A cross-validated multifactorial index of perioperative risks in adults undergoing anaesthesia for non-cardiac surgery. Analysis of perioperative events in 26907 anaesthetic procedures

Comparing peri-operative complications of paediatric and adult anaesthesia: A retrospective cohort study of 81 267 cases

BACKGROUND

Comparisons of peri-operative complications associated with paediatric (≤16 years) and adult anaesthesia are poorly available, especially in which cardiac surgery, organ transplantation and neurosurgery are involved.

OBJECTIVE

The aim of this study was to evaluate the nature and incidence of peri-operative complications that might be due to anaesthesia and to identify independent risk factors for complications in children and adults, including those undergoing cardiac surgery, organ transplantation and neurosurgery.

DESIGN

Retrospective cohort study.

SETTING

The study was performed at the University Medical Centre Groningen in the 4 years between 1 January 2010 and the 31 December 2013.

MAIN OUTCOME MEASURES

Complications and their severity were graded according to the standard complication score (20 items) of the Dutch Society of Anaesthesia. Univariate and multivariate regression analysis was used to identify independent risk factors for the reported complications.

RESULTS

A total of 81 267 anaesthetic cases were included. In the paediatric cohort, there were 410 (2.9%) complications and 1675 (2.5%) in the adults. In both cohorts age, American Society of Anaesthesiologists classification and emergency treatment were independent risk factors for complications. With respect to age, infants less than 1 year were at the highest risk, whereas in the adult cohort, increased age was related to a greater number of complications. The incidences of the specific complications were different between both cohorts. Upper airway obstruction was more frequently observed in paediatric patients (26%), whereas in the adults, complications with the highest incidence concerned conversion of regional-to-general anaesthesia (25%) and hypotension (17%).

CONCLUSION

Risk factors for all peri-operative complications were similar for paediatric and adult anaesthesia. However, the incidence of specific complications differed between both age categories.

Provider Board Certification Status and Practice Patterns in Total Knee Arthroplasty

PURPOSE

The presumption that board certification directly affects the quality of clinical care is a topic of ongoing discussion in medical literature. Recent studies have demonstrated disparities in patient outcomes associated with type of anesthesia provided for total knee arthroplasty (TKA); improved outcomes are associated with neuraxial (or regional) versus general anesthesia. Whether board-certified (BC) and non-board-certified (nBC) anesthesiologists make different choices in the anesthetic they administer is unknown. The authors sought to study potential associations of board certification status with anesthesia practice patterns for TKA.

METHOD

The authors accessed records of anesthetics provided from 2010 to 2013 from the National Anesthesia Clinical Outcomes Registry database. They identified TKA cases using Clinical Classifications Software and Current Procedural Terminology codes. The authors divided practitioners into two groups: those who were BC and those who were nBC. For each of these groups, the authors compared the following: their patient populations, the hospitals in which they worked, the nature of their practices, and the anesthetics they administered to their patients.

RESULTS

BC anesthesiologists provided care for 81.7% of 97,508 patients having TKA; 18.3% were treated by nBC anesthesiologists. BC anesthesiologists administered neuraxial/regional anesthesia more frequently than nBC anesthesiologists (41.4% versus 21.2%; P < .001).

CONCLUSIONS

The rates at which regional/neuraxial anesthesia were administered for TKA were relatively low, and there were significant differences in practice patterns of BC and nBC anesthesiologists providing care for patients undergoing TKA. More research is necessary to understand the causes of these disparities.

Reporting critical incidents in a tertiary hospital: a historical cohort study of 110,310 procedures

Purpose

Investigation of adverse events associated with anesthetic procedures is a method of quality control that identifies topics to improve clinical care and patient safety. Most research to date has been based on closed claim registries and anonymous reports which have specific limitations. Therefore, to evaluate a hospital’s reporting system, the present study was designed to describe critical incidents that anesthesiologists voluntarily and non-anonymously reported through an anesthesia information management system.

Methods

This is a historical observational cohort study on patients (age > 18 yr) undergoing anesthetic procedures in a tertiary referral hospital. A 20-item list of complications, as developed by the Netherlands Society of Anesthesiologists, was prospectively completed for each procedure. All critical incidents registered in the anesthesia information management system were then reclassified into 95 different critical incidents in a reproducible way.

