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Biomedical subjects

J A Alexander

Publications and source records attributed to J A Alexander.

At least 127 records · Page 7Linked to original sources
PubMed1986

Coronary angioplasty at the time of initial cardiac catheterization.

Following initial diagnostic cardiac catheterization in 20 patients with unstable angina, percutaneous transluminal angioplasty (PTCA) was successfully performed either immediately (15 patients) or later in the day (five patients). This approach offers certain clinical and financial advantages. PTCA immediately following diagnostic catheterization should probably only be performed by experienced operators and only when excellent cooperation with cardiovascular surgeons is possible.

Adult↗
PubMed1986

Organizational growth, survival and death in the U.S. hospital industry: a population ecology perspective.

This article develops an analytic framework for predicting organizational survival, growth and death in the U.S. hospital industry. The population ecology perspective is used to identify the environmental conditions under which health service organizations with specialist or generalist characteristics will survive. Hypotheses derived from the framework focus on the particular form hospitals and multihospital systems will take, how they are likely to develop and the configuration of the health care delivery system under different assumptions about the environment.

Environment↗
PubMed1986

Models of governance in multihospital systems. Implications for hospital and system-level decision-making.

This study utilizes data from a national survey of 159 multihospital systems in order to describe the types of governance structures currently being utilized, and to compare the policy making process for various types of decisions in systems with different approaches to governance. Survey results indicate that multihospital systems most often use one of three governance models. Forty-one percent of the systems (including 33% of system hospitals) use a parent holding company model in which there is a system-wide corporate governing board and separate governing boards for each member hospital. Twenty-two percent of systems in the sample (but 47% of all system hospitals) utilize what we have termed a modified parent holding company model in which there is one system-wide governing board, but advisory boards are substituted for governing boards at the local hospital level. Twenty-three percent of the sampled systems (including 11% of system hospitals) use a corporate model in which there is one system-wide governing board but no other governing or advisory boards at either the divisional, regional or local hospital levels. A comparison of systems using these three governance approaches found significant variation in terms of system size, ownership and the geographic proximity of member hospitals. In order to examine the relationship between alternative approaches to governance and patterns of decision-making, the three model types were compared with respect to the percentages of systems reporting that local boards, corporate management and/or system-wide corporate boards have responsibility for decision-making in a number of specific issue areas. Study results indicate that, regardless of model type, corporate boards are most likely to have responsibility for decisions regarding the transfer, pledging and sale of assets; the formation of new companies; purchase of assets greater than $100,000; changes in hospital bylaws; and the appointment of local board members. In contrast corporate management is relatively uninvolved in these issues, again regardless of governance model type. There is substantial variation in the locus of decision-making responsibility by governance model type for a variety of other issues, however, including: hospital-level service additions and deletions; operating and capital budgets; medical staff privileges, hospital-level long-range planning; hospital CEO performance evaluation and the appointment of hospital CEOs.(ABSTRACT TRUNCATED AT 400 WORDS)

Decision Making, Organizational↗
PubMed1986

Somatosensory evoked potential monitoring of spinal cord ischemia during aortic operations.

Somatosensory evoked potentials were monitored in 22 consecutive patients undergoing surgical correction of an aortic coarctation. Induction of spinal cord ischemia by cross clamping of the aorta elicited a change in the evoked potential in 9 patients (41%). These alterations occurred within 5 minutes of aortic clamping in 3 cases and after 18 to 21 minutes in the remaining 6 cases. Loss of the somatosensory evoked potential for more than 14 minutes was associated with postoperative neurological deficit. Alteration of the evoked potential within 5 minutes of aortic cross clamping was significantly related to poor collateral circulation shown on the preoperative aortogram. The pathophysiology of evoked potential changes in spinal ischemia is discussed in detail.

Adolescent↗
PubMed1986

DNA damage in cultured L1210 cells by 2-haloethyl esters of (methylsulfonyl)methanesulfonic acid.

