Effects of empagliflozin on progression of chronic kidney disease: a prespecified secondary analysis from the empa-kidney trial

BACKGROUND

Sodium-glucose co-transporter-2 (SGLT2) inhibitors reduce progression of chronic kidney disease and the risk of cardiovascular morbidity and mortality in a wide range of patients. However, their effects on kidney disease progression in some patients with chronic kidney disease are unclear because few clinical kidney outcomes occurred among such patients in the completed trials. In particular, some guidelines stratify their level of recommendation about who should be treated with SGLT2 inhibitors based on diabetes status and albuminuria. We aimed to assess the effects of empagliflozin on progression of chronic kidney disease both overall and among specific types of participants in the EMPA-KIDNEY trial.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA), and included individuals aged 18 years or older with an estimated glomerular filtration rate (eGFR) of 20 to less than 45 mL/min per 1·73 m2, or with an eGFR of 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher. We explored the effects of 10 mg oral empagliflozin once daily versus placebo on the annualised rate of change in estimated glomerular filtration rate (eGFR slope), a tertiary outcome. We studied the acute slope (from randomisation to 2 months) and chronic slope (from 2 months onwards) separately, using shared parameter models to estimate the latter. Analyses were done in all randomly assigned participants by intention to treat. EMPA-KIDNEY is registered at ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and then followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroups of eGFR included 2282 (34·5%) participants with an eGFR of less than 30 mL/min per 1·73 m2, 2928 (44·3%) with an eGFR of 30 to less than 45 mL/min per 1·73 m2, and 1399 (21·2%) with an eGFR 45 mL/min per 1·73 m2 or higher. Prespecified subgroups of uACR included 1328 (20·1%) with a uACR of less than 30 mg/g, 1864 (28·2%) with a uACR of 30 to 300 mg/g, and 3417 (51·7%) with a uACR of more than 300 mg/g. Overall, allocation to empagliflozin caused an acute 2·12 mL/min per 1·73 m2 (95% CI 1·83-2·41) reduction in eGFR, equivalent to a 6% (5-6) dip in the first 2 months. After this, it halved the chronic slope from -2·75 to -1·37 mL/min per 1·73 m2 per year (relative difference 50%, 95% CI 42-58). The absolute and relative benefits of empagliflozin on the magnitude of the chronic slope varied significantly depending on diabetes status and baseline levels of eGFR and uACR. In particular, the absolute difference in chronic slopes was lower in patients with lower baseline uACR, but because this group progressed more slowly than those with higher uACR, this translated to a larger relative difference in chronic slopes in this group (86% [36-136] reduction in the chronic slope among those with baseline uACR <30 mg/g compared with a 29% [19-38] reduction for those with baseline uACR ≥2000 mg/g; ptrend<0·0001).

INTERPRETATION

Empagliflozin slowed the rate of progression of chronic kidney disease among all types of participant in the EMPA-KIDNEY trial, including those with little albuminuria. Albuminuria alone should not be used to determine whether to treat with an SGLT2 inhibitor.

FUNDING

Boehringer Ingelheim and Eli Lilly.

Impact of primary kidney disease on the effects of empagliflozin in patients with chronic kidney disease: secondary analyses of the EMPA-KIDNEY trial

BACKGROUND

The EMPA-KIDNEY trial showed that empagliflozin reduced the risk of the primary composite outcome of kidney disease progression or cardiovascular death in patients with chronic kidney disease mainly through slowing progression. We aimed to assess how effects of empagliflozin might differ by primary kidney disease across its broad population.

