CACNG, CHRNA6, P2X7R, cytokine-associated genes, human leucocyte antigens, DRD2, and ATXN1. Conclusions: Research on the topic of genetic variants associated with CPSP is still in its initial phase. Hypothesis-free, genome-wide association studies on large cohorts are needed in this field. In addition, future studies may also integrate genetic risk factors and patient characteristic, clinical, and psychological predictors for CPSP.
Background: Preoperative cardiorespiratory fitness, as measured by cardiopulmonary testing or est... more Background: Preoperative cardiorespiratory fitness, as measured by cardiopulmonary testing or estimated using the less sophisticated incremental shuttle walk test, timed up-and-go test or stair climb test is known to be associated with postoperative outcome. This study aimed to evaluate whether parameters of physical fitness are associated with postoperative outcome in patients with colorectal cancer scheduled for elective resection. Patients and Methods: Perioperative data of patients who underwent colorectal resection at Maastricht University Medical Center were retrospectively analyzed. Preoperative variables (e.g., age, body mass index, comorbidities, physical fitness, tumour characteristics, neoadjuvant treatment, American Society of Anesthesiologists score, level of perceived fatigue and nutritional status) were compared with postoperative outcomes. Results: Out of 80 consecutive cases, 75 (93.8%) were available for analysis (57.3% male, median AE interquartile range age 69.2 AE 11.7 years). A higher Charlson comorbidity index (odds ratio (OR) of 1.604, 95% confidence interval (CI) 1.120e2.296), worse functional exercise capacity (in meters, OR of 0.995, 95% CI 0.991e1.000), a lower physical activity level (in min/day, OR of 0.994, 95% CI 0.988e1.000), and a higher level of perceived fatigue (OR of 1.047, 95% CI 1.016e1.078), were associated with a slower time to recovery of physical functioning. A better functional exercise capacity was associated with a lower OR (OR of 0.995, 95% CI 0.991e1.000) for nonsurgical complications. Conclusion: There is an association between preoperative parameters and postoperative outcomes in patients with colorectal cancer scheduled for resection. Patients benefit from an optimal preoperative physical fitness level. Specific interventions can target this physical fitness level.
Journal of Cardiothoracic and Vascular Anesthesia, 2016
In the present study, the authors investigated the predictive value of postoperative peak arteria... more In the present study, the authors investigated the predictive value of postoperative peak arterial lactate levels for early and late mortality after cardiac surgery. Retrospective analysis of prospectively collected data. Single-center study in an academic hospital. Adult patients who underwent cardiac surgery between 2004 and 2014 (n = 16,376). Different cardiac surgical procedures. Patients were classified according to the peak arterial lactate level (PALL) within 3 days postoperatively. Logistic regression analysis and Cox regression analysis were performed to identify postoperative peak arterial lactate level as a predictor for early and late mortality respectively. In 8460 patients (51.7%), lactate was not measured postoperatively because these patients were managed according to the fast-track protocol. These patients constituted group 1 in our population but were excluded from the regression analysis. The remaining patients (n = 7,916; 48.3%) were divided according to the postoperative peak arterial lactate level (PALL): PALL<5 mmol/L (group 2), PALL 5 to 10 mmol/L (group 3), and PALL of>10 mmol/L (group 4). Early mortality was 3.7%, 20.4%, and 62.9% in groups 2, 3, and 4 respectively (p<0.0001). This mortality rate was significantly higher than that of group 1 (1.6%); p<0.0001. Multivariate regression analyses revealed postoperative peak arterial lactate as a significant predictor of 30-day mortality (odds ratio = 1.44 [1.39-1.48], p<0.001) as well as for late mortality (hazard ratio = 1.05 [1.01-1.10], p<0.025). Postoperative peak arterial lactate level in patients undergoing cardiac surgery is an independent predictor for both early and late mortality.
The validity of each new cardiac output (CO) monitor should be established before implementation ... more The validity of each new cardiac output (CO) monitor should be established before implementation in clinical practice. For this purpose, method comparison studies investigate the accuracy and precision against a reference technique. With the emergence of continuous CO monitors, the ability to detect changes in CO, in addition to its absolute value, has gained interest. Therefore, method comparison studies increasingly include assessment of trending ability in the data analysis. A number of methodological challenges arise in method comparison research with respect to the application of Bland-Altman and trending analysis. Failure to face these methodological challenges will lead to misinterpretation and erroneous conclusions. We therefore review the basic principles and pitfalls of Bland-Altman analysis in method comparison studies concerning new CO monitors. In addition, the concept of clinical concordance is introduced to evaluate trending ability from a clinical perspective. The pr...
