The ankle-to-arm blood pressure index predicts risk of cardiac complications after noncardiac surgery.

BACKGROUND: Peripheral arterial disease, as detected by a reduced ankle-to-arm blood pressure index (AAI), has been shown to predict future cardiac events. However, the utility of measuring the AAI to predict postoperative cardiac complications in patients undergoing noncardiac surgery is unknown. METHODS: We prospectively studied 242 consecutive patients aged 50 yr or older presenting to a university hospital preadmission clinic before elective noncardiac surgery. We performed a standardized clinical evaluation that included calculation of the revised cardiac risk index (rCRI) and measurement of the AAI using both palpation and Doppler techniques. Independent observers, blinded to preoperative assessment and AAI results, ascertained cardiac complications in the first 7 days after surgery. We assessed the ability of an abnormal AAI (

Accuracy of the preoperative assessment in predicting pulmonary risk after nonthoracic surgery.

We examined the accuracy of preoperative assessment in predicting postoperative pulmonary risk in a prospective cohort of 272 consecutive patients referred for evaluation before nonthoracic surgery. Outcomes were assessed by an independent investigator who was blinded to the preoperative data. There were 22 (8%) postoperative pulmonary complications. Statistically significant predictors of pulmonary complications (all p < or = 0.005) were as follows: hypercapnea of 45 mm Hg or more (odds ratio, 61.0), a FVC of less than 1.5 L/minute (odds ratio, 11.1), a maximal laryngeal height of 4 cm or less (odds ratio, 6.9), a forced expiratory time of 9 seconds or more (odds ratio, 5.7), smoking of 40 pack-years or more (odds ratio, 5.7), and a body mass index of 30 or more (odds ratio, 4.1). Multiple regression analyses revealed three preoperative clinical factors that are independently associated with pulmonary complications: an age of 65 years or more (odds ratio, 1.8; p = 0.02), smoking of 40 pack-years or more (odds ratio, 1.9; p = 0.02), and maximum laryngeal height of 4 cm or less (odds ratio, 2.0; p = 0.007). Thus, preoperative factors can identify those patients referred to pulmonologists or internists who are at increased risk for pulmonary complications after nonthoracic surgery.

Assessment and reporting of perioperative cardiac risk by Canadian general internists: art or science?

OBJECTIVE: Physicians may use several validated risk indices to estimate perioperative cardiac risk, but there is little evidence for interventions to reduce this risk. We were interested in evaluating how general internists assess, define, communicate, and attempt to modify perioperative cardiac risk. DESIGN: Cross-sectional survey of all 312 general internists in the Canadian Society of Internal Medicine with Canadian mailing addresses; 117 (38%) responded. RESULTS: Respondents' mean age was 46 years, 79% were male, and on average they did 17 preoperative consults per month. Of the 104 respondents who routinely performed preoperative assessments, 96% (100/104) informed patients of their perioperative cardiac risk, but 77% did so only subjectively (i.e., stating risk as low, moderate, or high). Respondents provided 8, 27, and 12 different definitions for low, moderate, and high risk, respectively, with marked variability in the range of definitions they provided: from <1% to < 20% for "low risk," from 1% to 2% to 20% to 50% for "moderate risk," and from >2% to >50% for "high risk." The 67% of respondents who reported using a perioperative cardiac risk index used a variety of indices and exhibited just as much variability in their risk estimates and definitions as those who didn't use risk indices. While virtually all advised perioperative beta blockade in patients with known coronary artery disease, they varied substantially in the recommended agent or dose; further, these internists were evenly split on whether antiplatelet agents should be held or continued perioperatively. CONCLUSIONS: These physicians differed widely in their assessment of perioperative cardiac risk and their definitions of low, moderate, or high risk. This raises concerns about whether patients (and surgeons) are provided with adequate information to make fully informed decisions about the potential risks of elective surgical operations.

Predicting pulmonary complications after nonthoracic surgery: a systematic review of blinded studies.

PURPOSE: To determine the performance of variables commonly used in the prediction of postoperative pulmonary complications in patients undergoing nonthoracic surgery. METHODS: We conducted a systematic review of the literature in English, using MEDLINE (1966-2001), manual searches of identified articles, and contact with content experts. All studies reporting independent and blinded comparisons of preoperative or operative factors with postoperative pulmonary complications were included. Two reviewers independently abstracted inclusion and exclusion criteria, study designs, patient characteristics, predictors of interest, and the nature and occurrence of postoperative pulmonary complications. RESULTS: Seven studies fulfilled the inclusion criteria. The definition of postoperative pulmonary complications differed among studies, and the incidence of postoperative pulmonary complications varied from 2% to 19%. Of the 28 preoperative or operative predictors that were evaluated in the 7 studies, 16 were associated significantly with postoperative pulmonary complications, although only 2 (duration of anesthesia and postoperative nasogastric tube placement) were significant in more than one study. The positive (2.2 to 5.1) and negative (0.2 to 0.8) likelihood ratios for these 16 variables suggest that they have only modest predictive value. Neither hypercarbia nor reduced spirometry values were independently associated with an increased risk of postoperative pulmonary complications. CONCLUSION: Few studies have rigorously evaluated the performance of the preoperative or operative variables in the prediction of postoperative pulmonary complications. Prospective studies with independent and blinded comparisons of these variables with postoperative outcomes are needed.