METHODS

EMPA-KIDNEY, a randomised, controlled, phase 3 trial, was conducted at 241 centres in eight countries (Canada, China, Germany, Italy, Japan, Malaysia, the UK, and the USA). Patients were eligible if their estimated glomerular filtration rate (eGFR) was 20 to less than 45 mL/min per 1·73 m2, or 45 to less than 90 mL/min per 1·73 m2 with a urinary albumin-to-creatinine ratio (uACR) of 200 mg/g or higher at screening. They were randomly assigned (1:1) to 10 mg oral empagliflozin once daily or matching placebo. Effects on kidney disease progression (defined as a sustained ≥40% eGFR decline from randomisation, end-stage kidney disease, a sustained eGFR below 10 mL/min per 1·73 m2, or death from kidney failure) were assessed using prespecified Cox models, and eGFR slope analyses used shared parameter models. Subgroup comparisons were performed by including relevant interaction terms in models. EMPA-KIDNEY is registered with ClinicalTrials.gov, NCT03594110.

FINDINGS

Between May 15, 2019, and April 16, 2021, 6609 participants were randomly assigned and followed up for a median of 2·0 years (IQR 1·5-2·4). Prespecified subgroupings by primary kidney disease included 2057 (31·1%) participants with diabetic kidney disease, 1669 (25·3%) with glomerular disease, 1445 (21·9%) with hypertensive or renovascular disease, and 1438 (21·8%) with other or unknown causes. Kidney disease progression occurred in 384 (11·6%) of 3304 patients in the empagliflozin group and 504 (15·2%) of 3305 patients in the placebo group (hazard ratio 0·71 [95% CI 0·62-0·81]), with no evidence that the relative effect size varied significantly by primary kidney disease (pheterogeneity=0·62). The between-group difference in chronic eGFR slopes (ie, from 2 months to final follow-up) was 1·37 mL/min per 1·73 m2 per year (95% CI 1·16-1·59), representing a 50% (42-58) reduction in the rate of chronic eGFR decline. This relative effect of empagliflozin on chronic eGFR slope was similar in analyses by different primary kidney diseases, including in explorations by type of glomerular disease and diabetes (p values for heterogeneity all >0·1).

INTERPRETATION

In a broad range of patients with chronic kidney disease at risk of progression, including a wide range of non-diabetic causes of chronic kidney disease, empagliflozin reduced risk of kidney disease progression. Relative effect sizes were broadly similar irrespective of the cause of primary kidney disease, suggesting that SGLT2 inhibitors should be part of a standard of care to minimise risk of kidney failure in chronic kidney disease.

FUNDING

Boehringer Ingelheim, Eli Lilly, and UK Medical Research Council.

A machine-learning approach for decision support and risk stratification of pediatric perioperative patients based on the APRICOT dataset

BACKGROUND

Pediatric anesthesia has evolved to a high level of patient safety, yet a small chance remains for serious perioperative complications, even in those traditionally considered at low risk. In practice, prediction of at-risk patients currently relies on the American Society of Anesthesiologists Physical Status (ASA-PS) score, despite reported inconsistencies with this method.

AIMS

The goal of this study was to develop predictive models that can classify children as low risk for anesthesia at the time of surgical booking and after anesthetic assessment on the procedure day.

METHODS

Our dataset was derived from APRICOT, a prospective observational cohort study conducted by 261 European institutions in 2014 and 2015. We included only the first procedure, ASA-PS classification I to III, and perioperative adverse events not classified as drug errors, reducing the total number of records to 30 325 with an adverse event rate of 4.43%. From this dataset, a stratified train:test split of 70:30 was used to develop predictive machine learning algorithms that could identify children in ASA-PS class I to III at low risk for severe perioperative critical events that included respiratory, cardiac, allergic, and neurological complications.

RESULTS

Our selected models achieved accuracies of >0.9, areas under the receiver operating curve of 0.6-0.7, and negative predictive values >95%. Gradient boosting models were the best performing for both the booking phase and the day-of-surgery phase.

CONCLUSIONS

This work demonstrates that prediction of patients at low risk of critical PAEs can be made on an individual, rather than population-based, level by using machine learning. Our approach yielded two models that accommodate wide clinical variability and, with further development, are potentially generalizable to many surgical centers.