Journal of clinical monitoring and computing, Jan 31, 2015
Uncalibrated arterial waveform analysis enables dynamic preload assessment in a minimally invasiv... more Uncalibrated arterial waveform analysis enables dynamic preload assessment in a minimally invasive fashion. Evidence about the validity of the technique in patients with impaired left ventricular function is scarce, while adequate cardiac preload assessment would be of great value in these patients. The aim of this study was to investigate the diagnostic accuracy of stroke volume variation (SVV) measured with the FloTrac/Vigileo™ system in patients with impaired left ventricular function. In this prospective, observational study, 22 patients with a left ventricular ejection fraction of 40 % or less undergoing elective coronary artery bypass grafting were included. Patients were considered fluid responsive if cardiac output increased with 15 % or more after volume loading (7 ml kg(-1) ideal body weight). The following variables were calculated: area under the receiver operating characteristics (ROC) curve, ideal cut-off value for SVV, sensitivity, specificity, positive and negative p...
With profound interest we read the article written by Kodali, Kim, Flanagan, Urman and you in the... more With profound interest we read the article written by Kodali, Kim, Flanagan, Urman and you in the February 2014 issue of the Journal of Medical Systems [1]. The article dealt with a large dataset retrieved from two American academic institutions and analyzed anesthesia-controlled times (ACT) per subspecialty service, thereafter compared them to previously published ACT data. The authors concluded that individual specialty-specific ACT should be used to improve operating room (OR) scheduling and to benchmark anesthesia performance. We could not agree more with the content and conclusions of this interesting and well-executed study. The publication stated that little work has been done to establish ACT This article is part of the Topical Collection on Systems-Level Quality Improvement Electronic supplementary material The online version of this article
European Journal of Vascular and Endovascular Surgery, 2013
With the current study we have identified independent predictors and we have developed a predicti... more With the current study we have identified independent predictors and we have developed a prediction model for the likelihood of shunt use during carotid endarterectomy that is based on the configuration of the circle of Willis (CoW) assessed by magnetic resonance angiography. Because with our model discrimination can be improved to a likelihood of about 5% for the group with a risk of 10% or lower and about 51% for the group with a risk of 30% or higher, this model can potentially be of help in clinical decision-making regarding surgical strategy and in the design of future studies on prediction models for shunt use in carotid revascularization. Objectives: The occurrence of cerebral ischemia during carotid endarterectomy (CEA) can be prevented by (selective) placement of an intraluminal shunt during cross-clamping. We set out to develop a rule to predict the likelihood for shunting during CEA based on preoperative assessment of collateral cerebral circulation and patient characteristics. Methods: Patients who underwent CEA between 2004 and 2010 were included. Patients without preoperative magnetic resonance (MRA) or computed tomography angiography (CTA) were excluded. The primary endpoint was intraluminal shunt placement based on electroencephalography changes. Age, sex, cardiovascular risk factors peripheral artery disease, symptomatic status, degree of ipsilateral and contralateral carotid, status of the vertebral arteries, and morphology of the CoW were studied as potential predictors for shunt use. A prediction model was derived from a multivariable regression model using discrimination, calibration, and bootstrapping approaches and transformed into a clinical prediction model. Results: A total of 431 patients were included, of which 65 patients (15%) received an intraluminal shunt. In the MRA group (n ¼ 285) factors related to shunt use in multivariate analysis were ipsilateral carotid stenosis 90e 99% (odds ratio [OR] 0.15, 95% CI 0.04e0.53), contralateral carotid occlusion (OR 4.29, 95% CI 1.68e10.95) and any not-visible anterior (OR 4.96, 95% CI 1.95e12.58) or ipsilateral posterior segment of the CoW (OR 5.08, 95% CI 2.10e12.32). In the CT group none of the factors were independently related to shunt use; therefore, only predictors describing morphology of CoW derived from MRA findings were included in our model. The c-statistic of this model was 0.79 (95% CI 0.72e0.86). Among patients with an estimated chance of needing a shunt of under 10% (49% of the population), the likelihood of shunting was 5%. In those in whom this chance was estimated higher than 30% (13% of the population) the likelihood was 51%. Conclusions: Among patients scheduled for CEA, assessment of cerebral arteries and of the configuration of the CoW based on MRA-derived images can help to identify patients with low and high likelihood of the need of shunt use during surgery.
