Biomedical subjects

A A El-Solh

Publications and source records attributed to A A El-Solh.

10 recordsLinked to original sources

PubMed2006

Noninvasive ventilation for prevention of post-extubation respiratory failure in obese patients.

Current recommendations for management of obese patients post-extubation are based on clinical experience and expert opinions. It was hypothesised that the application of noninvasive ventilation (NIV) during the first 48 h after extubation in severely obese patients would reduce post-extubation failure and avert the need for reintubation. Following protocol-driven weaning trials, 62 consecutive severely obese patients (body mass index > or =35 kg x m(-2)) were assigned to NIV via nasal mask immediately post-extubation and compared with 62 historically matched controls who were treated with conventional therapy. The primary end-point was the incidence of respiratory failure in the first 48 h post-extubation. Compared with conventional therapy, the institution of NIV resulted in 16% (95% confidence interval 2.9-29.3%) absolute risk reduction in the rate of respiratory failure. There was a significant difference in the intensive care unit and lengths of hospital stay between the two groups. Subgroup analysis of hypercapnic patients showed reduced hospital mortality in the NIV group compared with the control group. In conclusion, noninvasive ventilation may be effective in averting respiratory failure in severely obese patients when applied during the first 48 h post-extubation. In selected patients with chronic hypercarbia, early application of noninvasive ventilation may confer a survival benefit.

Adult↗

PubMed2005

Clinical factors associated with hyperkalemia in patients with congestive heart failure.

BACKGROUND: Patients with congestive heart failure (CHF) are at risk for hyperkalemia because of coexisting comorbidities and use of multiple medications that impair potassium (K) excretion such as angiotensin converting enzyme (ACE) inhibitors. OBJECTIVE: To identify clinical factors associated with hyperkalemia on initial presentation in patients hospitalized for CHF. DESIGN: A case-control study. SETTING: Two university-affiliated tertiary-care hospitals. SUBJECTS: Using ICD-9 code for CHF, CHF admissions with hyperkalemia on presentation (cases) were identified from a population of 938 non-dialysis-dependent CHF patients. CHF admissions with normokalemia on presentation were used as controls. Hyperkalemia was defined as serum K > or = 5.6 mmol/L, and normokalemia as serum K > or = 3.5 and < or =5.5. METHODS: Data were collected on demographic characteristics, clinical variables, comorbidity and medication use. Factors associated with hyperkalemia on initial presentation were examined. RESULTS: Mean age did not differ between cases [76 years, standard deviation (SD) = 12] and controls (75 years, SD = 12) (P = 0.824). Mean potassium levels for cases and controls were 6.2 mmol/L (range 5.6 to 8.2) and 4.3 mmol/L respectively (P < 0.001). On multivariate analysis, diabetes mellitus [odds ratio (OR) = 2.42, 95% confidence interval (CI) = 1.04-5.59], creatinine clearance <40 mL/min (OR = 8.36, CI = 2.73-25.56), use of spironolactone (OR = 4.18, CI = 1.27-13.79), and use of ACE inhibitors (OR = 2.55, CI = 1.06-6.13) were independently associated with hyperkalemia. CONCLUSIONS: In CHF patients, hyperkalemia on presentation is independently associated with diabetes, creatinine clearance <40 mL/min, use of spironolactone, and use of ACE inhibitors. Recommendations for use of spironolactone and ACE inhibitors in CHF, and the intensity of serum K monitoring need to be clarified to account for patients at higher risk for hyperkalemia.

Aged↗

PubMed2001

Outcome of older patients with severe pneumonia predicted by recursive partitioning.

