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Biomedical subjects

R I Katz

Publications and source records attributed to R I Katz.

At least 19 recordsLinked to original sources

Factors influencing the reporting of adverse perioperative outcomes to a quality management program.

UNLABELLED: Quality management programs have used several data reporting sources to identify adverse perioperative outcomes. We compared reporting sources and identified factors that might improve data capture. Adverse perioperative outcomes between January 1, 1992, and December 31, 1994, were reported to the Department of Anesthesiology Quality Management program by anesthesiologists, hospital chart reviewers, and other hospital personnel using incident reports. The reports were compared for preoperative health status, severity of outcome, and associated human error. Subsequently, personnel representing the various sources were surveyed regarding factors that might affect their reporting of adverse outcomes. Of 37,924 anesthetics, 734 (1. 9%) adverse outcomes were reported, 519 (71%) of which were identified by anesthesiologists, 282 (38%) by chart reviewers, and 67 (9.1%) by incident report. There was no statistically significant difference in reporting rates by anesthesiologists according to preexisting disease, severity of outcome, or presence of human error. Thirteen cases involving human error, however, resulted in disabling patient injury, with a higher rate of self-reporting for these cases (92%, P < 0.05). Rates of reporting by chart reviewers varied (P < 0.05) according to severity of patient illness and severity of outcome. Incident reports identified only 67 adverse outcomes (9.1%), but included a significantly higher percentage of the adverse outcomes involving human error (23.3%, P < 0.05). Twenty attending anesthesiologists, 15 resident anesthesiologists, 29 operating room nurses, 19 postanesthesia care unit nurses, and 6 hospital chart reviewers responded to the survey. Only the potential to improve quality of patient care influenced or strongly influenced a decision by all groups to report an adverse outcome to a peer review process. Physician self-reporting is a more reliable method of identifying adverse outcomes than either medical chart review or incident reporting. IMPLICATIONS: Physician self-reporting is a more reliable method of identifying adverse outcomes than either medical chart review or incident reporting. Reporting by chart reviewers is biased both by the severity of outcome and severity of patient illness, whereas incident reports tend to focus on human error. All groups feel compelled to report adverse outcomes when the data may result in improved patient care.

Adverse Drug Reaction Reporting Systems↗

Intraoperative management of a patient with a chronic, previously undiagnosed traumatic diaphragmatic hernia.

Traumatic diaphragmatic hernia (TDH) occurs in approximately 5% of hospitalized motor vehicle accident victims and 10% of victims of penetrating chest injury. Although most such injuries are diagnosed at the time of initial trauma, approximately 10% become apparent only months or years later. The TDH patient is at risk for surgical complications, including pulmonary aspiration, hypoxemia, and hemodynamic instability. Diagnosis and proper management of TDH is essential in order to minimize such complications. The anesthetic management of a patient with a preexisting TDH presenting for lumbar laminectomy is discussed.

Anesthesia↗

Haemodynamic stability and ketamine-alfentanil anaesthetic induction.

We have determined if alfentanil could obtund the haemodynamic instability commonly seen at induction of anaesthesia with ketamine. Five groups of ASA I and II patients received ketamine 1 mg kg-1 i.v., preceded by saline (group 1) or alfentanil 10, 20, 30 or 40 micrograms kg-1 (groups 2-5, respectively). Heart rate (HR), mean arterial pressure (AP), postoperative patient complaints and dysphoria were noted. All groups showed increases (P < 0.05) in both HR and AP after administration of ketamine, which were progressively smaller as the dose of alfentanil increased. After tracheal intubation, all groups showed further increases in HR and AP, with groups 3-5 (alfentanil 20-40 micrograms kg-1) showing significant obtundation (P < 0.05) of these increases compared with group 1. No patient in any group reported postoperative dysphoria or dissatisfaction with their anaesthetic. Ketamine 1 mg kg-1 with alfentanil 20-40 micrograms kg-1 provided statistically significant obtundation of the haemodynamic instability that is common with ketamine alone.

Adolescent↗

A survey on the intended purposes and perceived utility of preoperative cardiology consultations.

UNLABELLED: Cardiology consultations are often requested by surgeons and anesthesiologists for patients with cardiovascular disease. There can be confusion, however, regarding both the reasons for a consultation and their effect on patient management. This study was designed to determine the attitudes of physicians toward preoperative cardiology consultations and to assess the effect of such consultations on perioperative management. A multiple-choice survey regarding the purposes and utility of cardiology consultations was sent to randomly selected New York metropolitan area anesthesiologists, surgeons, and cardiologists. In addition, the charts of 55 consecutive patients aged >50 yr who received preoperative cardiology consultations were examined to determine the stated purpose of the consult, recommendations made, and concordance by surgeons and anesthesiologists with cardiologists' recommendations. Of the 400 surveys sent to each specialty, 192 were returned from anesthesiologists, 113 were returned from surgeons, and 129 were returned from cardiologists. There was substantial disagreement on the importance and purposes of a cardiology consult: intraoperative monitoring, "clearing the patient for surgery," and advising as to the safest type of anesthesia were regarded as important by most cardiologists and surgeons but as unimportant by anesthesiologists (all P < 0.05). Most surgeons (80.2%) felt obligated to follow a cardiologist's recommendations, whereas few anesthesiologists (16.6%) felt so obligated (P < 0.05). The most commonly stated purpose of the 55 cardiology consultations examined was "preoperative evaluation." Only 5 of these (9%) were obtained for patients in whom there was a new finding. Of the cardiology consultations, 40% contained no recommendations other than "proceed with case," "cleared for surgery," or "continue current medications." Recommendations regarding intraoperative monitoring or cardiac medications were largely ignored. IMPLICATIONS: We conclude that there seems to be considerable disagreement among anesthesiologists, cardiologists, and surgeons as to the purposes and utility of cardiology consultations. A review of 55 consecutive cardiology consultations suggests that most of them give little advice that truly affects management.