ments performed in the first postoperative hour (⌬ V mean , ⌬ rSO 2 , respectively). Logistic reg... more ments performed in the first postoperative hour (⌬ V mean , ⌬ rSO 2 , respectively). Logistic regression analysis was performed to determine the relationship between ⌬ V and ⌬ rSO 2 and the occurrence of CHS. Subsequently, receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff values. Diagnostic values were shown as positive and negative predictive values (PPV and NPV). Results: In total, 151 patients were included, of which 7 patients developed CHS. The ⌬ V mean and ⌬ rSO 2 differed between CHS and non-CHS patients (median, interquartile range), i.e. 74% (67-103) versus 16% (-2 to 41), p = 0.001, and 7% (4-15) versus 1% (-6 to 7), p = 0.009, respectively. The mean arterial blood pressure did not change. Postoperative ⌬ V mean and ⌬ rSO 2 were significantly related to the occurrence of CHS [odds ratio (OR) 1.40 (95% CI 1.02-1.93) per 30% increase in V mean and OR 1.82 (95% CI 1.11-2.99) per 5% increase in rSO 2 ]. ROC curve analysis showed an area under the curve of 0.88 (p = 0.001) for ⌬ V mean and an optimal cutoff value of 67% increase (PPV 38% and NPV 99%), and an area under the curve of 0.79 (p = 0.009) for ⌬ rSO 2 and an optimal cutoff value of 3% rSO 2 increase (PPV 11% and NPV 100%). The combination of both monitoring techniques provided a PPV of 58% and an NPV of 99%. Conclusions: Both TCD and NIRS measurements can be used to safely identify patients not at risk of developing CHS. It appears that NIRS is a good alternative when a TCD signal cannot be obtained.
the end of infusion. The concentration vs time profile in brain ECF is shown in Figure 1. This li... more the end of infusion. The concentration vs time profile in brain ECF is shown in Figure 1. This limited brain distribution of cefotaxime may be explained by the blood-brain barrier which is known to express efflux transporters like P-glycoprotein (P-gp) or multidrug resistant-associated protein (MRP). 8 To circumvent this problem, antibiotic doses are increased for the prevention or treatment of CNS infections. Without severe side-effects, cefotaxime doses may be increased from 6 g up to 24 g per day for meningitis. Cefotaxime t.MIC in the brain were, respectively, equal to 78% (6.2 h) and 46% (3.7 h) for MIC values of 2 and 4 mg ml 21. To get effective bacteriostatic and bactericidal effect in vivo, t.MIC should, respectively, be 40 and 70% of the dosing interval, suggesting a bacteriostatic effect even for the highest MIC (4 mg ml 21) and a bactericidal effect only for MIC values of 2 mg ml 21. Cefotaxime dosing regimen for adult's meningitis treatment is 4 g every 4-6 h, 9 but this case indicates that 4 g every 8 h could provide sufficient brain tissue concentration for preventing infections of resistant pneumococcal strains and treating intermediate ones. In conclusion, the ECF brain concentrations indicate that an adequate exposure to cefotaxime is achieved in prevention and treatment of most CNS infections. Acknowledgement We thank Pharsight Corporation for the free supply of Win-NonLin through the PAL programme.
To evaluate the effect of implementation of the WHO&a... more To evaluate the effect of implementation of the WHO's Surgical Safety Checklist on mortality and to determine to what extent the potential effect was related to checklist compliance. 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. 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. 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. 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.