Results

There were 110,310 procedures performed in 65,985 patients, and after excluding 158 reports that did not depict a critical incident, 3,904 critical incidents in 3,807 (3.5%) anesthetic procedures remained. Technical difficulties with regional anesthesia (n = 445; 40 per 10,000 anesthetics; 95% confidence interval [CI], 36 to 44), hypotension (n = 432; 39 per 10,000 anesthetics; 95% CI, 35 to 43), and unexpected difficult intubation (n = 216; 20 per 10,000 anesthetics; 95% CI, 18 to 23) were the most frequently documented critical incidents.

Conclusion

Accurate measurement and monitoring of critical incidents is crucial for patient safety. Despite the risk of underreporting and probable misclassification of manual reporting systems, our results give a comprehensive overview on the occurrence of voluntarily reported anesthesia-related critical incidents. This overview can direct development of a new reporting system and preventive strategies to decrease the future occurrence of critical incidents.

Anesthesia-related critical incidents in the perioperative period in children; a proposal for an anesthesia-related reporting system for critical incidents in children

BACKGROUND

The incidence, type and severity of anesthesia-related critical incidents during the perioperative phase has been investigated less in children than in adults.

AIM

The aim of the study was to identify and analyze anesthesia-related critical incidents in children to identify areas to improve current clinical practice, and to propose a specialized anesthesia-related critical incidence registration for children.

METHOD

All reported pediatric anesthesia-related critical incidents reported on a voluntary reporting based on a 20-item complication list of the Dutch Society of Anesthesiology between January 2007 and August 2013 were analyzed. An anesthesia-related critical incident was defined as 'any incident that affected, or could have affected, the safety of the patient while under the care of an anesthetist'. As the 20-item complications list was too crude for detailed analyses, all critical incidents were reclassified into the more detailed German classification lists with the adjustment of specific items for children (in total 10 categories with 101 different subcategories).

RESULTS

During the 6-year period, a total of 1214 critical incidents were reported out of 35 190 anesthetics (cardiac and noncardiac anesthesia cases). The most frequently reported incidents (46.5%) were related to the respiratory system. Infants <1 year, children with ASA physical status III and IV, and emergency procedures had a higher rate of adverse incidents.

CONCLUSION

Respiratory events were the most reported commonly critical incidents in children. Both the Dutch and German existing lists of critical incident definitions appeared not to be sufficient for accurate classification in children. The present list can be used for a new registration system for critical incidents in pediatric anesthesia.

Apnea-hypopnea index use among intensive care patients: a case series

INTRODUCTION

ApneaLink™ (RESMED-Munich, Germany) is a simple and inexpensive device that determines the apnea-hypopnea index. The sensitivity and specificity of the apnea-hypopnea index are 100 and 87.5%, respectively. Our hypothesis can be used to create a treatment plan using the apnea-hypopnea index for intensive care unit patients.

CASE PRESENTATION

This treatment plan has been created by determining the apnea-hypopnea index of eight Caucasian patients with a variety of diagnoses. Case 1 is that of a 70-year-old man diagnosed with rectum cancer and scheduled for elective surgery. Case 2 is that of a 65-year-old man diagnosed with rectum cancer and scheduled for elective surgery. Case 3 is that of a 78-year-old woman diagnosed with chronic obstructive pulmonary disease-pneumonia. Case 4 is that of a 26-year-old man diagnosed with head trauma. Case 5 is that of an 80-year-old man diagnosed with cerebrovascular disease. Case 6 is that of a 79-year-old man diagnosed with cerebrovascular disease. Case 7 is that of an 8-year-old girl diagnosed with ventricular septal defect-epidural hemorragia. Case 8 is that of a 42-year-old man diagnosed with subarachnoid hemorrage.

CONCLUSIONS

The apnea-hypopnea index can be informative regarding prognosis and outcomes, and helps to take precautions and develop new treatment strategies among critical patients in intensive care. The integration of developments in sleep medicine to intensive care unit practices means that we can be more informed about critical patients.