How do we measure organisational wellness? Development of a comprehensive patient-centred and employee-centred visual analytical solution

BACKGROUND

Dashboards are visual information systems frequently employed by healthcare organisations to track key quality improvement and patient safety performance metrics. The typical healthcare dashboard focuses on specific metrics, disease processes or units within a larger healthcare organisation. Here, we describe the development of a visual analytical solution (keystone dashboard) for monitoring an entire healthcare organisation.

METHODS

The improvement team reviewed and assessed various data sources across the organisation and selected a group of patient and employee related metrics that afforded a broad overview of the organisation's well-being. Metrics spanned the organisation and included data from patient safety, quality improvement, human resources, risk management and medical staff affairs. Each metric was assigned a numeric weight that correlated with its impact. A visual model incorporating the various data fields was then constructed.

RESULTS

The keystone dashboard incorporates a data heatmap and density visualisation to emphasis areas of higher density and/or weighted values. The heatmap is used to indicate the weight/magnitude of each metric within a data range in two dimensions: location and time. The visualisation 'heats up' depending on the combination of counts events and their assigned impact for the reporting month. Most data sources update in near real time.

SUMMARY

The keystone dashboard serves as a comprehensive and collaborative integration of data from patient safety, quality improvement, human resources, risk management and medical staff affairs. This visual analytical solution incorporates and analyses metrics into a single view with the intent of providing valuable insight into the health of an entire organisation. This dashboard is unique as it provides a broad overview of a healthcare organisation by incorporating key metrics that span the organisation.

Timely completion of spinal fusion: A multidisciplinary quality improvement initiative to improve operating room efficiency

BACKGROUND

Failure to complete surgery within the scheduled timeframe impairs operating room efficiency leading to patient dissatisfaction and unplanned labor costs. We sought to improve timely completion (within 30 min of scheduled time) of first-case spine fusion surgery (for idiopathic scoliosis) from a baseline of 25%-80% over 12 months. We also targeted timely completion of perioperative stages within predetermined target completion times.

METHODS

The project was conducted in three overlapping phases over 16 months. A simplified process map outlining five sequential perioperative stages, preintervention baselines (N = 24) and time targets were defined. A multidisciplinary team conducted a series of tests of change addressing the aims. The key drivers included effective scheduling, team communications, family engagement, data collection veracity, standardized pathways, and situational awareness. Data collected by an independent data collector and from electronic medical records were analyzed using control charts and statistical process control methods.

RESULTS

Post-intervention, timely case completion increased from 25% to 68% (N = 49) (95% CI 15.1-62.7), (p = 0.003) and was sustained (N = 14). Implementation of prediction model for case-scheduling decreased difference between scheduled and actual case end-time (33 vs. 53 min [baseline]) and variance [lower/upper control limits ([-26, 51] vs. [-109, 216] min [baseline]). Average start time delay decreased from 6 to 2 min and on-time surgical starts improved from 50% to 70% (95% CI 3.2-41.6%). Timely completion increased for anesthesia induction (60% to 85%), surgical procedure (26% to 48%) and emergence from anesthesia (44% to 80%) but not for intraoperative patient preparation (30% to 25%) perioperative stages. Families reported satisfaction with preoperative processes (N = 14), and no untoward intraoperative safety events occurred.

CONCLUSIONS

Application of QI methodology reduced time variation of several tasks and improved timely completion of spine surgery. Beyond the study period, sustained team behavior, adaptive changes, and vigilant monitoring are imperative for continued success.

Factors Associated With Postadenotonsillectomy Unexpected Admissions in Children

BACKGROUND

Postadenotonsillectomy unexpected admission remains an important challenge. Unexpected admissions can be quite frightening, increase health care burden, and cause unnecessary suffering in children and families. Identifying factors associated with postadenotonsillectomy unexpected admissions using a pragmatic approach could lead to a shift in the assessment and management of children presenting for adenotonsillectomy.