Introduction. Evaluation of accuracy, precision, and trending ability of cardiac index (CI) measu... more Introduction. Evaluation of accuracy, precision, and trending ability of cardiac index (CI) measurements using the Aesculon™ bioimpedance electrical cardiometry (Aesc) compared to the continuous pulmonary artery thermodilution catheter (PAC) technique before, during, and after cardiac surgery. Methods. A prospective observational study with fifty patients with ASA 3-4. At six time points (T), measurements of CI simultaneously by continuous cardiac output pulmonary thermodilution and thoracic bioimpedance and standard hemodynamics were performed. Analysis was performed using Bland-Altman, four-quadrant plot, and polar plot methodology. Results. CI obtained with pulmonary artery thermodilution and thoracic bioimpedance ranged from 1.00 to 6.75 L min−1 and 0.93 to 7.25 L min−1, respectively. Bland-Altman analysis showed a bias between CIBIO and CIPAC of 0.52 liters min−1 m−2, with LOA of [−2.2; 1.1] liters min−1 m−2. Percentage error between the two techniques was above 30% at every ti...
Objectives: This study identified characteristics of patients with moderate internal carotid arte... more Objectives: This study identified characteristics of patients with moderate internal carotid artery stenosis that are at increased risk for disease progression. Methods: Patients with asymptomatic moderate internal carotid disease (peak systolic velocity [PSV] Ͼ125cm/ sec and end diastolic velocity [EDV] Ͻ125cm/sec by duplex ultrasonography) correlating to 50-75% diameter reduction were followed for 3 years. Progression to greater than 75% diameter reduction (EDV Ͼ 125cm/sec) or presentation with focal neurological symptoms (stroke, amaurosis fugax, transient ischemic attack [TIA]) was documented. Co-morbidities, smoking status and medications were recorded. Log-rank testing, Wilcoxson models, and Kaplan-Meier plots provided statistical analysis. Results: During 3 year follow up, 26 (9%) of 288 patients (137 men, 151 women) developed symptoms [stroke: 9 (3.1%), TIA: 3 (1%), amaurosis fugax: 3 (1%)] or asymptomatic increase in diameter to Ͼ75% [11 (3.8%)]. All-cause mortality was 11% (33 patients). 17 patients (5.9%) underwent carotid endarterectomy and 5 (1.7%) had carotid stent placement. The event incidence was significantly higher for men (Pϭ.02), but survival was not different. The rate of disease progression and/or development of symptoms was 5.5% at 12 months and increased to 7.2% by 24 months. Co-morbidities with the highest associated event incidences were coronary artery disease [CAD] (8.1%), hyperlipidemia (7.3%), and hypertension [HTN] (6.7%). Medications associated with lower event incidences were insulin (2.8%) and angiotensin receptor blockers (1.9%). Conclusions: 9% of patients with asymptomatic moderate carotid stenosis progressed to severe stenosis or developed ipsilateral neurological symptoms at three year follow-up. The rate of asymptomatic disease progression or symptom development was to 7.2% by 24 months. Male patients with CAD, hyperlipidemia, and HTN are at increased risk and are candidates for frequent screening and/or early intervention.
European Journal of Vascular and Endovascular Surgery, 2012
WHAT THIS PAPER ADDS Cerebral hyperperfusion syndrome (CHS) after carotid endarterectomy (CEA) is... more WHAT THIS PAPER ADDS Cerebral hyperperfusion syndrome (CHS) after carotid endarterectomy (CEA) is potentially life threatening and therefore identification of patients at risk is essential. Intra-operative transcranial Doppler (TCD) monitoring is associated with both false positive and false negative results. In the present study we assessed the predictive values of an additional TCD measurement in the early postoperative phase. We found that postoperative TCD significantly increased both the positive and negative predictive values. Our adjusted monitoring strategy using perioperative TCD may contribute to the further reduction of adverse events after carotid revascularisation.