Anesthesiology↗

Defining quality of perioperative care by statistical process control of adverse outcomes.

BACKGROUND: Through peer review, we separated the contributions of system error and human (anesthesiologist) error to adverse perioperative outcomes. In addition, we monitored the quality of our perioperative care by statistically defining a predictable rate of adverse outcome dependent on the system in which practice occurs and respondent to any special causes for variation. METHODS: Traditional methods of identifying human errors using peer review were expanded to allow identification of system errors in cases involving one or more of the anesthesia clinical indicators recommended in 1992 by the Joint Commission on Accreditation of Healthcare Organizations. Outcome data also were subjected to statistical process control analysis, an industrial method that uses control charts to monitor product quality and variation. RESULTS: Of 13,389 anesthetics, 110 involved one or more clinical indicators of the Joint Commission on Accreditation of Healthcare Organizations. Peer review revealed that 6 of 110 cases involved two separate errors. Of these 116 errors, 9 (7.8%) were human errors and 107 (92.2%) were system errors. Attribute control charts demonstrated all indicators, excepting one (fulminant pulmonary edema), to be in statistical control. CONCLUSIONS: The major determinant of our patient care quality is the system through which services are delivered and not the individual anesthesia care provider. Outcome of anesthesia services and perioperative care is in statistical control and therefore stable. A stable system has a measurable, communicable capability that allows description and prediction of the quality of care we provide on a monthly basis.

Aftercare↗

Effect of cardiopulmonary bypass on plasma levels of nifedipine.

Blood levels of many medications are acutely lowered by cardiopulmonary bypass (CPB). Because nifedipine is often used to provide protection from coronary ischemia, a determination of the effect of CPB on plasma nifedipine levels might help to determine the potential clinical benefit of nifedipine during and after bypass. Four samples of blood were drawn from each of eight patients undergoing cardiac surgery: one before, two during, and one after CPB. Although plasma levels of nifedipine declined during and after bypass (P less than 0.05, analysis of variance), the time-course and slope of the decline indicate that this was an effect of normal metabolism of the drug rather than an effect of physiologic changes occurring during CPB. An important additional finding was that the majority of patients had subtherapeutic levels of nifedipine before bypass, suggesting that additional nifedipine given during and after surgery might be of benefit. The effect of the CPB circuit itself was also examined in vitro by mixing nifedipine into a pump prime solution that was then recirculated with 2 U of outdated blood while levels of nifedipine were measured for 3 h. Plasma levels did not change in either a CPB circuit exposed to light or kept in a darkened room.

Cardiopulmonary Bypass↗

Pulse oximetry for evaluation of radial and ulnar arterial blood flow.

This study was designed to assess the use of pulse oximetry (PO) to determine the adequacy of radial and ulnar arterial blood flow by comparing measurements of digital arterial hemoglobin oxygen saturation (SaO2) with conventional visual determination of palmar flush (PF) using a simple occlusion test (SOT) or the Allen's test (AT) in 48 healthy volunteers. Baseline SaO2 values ranged from 94% to 100% with a mean saturation of 97.2%. Eight subjects with initially abnormal reperfusion times were re-evaluated. Of those eight subjects, three remained abnormal. The predictability of an abnormal reperfusion time based on pretesting history was very low. AT reperfusion times as measured by PO and PF showed excellent correlation (r = 0.882). The SOT does not require subject cooperation and provides information similar to the AT. PO, whether combined with the AT or the SOT, has the distinct advantage of providing objective data.

Adult↗

The effect of sublingual nifedipine on coronary venous graft resistance immediately following cardiopulmonary bypass.

The purpose of this study was to determine the effects of sublingual nifedipine administered immediately after discontinuation of cardiopulmonary bypass on coronary graft resistance and systemic hemodynamics. Twenty patients were prospectively randomized into two groups; one given 10 mg sublingual nifedipine after weaning from bypass, the other given a placebo. Coronary graft blood flow was measured under blinded conditions and graft resistance calculated from measurements obtained with an electromagnetic flow probe applied directly to the graft prior to and 15 minutes after drug administration. Serum nifedipine levels were determined immediately before and 15, 30, and 60 minutes after sublingual administration. All patients receiving nifedipine had therapeutic serum levels. Graft resistance in patients given nifedipine decreased a statistically significant average of 27% and increased slightly, but not statistically significantly so, in patients given sublingual placebos. There were no differences between the two groups in cardiac index or pulmonary capillary wedge pressures. We conclude that the administration of sublingual nifedipine to patients in the immediate postbypass period results in therapeutic serum nifedipine levels and decreases coronary graft resistance without affecting cardiac performance.