METHODS

Institutional review board (IRB) approval, consent, and assent were obtained for this single-center, prospective, observational study done in children aged 0-17 years undergoing tonsillectomy. Data were collected from direct observation, electronic medical record, and phone calls using Research Electronic Data Capture (REDCap) database. Incidence, causes, and factors associated with 3-week and 3-day postadenotonsillectomy unexpected admissions were analyzed.

RESULTS

The study included 2375 children. Clinical intraoperative adverse events were reported in 6.2%. Three-week and 3-day unexpected admissions occurred in 7.9% and 5.9%, respectively, with bleeding being the commonest reason for both. On multivariable analysis, for 3-week unexpected admissions, the odds ratio was 2.3 (95% confidence interval, 1.45-1.69) with using preoperative medications, 1.4 (1.02-1.97) with home medications for comorbidities, 0.56 (0.34-0.90) with using intraoperative acetaminophen, and 0.60 (0.36-0.94) with otolaryngologic preoperative comorbidity versus otherwise. For 3-day unexpected admissions, the odds ratio was 1.10 (1.05-1.16) with 1 U increase in total comorbidities, 1.70 (1.03-2.81) with the presence of recent upper respiratory infection, and 1.83 (1.16-2.90) with intravenous versus inhalational anesthesia induction.

CONCLUSIONS

Overall, our study shows the factors that contribute to unexpected admissions postadenotonsillectomy. Identification of both modifiable and nonmodifiable factors associated with unexpected admissions after adenotonsillectomy will enable appropriate risk mitigation.

Infusion Medication Error Reduction by Two-Person Verification: A Quality Improvement Initiative

OBJECTIVE

Errors made in the administration of intravenous medication can lead to catastrophic harm. The frequency of hospital settings in which medication pumps are being used are increasing. We sought to improve medication safety by implementing a 2-person verification system before medication administration.

METHODS

Our quality improvement initiative took place in an anesthesia radiology imaging service at a tertiary pediatric hospital. Key drivers included frequent educational meetings with clinicians, written reminders, display of visual reminders, constant feedback in the clinical areas that carried out the processes, and sharing of knowledge on displayed run charts. A multidisciplinary team conducted a series of tests of changes to address the interventions. Data were collected and entered into a database by an independent and impartial data collector. Data were analyzed via run charts and statistical process control methods.

RESULTS

The team ran 24 plan-do-study-act ramps. The rate of 2-person verification of infusion pump programming increased from 0% to 90% and was sustained. Overall, 4 errors were rectified before the medication was administered to the patient. There was no delay in case starts (>90% before and during the project). This project played a key role, as part of a larger initiative within the department of anesthesia, in reducing medication errors.

CONCLUSIONS

A brief 2-person verification approach can reduce medication errors due to inaccurate infusion pump programming. This improvement was achieved with the use of plan-do-study-act cycles. The impact can be significant and will promote a hospital safety culture.

A quality improvement project to reduce the intraoperative use of single-dose fentanyl vials across multiple patients in a pediatric institution

OBJECTIVE

The use of a single-dose vial across multiple patients presents a risk to sterility and is against CDC guidelines. We initiated a quality improvement (QI) project to reduce the intraoperative use of single-dose vials of fentanyl across multiple patients at Cincinnati Children's Hospital Medical Center (CCHMC).

METHODS

The initial step of the improvement project was the development of a Key Driver Diagram. The diagram has the SMART aim of the project, key drivers inherent to the process we are trying to improve, and specific interventions targeting the key drivers. The number of patients each week receiving an IV dose of fentanyl, from a vial previously accessed for another patient was tracked in a high turnover operating room (OR). The improvement model used was based on the concept of building Plan-Do-Study-Act (PDSA) cycles. Tests of change included provider education, provision of an increased number of fentanyl vials, alternate wasting processes, and provision of single-use fentanyl syringes by the pharmacy.