† Compared to propofol, isoflurane does not reduce myocardial injury in a trial of CABG patients.... more † Compared to propofol, isoflurane does not reduce myocardial injury in a trial of CABG patients. † No differences in shortand long-term morbidity and mortality were observed. † Cardioprotective properties of volatile anaesthetics seem to be dependent on the context of application. † Clinical relevance is questionable since significant volatile cardioprotection is only detected in very homogenous groups. Background. In experimental and clinical studies, volatile anaesthesia has proven to possess cardioprotective properties. However, no randomized controlled trials on the use of isoflurane during the entire cardiac surgical procedure are available. We therefore compared isofluranesufentanil vs propofol-sufentanil anaesthesia in patients undergoing coronary artery bypass grafting. Methods. One hundred patients were randomly assigned to receive isoflurane-sufentanil (I) (n ¼ 51) or propofol-sufentanil (P) (n ¼ 49) anaesthesia, aimed at the same hypnotic depth. Postoperative concentrations of cardiac troponin I (cTnI) were followed for 72 h. Secondary outcome variables were length of stay (LOS) in the intensive care unit (ICU) and in hospital, and 30 day and 1 yr mortality and morbidity, defined as acute myocardial infarction, arrhythmias, and cardiac dysfunction. Groups were compared by an on-treatment analysis, using linear mixed models for repeated measures. Results. Eighty-four patients completed the protocol (I: 41 vs P: 43). Postoperative cTnI concentrations increased to a maximum of I: 2.72 ng ml 21 (1.78-5.85) and P: 2.64 ng ml 21 (1.67-4.83), but did not differ between groups (P¼0.11). LOS in the ICU and in hospital was similar [ICU
Resolving the blind spot of transoesophageal echocardiography: a new diagnostic device for visual... more Resolving the blind spot of transoesophageal echocardiography: a new diagnostic device for visualizing the ascending aorta in
Assessment of stroke volume index with three different bioimpedance algorithms: lack of agreement... more Assessment of stroke volume index with three different bioimpedance algorithms: lack of agreement compared to thermodilution
Division of Perioperative Care and Emergency Medicine, University Medical Center Utrecht, Utrecht... more Division of Perioperative Care and Emergency Medicine, University Medical Center Utrecht, Utrecht, The Netherlands Background: Atherosclerosis of the ascending aorta (AA) and emboli-related complications after cardiac surgery are related. Knowledge on presence of AA-atherosclerosis before sternotomy allows changes in surgical strategy that avoid manipulation of the AA. The “Gold”-standard for assessment of AAatherosclerosis is epiaortic ultrasound scanning (EUS), but this can only be performed after sternotomy. Transesophageal echocardiography (TEE) is unable to detect atherosclerosis in distal AA due to the “blind” spot. A new method (A-View® method, an extension of TEE) enables assessment, preoperatively, of AA-atherosclerosis using a intra-tracheal fluid-filled balloon catheter. The aim of this diagnostic study was to evaluate if the A-View® method enables visualization of distal AA and safety of the diagnostic. Methods: In a cross-sectional diagnostic trial; patients undergoing ...
Background: Although several patient characteristic, clinical, and psychological risk factors for... more Background: Although several patient characteristic, clinical, and psychological risk factors for chronic postsurgical pain (CPSP) have been identified, genetic variants including single nucleotide polymorphisms have also become of interest as potential risk factors for the development of CPSP. The aim of this review is to summarize the current evidence on genetic polymorphisms associated with the prevalence and severity of CPSP in adult patients. Methods: A systematic review of the literature was performed, and additional literature was obtained by reference tracking. The primary outcome was CPSP, defined as pain at least 2 months after the surgery. Studies performed exclusively in animals were excluded. Results: Out of the 1001 identified studies, 14 studies were selected for inclusion. These studies described 5269 participants in 17 cohorts. A meta-analysis was not possible because of heterogeneity of data and data analysis. Associations with the prevalence or severity of CPSP were reported for genetic variants in the COMT gene, OPRM1, potassium channel genes, GCH1, CACNG, CHRNA6, P2X7R, cytokine-associated genes, human leucocyte antigens, DRD2, and ATXN1. Conclusions: Research on the topic of genetic variants associated with CPSP is still in its initial phase. Hypothesis-free, genome-wide association studies on large cohorts are needed in this field. In addition, future studies may also integrate genetic risk factors and patient characteristic, clinical, and psychological predictors for CPSP.