OBJECTIVES: To develop a prognostic model to predict outcome of older patients with severe pneumonia requiring mechanical ventilation. DESIGN: A nonconcurrent prospective study. SETTING: A 24-bed intensive care unit (ICU) within two university-affiliated tertiary care hospitals. PARTICIPANTS: All patients age 75 and older with severe pneumonia between June 1996 and September 1999 were included. Demographic data including activities of daily living (ADL) index score before admission, and clinical and laboratory data were collected in the first 24 hours of admission to the ICU. One hundred four patients (mean age +/- standard deviation (SD) 82.3 +/- 5.5 years) met the inclusion criteria. MEASUREMENTS: A classification tree was developed using binary recursive partitioning to predict hospital discharge. The model was compared with a logistic regression model using variables selected by the tree analysis and with the Acute Physiologic and Chronic Health Evaluation (APACHE) II. RESULTS: Outcome predictors for the classification tree were use of vasopressors, presence of multilobar pneumonia on chest radiograph, ratio of blood urea nitrogen to creatinine, Glasgow Coma Scale, urine output, and ADL score before admission. The tree achieved a sensitivity of 83.8% (95% confidence interval (CI) 69.2-92.4) and a specificity of 93.3% (95% CI 83-98.1). The predictive accuracy as assessed by the area under the curve (c-index +/- standard error) was significantly higher with the classification tree (0.932 +/- 0.03) than with logistic regression and APACHE II, (0.801 +/- 0.028 and 0.711 +/- 0.049, respectively (P < .05). CONCLUSIONS: The classification tree model demonstrated a superior predictive accuracy to that of logistic regression and APACHE II. If validated prospectively, the classification tree can be used as a tool to assess the outcome of older patients with severe pneumonia requiring mechanical ventilation on admission to the ICU. In addition, the classification tree can be used to assist healthcare workers in providing a concise summary of local outcome experience and prognostic information to patients and their surrogates.

APACHE↗

PubMed2001

Etiology of severe pneumonia in the very elderly.

The etiology of severe pneumonia requiring mechanical ventilation in the very elderly has been imprecise because of lack of comprehensive studies and low yield of diagnostic approach. Overall, 104 patients 75 yr of age and older with severe pneumonia were studied prospectively at two university-affiliated hospitals. Microbial investigation included blood culture, serology, pleural fluid, and bronchoalveolar secretions. Streptococcus pneumoniae (14%), gram-negative enteric bacilli (14%), Legionella sp. (9%), Hemophilus influenzae (7%), and Staphylococcus aureus (7%) were the predominant pathogens in community-acquired pneumonia (CAP). Staphylococcus aureus (29%), gram-negative enteric bacilli (15%), Streptococcus pneumoniae (9%), and Pseudomonas aeruginosa (4%) accounted for most isolates of nursing home-acquired pneumonia (NHAP). The case fatality rate was 55% (53% for CAP and 57% for NHAP; p > 0.5). Activity of Daily Living (ADL) Index, pulmonary, endocrine and central nervous system (CNS) comorbidities were associated with distinct microbial etiology. By multivariate analysis, hospital mortality was associated independently with 24-h urine output (odds ratio [OR], 5.6; 95% confidence interval [CI], 2.5 to 7.9; p < 0.001), septic shock (OR, 4.3; 95% CI, 1.9 to 8.9; p = 0.0059), radiographic multilobar involvement (OR, 3.7; 95% CI, 1.8 to 15.6; p = 0.02), and inadequate antimicrobial therapy (OR, 2.6; 95% CI, 1.4 to 23.9; p = 0.034). Further studies should focus on identifying effective antimicrobial regimens in randomized trials.

Age Factors↗

PubMed2000

A comparison of severity of illness scoring systems for elderly patients with severe pneumonia.

OBJECTIVE: To evaluate the predictive ability of three severity of illness scoring systems in elderly patients with severe pneumonia requiring mechanical ventilation compared to a younger age group. DESIGN: Prospective cohort study. SETTING: Two university-affiliated tertiary care hospitals. PATIENTS AND PARTICIPANTS: One hundred four patients 75 years of age and older and 253 patients younger than 75 years of age enrolled from medical intensive care units. MEASUREMENTS AND RESULTS: Probabilities of hospital death for patients were estimated by the Acute Physiology and Chronic Health Evaluation (APACHE) II, the Mortality Probability Model (MPM) II and the Simplified Acute Physiology Score (SAPS) II. Predicted risks of hospital death were compared with observed outcomes using three methods of assessing the overall goodness of fit. The actual mortality of the elderly group was 54.87 % (95 % confidence interval [CI]: 45.2-64.4 %) compared to 28.9 % (95 % CI, 23.3-34.4 %) in the younger age group. There was a significant difference in the predictive accuracy of the scoring systems as assessed by the c-index, which is equivalent to the area under the receiver operator characteristics (ROC) curve, between the two groups, but not within individual groups. Calibration was insufficient for APACHE II and SAPS II in the elderly cohort as in-hospital mortality was lower than the predicted mortality for both models. CONCLUSIONS: Although the three severity of illness scoring systems (APACHE II, MPM II and SAPS II) demonstrated average discrimination when applied to estimate hospital mortality in the elderly patients with severe pneumonia, MPM II had the closest fit to our database. Alternative modeling approaches might be needed to customize the model coefficients to the elderly population for more accurate probabilities or to develop specialized models targeted to the designed population.

