15 Jan 12

Utility of clinical risk predictors for preoperative cardiovascular risk prediction

Posted in Pre-operatie evaluation at 2:48 by Laci

By B M Biccard and R N Rodseth

Br. J. Anaesth 2011;107:133-143

Cardiovascular risk prediction using clinical risk factors is integral to both the European and the American algorithms for preoperative cardiac risk assessment and perioperative management for non-cardiac surgery. We have reviewed these risk factors and their ability to guide clinical decision making. We examine their limitations and attempt to identify factors which may improve their performance when used for clinical risk stratification. To improve the performance of the clinical risk factors, it is necessary to create uniformity in the definitions of both cardiovascular outcomes and the clinical risk factors. The risk factors selected should reflect the degree of organ dysfunction rather than a historical diagnosis. Parsimonious model design should be applied, making use of a minimal number of continuous variables rather than creating overfitted models. The inclusion of age in the model may assist partly in controlling for the duration of risk factor exposure. Risk assignment should occur throughout the perioperative period and the risk factors chosen for model inclusion should vary depending on when the assignment occurs (before operation, intraoperatively, or after operation).

08 Jan 12

Computerized model for preoperative risk assessment

Posted in Pre-operatie evaluation at 11:41 by Laci

By X. Zuidema, R. C. Tromp Meesters, I. Siccama and P. L. Houweling

Br. J. Anaesth. 2011;107:180-185

In order to improve the consistency of anaesthetic risk scoring, we have developed an automated method for the calculation of ASA (cASA) scores using decision logic programming. We investigated whether ASA scoring by anaesthetic caregivers could be matched or closely approximated by a cASA.

Methods
We used a web-based preoperative assessment system to present a structured questionnaire comprising 22 questions. These were designed to score and identify conditions that are known, from the literature and expert opinion, to be risk factors. The answers from 14 349 cases were processed using decision logic to provide a variety of risk scores including a computed overall anaesthetic risk (cASA), which was then compared with the ASA score estimated by anaesthesia caregivers (eASA).

Results
We found a close agreement between the two measures in almost all cases. In 159 cases (1.1%), there was an underestimation of cASA, in comparison with the eASA, which appeared to be a result predominantly of incorrect or incomplete answers, or an overestimation of the ASA score by the human classifier (43%).

Conclusion
We showed that ASA scores estimated by a heterogeneous group of anaesthesia caregivers (anaesthetists, anaesthesia trainees, and physician assistants) could be mimicked by the cASA computed by our preoperative assessment system.

02 Jan 12

Anesthesia for the child with an upper respiratory tract infection: still a dilemma?

Posted in Anesthesia, Pre-operatie evaluation at 18:08 by Laci

By A R. Tait and S Malviya

Anesth Analg January 2005 100:59-65;

One of the most controversial issues in pediatric anesthesia has revolved around the decision to proceed with anesthesia and surgery for the child who presents with an upper respiratory tract infection (URI). In the past, doctrine dictated that children with URIs have their surgery postponed until the child was symptom free. This practice was based on the empirically supported premise that anesthesia increased the risk of serious complications and complicated the child’s postoperative course. Although recent clinical data confirm that some children with URIs are at increased risk of perioperative complications, these complications can, for the most part, be anticipated, recognized, and treated. Although the child with a URI still presents a challenge, anesthesiologists are now in a better position to make informed decisions regarding the assessment and management of these children, such that blanket cancellation has now become a thing of the past.

30 Oct 11

Bilateral total knee arthroplasty: risk factors for major morbidity and mortality

Posted in Anesthesia, Pre-operatie evaluation at 0:52 by Laci

By S Memtsoudis, Y Ma, Y-L Chiu, L Poultsides, A Gonzalez Della Valle and M Mazumdar

Anesth Analg 2011;113:784-790

Bilateral total knee arthroplasty (BTKA) performed during the same hospitalization carries increased risk for morbidity and mortality compared with the unilateral approach. However, no evidence-based stratifications to identify patients at risk for major morbidity and mortality are available. Our objective was to determine the incidence and patient-related risk factors for major morbidity and mortality among patients undergoing BTKA.

Methods
Nationwide Inpatient Survey data collected for the years 1998 to 2007 were analyzed and cases of elective BTKA procedures were included. Patient demographics, including comorbidities, were analyzed and frequencies of mortality and major complications were computed. Subsequently, a multivariate analysis was conducted to determine independent risk factors for major morbidity and mortality.

Results
Included were 42,003 database entries, representing an estimated 206,573 elective BTKAs. The incidence of major in-hospital complications and mortality was 9.5%. Risk factors for adverse outcome included advanced age (odds ratios [ORs] for age groups 65–74 and >75 years were 1.88 [confidence interval, CI: 1.72, 2.05] and 2.66 [CI: 2.42, 2.92], respectively, compared with the 45–65 years group), male gender (OR: 1.54 [CI: 1.44, 1.66]), and a number of comorbidities. The presence of congestive heart failure (OR: 5.55 [CI: 4.81, 6.39]) and pulmonary hypertension (OR: 4.10 [CI: 2.72, 6.10]) were the most significant risk factors associated with increased odds for adverse outcome.

Conclusions
We identified patient-related risk factors for major morbidity and mortality in patients undergoing BTKA. Our data can be used to aid in the selection of patients for this procedure.

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