The effects of the 2-chloroethyl, 2-bromoethyl, and 2-fluoroethyl esters of (methylsulfonyl)methanesulfonic acid upon the DNA of cultured L1210 cells have been measured and compared with each other and with the effects of chlorozotocin. Results obtained by the alkaline elution method indicated that, at equimolar and equitoxic concentrations, the esters caused more strand scission than chlorozotocin, but at compound concentrations that caused a 50% reduction in colony formation by cells following an exposure period of 2 h, they caused no detectable cross-linking, whereas chlorozotocin did cause cross-linking. Two in vitro experimental methods that are based upon the complexing of ethidium to calf thymus DNA also yielded data showing that, at equimolar concentrations, chlorozotocin caused cross-linking of calf thymus DNA, but the 2-chloroethyl ester did not. These results indicate that these esters might not kill cells by producing DNA-DNA cross-links. The three esters caused qualitatively similar effects, but the fluoro esters caused less strand scission than the chloro and bromo esters, which caused about the same extent of strand scission.

Animals↗
PubMed1985

Coronary artery bypass graft surgery: clinical comparison of cold blood potassium cardioplegia, warm cardioplegic induction, and secondary cardioplegia.

An analysis of myocardial protection was performed in 45 low-risk patients undergoing coronary bypass procedures who were divided into three equal groups with similar preoperative ejection fractions and coronary artery obstructions. Group 1 (N = 15) received cold blood cardioplegia, Group 2 received cold blood cardioplegia and secondary cardioplegia, and Group 3 received cold blood cardioplegia plus warm cardioplegic induction. The aortic cross-clamp time and the number of bypass grafts were similar among the groups. The following variables were measured serially: electrocardiographic changes, serum myocardial-specific isoenzyme of creatine kinase, cardiac output, left ventricular filling pressure, ejection fraction, and left ventricular wall motion. The three methods evaluated were all effective in protecting the myocardium during global myocardial ischemia. Patients who received secondary cardioplegia (Group 2) were more likely to exhibit spontaneous defibrillation (12/15) than those in Group 1 (5/15) or Group 3 (6/15) (p less than 0.05). However, measurements of left ventricular performance and evidence of perioperative myocardial infarction were similar among all three groups. These data suggest that a standard technique of cold potassium cardioplegia alone should be the method of choice in elective, low-risk coronary bypass operations rather than this technique in combination with either of the other two more costly and complex methods evaluated in this study.

Cold Temperature↗
PubMed1985

Mortality, morbidity, and cost-accounting related to coronary artery bypass graft surgery in the elderly.

The purpose of this study was to document early mortality, perioperative complication rate, duration of hospitalization, and costs related to coronary artery bypass graft (CABG) surgery in the elderly. Arbitrarily, elderly patients were defined by age greater than or equal to 65 years; younger patients were less than or equal to 60 years old. A detailed list of specific perioperative complications was analyzed. Early (30-day) mortality was similar between groups, while 120-day mortality was higher among elderly compared with younger patients (7.6% versus 1.3%; p = 0.05). The number of elderly patients with 1 or more complications was also higher than among the younger patients (62% versus 43%; p = 0.05). When the incidences of atrial arrhythmias and transient psychoses were considered minor complications and excluded from consideration, the incidence of major complications was higher in the elderly: 41 major events among 76 younger surviving patients compared with 89 major complications in 61 older surviving patients (p = 0.001). Time spent in the intensive care unit and the duration of postoperative hospitalization were also greater in the elderly (p = 0.01 and p = 0.001, respectively). Finally, the elderly group incurred greater costs than the younger patients (p = 0.03). The likelihood of increased perioperative morbidity in elderly patients is documented in this study. Also, it appears that the increased frequency of complications in elderly patients is associated with a longer hospital stay and greater financial expense. Consequently, the careful preoperative evaluation of these patients, including cautious patient selection, assumes greater importance. After CABG procedures, the highly symptomatic elderly patient may experience dramatic relief of symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMed1985

Emergency coronary artery bypass graft surgery for threatened acute myocardial infarction related to coronary artery catheterization.