Administration, Sublingual↗

Multistage analysis of exercise radionuclide angiography in coronary artery disease.

The hypothesis that serial assessment of left ventricular function during exercise radionuclide angiography provides improved diagnostic criteria for coronary artery disease (CAD) was examined. Fifty-eight consecutive patients without previous myocardial infarction were prospectively scheduled for cardiac catheterization and multistage radionuclide angiographic exercise studies. Forty-one patients had significant CAD. The traditional criterion--failure to achieve a 5% increment in ejection fraction (EF) during exercise compared with the value at rest--had 85% sensitivity but only 41% specificity for CAD. In 12 patients, EF increased early in exercise by at least 4% and then decreased a mean of 7.5%, often with worsening regional wall motion. This "up-down" EF pattern was applied as a diagnostic test in the overall study group. Analysis of changes in EF from the maximal value achieved to that at the end of exercise resulted in criteria with greater sensitivity (p less than 0.0001) for CAD than analysis of changes from rest, with similar specificity. Regional wall motion abnormalities occurring during the first exercise stage resulted in 94% specificity for CAD (p = 0.05 vs end-stage analysis), although sensitivity was low. Analyzing the maximal EF during exercise results in improved sensitivity, while analyzing the early onset of regional dysfunction results in high specificity for CAD.

Adult↗

Prognostic significance of severe narrowing of the proximal portion of the left anterior descending coronary artery.

To determine the prognostic importance of significant narrowings involving the proximal left anterior descending coronary artery (LAD), 866 medically treated patients with significant coronary artery disease (CAD) were followed after cardiac catheterization for a mean of 17 months (range 1 to 46). Coronary narrowings in all patients were evaluated based on site relative to large branches and on angiographic severity. Prognosis was best predicted by the presence of at least 70% diameter reductions in the LAD before the first 2 large branches (chi 2 = 16, p = 0.0001). At 3 years, there was a 94% cumulative survival rate in patients with less than 70% stenoses at this location, but an 82% survival rate in patients with 70% or more stenoses (p less than 0.0001). In addition, although the presence of proximal LAD narrowings was the best predictor of prognosis in patients with a low global ejection fraction, this was not so in patients with normal ejection fractions, as this subgroup had an excellent overall prognosis. Thus, the presence and severity of significant stenoses in the proximal LAD are stronger predictors of prognosis than stenoses elsewhere in the major coronary arteries. The presence of an angiographically significant narrowing in this anatomic location is highly correlated with an increased 1- to 3-year mortality rate.

Coronary Disease↗

A sequential approach to the diagnosis of coronary artery disease using multivariate analysis.

There has been considerable interest in recent years in enhancing the accuracy of noninvasive tests in diagnosing coronary artery disease. The recognition that no currently available test is a perfect predictor has led to the use of probability analysis as a means of assessing the presence or absence of coronary disease. In this article we present a multivariate approach to the diagnosis of coronary disease. One hundred forty-seven patients undergoing coronary angiography, thallium-201 imaging, and exercise ECG were studied. Patients were classified according to age, sex, and typical vs atypical chest pain. Sequential stepwise logistic regression analysis was performed to develop probability statements prior to testing, after exercise ECG, and after exercise ECG and thallium-201. The results indicate that this sequential approach can be used to develop strategies for the diagnosis of coronary disease in the same way as Bayes' theorem, while permitting integration of multiple characteristics into one model.

Adult↗

Critical analysis of the application of Bayes' theorem to sequential testing in the noninvasive diagnosis of coronary artery disease.

The utility of Bayes' theorem in the noninvasive diagnosis of coronary artery disease (CAD) was analyzed in 147 patients who underwent electrocardiographic stress testing, thallium-201 perfusion imaging and coronary angiography. Eighty-nine patients had typical anginal chest discomfort and 58 had atypical chest pain. Sensitivity and specificity of the tests and prevalence of CAD at each level of testing were tabulated and compared with the results generated from Bayes' theorem. The sensitivity of electrocardiographic stress was higher in patients with multivessel CAD than in patients with 1-vessel CAD. Sensitivity, but not specificity, of each test was dependent, in part, on the result of the other test. However, the probabilities calculated from Bayes' theorem when used for sequential testing are remarkably close to the tabulated data. Thus, Bayes' theorem is useful clinically despite some evidence of test dependence. Sequential test analysis by Bayes' theorem is most useful in establishing or ruling out a diagnosis when the pretest prevalence is approximately 50% and when the 2 tests are concordant.

Aged↗

Asterixis following metrizamide myelography.

Two patients seen after lumbar myelography with metrizamide demonstrated transient confusion and asterixis. Metabolic etiologies were excluded. To our knowledge, these are the first reported cases of asterixis following myelography with metrizamide.

Brain Diseases↗