Background: Preoperative cardiorespiratory fitness, as measured by cardiopulmonary testing or est... more Background: Preoperative cardiorespiratory fitness, as measured by cardiopulmonary testing or estimated using the less sophisticated incremental shuttle walk test, timed up-and-go test or stair climb test is known to be associated with postoperative outcome. This study aimed to evaluate whether parameters of physical fitness are associated with postoperative outcome in patients with colorectal cancer scheduled for elective resection. Patients and Methods: Perioperative data of patients who underwent colorectal resection at Maastricht University Medical Center were retrospectively analyzed. Preoperative variables (e.g., age, body mass index, comorbidities, physical fitness, tumour characteristics, neoadjuvant treatment, American Society of Anesthesiologists score, level of perceived fatigue and nutritional status) were compared with postoperative outcomes. Results: Out of 80 consecutive cases, 75 (93.8%) were available for analysis (57.3% male, median AE interquartile range age 69.2 AE 11.7 years). A higher Charlson comorbidity index (odds ratio (OR) of 1.604, 95% confidence interval (CI) 1.120e2.296), worse functional exercise capacity (in meters, OR of 0.995, 95% CI 0.991e1.000), a lower physical activity level (in min/day, OR of 0.994, 95% CI 0.988e1.000), and a higher level of perceived fatigue (OR of 1.047, 95% CI 1.016e1.078), were associated with a slower time to recovery of physical functioning. A better functional exercise capacity was associated with a lower OR (OR of 0.995, 95% CI 0.991e1.000) for nonsurgical complications. Conclusion: There is an association between preoperative parameters and postoperative outcomes in patients with colorectal cancer scheduled for resection. Patients benefit from an optimal preoperative physical fitness level. Specific interventions can target this physical fitness level.
Journal of Cardiothoracic and Vascular Anesthesia, 2016
In the present study, the authors investigated the predictive value of postoperative peak arteria... more In the present study, the authors investigated the predictive value of postoperative peak arterial lactate levels for early and late mortality after cardiac surgery. Retrospective analysis of prospectively collected data. Single-center study in an academic hospital. Adult patients who underwent cardiac surgery between 2004 and 2014 (n = 16,376). Different cardiac surgical procedures. Patients were classified according to the peak arterial lactate level (PALL) within 3 days postoperatively. Logistic regression analysis and Cox regression analysis were performed to identify postoperative peak arterial lactate level as a predictor for early and late mortality respectively. In 8460 patients (51.7%), lactate was not measured postoperatively because these patients were managed according to the fast-track protocol. These patients constituted group 1 in our population but were excluded from the regression analysis. The remaining patients (n = 7,916; 48.3%) were divided according to the postoperative peak arterial lactate level (PALL): PALL<5 mmol/L (group 2), PALL 5 to 10 mmol/L (group 3), and PALL of>10 mmol/L (group 4). Early mortality was 3.7%, 20.4%, and 62.9% in groups 2, 3, and 4 respectively (p<0.0001). This mortality rate was significantly higher than that of group 1 (1.6%); p<0.0001. Multivariate regression analyses revealed postoperative peak arterial lactate as a significant predictor of 30-day mortality (odds ratio = 1.44 [1.39-1.48], p<0.001) as well as for late mortality (hazard ratio = 1.05 [1.01-1.10], p<0.025). Postoperative peak arterial lactate level in patients undergoing cardiac surgery is an independent predictor for both early and late mortality.
The validity of each new cardiac output (CO) monitor should be established before implementation ... more The validity of each new cardiac output (CO) monitor should be established before implementation in clinical practice. For this purpose, method comparison studies investigate the accuracy and precision against a reference technique. With the emergence of continuous CO monitors, the ability to detect changes in CO, in addition to its absolute value, has gained interest. Therefore, method comparison studies increasingly include assessment of trending ability in the data analysis. A number of methodological challenges arise in method comparison research with respect to the application of Bland-Altman and trending analysis. Failure to face these methodological challenges will lead to misinterpretation and erroneous conclusions. We therefore review the basic principles and pitfalls of Bland-Altman analysis in method comparison studies concerning new CO monitors. In addition, the concept of clinical concordance is introduced to evaluate trending ability from a clinical perspective. The pr...
Journal of clinical monitoring and computing, Jan 31, 2015
Uncalibrated arterial waveform analysis enables dynamic preload assessment in a minimally invasiv... more Uncalibrated arterial waveform analysis enables dynamic preload assessment in a minimally invasive fashion. Evidence about the validity of the technique in patients with impaired left ventricular function is scarce, while adequate cardiac preload assessment would be of great value in these patients. The aim of this study was to investigate the diagnostic accuracy of stroke volume variation (SVV) measured with the FloTrac/Vigileo™ system in patients with impaired left ventricular function. In this prospective, observational study, 22 patients with a left ventricular ejection fraction of 40 % or less undergoing elective coronary artery bypass grafting were included. Patients were considered fluid responsive if cardiac output increased with 15 % or more after volume loading (7 ml kg(-1) ideal body weight). The following variables were calculated: area under the receiver operating characteristics (ROC) curve, ideal cut-off value for SVV, sensitivity, specificity, positive and negative p...