In 20 patients undergoing cardiac catheterization, usually involving balloon-catheter dilation or streptokinase infusion, catheter-induced coronary artery intimal damage resulted in severe chest pain, electrocardiographic evidence of obstruction or dissection of a major coronary artery. These patients were surgically revascularized within 8 hours after the onset of the acute chest pain syndrome. Our experience with pharmacological and catheter-related manipulations to improve coronary blood flow after the ischemic episode but before operation suggested that the additional time spent in the catheterization laboratory was worthwhile. The injured coronary artery was the left anterior descending in 10 patients, the right in 8, the left main in 1 patient, and an obtuse marginal branch of the circumflex in 1. The average number of grafts per patient was 2.5; only 6 patients had single bypass grafts. In 5 patients, intraaortic balloon pumping was used either preoperatively or postoperatively. Inotropic support was used postoperatively in 5 patients, and 7 patients received lidocaine for ventricular irritability. Abnormal elevation of the serum isoenzyme of creatine kinase (CK-MB) was seen in 8 patients, and new Q waves were noted in 4 patients; 3 of these 4 patients with new Q waves also had abnormal serum CK-MB levels. Global ejection fraction obtained by the equilibrium-gated blood pool scan postoperatively was 60 +/- 3%, which was similar to the 62 +/- 3% obtained from the contrast-determined ventriculogram done preoperatively prior to the catheter-related injury. There were no early or late deaths, but morbidity was much higher in the group who had emergency coronary artery bypass grafting (CABG) compared with those who had elective CABG.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗
PubMed1985

Public hospitals under contract management. An assessment of operating performance.

Numerous changes in their operating environments have caused many public hospitals to experience serious fiscal deterioration. One increasingly common response to this situation is contracting with private organizations for the provision of total management services. This study examines the effects of these contract management arrangements on the operating performance of public hospitals. Three areas of performance are considered: operating efficiency, service structure, and Medicare/Medicaid case load. Eighty short-term public hospitals operating under contract management in 1980 are compared with 122 traditionally managed public hospitals and 74 hospitals 1-2 years prior to entering contract management. Controlling for a series of hospital and environmental variables, contract managed hospitals display several financial and organizational differences vis a vis the comparison groups. These findings are discussed in terms of their implications for policymakers, hospital managers, and researchers.

Contract Services↗
PubMed1985

Toward an empirical classification of hospitals in multihospital systems.

Inconsistency and lack of utility in multihospital systems research is often attributable to misspecification of the unit of analysis and lack of generalizability of research findings. The typical, system-level focus takes an "organizations are all alike" approach that masks potentially important variation among constituent hospitals in systems. This article develops and validates a multivariate, empirical typology of hospitals affiliated with multihospital systems. The objective of the typology is to identify prevalent types of system hospitals that share similar organizational and operational characteristics. Three hundred and sixty-six hospitals affiliated with secular, not-for-profit multihospital systems were subjected to cluster analysis within and across affiliation categories (owned, leased, and contract managed). Findings indicate that the population of hospitals in not-for-profit systems is organizationally heterogeneous but that distinct groupings of hospitals, based largely on size and affiliation status, occur within this population. Homogeneous groupings of hospitals were tested for differences in governance and performance characteristics. Although these clusters differ only slightly in their governance characteristics, they do manifest several differences in performance characteristics. Implications and applications of these findings are discussed.

Contract Services↗
PubMed1985

Formal relationships among governing boards, CEOs, and medical staffs in independent and system hospitals.

This study examines the impact of hospital participation in multi-institutional arrangements on formal relationships between hospital governing boards and chief executive officers (CEOs) and between governing boards and hospital medical staffs. Hypotheses are derived from Mintzberg's general theory of organizational design and are tested using combined data from three American Hospital Association Surveys of nonfederal, short-term hospitals. Analysis results provide considerable support for the study hypotheses. CEOs were found in general to have more formal influence in decisionmaking but also were more likely to be held accountable for performance standards in those hospitals that are part of multi-institutional arrangements. In addition, analyses using both 1976 and 1982 survey data indicate that hospital participation in multi-institutional arrangements is associated with lower levels of formal involvement of the medical staff in institutional decisionmaking. Relationships, for the most part, remain unchanged after the introduction of statistical controls for hospital size. One important issue raised by these findings is the possible impact on hospital performance of less participation by medical staff in the governance of hospitals whose boards are either responsible for multiple hospitals or accountable to higher organizational authority.

Decision Making, Organizational↗