Patient Injuries from Anesthesia Gas Delivery Equipment

Background:

Improvements in anesthesia gas delivery equipment and provider training may increase patient safety. The authors analyzed patient injuries related to gas delivery equipment claims from the American Society of Anesthesiologists Closed Claims Project database over the decades from 1970s to the 2000s.

Methods:

After the Institutional Review Board approval, the authors reviewed the Closed Claims Project database of 9,806 total claims. Inclusion criteria were general anesthesia for surgical or obstetric anesthesia care (n = 6,022). Anesthesia gas delivery equipment was defined as any device used to convey gas to or from (but not involving) the airway management device. Claims related to anesthesia gas delivery equipment were compared between time periods by chi-square test, Fisher exact test, and Mann–Whitney U test.

Results:

Anesthesia gas delivery claims decreased over the decades (P &lt; 0.001) to 1% of claims in the 2000s. Outcomes in claims from 1990 to 2011 (n = 40) were less severe, with a greater proportion of awareness (n = 9, 23%; P = 0.003) and pneumothorax (n = 7, 18%; P = 0.047). Severe injuries (death/permanent brain damage) occurred in supplemental oxygen supply events outside the operating room, breathing circuit events, or ventilator mishaps. The majority (85%) of claims involved provider error with (n = 7) or without (n = 27) equipment failure. Thirty-five percent of claims were judged as preventable by preanesthesia machine check.

Conclusions:

Gas delivery equipment claims in the Closed Claims Project database decreased in 1990–2011 compared with earlier decades. Provider error contributed to severe injury, especially with inadequate alarms, improvised oxygen delivery systems, and misdiagnosis or treatment of breathing circuit events.

[Systematic collection and analysis of intraoperative anaesthetic-related problems]

OBJECTIVE

The purpose of the study was to systematically collect and analyse the frequency, type and severity of all untoward intraoperative anaesthetic-related problems in a hospital over a 6-month period.

METHODS

An observational, systematic, prospective, and cross sectional study was conducted on the events and their risk factors. The study is based on a system in which anaesthesia-related data are recorded from all anaesthetic cases on a routine basis, including sedation and obstetric analgesia. The variables were demographic, procedural data, and a checklist with problem type and severity. Data were analysed using chi-square, Fisher's test, or Student's test. A P<.05 was considered statistically significant.

RESULTS

The frequency of intraoperative anaesthetic-related problems was 17.2%, with 1.3 anaesthetic problems per case, being 9 times more frequent the adverse effects with low severity grade. During anaesthesia, respiratory problems occurred in 13, circulatory problems in 8, and technical problems in 2 out of every 100 procedures. The factors associated with the patient in whom the anaesthetic problem occurred were: the use of general anaesthesia, supraumbilical surgery, and a higher preoperative anaesthetic risk.

CONCLUSIONS

Use of a systematic intraoperative anaesthetic-related database with a checklist of problems and severity plays an important part in quality assurance strategies. An analysis of non-fatal problems provides a basis for establishing corrective strategies before significant morbidity occurs, and by separating the surgical and anaesthesia problems.

Obstructive sleep apnea syndrome and perioperative complications: a systematic review of the literature

Obstructive sleep apnea syndrome (OSAS) is a common sleep related breathing disorder. Its prevalence is estimated to be between 2% and 25% in the general population. However, the prevalence of sleep apnea is much higher in patients undergoing elective surgery. Sedation and anesthesia have been shown to increase the upper airway collapsibility and therefore increasing the risk of having postoperative complications in these patients. Furthermore, the majority of patients with sleep apnea are undiagnosed and therefore are at risk during the perioperative period. It is important to identify these patients so that appropriate actions can be taken in a timely fashion. In this review article, we will discuss the epidemiology of sleep apnea in the surgical population. We will also discuss why these patients are at a higher risk of having postoperative complications, with the special emphasis on the role of anesthesia, opioids, sedation, and the phenomenon of REM sleep rebound. We will also review how to identify these patients preoperatively and the steps that can be taken for their perioperative management.

Postoperative mortality after inpatient surgery: Incidence and risk factors

Purpose:

This study determined the incidence of and identified risk factors for 48 hour (h) and 30 day (d) postoperative mortality after inpatient operations.

