Salome Dell-Kuster

Modifiable and Nonmodifiable Risk Factors for Postoperative Delirium After Cardiac Surgery With Cardiopulmonary Bypass

OBJECTIVES Postoperative delirium after cardiac surgery is associated with increased morbidity and mortality as well as prolonged stay in both the intensive care unit and the hospital. The authors sought to identify modifiable risk factors associated with the development of postoperative delirium in elderly patients after elective cardiac surgery in order to be able to design follow-up studies aimed at the prevention of delirium by optimizing perioperative management. DESIGN A post hoc analysis of data from patients enrolled in a randomized controlled trial was performed. SETTING A single university hospital. PARTICIPANTS One hundred thirteen patients aged 65 or older undergoing elective cardiac surgery with cardiopulmonary bypass. INTERVENTIONS None. MEASUREMENTS AND MAINS RESULTS: Screening for delirium was performed using the Confusion Assessment Method (CAM) on the first 6 postoperative days. A multivariable logistic regression model was developed to identify significant risk factors and to control for confounders. Delirium developed in 35 of 113 patients (30%). The multivariable model showed the maximum value of C-reactive protein measured postoperatively, the dose of fentanyl per kilogram of body weight administered intraoperatively, and the duration of mechanical ventilation to be independently associated with delirium. CONCLUSIONS In this post hoc analysis, larger doses of fentanyl administered intraoperatively and longer duration of mechanical ventilation were associated with postoperative delirium in the elderly after cardiac surgery. Prospective randomized trials should be performed to test the hypotheses that a reduced dose of fentanyl administered intraoperatively, the use of a different opioid, or weaning protocols aimed at early extubation prevent delirium in these patients.

Pre-analytical effects of pneumatic tube transport on impedance platelet aggregometry.

Point-of-care platelet monitoring is increasingly used in cardiac patients treated with antiplatelet agents. The validity of a new assay needs to be evaluated not only for reproducible data in clinical samples, but also for other pre-analytical conditions that may influence measurements. The aim of this study was to evaluate the influence of a pneumatic tube system (PTS) for specimen transport on impedance platelet aggregometry. We evaluated 50 consecutive patients scheduled for coronary artery bypass surgery under oral therapy with 100 mg/d acetylsalicylic acid (aspirin). In each patient, three blood samples for platelet function analysis were taken before induction of anesthesia. The first sample was measured in the operating room (OR) area and designated as the reference value. The second sample was again measured by the same operator in the OR area using a random PTS transport. The third sample was sent to the central laboratory by PTS where it was measured by a local technician. Platelet function was assessed in whole blood by impedance aggregometry with a Multiplate™ analyzer using thrombin-related activation peptide (TRAP test) and arachidonic acid (ASPI test) (Dynabite GmbH, Munich, Germany). Mean ± SD for TRAP test was 1009 ± 196 in the reference measurement. Bias ± 95% limit of agreement between the reference measurement and a second measurement for TRAP test were 126 ± 284 (n = 25) for untransported and 181 ± 316 (n = 25) for PTS transported samples. In the reference measurements, 48/50 (96%) of TRAP values were within the normal range. After PTS transport, 35/50 (70%) of TRAP measurements in the central laboratory were within the normal range (p < 0.001). Mean ± SD for ASPI test was 175 ± 137. Bias ± 95% limit of agreement for ASPI test were 12 ± 109 (n = 25) for untransported and 68 ± 250 (n = 25) for PTS transported samples. In the reference measurements, 7/50 (14%) ASPI values were above the cut-off level and defined as reduced aspirin responsiveness. After PTS transport, only 1/50 (2%) of the patients showed reduced aspirin responsiveness in the central laboratory measurements (p = 0.031). In conclusion, PTS transport had a significant influence on platelet function testing by the Multiplate™ analyzer. Significantly fewer test results indicated normal platelet function in TRAP test and reduced aspirin responsiveness in ASPI test after PTS transport. Therefore, clinical decisions regarding platelet function and aspirin responsiveness should not be based on blood specimens transported by a PTS system.