With profound interest we read the article written by Kodali, Kim, Flanagan, Urman and you in the... more With profound interest we read the article written by Kodali, Kim, Flanagan, Urman and you in the February 2014 issue of the Journal of Medical Systems [1]. The article dealt with a large dataset retrieved from two American academic institutions and analyzed anesthesia-controlled times (ACT) per subspecialty service, thereafter compared them to previously published ACT data. The authors concluded that individual specialty-specific ACT should be used to improve operating room (OR) scheduling and to benchmark anesthesia performance. We could not agree more with the content and conclusions of this interesting and well-executed study. The publication stated that little work has been done to establish ACT This article is part of the Topical Collection on Systems-Level Quality Improvement Electronic supplementary material The online version of this article
European Journal of Vascular and Endovascular Surgery, 2013
With the current study we have identified independent predictors and we have developed a predicti... more With the current study we have identified independent predictors and we have developed a prediction model for the likelihood of shunt use during carotid endarterectomy that is based on the configuration of the circle of Willis (CoW) assessed by magnetic resonance angiography. Because with our model discrimination can be improved to a likelihood of about 5% for the group with a risk of 10% or lower and about 51% for the group with a risk of 30% or higher, this model can potentially be of help in clinical decision-making regarding surgical strategy and in the design of future studies on prediction models for shunt use in carotid revascularization. Objectives: The occurrence of cerebral ischemia during carotid endarterectomy (CEA) can be prevented by (selective) placement of an intraluminal shunt during cross-clamping. We set out to develop a rule to predict the likelihood for shunting during CEA based on preoperative assessment of collateral cerebral circulation and patient characteristics. Methods: Patients who underwent CEA between 2004 and 2010 were included. Patients without preoperative magnetic resonance (MRA) or computed tomography angiography (CTA) were excluded. The primary endpoint was intraluminal shunt placement based on electroencephalography changes. Age, sex, cardiovascular risk factors peripheral artery disease, symptomatic status, degree of ipsilateral and contralateral carotid, status of the vertebral arteries, and morphology of the CoW were studied as potential predictors for shunt use. A prediction model was derived from a multivariable regression model using discrimination, calibration, and bootstrapping approaches and transformed into a clinical prediction model. Results: A total of 431 patients were included, of which 65 patients (15%) received an intraluminal shunt. In the MRA group (n ¼ 285) factors related to shunt use in multivariate analysis were ipsilateral carotid stenosis 90e 99% (odds ratio [OR] 0.15, 95% CI 0.04e0.53), contralateral carotid occlusion (OR 4.29, 95% CI 1.68e10.95) and any not-visible anterior (OR 4.96, 95% CI 1.95e12.58) or ipsilateral posterior segment of the CoW (OR 5.08, 95% CI 2.10e12.32). In the CT group none of the factors were independently related to shunt use; therefore, only predictors describing morphology of CoW derived from MRA findings were included in our model. The c-statistic of this model was 0.79 (95% CI 0.72e0.86). Among patients with an estimated chance of needing a shunt of under 10% (49% of the population), the likelihood of shunting was 5%. In those in whom this chance was estimated higher than 30% (13% of the population) the likelihood was 51%. Conclusions: Among patients scheduled for CEA, assessment of cerebral arteries and of the configuration of the CoW based on MRA-derived images can help to identify patients with low and high likelihood of the need of shunt use during surgery.