Methods:

A retrospective cohort study was conducted using Anesthesiology’s Quality Indicator database as the main data source. The database was queried for data related to the surgical procedure, anesthetic care, perioperative adverse events, and birth/death/operation dates. The 48 h and 30 d cumulative incidence of postoperative mortality was calculated and data were analyzed using Chi-square or Fisher’s exact test and generalized estimating equations.

Results:

The 48 h and 30 d incidence of postoperative mortality was 0.57% and 2.1%, respectively. Higher American Society of Anesthesiologists physical status scores, extremes of age, emergencies, perioperative adverse events and postoperative Intensive Care Unit admission were identified as risk factors. The use of monitored anesthesia care or general anesthesia versus regional or combined anesthesia was a risk factor for 30 d postoperative mortality only. Time under anesthesia care, perioperative hypothermia, trauma, deliberate hypotension and invasive monitoring via arterial, pulmonary artery or cardiovascular catheters were not identified as risk factors.

Conclusions:

Our findings can be used to track postoperative mortality rates and to test preventative interventions at our institution and elsewhere.

Anesthesia-related perioperative adverse events during in-patient and out-patient procedures

PURPOSE

This paper aims to determine the one-year incidence of, and risk factors for, perioperative adverse events during in-patient and out-patient anesthesia-assisted procedures.

DESIGN/METHODOLOGY/APPROACH

A quality assurance database was the primary data source. Outcome variables were death and the occurrence of any adverse event. Risk factors were ASA physical status (PS), age, duration and type of anesthesia care, number of operating rooms running, concurrency level and medical staff. Data were stratified by in-patient or out-patient, surgical (e.g. thoracotomy) or non-surgical (e.g. electroconvulsive therapy), and were analyzed using Chi square, Fisher's exact test and generalized estimating equations.

FINDINGS

Of 27,970 procedures, 49.8 percent were out-patient and greater than 80 percent were surgical. For surgical procedures, adverse event rates were higher for in-patient than out-patient procedures (2.11 percent vs. 1.45 percent; p < 0.001). For non-surgical procedures, adverse event rates were similar for in-patients and out-patients (0.54 percent vs. 0.36 percent). The types of adverseevents differed for in-patient and out-patient surgical procedures (p < 0.001), but not for non-surgical procedures. ASA PS, age, duration of anesthesia care, anesthesia type and medical staff assigned to the case were each associated with adverse event rates, but the association depended on the type of procedure.

PRACTICAL IMPLICATIONS

In-patient and out-patient surgical procedures differ in the incidence of perioperative adverse events, and in risk factors, suggesting a need to develop separate monitoring strategies.

ORIGINALITY/VALUE

The paper is the first to assess perioperative adverse events amongst in-patient and out-patient procedures.

Perioperative complications in obese women vs normal-weight women who undergo vaginal surgery

OBJECTIVE

The purpose of this study was to compare the incidence of perioperative complications in obese and normal-weight patients who undergo vaginal urogynecologic surgery.

STUDY DESIGN

A retrospective cohort analysis was conducted for obese patients (body mass index, > or = 30 kg/m2) who underwent vaginal surgery and who were matched with patients with normal body mass indices (> 18.5 kg/m2 but < 30 kg/m2) by surgical procedures. Demographic information, comorbidities, and perioperative (< or = 6 weeks) complications were documented. Logistic regression analysis was used to compare the incidence of perioperative complications and to adjust for baseline differences.

RESULTS

Seven hundred forty-two patients underwent vaginal surgery during the study period; 235 women were considered to have obese body mass indices. We matched 194 of these patients with normal-weight control subjects. There was no statistical difference in the proportion of subjects who had at least 1 perioperative complication (20% [obese] vs 15% [nonobese]). However, obese subjects were more likely to have an operative site infection (adjusted odds ratio, 5.5; [95% CI, 1.7-24.7]; P = .01).

CONCLUSION

The overall perioperative complication rate in obese and nonobese women is low, with obesity as an independent risk factor for the development of operative site infections.

Corrected incidences of co-morbidities – a statistical approach for risk-assessment in anesthesia using an AIMS

OBJECTIVE

In anesthesia and intensive care logistic regression analysis are often used to generate predictive models for risk assessment. Strictly seen only independent variables should be represented in such prognostic models. Using anesthesia-information-management-systems a lot of (depending) information is stored in a database during the preoperative ward round. The objective of this study was to evaluate a statistical algorithm to process the different dependent variables without losing the information of each variable on patient's conditions.