Completion and publication rates of randomized controlled trials in surgery: an empirical study

OBJECTIVE To investigate the prevalence of discontinuation and nonpublication of surgical versus medical randomized controlled trials (RCTs) and to explore risk factors for discontinuation and nonpublication of surgical RCTs. BACKGROUND Trial discontinuation has significant scientific, ethical, and economic implications. To date, the prevalence of discontinuation of surgical RCTs is unknown. METHODS All RCT protocols approved between 2000 and 2003 by 6 ethics committees in Canada, Germany, and Switzerland were screened. Baseline characteristics were collected and, if published, full reports retrieved. Risk factors for early discontinuation for slow recruitment and nonpublication were explored using multivariable logistic regression analyses. RESULTS In total, 863 RCT protocols involving adult patients were identified, 127 in surgery (15%) and 736 in medicine (85%). Surgical trials were discontinued for any reason more often than medical trials [43% vs 27%, risk difference 16% (95% confidence interval [CI]: 5%-26%); P = 0.001] and more often discontinued for slow recruitment [18% vs 11%, risk difference 8% (95% CI: 0.1%-16%); P = 0.020]. The percentage of trials not published as full journal article was similar in surgical and medical trials (44% vs 40%, risk difference 4% (95% CI: -5% to 14%); P = 0.373). Discontinuation of surgical trials was a strong risk factor for nonpublication (odds ratio = 4.18, 95% CI: 1.45-12.06; P = 0.008). CONCLUSIONS Discontinuation and nonpublication rates were substantial in surgical RCTs and trial discontinuation was strongly associated with nonpublication. These findings need to be taken into account when interpreting surgical literature. Surgical trialists should consider feasibility studies before embarking on full-scale trials.

Video Gaming in Children Improves Performance on a Virtual Reality Trainer but Does Not yet Make a Laparoscopic Surgeon

Background: In children, video game experience improves spatial performance, a predictor of surgical performance. This study aims at comparing laparoscopic virtual reality (VR) task performance of children with different levels of experience in video games and residents. Participants and methods: A total of 32 children (8.4 to 12.1 years), 20 residents, and 14 board-certified surgeons (total n = 66) performed several VR and 2 conventional tasks (cube/spatial and pegboard/fine motor). Performance between the groups was compared (primary outcome). VR performance was correlated with conventional task performance (secondary outcome). Results: Lowest VR performance was found in children with low video game experience, followed by those with high video game experience, residents, and board-certified surgeons. VR performance correlated well with the spatial test and moderately with the fine motor test. Conclusions: The use of computer games can be considered not only as pure entertainment but may also contribute to the development of skills relevant for adequate performance in VR laparoscopic tasks. Spatial skills are relevant for VR laparoscopic task performance.

Long-term follow-up of a randomized controlled trial of Lichtenstein's operation versus mesh plug repair for inguinal hernia.

Objective:To compare long-term results of Lichtensteins operation versus mesh plug repair for open inguinal hernia repair. Background:The technique of best choice in open prosthetic inguinal hernia repair remains a subject of ongoing debate. Methods:In this prospective, randomized controlled multicenter trial, patients with primary or recurrent inguinal hernias were randomized to undergo either Lichtensteins operation or mesh plug repair. The primary endpoint was the long-term recurrence rate. Secondary endpoints included chronic pain, sensibility disorders, and reoperation rate. Results:In total, 697 hernias in 594 patients were randomized (297 patients per group). At a median follow-up of 6.5 years, 528 (76%) operated hernias in 444 (75%) patients were clinically evaluated. The recurrence rate was similar in both groups [mesh plug: 21/268 hernias = 7.8%; Lichtenstein: 21/260 hernias = 8.1%; adjusted odds ratio (OR): 0.92; 95% confidence interval (CI): 0.51, 1.68; P = 0.795]. We did not find a significant difference for chronic pain (Visual Analog Scale score >3) (OR: 0.58; 95% CI: 0.31, 1.09; P = 0.088) and sensory testing (17% vs 20% of patients; OR: 0.53; 95% CI: 0.21, 1.37; P = 0.190) between the 2 groups. There were less reoperations in the mesh plug than in the Lichtensteins operation group (OR: 0.43; 95% CI: 0.22, 0.85; P = 0.016). Conclusions:The long-term results of this trial indicate not enough evidence for differences in recurrence, chronic pain, and sensibility disorders between mesh plug repair and Lichtensteins operation but a lower likelihood for reoperation for mesh plug repair. Estimates for all endpoints were statistically not significant or based on large CIs. Clinical Trials Registration:ClinicalTrials.gov Identifier: NCT01637818.

Effect of intraoperative infiltration with local anesthesia on the development of chronic pain after inguinal hernia repair: A randomized, triple-blinded, placebo-controlled trial