RESULTS

Prior to initiation of this project, it was common for a single fentanyl vial to be accessed for multiple patients. Our data showed an average percentage of failures of just over 50%. During the end of the project, after 7 months, the mean percentage failures had dropped to 5%. Preparation of 20 mcg single-use fentanyl syringes by pharmacy, combined with education of providers on appropriate use, was successful in reducing failures to below our goal of 25%.

CONCLUSIONS

Appropriately sized fentanyl syringes prepared by pharmacy, education on correct use of single-dose vials, and reminders in the OR, reduced the percentage of patients receiving a dose of fentanyl from a vial previously accessed for another patient in a high-volume otolaryngology room.

Development of a nurse-assisted preanesthesia evaluation program for pediatric outpatient anesthesia

BACKGROUND

Historically, anesthesiologists have conducted preanesthesia evaluation, but more recently, nurse practitioners (NPs) are increasingly assisting with the preanesthesia evaluation of children. In the current economic environment for healthcare, strategies to provide superior outcomes and exceptional patient experience at the lowest possible cost are constantly being explored. We examined whether well trained nurses, working alongside NPs, could safely and effectively assist in preanesthesia evaluation. The aim of this quality improvement project was to implement a new model for preanesthesia evaluation for healthy outpatient pediatric patients: nurse-assisted preanesthesia evaluation (NAPE).

METHODS

Using quality improvement methods, Key Driver Diagrams and SMART aims gave direction for the training and clinical implementation of this new process. Using small tests of change and Plan-Do-Study-Act cycles, we developed a training process and a stepwise process to integrate them into the clinical work flow. The primary outcome measure was the proportion of the total preanesthesia evaluations in which the Anesthesia Nurses assisted. To ensure quality and safety, data on balancing measures and quality metrics were collected.

RESULTS

The weekly percentage of outpatients evaluated by Anesthesia Nurses increased from 0% to 55% within the first 4 months and was then sustained. The remaining patients were evaluated by the Anesthesia NPs. The balancing measures did not show any significant negative effect. Our perioperative quality metrics were also not changed significantly.

CONCLUSION

Using quality improvement methods, we successfully improved the utilization of staff resources by adding an Anesthesia Nurse-assisted preanesthesia evaluation program alongside our NPs to provide outstanding preanesthesia care at the lowest possible cost.

Wake Up Safe and root cause analysis: quality improvement in pediatric anesthesia

In 2006, the Quality and Safety Committee of the Society for Pediatric Anesthesia initiated a quality improvement project for the specialty of pediatric anesthesiology that ultimately resulted in the development of Wake Up Safe (WUS), a patient safety organization that maintains a registry of de-identified, serious adverse events. The ultimate goal of WUS is to implement change in processes of care that improve the quality and safety of anesthetic care provided to pediatric patients nationwide. Member institutions of WUS submit data regarding the types and numbers of anesthetics performed and information pertaining to serious adverse events. Before a member institution submits data for any serious adverse event, 3 anesthesiologists who were not involved in the event must analyze the event with a root cause analysis (RCA) to identify the causal factor(s). Because institutions across the country use many different RCA methods, WUS educated its members on RCA methods in an effort to standardize the analysis and evaluate each serious adverse event that is submitted. In this review, we summarize the background and development of this patient safety initiative, describe the standardized RCA method used by its members, demonstrate the use of this RCA method to analyze a serious event that was reported, and discuss the ways WUS plans to use the data to promote safer anesthetic practices for children.

Cost-effectiveness of intravenous acetaminophen for pediatric tonsillectomy

OBJECTIVE

The primary outcome of this study was to examine the cost-effectiveness of the intraoperative combination of intravenous (IV) acetaminophen and IV opioids, versus IV opioids alone, as a part of an inhalational anesthetic technique for tonsillectomy in children.