METHOD

Based on data about prognostic models in anesthesia an iterative statistical algorithm was initiated to summarize dependent variables to subscores. Seven subscores out of several preoperative variables were calculated corresponding to the proper incidence and the correlation to the occurrence of intraoperative cardiovascular events was evaluated. After that first step logistic regression was used to build a predictive model out of the seven subscores, 10 patient-related, and two surgery-related variables. Performance of the prognostic model was assessed using analysis of discrimination and calibration.

RESULT

Four out of seven subscores together with age, type and urgency of surgery are represented in the prognostic model to predict the occurrence of intraoperative cardiovascular events. The prognostic model demonstrated good discriminative power with an area under the ROC curve (AUC) of 0.734.

CONCLUSION

Due to reduced calibration, the clinical use of the prediction model is limited.

Evaluation of cardiac involvement following major orthopedic surgery

BACKGROUND

Cardiovascular morbidity is frequent after non-cardiac surgery and the early recognition of cardiac involvement is an essential tool for clinical risk stratification and management. The aim of this study was to investigate the behavior of traditional and emerging cardiac markers, including NT-prohormone-brain natriuretic peptide (NT-proBNP) and ischemia-modified albumin (IMA), in the perioperative period in patients undergoing major uncomplicated orthopedic surgery.

METHODS

A total of 37 patients undergoing major orthopedic surgery were longitudinally evaluated for NT-proBNP, IMA, cardiac troponin T (cTnT), creatine kinase isoenzyme MB and myoglobin 3 h before surgery and 4 and 72 h thereafter.

RESULTS

NT-proBNP values were significantly increased at 72 h postoperative compared to both 3 h preoperative and 4 h postoperative (NT-proBNP: 20 vs. 4.5 pmol/L, p<0.001 and 20 vs. 5.9 pmol/L, p<0.001). IMA levels were significantly increased at 4 and 72 h postoperative vs. 3 h preoperative (132 vs. 113 kU/L, p=0.02 and 151 vs. 113 kU/L, p<0.001). In a stepwise regression model, the perioperative liquid amount and degree of modification in postoperative creatinine levels (delta-creatinine) were independently related to the NT-proBNP increase.

CONCLUSIONS

The significant increase observed in NT-proBNP suggests that patients undergoing major uncomplicated orthopedic surgery may develop subclinical cardiac stress, presumably attributable to the considerable infusion of liquids. The clinical significance of this finding deserves further investigation, especially in patients at higher risk of heart failure.

Functional status decline as a measure of adverse events in home health care: an observational study

BACKGROUND

Research that examines the quality of home health care is complex because no gold standard exists for measuring adverse outcomes, and because the patient and clinician populations are highly heterogeneous. The objectives in this study are to develop models to predict functional decline for three indices of functional status as measures of adverse events in home health care and determine which index is most appropriate for risk-adjusting for future quality research.

METHODS

Data come from the Outcomes and Assessment Information Set (OASIS) from a large urban home health care agency and other agency data. Prognostic data yields 49,437 episodes, while follow-up data yields 47,684 episodes. We tested three indices defined as substantial decline in three or more (gt3_ADLs), two or more (gt2_ADLs), and one or more (gt1_ADLs) ADLs. Multivariate logistic regression determines the performance of the models for each index as measured by the c-statistic and Hosmer-Lemeshow chi square (chi2).

RESULTS

Frequencies for gt3_ADLs, gt2_ADLs, and gt1_ADLs are 212 (0.43%), 783 (1.58%), and 4,271 (8.64%) respectively. Follow-up results are comparable with frequencies of 218 (0.46%), 763 (1.60%), and 3,949 (8.28%) for each index. Gt3_ADLs does not produce valid models. The model for gt2_ADLs consistently yields a higher c-statistic compared to gt1_ADLs (0.754 vs. 0.679, respectively). Both indices' models yield non-significant Hosmer-Lemeshow chi square indicating reasonable model fit. Findings for gt2_ADLs and gt1_ADLs are consistent over time as indicated by follow-up data results.

