Improving the efficiency of the cardiac catheterization laboratories through understanding the stochastic behavior of the scheduled procedures

  Background: In this study, we sought to analyze the stochastic behavior of Catherization Labora­tories (Cath Labs) procedures in our institution. Statistical models may help to improve estimated case durations to support management in the cost-effective use of expensive surgical resources. Methods: We retrospectively analyzed all the procedures performed in the Cath Labs in 2012. The duration of procedures is strictly positive (larger than zero) and has mostly a large mini­mum duration. Because of the strictly positive character of the Cath Lab procedures, a fit of a lognormal model may be desirable. Having a minimum duration requires an estimate of the threshold (shift) parameter of the lognormal model. Therefore, the 3-parameter lognormal model is interesting. To avoid heterogeneous groups of observations, we tested every group-car­diologist-procedure combination for the normal, 2- and 3-parameter lognormal distribution. Results: The total number of elective and emergency procedures performed was 6,393 (8,186 h). The final analysis included 6,135 procedures (7,779 h). Electrophysiology (intervention) pro­cedures fit the 3-parameter lognormal model 86.1% (80.1%). Using Friedman test statistics, we conclude that the 3-parameter lognormal model is superior to the 2-parameter lognormal model. Furthermore, the 2-parameter lognormal is superior to the normal model. Conclusions: Cath Lab procedures are well-modelled by lognormal models. This information helps to improve and to refine Cath Lab schedules and hence their efficient use.

HMG-coenzyme A reductase inhibition, type 2 diabetes, and bodyweight: evidence from genetic analysis and randomised trials.

BACKGROUND: Statins increase the risk of new-onset type 2 diabetes mellitus. We aimed to assess whether this increase in risk is a consequence of inhibition of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), the intended drug target. METHODS: We used single nucleotide polymorphisms in the HMGCR gene, rs17238484 (for the main analysis) and rs12916 (for a subsidiary analysis) as proxies for HMGCR inhibition by statins. We examined associations of these variants with plasma lipid, glucose, and insulin concentrations; bodyweight; waist circumference; and prevalent and incident type 2 diabetes. Study-specific effect estimates per copy of each LDL-lowering allele were pooled by meta-analysis. These findings were compared with a meta-analysis of new-onset type 2 diabetes and bodyweight change data from randomised trials of statin drugs. The effects of statins in each randomised trial were assessed using meta-analysis. FINDINGS: Data were available for up to 223 463 individuals from 43 genetic studies. Each additional rs17238484-G allele was associated with a mean 0·06 mmol/L (95% CI 0·05-0·07) lower LDL cholesterol and higher body weight (0·30 kg, 0·18-0·43), waist circumference (0·32 cm, 0·16-0·47), plasma insulin concentration (1·62%, 0·53-2·72), and plasma glucose concentration (0·23%, 0·02-0·44). The rs12916 SNP had similar effects on LDL cholesterol, bodyweight, and waist circumference. The rs17238484-G allele seemed to be associated with higher risk of type 2 diabetes (odds ratio [OR] per allele 1·02, 95% CI 1·00-1·05); the rs12916-T allele association was consistent (1·06, 1·03-1·09). In 129 170 individuals in randomised trials, statins lowered LDL cholesterol by 0·92 mmol/L (95% CI 0·18-1·67) at 1-year of follow-up, increased bodyweight by 0·24 kg (95% CI 0·10-0·38 in all trials; 0·33 kg, 95% CI 0·24-0·42 in placebo or standard care controlled trials and -0·15 kg, 95% CI -0·39 to 0·08 in intensive-dose vs moderate-dose trials) at a mean of 4·2 years (range 1·9-6·7) of follow-up, and increased the odds of new-onset type 2 diabetes (OR 1·12, 95% CI 1·06-1·18 in all trials; 1·11, 95% CI 1·03-1·20 in placebo or standard care controlled trials and 1·12, 95% CI 1·04-1·22 in intensive-dose vs moderate dose trials). INTERPRETATION: The increased risk of type 2 diabetes noted with statins is at least partially explained by HMGCR inhibition. FUNDING: The funding sources are cited at the end of the paper

