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J T Owings

Publications and source records attributed to J T Owings.

32 records · Page 2Linked to original sources
PubMed1997

Posttraumatic empyema. Risk factor analysis.

BACKGROUND: Empyema remains a distressing complication after thoracic injury. OBJECTIVE: To identify high-risk factors associated with the development of empyema. DESIGN: Retrospective cohort review. SETTING: University hospital, level I trauma center. PATIENTS: Trauma patients who required tube thoracostomy (TT) between January 1, 1991, and November 31, 1993 (n = 584). METHODS: Data (demographic characteristics, injuries, chest x-ray film reports, and setting of TT) were assessed using a stepwise logistic regression analysis to identify risk factors associated with the development of post-traumatic empyema. RESULTS: Empyema that required decortication developed in 25 patients (4%). Factors predictive of development of empyema were retained hemothorax (odds ratio, 12.5; 95% confidence interval, 0.96-163), pulmonary contusion (odds ratio, 6.3; 95% confidence interval, 1.53-25.8), and multiple chest tube placement (odds ratio, 2.5; 95% confidence interval, 1.91-3.28); factors not predictive of empyema were severity of injury, mechanism of injury, setting in which TT was performed, number of days chest tubes were in place, and antibiotic drugs at the time of TT. CONCLUSIONS: The extent of pulmonary injury (pulmonary contusion) is an important predictor of empyema development. Previously implicated factors such as setting in which a TT was performed and mechanism of injury did not correlate with the development of posttraumatic empyema. Based on the results of our study, we recommend early drainage of the pleural space with video-assisted thoracoscopic techniques in patients at risk of empyema, which may spare them the morbidity of a thoracotomy.

Empyema, Pleural↗
PubMed1997

Timing of the occurrence of pulmonary embolism in trauma patients.

OBJECTIVE: To determine how soon after trauma pulmonary embolism (PE) occurs and if there is an association between the duration of this interval and mortality. DESIGN: Retrospective case series. PATIENTS: All patients admitted to our trauma service with established PE based on high probability findings on ventilation perfusion scan, positive results on a pulmonary arteriogram, or autopsy from July 1, 1990, to September 30, 1995. MAIN OUTCOME MEASURE: Time interval between injury and PE. SETTING: Level I university trauma center. RESULTS: Of 18,255 trauma patients identified, 63 met our criteria for PE (30 using a pulmonary arteriogram; 26, a ventilation perfusion scan; and 7, autopsy). Four patients (6%) had a documented PE on day 1 following injury. Mortality was not correlated with the interval between injury and PE. Of the 63 patients, 58 (92%) had 1 or more established risk factors for thromboembolism. The ratio of PaO2 to fraction of inspired oxygen was the only factor predictive of mortality (P = .02, logistic regression analysis). CONCLUSIONS: Pulmonary embolism occurs in the immediate period following injury. Aggressive workup in patients with signs consistent with PE should be instituted promptly. Trauma patients who have at least 1 risk factor for thromboembolism should receive prophylaxis as soon after injury as possible.

Adult↗
PubMed1997

Right ventricular volumes overestimate left ventricular preload in critically ill patients.

BACKGROUND: Studies have shown right ventricular end-diastolic volume (RVEDV) to be a more accurate estimate of left ventricular preload than pulmonary artery wedge pressure. We prospectively evaluated the ability of RVEDV to predict left ventricular end-diastolic volume (LVEDV) in critically ill patients. METHODS: Thirty critically ill patients in the surgical intensive care unit underwent concurrent measurement of RVEDV and LVEDV. RVEDV was measured using a residual fraction Swan-Ganz catheter (RF Swan). LVEDV was measured using transesophageal echocardiography with acoustic quantification. Intracardiac, intra-abdominal, and ventilatory pressures were also measured. RESULTS: RVEDV as measured by the RF Swan was significantly larger (by a factor of 2) than LVEDV (p < 0.0001 analysis of variance). However, the RVEDV and LVEDV were strongly correlated (r = 0.71, p < 0.0001, Pearson's correlation). CONCLUSIONS: RVEDV from the RF Swan markedly overestimated left ventricular preload. If RVEDV is used as an absolute value for determining preload, patients may be underresuscitated. Transesophageal echocardiography in conjunction with RF Swan can be used to more accurately determine preload and cardiac performance than RF Swan alone in critically ill patients.