CONCLUSION

Gt2_ADLs yields the best models as indicated by a high c-statistic and a non-significant Hosmer-Lemeshow chi2, both of which exhibit exceptional consistency. We conclude that gt2_ADLs may be preferable in defining ADL adverse events in the context of home health care.

Systolic Anterior Motion of the Mitral Valve with Left Ventricular Outflow Tract Obstruction: Three Cases of Acute Perioperative Hypotension in Noncardiac Surgery

In this report we describe three cases of severe perioperative hypotension in noncardiac surgery patients. As systolic anterior motion of the mitral valve in combination with subaortic left ventricular outflow tract obstruction is an unrecognized cause for hypotension in noncardiac surgery patients, delayed diagnosis can result in erroneous treatment regimen. The aim of the present report is to provide an informative and brief synopsis of the pathophysiological consequences and diagnostic/therapeutic strategies for the perioperative management of systolic anterior motion.

The incidence and prediction of automatically detected intraoperative cardiovascular events in noncardiac surgery

The objective of this study was to evaluate prognostic models for quality assurance purposes in predicting automatically detected intraoperative cardiovascular events (CVE) in 58458 patients undergoing noncardiac surgery. To this end, we assessed the performance of two established models for risk assessment in anesthesia, the Revised Cardiac Risk Index (RCRI) and the ASA physical status classification. We then developed two new models. CVEs were detected from the database of an electronic anesthesia record-keeping system. Logistic regression was used to build a complex and a simple predictive model. Performance of the prognostic models was assessed using analysis of discrimination and calibration. In 5249 patients (17.8%) of the evaluation (n = 29437) and 5031 patients (17.3%) of the validation cohorts (n = 29021), a minimum of one CVE was detected. CVEs were associated with significantly more frequent hospital mortality (2.1% versus 1.0%; P < 0.01). The new models demonstrated good discriminative power, with an area under the receiver operating characteristic curve (AUC) of 0.709 and 0.707 respectively. Discrimination of the ASA classification (AUC 0.647) and the RCRI (AUC 0.620) were less. Neither the two new models nor ASA classification nor the RCRI showed acceptable calibration. ASA classification and the RCRI alone both proved unsuitable for the prediction of intraoperative CVEs.

IMPLICATIONS

The objective of this study was to evaluate prognostic models for quality assurance purposes to predict the occurrence of automatically detected intraoperative cardiovascular events in 58,458 patients undergoing noncardiac surgery. Two newly developed models showed good discrimination but, because of reduced calibration, their clinical use is limited. The ASA physical status classification and the Revised Cardiac Risk Index are unsuitable for the prediction of intraoperative cardiovascular events.

Statistical process control methods allow the analysis and improvement of anesthesia care

PURPOSE

Quality aspects of the anesthetic process are reflected in the rate of intraoperative adverse events. The purpose of this report is to illustrate how the quality of the anesthesia process can be analyzed using statistical process control methods, and exemplify how this analysis can be used for quality improvement.

METHODS

We prospectively recorded anesthesia-related data from all anesthetics for five years. The data included intraoperative adverse events, which were graded into four levels, according to severity. We selected four adverse events, representing important quality and safety aspects, for statistical process control analysis. These were: inadequate regional anesthesia, difficult emergence from general anesthesia, intubation difficulties and drug errors. We analyzed the underlying process using 'p-charts' for statistical process control.

RESULTS

In 65,170 anesthetics we recorded adverse events in 18.3%; mostly of lesser severity. Control charts were used to define statistically the predictable normal variation in problem rate, and then used as a basis for analysis of the selected problems with the following results: Inadequate plexus anesthesia: stable process, but unacceptably high failure rate; Difficult emergence: unstable process, because of quality improvement efforts; Intubation difficulties: stable process, rate acceptable; Medication errors: methodology not suited because of low rate of errors.

CONCLUSION

By applying statistical process control methods to the analysis of adverse events, we have exemplified how this allows us to determine if a process is stable, whether an intervention is required, and if quality improvement efforts have the desired effect.