BACKGROUND Chronic pain is a common complication after inguinal hernia repair. The objective of this randomized trial was to assess the effect of intraoperative infiltration with local anesthetic versus placebo on the development of chronic pain after inguinal hernia repair. METHODS Patients with single- or double-sided inguinal hernia were enrolled in a randomized, controlled, triple-blinded trial with a sequential adaptive design. Hernias were randomized to 1 of 2 treatment groups. The intervention group received a local infiltration of 20 mL bupivacaine 0.25% and the placebo group 20 mL saline 0.9% at the end of the operation. Two interim analyses were performed according to predefined stopping criteria allowing for design and sample size adaption. The primary endpoint was chronic pain defined on a visual analog scale (VAS) as ≥30 in any quality (at rest, lying, walking, climbing stairs, and bending over) 3 months postoperatively. A logistic regression model was built to compare the incidence of chronic pain using generalized estimating equations to adjust for clustering in bilateral hernias. RESULTS Among 357 patients, there were 406 hernias randomized. A total of 5.8% (10/173) experienced VAS ≥ 30 in any quality in the intervention group and 2.3% (4/174) in the placebo group (P = .114) at 3 months postoperatively. Multivariable analysis revealed no evidence of between-group differences for the development of any pain (odds ratio [OR], 1.03; 95% CI, 0.67-1.57; P = .905), whereas preoperative pain was an independent risk factor (OR, 2.52; 95% CI, 1.12-5.68; P = .025). CONCLUSION We did not find any evidence that intraoperative infiltration of local anesthetic had an impact on the development of chronic postoperative pain.

Propofol sedation alone or in combination with pharyngeal lidocaine anesthesia for routine upper GI endoscopy: a randomized, double-blind, placebo-controlled, non-inferiority trial

BACKGROUND In patients undergoing routine upper EGD, propofol is increasingly used without pharyngeal anesthesia because of its excellent sedative properties. It is unclear whether this practice is non-inferior in regard to ease of endoscopic intubation and patient comfort. OBJECTIVE To assess the relevance of local pharyngeal anesthesia regarding the ease of EGD performance in patients sedated with propofol as monotherapy. DESIGN Randomized, double-blind, placebo-controlled, non-inferiority trial. SETTING One community hospital and one university hospital in Switzerland. PATIENTS We enrolled 300 consecutive adult patients undergoing elective EGD. INTERVENTION Pharyngeal anesthesia with 4 squirts of lidocaine spray versus placebo spray immediately before propofol sedation. MAIN OUTCOME MEASUREMENTS Number of gag reflexes (primary endpoint), number of intubation attempts, and degree of salivation during intubation (secondary endpoints) assessed by the endoscopists and staff. RESULTS In the lidocaine group, 122 patients (82%) had no gag events, and 25 patients had a total of 39 gag events, whereas in the placebo group 104 patients (71%) had no gag events, and 43 patients had a total of 111 gag events. The rate ratio of gagging with quasi-likelihood estimation of placebo compared with lidocaine was 2.85 (95% confidence interval [CI], 1.42-6.19; P = .005). In adjusted logistic regression analysis, the odds ratio for gagging for placebo pharyngeal anesthesia compared with lidocaine was 1.9 (95% CI, 1.03-3.54). The number of intubation attempts and the degree of salivation were similar in both groups. Two patients in the placebo group experienced oxygen desaturation and needed short-term mask ventilation. LIMITATIONS The level of sedation and possible long-term side effects of pharyngeal anesthesia were not assessed. CONCLUSION Topical pharyngeal anesthesia reduces the gag reflex in patients sedated with propofol even though it does not seem to have an influence on the ease of the procedure and on patient or endoscopist satisfaction in adequately sedated patients.

Serum anticholinergic activity and postoperative cognitive dysfunction in elderly patients.

BACKGROUND:Cerebral cholinergic transmission plays a key role in cognitive function, and anticholinergic drugs administered during the perioperative phase are a hypothetical cause of postoperative cognitive dysfunction (POCD). We hypothesized that a perioperative increase in serum anticholinergic activity (SAA) is associated with POCD in elderly patients. METHODS:Seventy-nine patients aged >65 years undergoing elective major surgery under standardized general anesthesia (thiopental, sevoflurane, fentanyl, and atracurium) were investigated. Cognitive functions were assessed preoperatively and 7 days postoperatively using the extended version of the CERAD-Neuropsychological Assessment Battery. POCD was defined as a postoperative decline >1 z-score in at least 2 test variables. SAA was measured preoperatively and 7 days postoperatively at the time of cognitive testing. Hodges-Lehmann median differences and their 95% confidence intervals were calculated for between-group comparisons. RESULTS:Of the patients who completed the study, 46% developed POCD. Patients with POCD were slightly older and less educated than patients without POCD. There were no relevant differences between patients with and without POCD regarding gender, demographically corrected baseline cognitive functions, and duration of anesthesia. There were no large differences between patients with and without POCD regarding SAA preoperatively (pmol/mL, median [interquartile range]/median difference [95% CI], P; 1.14 [0.72, 2.37] vs 1.13 [0.68, 1.68]/0.12 [−0.31, 0.57], P = 0.56), SAA 7 days postoperatively (1.32 [0.68, 2.59] vs 0.97 [0.65, 1.83]/0.25 [−0.26, 0.81], P = 0.37), or changes in SAA (0.08 [−0.50, 0.70] vs −0.02 [−0.53, 0.41]/0.1 [−0.31, 0.52], P = 0.62). There was no significant relationship between changes in SAA and changes in cognitive function (Spearman rank correlation coefficient preoperatively of 0.03 [95% CI, −0.21, 0.26] and postoperatively of −0.002 [95% CI, −0.24, 0.23]). CONCLUSIONS:In this panel of patients with low baseline SAA and clinically insignificant perioperative anticholinergic burden, although a relationship cannot be excluded in some patients, our analysis suggests that POCD is probably not a substantial consequence of anticholinergic medications administered perioperatively but rather due to other mechanisms.