Analysis of Variance↗
PubMed1997

Clinical application of ventricular end-systolic elastance and the ventricular pressure-volume diagram.

The ability to clinically assess myocardial contractility in a load-independent fashion facilitates the selection of appropriate inotropes, when needed, during shock resuscitation. Within the framework of the ventricular pressure-volume diagram, the slope of the ventricular end-systolic pressure-volume relationship (expressed as ventricular end-systolic elastance, Ees), has been shown to accurately reflect ventricular inotropic state, and to be insensitive to loading conditions. It has not, however, been widely used at the bedside. Our goal was to evaluate the clinical utility of Ees and the ventricular pressure-volume diagram as bedside methods of hemodynamic assessment. We performed a prospective study of 123 hemodynamic interventions in 100 trauma patients during shock resuscitation in which contractility (Ees), preload (left ventricular end-diastolic volume index), and afterload (effective arterial elastance) were calculated before and after addition of inotropes, fluid bolus, and afterload reduction. Mean values of each variable were compared before and after each type intervention using the paired t test. The ventricular pressure-volume diagram was used to predict changes in the studied variables, and the experimental results were compared with predicted changes. Ees (mmHg/mL/m2) increased significantly with inotropes (4.7 +/- 3.2 to 10 +/- 8.7, p < .0001), but was not affected by clinically significant fluid administration (7.0 +/- 4.7 to 8.3 +/- 8.0, p = .10) or afterload reduction (9.6 +/- 5.2 to 9.2 +/- 4.7, p = .72). Left ventricular end-diastolic volume index (mL/m2) improved with fluid administration (54 +/- 8.9 to 62 +/- 9.8, p < .0001) and effective arterial elastance (mmHg/mL/m2) decreased with afterload reduction (3.3 +/- .9 to 2.6 +/- .7, p < .0001). We conclude that Ees is a load-independent measure of contractility, which is measurable at the bedside. The pressure-volume diagram is a useful method of monitoring hemodynamic changes associated with interventions during shock resuscitation.

Adult↗
PubMed1997

Acquired antithrombin deficiency following severe traumatic injury: rationale for study of antithrombin supplementation.

Hemorrhage, head injury, and multiple organ dysfunction are the most frequent causes of mortality in patients who experience severe injury. Acceleration of the coagulation cascade is known to result in hemorrhage secondary to disseminated intravascular coagulation (DIC) and end-organ dysfunction, as manifest by pulmonary and renal failure. Few studies have been conducted to evaluate the effects of injury on the endogenous anticoagulants that inhibit excessive coagulation activation. We evaluated a group of patients following severe injury and found that procoagulant markers (prothrombin fragment 1.2, thrombin antithrombin complexes, and D dimers) were significantly elevated for the population as a whole. Levels of circulating endogenous anticoagulants [antithrombin (AT) and protein C] were relatively unchanged for the total population. However, patients with adverse outcomes [DIC and adult respiratory distress syndrome (ARDS)] had significant reductions in AT and protein C activities. Decreased levels of AT and protein C 8 hours after admission served as independent predictors of both DIC and ARDS. Prospective, randomized studies should be conducted to evaluate the effect of supplementation of these factors after severe injury has occurred.

Adolescent↗
PubMed1996

Low-dose heparin thromboembolism prophylaxis.