Balancing Workload in the PACU by Using an Integrated OR Planning Methodology

Purpose: The individual scheduling of the operating rooms (ORs) has a significant influence on postoperative care at hospital facilities. We studied the effect of incorporating postoperative departments in the decision process with regard to scheduling ORs and developed an integrated OR planning methodology that determines an optimal surgery sequence and postanesthesia care unit (PACU) nursing staff level, with the objective to level the variability in inflow of patients in the PACU. Design: We developed an integrated OR planning methodology that investigates the sequencing of a surgical suite process with multiple ORs and postoperative hospital facilities. Methods: This research was performed by representing a discrete-time two-stage flow shop problem. A retrospective study was performed in which the derived model was validated using discrete-event simulation. Findings: Simulation results show that applying the integrated planning methodology decreased the variability in bed demand and smoothed the workload for the nursing staff in the PACU. Moreover, applying the algorithm led to a decrease in PACU completion time and a reduced amount of overtime hours for the surgical suite. Based on our results, we derived simple scheduling guidelines. Conclusions: Our simulation results confirmed the hypothesis that prospectively sequencing ORs' cases can effectively decrease the variability in bed demand and smoothen the workload for the staff personnel. Moreover, applying the algorithm leads to a decrease in PACU completion time and less overtime hours for the surgical suite. As such, an integrated OR planning methodology facilitates hospitals in improving OR efficiency

Improving the efficiency of the cardiac catheterization laboratories through understanding the stochastic behavior of the scheduled procedures

\u3cp\u3eBACKGROUND: In this study, we sought to analyze the stochastic behavior of Catherization Laboratories (Cath Labs) procedures in our institution. Statistical models may help to improve estimated case durations to support management in the cost-effective use of expensive surgical resources.\u3c/p\u3e\u3cp\u3eMETHODS: We retrospectively analyzed all the procedures performed in the Cath Labs in 2012. The duration of procedures is strictly positive (larger than zero) and has mostly a large minimum duration. Because of the strictly positive character of the Cath Lab procedures, a fit of a lognormal model may be desirable. Having a minimum duration requires an estimate of the threshold (shift) parameter of the lognormal model. Therefore, the 3-parameter lognormal model is interesting. To avoid heterogeneous groups of observations, we tested every group-cardiologist-procedure combination for the normal, 2- and 3-parameter lognormal distribution.\u3c/p\u3e\u3cp\u3eRESULTS: The total number of elective and emergency procedures performed was 6,393 (8,186 h). The final analysis included 6,135 procedures (7,779 h). Electrophysiology (intervention) procedures fit the 3-parameter lognormal model 86.1% (80.1%). Using Friedman test statistics, we conclude that the 3-parameter lognormal model is superior to the 2-parameter lognormal model. Furthermore, the 2-parameter lognormal is superior to the normal model.\u3c/p\u3e\u3cp\u3eCONCLUSIONS: Cath Lab procedures are well-modelled by lognormal models. This information helps to improve and to refine Cath Lab schedules and hence their efficient use.\u3c/p\u3

The RAQET Study: the Effect of Eating a Popsicle Directly After Bariatric Surgery on the Quality of Patient Recovery; a Randomised Controlled Trial

Quality of recovery could be influenced positively if there is less postoperative sore throat (POST). Eating a popsicle might attenuate this sore throat. Especially for bariatric surgery, early recovery is important. Adding popsicles to the postoperative protocol could be beneficial. Our hypothesis is that offering a popsicle in the recovery room to patients after bariatric surgery will decrease POST and will increase quality of postoperative recovery. Patients undergoing elective bariatric surgery, between the 23 February 2015 and 3 April, were randomised to either the popsicle group or control group. Primary endpoint was the incidence of POST and secondly if a reduction in POST influences quality of recovery at the first day postoperative measured with the Bariatric Quality Of Recovery (BQoR) questionnaire. One hundred and thirty-three patients were assessed for eligibility. For the final analysis, 44 patients in the intervention and 65 in the control group were available. Eating a popsicle after bariatric surgery had no significant effect on the incidence of POST. Significant effects (in favour of the popsicle group) were seen in muscle pain score (p = 0.047) and sore mouth score (p = 0.012). Popsicle intragroup analysis revealed that eating the whole popsicle (compared to partially eating the popsicle) has positive effects on nausea (p = 0.059), feeling cold (p = 0.008), and mean total comfort score (p = 0.011). Of the patients who became nauseous and/or had to vomit because of the popsicle, n = 4 had more severe pain (p = 0.04) and the mean pain score was higher (p = 0.09). The present study demonstrates that offering a popsicle early during recovery after bariatric surgery is feasible without adverse effects, although eating popsicle did not reduce postoperative sore throat. There are possible beneficial effects, such as reduced muscle pains and less sore mouth, that may enhance the quality of recovery. More research is necessary to further substantiate the effect of eating popsicles on the quality of recovery in this patient population.Trial Registration: Registration n\Address="http://www.trialregister.nl)