METHODS

We used Decision Maker® software to construct and analyze a decision analytic model. Base-case and sensitivity analyses were performed. We studied the use of rescue analgesics in the postanesthesia care unit (PACU), adverse effects of acetaminophen and opioids, and costs associated with adverse effects. Costs were in 2013 US dollars, and effectiveness was measured as frequency of avoiding the need for rescue analgesics. Direct medical costs included medication, equipment, supplies, and labor associated with the treatment of adverse events from pain medications. Medication costs assumed single-dose vials.

RESULTS

In the base case, IV acetaminophen in combination with opioids was both less costly ($17.12) and more effective (3.3% fewer rescue events). In sensitivity analyses, the combination strategy remained cost-effective as long as the frequency of rescue analgesic administration was less than that in the opioid-alone strategy. Although medication costs of the combination strategy were higher, the overall costs were less than the competing strategy due to reduced adverse effects and reduced time spent in PACU.

CONCLUSIONS

The routine use of IV acetaminophen as an adjuvant to IV opioids for tonsillectomy with or without adenoidectomy in children aged <17 years should be considered as a means to reduce the need for rescue analgesia and in turn reduce costs.

Perspectives on quality and safety in pediatric anesthesia

Organizational culture underlies every improvement strategy; without a strong culture, a change, even if initially successful, is short lived. Changing culture and improving quality require commitment of leadership, and leaders must play an active and visible role to articulate the vision and create the proper environment. Quality-improvement projects require a consistent framework for outlining a process, identifying problems, and testing, evaluating, and implementing changes. Wake Up Safe is a patient safety organization that strives to use quality improvement to make anesthesia care safer. Root cause analysis is a methodology in safety analytics based on a sequence of events model of safety.

Future of pediatric tonsillectomy and perioperative outcomes

OBJECTIVE

Although commonly performed, pediatric tonsillectomy is not necessarily a low risk procedure due to potentially life threatening perioperative complications. There is paucity of literature on lethal anesthesia and surgical complications of tonsillectomy. In this article, we have reviewed both minor and serious complications following tonsillectomy. Hemorrhage, burn injuries, respiratory complications, postoperative nausea and vomiting, and pain management are discussed. We have highlighted our practice of pain management at Cincinnati Children's Hospital after tonsillectomy recent warning about codeine by the FDA on children undergoing tonsillectomy. We describe post-tonsillectomy outcomes including postanesthesia care unit stay, post discharge maladaptive behavioral outcomes and finally effective ways to identify children at risk for anesthesia and a few preventive strategies.

METHODS

In addition to literature review, the LexisNexis "MEGA™ Jury Verdicts and Settlements" database was reviewed from 1984 through 2010 for deaths and complications during and following tonsillectomy. Data including year of case, cause of death, surgical, anesthetic and postoperative opioid related complications, injury, case result, and judgment awarded were collected and analyzed.

RESULTS

The results of this analysis are presented with an emphasis on hemorrhage and on anesthesia and opioid related claims and their characteristics. Two hundred and thirty-three claim reports were reviewed. There were 96 deaths (41%) and 137 perioperative injuries (59%). Deaths were primarily related to surgery (n=46, 48%) with post-tonsillectomy bleed the most frequent cause (n=38, 40%) followed by opioid toxicity (n=17, 18%) and anesthesia complications (n=9, 9%). Non-fatal injuries included, postoperative bleeding (n=59, 25%), impaired function (n=29, 12%), anoxic events (n=20, 9%) and postoperative opioid toxicity (n=20, 8.6%). Anoxic event was noted to have the highest monetary award with a mean award at $9,017,379. Injuries (including anoxia) had higher mean monetary awards than deaths.

CONCLUSION

Tonsillectomy in children carries a high risk of perioperative complications and malpractice claims. Though postoperative bleeding is the most common complication associated with malpractice claims, anoxia related to anesthesia and opioids had the greatest overall risk from a monetary standpoint.