OBJECTIVE: To determine a rational approach to heparin dosing for thromboembolism prophylaxis. DESIGN: Literature review. RESULTS: Three commonly used heparin dosing regimens were identified: (1) standard low-dose heparin (5000 U administered subcutaneously 2-3 times per day); (2) adjusted-dose heparin (adequate to elevate the activated partial thromboplastin time to 5 seconds above the upper limit of normal); and (3) low-molecular-weight heparin (30 mg subcutaneously twice daily without monitoring). CONCLUSIONS: Adjusted-dose heparin thromboembolism prophylaxis is both the safest and most reliable method currently available.

Heparin↗
PubMed1996

Effect of critical injury on plasma antithrombin activity: low antithrombin levels are associated with thromboembolic complications.

OBJECTIVE: Determine whether severe injury results in decreased plasma antithrombin (AT) activity and whether this decreased AT activity is associated with thromboembolic complications. DESIGN: Prospective observational. SUBJECTS: A total of 157 critically injured trauma patients. METHODS: Each patient underwent laboratory analysis on arrival to the emergency room at hours 8, 16, 24, and 48, and days 3, 4, 5, and 6. Laboratory analyses included AT, tissue factor pathway inhibitor, protein C, prothrombin fragment 1.2, thrombin-antithrombin complex, and D-dimer. Patients were followed for thromboembolic complications including: deep venous thrombosis (DVT), pulmonary embolus, disseminated intravascular coagulation (DIC) and adult respiratory distress syndrome (ARDS). RESULTS: Mean Injury Severity Score was 23 (+/-11). AT activity fell below normal in 95 (61%) patients; AT activity rose to greater than normal in 51 (32%) patients. Nine (6%) patients developed DVT, two (1%) pulmonary embolus, 13 (8%) DIC and 26 (17%) ARDS. Using logistic regression analysis, low AT levels were a significant predictor of DVT, DIC, and ARDS (p < 0.05). Supranormal At levels were associated with closed head injury (p < 0.05). D-dimer levels were inversely correlated with AT (p < 0.05). CONCLUSIONS: AT activity was depressed in critically injured patients. Patients with head injury developed supranormal AT activity. The risk factors for AT deficiency mimicked those for thromboembolism. Patients with decreased AT activity were at increased risk for thromboembolic complications. Given heparin's dependence on AT, these data call into question the use of unmonitored heparin thromboembolism prophylaxis.

Adult↗
PubMed1995

Developing guidelines for biotechnology drug use: experience with antithrombin III.

Development of institutional guidelines for use of high-cost biotechnology drugs, such as antithrombin III, is a valuable tool in formulary management. This article describes the process by which the University of California Davis Medical Center used an ad hoc committee to the P & T Committee to develop guidelines for antithrombin III use. Performing an objective analysis of available literature to address the appropriate role of a biotechnology agent is necessary to develop consensus guidelines. Approval of use guidelines by the P & T Committee provides the necessary structure for optimal use of biotechnology agents, such as antithrombin III.

Antithrombin III↗
PubMed1993

Effect of preoperative suggestion on postoperative gastrointestinal motility.

Autonomic behavior is subject to direct suggestion. We found that patients undergoing major operations benefit more from instruction than from information and reassurance. We compared the return of intestinal function after intra-abdominal operations in 2 groups of patients: the suggestion group received specific instructions for the early return of gastrointestinal motility, and the control group received an equal-length interview offering reassurance and nonspecific instructions. The suggestion group had a significantly shorter average time to the return of intestinal motility, 2.6 versus 4.1 days. Time to discharge was 6.5 versus 8.1 days. Covariates including duration of operation, amount of intraoperative bowel manipulation, and amount of postoperative narcotics were also examined using the statistical model analysis of covariance. An average savings of $1,200 per patient resulted from this simple 5-minute intervention. In summary, the use of specific physiologically active suggestions given preoperatively in a beleivable manner can reduce the morbidity associated with an intra-abdominal operation by reducing the duration of ileus.

Adolescent↗