Consent and anaesthetic risk

The incidences of mortality and morbidity associated with anaesthesia were reviewed. Most of the published incidences for common complications of anaesthesia vary considerably. Where possible, a realistic estimate of the incidence of each morbidity has been made, based on the best available data. Perception of risk and communication of anaesthetic risk to patients are discussed. The incidences of anaesthetic complications are compared with the relative risks of everyday events, using a community cluster logarithmic scale, in order to place the risks in perspective when compared with other complications and with the inherent risks of surgery. Documentation of these risks and discussion with patients should allow them to be better informed of the relative risks of anaesthetic complications. Depending on specific comorbidities and the severity of operation, these risks associated with anaesthesia may increase for any one individual.

Intra-operative tachycardia and peri-operative outcome

BACKGROUND

Intra-operative tachycardia is a common adverse event, often recorded as an indicator for process quality in quality assurance projects in anaesthesia.

METHODS

This retrospective study is based on data sets of 28,065 patients recorded with a computerised anaesthesia record-keeping system from 23 February 1999 to 31 December 2000 at a tertiary care university hospital. Cases were defined as patients with intra-operative tachycardia; references were automatically selected according to matching variables (high-risk surgery, severe congestive heart failure, severe coronary artery disease, significant carotid artery stenosis and/or history of stroke, renal failure, diabetes mellitus and urgency of surgery) in a stepwise fashion. Main outcome measures were hospital mortality, admission to the intensive care unit (ICU) and prolonged hospital stay. Differences in outcome measures between the matched pairs were assessed by univariate analysis. Stepwise regression models were developed to predict the impact of intra-operative tachycardia on the different outcome measures.

RESULTS

In our study 474 patients (1.7%) were found to have had intra-operative tachycardia. Matching was successful for 99.4% of the cases, leading to 471 cases and references. The crude mortality rates for the cases and matched references were 5.5% and 2.5%, respectively (P=0.020). Of all case patients, 22.3% were treated in an ICU, compared to 11.0% of the matched references (P=0.001). Hospital stay was prolonged in 25.1% of the patients with tachycardia compared to 15.1% of the matched references (P=0.001).

CONCLUSIONS

In this study, patients with intra-operative tachycardia who were undergoing non-cardiac surgery had a greater peri-operative risk, leading to increased mortality, greater frequency of admission to an ICU and prolonged hospital stay.

Equipment problems during anaesthesia--are they a quality problem?

BACKGROUND

Anaesthesia equipment problems may contribute to anaesthetic morbidity and mortality. The magnitude and pattern of these problems are not established. We wanted to analyse the frequency, type and severity of equipment-related problems in our department, and if additional efforts to improve safety were needed.

METHODS

The study is based on a system in which anaesthesia-related data are recorded from all anaesthetic cases on a routine basis. The data include intraoperative problems and their severity. When a problem occurs, the anaesthetist responsible for the case writes a short description of the event on the anaesthetic chart. From all recorded cases of general and regional anaesthesia, we selected cases recorded with anaesthetic 'equipment/technical problems'. These charts were retrieved from departmental archives for analysis.

RESULTS

From 83 154 anaesthetics, we found the frequency of anaesthetic equipment problems to be 0.05% during regional anaesthesia, and 0.23% during general anaesthesia. One-third of problems involved the anaesthesia machine, and in a quarter, human error was involved. No patient died and none suffered any lasting morbidity.

CONCLUSION

The rate of equipment problems was low, and most often of low severity. Aside from improvements in routines for preoperative equipment checks, no specific strategies for problem reduction could be suggested. The incidence of equipment problems is not a good quality indicator because of the low rate of occurrence. However, recorded equipment problems may be useful for improving quality, by analysing causative factors, and suggesting preventative strategies.

[Serious intraoperative problems--a five-year review of 83,844 anesthetics]

PURPOSE

The low incidence of mortality and major morbidity in anesthesia makes it difficult to study the pattern of potential accidents and to develop preventive strategies. Anesthetic 'near-misses', however, occur more frequently. Using data from a simple routine-based system of problem reporting, we have analyzed the pattern and causes of serious non-fatal problems, in order to improve preventive strategies.