The use of perioperative antibiotics in tonsillectomy: does it decrease morbidity?

OBJECTIVE

To assess the efficacy of perioperative antibiotics in decreasing post-operative morbidity among patients undergoing tonsillectomy or adenotonsillectomy.

DESIGN

Meta-analysis based on a structured search of the literature, using MEDLINE and the Cochrane database.

SUBJECTS

Only articles, which included both treatment and control groups, were included in the final analysis. Studies were limited to ones that involved human subjects, including both children and adults. Studies using steroids and topical antibiotics were excluded.

OUTCOMES

Articles were abstracted for patient factors, elements of study design, methods of patient assignment to treatment and control groups, and clinical outcomes. The primary outcome, time required for return to normal oral intake, was analyzed in the final meta-analysis.

METHODS

Four hundred and twenty-eight articles were initially identified. There were 23 potentially appropriate articles. Of these, 18 were able to be located in full text form and in English. Seven of these studies directly studied the efficacy of perioperative antibiotics (versus no antibiotics) in decreasing post-operative morbidity. Four studies had sufficient information to calculate effects estimates (xi) and standard deviations (Si) for the primary outcome. Three studies either did not report the outcome of interest or did not report a measure of stability (e.g. p-value or confidence interval). The data available from the first four studies were combined in a quantitative meta-analysis. Statistical analyses were performed using STATA for Windows software.

RESULTS

The pooled estimate indicated that the antibiotic group returned to normal oral intake, on average, 1 day sooner than the controls. This difference was found to be statistically significant with a 95% confidence interval of 0.5-1.6 days. An additional assessment of three qualitative reports also suggested the use of perioperative antibiotics for adenotonsillectomy was associated with less post-operative pain. However, studies varied in terms of study quality, sample size, outcome examined, measure used and antibiotic administered. Definitive conclusions regarding the effect of perioperative antibiotics on other outcomes including bleeding, halitosis, fever, activity level and nausea and vomiting could not be drawn due to the small numbers of studies.

CONCLUSIONS

In this meta-analysis, the use of perioperative antibiotics in patients who have had tonsillectomy or adenotonsillectomy appears to be associated with a 1-day reduction in the time required for return to normal oral intake. For other potentially important outcomes, such as post operative pain or bleeding, sufficient data were not available to make any definitive conclusions regarding the effect of perioperative antibiotics.

Management of thymoma. A retrospective study

Thymoma is a relatively rare tumour. Twelve cases seen in Kuwait Cancer Control Centre over a period of 10 years were analyzed. Two patients had Myasthenia gravis at presentation, and one developed it after the treatment, during remission. Six patients had total resection and four had subtotal resection of the tumour; the remaining had only diagnostic biopsy. All the six patients who had total resection were alive, disease-free with three of them Stage III, whereas, of the four cases who had subtotal resection two are dead, one with local disease and the other with pulmonary metastases. Eight patients were given postoperative radiotherapy and none of them relapsed at the primary site. Of the three patients who had chemotherapy, two had partial remission, and the remaining one failed to show any response. Patients with predominantly epithelial type histology fared worse compared to predominantly lymphocytic type and mixed cell type. Histological subtypes, invasiveness of the tumour and completeness of resection and association of Myasthenia gravis as prognostic features are discussed. The role of radiotherapy and chemotherapy as adjunctive treatment to surgery is reviewed.

Cardiovascular Syncope

In brief Something as benign as a vasovagal reflex or as serious as hypertrophic cardiomyopathy can cause cardiovascular syncope. A thorough medical history and physical examination often provide clues to the underlying etiology. Laboratory tests such as a head-up tilt test, an event recorder, or a signal-averaged ECG can provide further diagnostic information. Treatment may include such simple measures as recommending that the patient avoid the sight of blood, or it may mean prescribing drug therapy or correcting a heart defect. Usually, an athlete can resume exercise after a syncopal episode, but sometimes modifications of activities are necessary.