Designing questionnaires: healthcare survey to compare two different response scales

BackgroundA widely discussed design issue in patient satisfaction questionnaires is the optimal length and labelling of the answering scale. The aim of the present study was to compare intra-individually the answers on two response scales to five general questions evaluating patients’ perception of hospital care.MethodsBetween November 2011 and January 2012, all in-hospital patients at a Swiss University Hospital received a patient satisfaction questionnaire on an adjectival scale with three to four labelled categories (LS) and five redundant questions displayed on an 11-point end-anchored numeric scale (NS). The scales were compared concerning ceiling effect, internal consistency (Cronbach’s alpha), individual item answers (Spearman’s rank correlation), and concerning overall satisfaction by calculating an overall percentage score (sum of all answers related to the maximum possible sum).ResultsThe response rate was 41% (2957/7158), of which 2400 (81%) completely filled out all questions. Baseline characteristics of the responders and non-responders were similar. Floor and ceiling effect were high on both response scales, but more pronounced on the LS than on the NS. Cronbach’s alpha was higher on the NS than on the LS. There was a strong individual item correlation between both answering scales in questions regarding the intent to return, quality of treatment and the judgement whether the patient was treated with respect and dignity, but a lower correlation concerning satisfactory information transfer by physicians or nurses, where only three categories were available in the LS. The overall percentage score showed a comparable distribution, but with a wider spread of lower satisfaction in the NS.ConclusionsSince the longer scale did not substantially reduce the ceiling effect, the type of questions rather than the type of answering scale could be addressed with a focus on specific questions about concrete situations instead of general questions. Moreover, the low correlation in questions about information provision suggests that only three possible response choices are insufficient. Further investigations are needed to find a more sensitive scale discriminating high-end ratings. Otherwise, a longitudinal within-hospital or a cross-sectional between-hospital comparison of patient care is questionable.

Histomorphometric, CT Arthrographic, and Biomechanical Mapping of the Human Ankle

Background: The specific morphological and biomechanical characteristics of the osteochondral unit of the ankle joint are not yet fully understood. This anatomical study aimed to map regional thickness of the articular hyaline uncalcified cartilage and its adjacent layers of mineralized cartilage and subchondral bone as well as to measure the regional indentation stiffness of human ankle joint cartilage. Materials and Methods: A total of 20 pairs of human cadaver ankle joints (median age: 78 years) were evaluated by histomorphometry and multidetector row double-contrast CT arthrography for cartilage thickness in 17 distinct anatomical regions. In addition, regional distribution of the subchondral bone plate and of the mineralized cartilage was scrutinized histologically. Cartilage indentation stiffness was measured using an arthroscopic handheld device (Artscan200), especially validated for use in thin cartilage. The correlation between the thickness of different components of the osteochondral unit and the cartilage indentation stiffness was evaluated. Results: The thinnest uncalcified cartilage was measured at the anterior talar dome and the distal fibula. The thickest uncalcified cartilage was found in the mid and posterior talar dome, as well as in the tibial plafond. Mineralized cartilage and subchondral bone showed highest values at the anteromedial talar dome. Cartilage indentation stiffness showed a bicentric distribution pattern in 14/20 ankle pairs and was highest in regions with thin cartilage. Positive correlation between the thickness of the mineralized cartilage and the subchondral bone plate was found. No correlation between the thickness of the uncalcified and the mineralized cartilage could be identified. Conclusion: This anatomical study provides a comprehensive mapping of the osteochondral unit of the human ankle joint in elderly people. Articular hyaline uncalcified cartilage and the subchondral bone plate showed clear regional differences and were reciprocally distributed. Cartilage indentation stiffness was inversely correlated to cartilage thickness in elderly people. Clinical Relevance: Thorough understanding of the osteochondral unit of the ankle joint could be helpful for clinicians and researchers in the development of improved operative repair techniques for osteochondral defects in the ankle joint, for example, in constructing specific tissue-engineered osteochondral plugs.