METHODS

We prospectively recorded anesthesia-related information from all anesthetics for five years. The data included intraoperative problems, which were graded into four levels, according to severity. We analyzed only the serious nonfatal problems, which were sorted according to clinical presentation, and also according to which factor was most important in the development of the problem. We assessed any untoward consequences for the patient, and whether the problems could have been prevented.

RESULTS

Serious problems were recorded in 315 cases out of 83,844 (0.4%). Anesthesia was considered the major contributing factor in 111 cases. Difficult intubation, difficult emergence from general anesthesia, allergic reactions, arrhythmia and hypotension were the dominating problems. Twenty-six anesthesia related problems resulted in changes in level of postoperative care, and one patient later died in the intensive care unit after anaphylactic shock. Eighty-two problems could have been prevented by simple strategies.

CONCLUSION

Analysis of serious nonfatal problems during anesthesia may contribute to improved preventive strategies. Data from a routine-based system are suitable for this type of analysis. Intubation, emergence, arrhythmia, hypotension and anaphylaxis cause most serious problems, and should be the object of preventive strategies.

The impact of minor perioperative anesthesia-related incidents, events, and complications on postanesthesia care unit utilization

The German Society of Anesthesiology and Intensive Care Medicine evaluates the standardized and routine reporting of perioperative anesthesia-related incidents, events, and complications (IEC). As part of the long-term project's definitions, IECs are graded according to severity and to their clinical consequence on further postanesthesia monitoring and treatment demands. The adult study population of our department comprised 37,079 patients recovering from anesthesia in a tertiary university hospital from July 1992 through June 1997. Cardiac, obstetric, craniotomy, thoracotomy, laparotomy, and emergency operations were excluded. Multivariate regression statistics were used to calibrate the impact of minor graded IECs on necessary postanesthesia care unit (PACU) utilization. Minor and severe IECs appeared in 22.1% and 0.2% of the patients. A minor IEC occurrence was a statistically significant (P < 0.001) predictor of PACU utilization in a multivariate regression model. The mean difference of PACU length of stay for patients with minor IECs was prolonged by a range of 6%-26% when adjusted for coexisting severity features such as age, gender, ASA physical status, and type and duration of anesthesia and surgery. We conclude that the IEC methodology integrates epidemiologic information about perioperative anesthesia outcome. Minor but frequently occurring IECs have an impact on PACU utilization and are thus important to measure and follow.

IMPLICATIONS

It is desirable to know how anesthesia-related incidents, events, and complications influence postanesthesia care. Analyses of standardized and routine perioperative outcome data, as proposed by the German anesthesia quality project, can show that even minor events consume relevant resources and are thus important to measure and follow.

Validation of routine incidence reporting of one anaesthesia provider institution within a nation-wide quality of process assessment program

In 1992, a long-term project was launched by the German Society for Anaesthesiology and Intensive Care Medicine to render quality comparisons between anaesthesia providers. As one of the first volunteer centres, we established the standardised reporting of perioperative anaesthesia related incidents, events, and complications (IEC) in any routine anaesthetic procedure performed. This present study is aimed to explore the longitudinal stability of IEC recordings in one institution, which should be a prerequisite for valid external comparisons. Methods. The analyses were completed on an adult population of 49945 consecutive anaesthetic procedures with peripheral surgery from July 1992 until December 1996. Attribute quality control charts with monthly samples of an average of 954 anaesthetics were used to assess statistical variability of specific IEC incidences. Results. Average proportions were 20% for moderate IEC, 2.7% for severe IEC, 13% for moderate cardio-vascular IEC, 1.3% for severe cardio-vascular IEC, and 2.4% for respiratory IEC. Moderate IEC proportions showed considerable variability during the study period. A series of excess proportions was probably due to educational activities on documentation discipline. In contrast, clinically severe IEC proportions were rather stable. Stability of cardio-vascular IEC proportions resembled the picture of the overall IEC assessment. Monthly respiratory IEC proportions showed smallest variability during the study period. Discussion. Use of the quality control statistics is suitable to distinguish random from systematic influence on quality indicators. IEC recordings that are not specific in pathophysiologic type or are of low grade of clinical severity, are heavily dependent on systematic documentation features. We assume that peak values, such as in times of optimised documentation discipline, better reflect reality than average values because missing reporting is much more likely than false positives.