Towards an Inter-disciplinary research agenda on climate Change, Water and Security in Southern Europe and Neighboring Countries

OBJECTIVES: Various studies have shown different parameters as independent risk factors in predicting the success of fast-track postoperative management in cardiac surgery. In the present study, we evaluated our 7-year experience with the fast-track protocol and investigated the preoperative predictors of successful outcome. METHODS: Between 2004 and 2010, 5367 consecutive patients undergoing cardiac surgery were preoperatively selected for postoperative admission in the postanaesthesia care unit (PACU) and were included in this study. These patients were then transferred to the ordinary ward on the same day of the operation. The primary end-point of the study was the success of the PACU protocol, defined as discharge to the ward on the same day, no further admission to the intensive care unit and no operative mortality. Logistic regression analysis was performed to detect the independent risk factors for failure of the PACU pathway. RESULTS: Of 11 895 patients undergoing cardiac surgery, 5367 (45.2%) were postoperatively admitted to the PACU. The protocol was successful in 4510 patients (84.0%). Using the multivariate logistic regression analysis, older age and left ventricular dysfunction were found to be independent risk factors for failure of the PACU protocol [odds ratio of 0.98/year (0.97-0.98) and 0.31 (0.14-0.70), respectively]. CONCLUSIONS: Our fast-track management, called the PACU protocol, is efficient and safe for the postoperative management of selected patients undergoing cardiac surgery. Age and left ventricular dysfunction are significant preoperative predictors of failure of this protocol

HMG-coenzyme A reductase inhibition, type 2 diabetes, and bodyweight: evidence from genetic analysis and randomised trials.

BackgroundStatins increase the risk of new-onset type 2 diabetes mellitus. We aimed to assess whether this increase in risk is a consequence of inhibition of 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), the intended drug target.MethodsWe used single nucleotide polymorphisms in the HMGCR gene, rs17238484 (for the main analysis) and rs12916 (for a subsidiary analysis) as proxies for HMGCR inhibition by statins. We examined associations of these variants with plasma lipid, glucose, and insulin concentrations; bodyweight; waist circumference; and prevalent and incident type 2 diabetes. Study-specific effect estimates per copy of each LDL-lowering allele were pooled by meta-analysis. These findings were compared with a meta-analysis of new-onset type 2 diabetes and bodyweight change data from randomised trials of statin drugs. The effects of statins in each randomised trial were assessed using meta-analysis.FindingsData were available for up to 223 463 individuals from 43 genetic studies. Each additional rs17238484-G allele was associated with a mean 0·06 mmol/L (95% CI 0·05-0·07) lower LDL cholesterol and higher body weight (0·30 kg, 0·18-0·43), waist circumference (0·32 cm, 0·16-0·47), plasma insulin concentration (1·62%, 0·53-2·72), and plasma glucose concentration (0·23%, 0·02-0·44). The rs12916 SNP had similar effects on LDL cholesterol, bodyweight, and waist circumference. The rs17238484-G allele seemed to be associated with higher risk of type 2 diabetes (odds ratio [OR] per allele 1·02, 95% CI 1·00-1·05); the rs12916-T allele association was consistent (1·06, 1·03-1·09). In 129 170 individuals in randomised trials, statins lowered LDL cholesterol by 0·92 mmol/L (95% CI 0·18-1·67) at 1-year of follow-up, increased bodyweight by 0·24 kg (95% CI 0·10-0·38 in all trials; 0·33 kg, 95% CI 0·24-0·42 in placebo or standard care controlled trials and -0·15 kg, 95% CI -0·39 to 0·08 in intensive-dose vs moderate-dose trials) at a mean of 4·2 years (range 1·9-6·7) of follow-up, and increased the odds of new-onset type 2 diabetes (OR 1·12, 95% CI 1·06-1·18 in all trials; 1·11, 95% CI 1·03-1·20 in placebo or standard care controlled trials and 1·12, 95% CI 1·04-1·22 in intensive-dose vs moderate dose trials).InterpretationThe increased risk of type 2 diabetes noted with statins is at least partially explained by HMGCR inhibition.FundingThe funding sources are cited at the end of the paper