Forum

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Consequences of angiotensin-converting enzyme inhibitor overdose

Overdose with angiotensin-converting enzyme (ACE) inhibitors is still a relatively underreported phenomenon. We report here a case of an unintentional overdose of enalapril (100 mg) together with other medications. The patient experienced no adverse consequences. Pharmacokinetic evaluation revealed a t 1/2 for enalaprilat (prodrug) of seven hours and for enalapril at 36 hours. Based on this case report as well as others, guidelines for assessment and treatment of these patients are proposed. Management of hypotension is the primary therapeutic intervention.

Ethambutol kinetics in patients with impaired renal function

The pharmacokinetics of ethambutol (EMB) were investigated in 13 hospitalized patients with varying degrees of compromised renal function. Each patient was administered 15 mg/kg EMB by a constant-rate, 1-h infusion. Plasma and urine samples were collected for as long as 24 and 96 h, respectively, for analysis of EMB by electron capture gas-liquid chromatography. Plasma EMB concentrations appeared to decline multi-exponentially, with a terminal phase half-life of 7.4 to 11.8 h. Total body clearance of EMB ranged from 2.0 to 9.6 ml/min/kg and the steady-state volume of distribution from 0.80 to 3.60 L/kg. The fraction of EMB dose excreted unchanged in the urine varied from 0.03 to 0.26, and renal clearance varied from 0.07 to 0.57 ml/min/kg. The results of this study clearly indicate that renal failure decreases total body clearance and renal clearance and prolongs elimination half-life of EMB when compared with that in normal volunteers. The terminal phase elimination rate constant correlated significantly with creatinine clearance and the reciprocal of serum creatinine (y = 0.037 X +0.060, r = 0.795, p less than 0.05; y = 0.042 X +0.061, r = 0.783, p less than 0.05, respectively). Either creatinine clearance or serum creatinine of an individual patient would thus serve as a useful predictor for his or her capacity to eliminate EMB. Dosage adjustment is mandatory for EMB in patients with compromised renal function in order to achieve optimal therapy and to avoid undesirable side effects.

Disposition kinetics of ethambutol in nephrectomized dogs

The effect of nephrectomy on the disposition of ethambutol was investigated in seven adult mongrel dogs: five were nephrectomized and two served as the control. Each dog was intravenously administered 500 mg ethambutol, followed by blood sample collection for 12 h. Total urine was collected over 24 h from the normal control dogs. Ethambutol contents in plasma and urine were assayed by a GC method. The nephrectomized group and the control group exhibited differences in the following pharmacokinetic parameters: half-life, 5.0 versus 4.1 h (significant at p less than 0.1); total body clearance, 8.4 versus 13.2 mL/min/kg (significant at p less than 0.1); and volume of distribution, 2.7 versus 3.8 L/kg (significant at p less than 0.1). Comparison of pharmacokinetic parameters among rabbits, dogs, and humans revealed distinct interspecies differences with regard to total body clearance, renal clearance, volume of distribution, and fractional renal excretion. One comparable parameter shared by all species is the beta-phase half-life.

Synthesis of [1-14C]1,2-cyclohexanedione bis(4-diethylenoxythiosemicarbazone) and preliminary biodistribution studies of this potential antitumor agent

A new compound, [1-14C]1,2-cyclohexanedione-bis(4-diethylenoxythiosemicarbazone) was found to have significant antitumor activity (% T/C = 245) when tested against sarcoma-180 ascites tumor in mice and thus may be a potentially useful drug. The compound can be easily labeled with 14C by employing the straightforward synthetic procedures detailed in this article. Results of the synthesis and purification are presented. Preliminary biodistribution studies of the labeled compound in both normal and tumor bearing mice were performed. The compound, when administered i.p., is rapidly absorbed and localized into most tissues. Urinary and biliary excretion are its major routes of elimination. Based on these studies, continued evaluation is recommended.