ments performed in the first postoperative hour (⌬ V mean , ⌬ rSO 2 , respectively). Logistic reg... more ments performed in the first postoperative hour (⌬ V mean , ⌬ rSO 2 , respectively). Logistic regression analysis was performed to determine the relationship between ⌬ V and ⌬ rSO 2 and the occurrence of CHS. Subsequently, receiver operating characteristic (ROC) curve analysis was used to determine the optimal cutoff values. Diagnostic values were shown as positive and negative predictive values (PPV and NPV). Results: In total, 151 patients were included, of which 7 patients developed CHS. The ⌬ V mean and ⌬ rSO 2 differed between CHS and non-CHS patients (median, interquartile range), i.e. 74% (67-103) versus 16% (-2 to 41), p = 0.001, and 7% (4-15) versus 1% (-6 to 7), p = 0.009, respectively. The mean arterial blood pressure did not change. Postoperative ⌬ V mean and ⌬ rSO 2 were significantly related to the occurrence of CHS [odds ratio (OR) 1.40 (95% CI 1.02-1.93) per 30% increase in V mean and OR 1.82 (95% CI 1.11-2.99) per 5% increase in rSO 2 ]. ROC curve analysis showed an area under the curve of 0.88 (p = 0.001) for ⌬ V mean and an optimal cutoff value of 67% increase (PPV 38% and NPV 99%), and an area under the curve of 0.79 (p = 0.009) for ⌬ rSO 2 and an optimal cutoff value of 3% rSO 2 increase (PPV 11% and NPV 100%). The combination of both monitoring techniques provided a PPV of 58% and an NPV of 99%. Conclusions: Both TCD and NIRS measurements can be used to safely identify patients not at risk of developing CHS. It appears that NIRS is a good alternative when a TCD signal cannot be obtained.
the end of infusion. The concentration vs time profile in brain ECF is shown in Figure 1. This li... more the end of infusion. The concentration vs time profile in brain ECF is shown in Figure 1. This limited brain distribution of cefotaxime may be explained by the blood-brain barrier which is known to express efflux transporters like P-glycoprotein (P-gp) or multidrug resistant-associated protein (MRP). 8 To circumvent this problem, antibiotic doses are increased for the prevention or treatment of CNS infections. Without severe side-effects, cefotaxime doses may be increased from 6 g up to 24 g per day for meningitis. Cefotaxime t.MIC in the brain were, respectively, equal to 78% (6.2 h) and 46% (3.7 h) for MIC values of 2 and 4 mg ml 21. To get effective bacteriostatic and bactericidal effect in vivo, t.MIC should, respectively, be 40 and 70% of the dosing interval, suggesting a bacteriostatic effect even for the highest MIC (4 mg ml 21) and a bactericidal effect only for MIC values of 2 mg ml 21. Cefotaxime dosing regimen for adult's meningitis treatment is 4 g every 4-6 h, 9 but this case indicates that 4 g every 8 h could provide sufficient brain tissue concentration for preventing infections of resistant pneumococcal strains and treating intermediate ones. In conclusion, the ECF brain concentrations indicate that an adequate exposure to cefotaxime is achieved in prevention and treatment of most CNS infections. Acknowledgement We thank Pharsight Corporation for the free supply of Win-NonLin through the PAL programme.
To evaluate the effect of implementation of the WHO&a... more To evaluate the effect of implementation of the WHO's Surgical Safety Checklist on mortality and to determine to what extent the potential effect was related to checklist compliance. 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. 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. 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. 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.
Introduction. Evaluation of accuracy, precision, and trending ability of cardiac index (CI) measu... more Introduction. Evaluation of accuracy, precision, and trending ability of cardiac index (CI) measurements using the Aesculon™ bioimpedance electrical cardiometry (Aesc) compared to the continuous pulmonary artery thermodilution catheter (PAC) technique before, during, and after cardiac surgery. Methods. A prospective observational study with fifty patients with ASA 3-4. At six time points (T), measurements of CI simultaneously by continuous cardiac output pulmonary thermodilution and thoracic bioimpedance and standard hemodynamics were performed. Analysis was performed using Bland-Altman, four-quadrant plot, and polar plot methodology. Results. CI obtained with pulmonary artery thermodilution and thoracic bioimpedance ranged from 1.00 to 6.75 L min−1 and 0.93 to 7.25 L min−1, respectively. Bland-Altman analysis showed a bias between CIBIO and CIPAC of 0.52 liters min−1 m−2, with LOA of [−2.2; 1.1] liters min−1 m−2. Percentage error between the two techniques was above 30% at every ti...
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Papers by Wolfgang Buhre