APACHE↗

PubMed2000

Validity of an artificial neural network in predicting discharge destination from a postacute geriatric rehabilitation unit.

OBJECTIVE: To develop an artificial neural network (ANN) designed to predict discharge destination from postacute geriatric rehabilitation units. DESIGN: Nonconcurrent prospective study. SETTING: Postacute geriatric rehabilitation units: a 20-bed unit in a nonproprietary skilled nursing facility and a 40-bed unit in a suburban private facility. PATIENTS: Consecutive sample of 661 patients admitted between January 1995 and February 1999, including a derivation group of 452 patients and a validation group of 209 patients. INTERVENTIONS: A feed-forward, back-propagation neural network to predict discharge destination. MAIN OUTCOME MEASURE: Discharge destination from postacute geriatric rehabilitation. RESULTS: An ANN was trained on clinical pattern set derived from 452 patients and validated prospectively on 209 consecutive patients admitted to postacute geriatric rehabilitation units. The neural network achieved a sensitivity of 85.7% (95% confidence interval [CI], 83.7-89.4) and specificity of 94.1% (95% CI, 84.4-99.1) in identifying discharge destination with a corresponding area under the curve of 95.7% (95% CI, 92.1-98.3). CONCLUSION: An ANN can predict discharge to the community postacute rehabilitation with a high degree of accuracy. It could have particular value to predict return to the community for older adults with multiple comorbidities after an acute hospitalization.

Activities of Daily Living↗

PubMed1999

Predicting active pulmonary tuberculosis using an artificial neural network.

BACKGROUND: Nosocomial outbreaks of tuberculosis (TB) have been attributed to unrecognized pulmonary TB. Accurate assessment in identifying index cases of active TB is essential in preventing transmission of the disease. OBJECTIVES: To develop an artificial neural network using clinical and radiographic information to predict active pulmonary TB at the time of presentation at a health-care facility that is superior to physicians' opinion. DESIGN: Nonconcurrent prospective study. SETTING: University-affiliated hospital. PARTICIPANTS: A derivation group of 563 isolation episodes and a validation group of 119 isolation episodes. INTERVENTIONS: A general regression neural network (GRNN) was used to develop the predictive model. MEASUREMENTS: Predictive accuracy of the neural network compared with clinicians' assessment. RESULTS: Predictive accuracy was assessed by the c-index, which is equivalent to the area under the receiver operating characteristic curve. The GRNN significantly outperformed the physicians' prediction, with calculated c-indices (+/- SEM) of 0.947 +/- 0.028 and 0.61 +/- 0.045, respectively (p < 0.001). When the GRNN was applied to the validation group, the corresponding c-indices were 0. 923 +/- 0.056 and 0.716 +/- 0.095, respectively. CONCLUSION: An artificial neural network can identify patients with active pulmonary TB more accurately than physicians' clinical assessment.

AIDS-Related Opportunistic Infections↗

PubMed1998

Clinical and radiographic manifestations of uncommon pulmonary nontuberculous mycobacterial disease in AIDS patients.

STUDY OBJECTIVE: To determine the clinical and radiographic findings of nontuberculous mycobacteria (NTM) other than Mycobacterium avium complex (MAC) and Mycobacterium kansasii in AIDS compared with non-AIDS patients. DESIGN: A retrospective chart review of all patients in whom NTM other than MAC complex and M kansasii were isolated between April 1, 1989, and October 31, 1995. SETTING: University-affiliated hospital. PATIENTS: Fifty-four patients met the criteria for uncommon pulmonary NTM disease: (1) repeated isolation of atypical mycobacterium in colony counts of > or = 3 from two or more sputum specimens; or isolation of the organism from transbronchial or open lung biopsy specimen with histologic changes suggestive of mycobacterial disease in the absence of other pathogens; and (2) either an abnormal chest radiograph, the cause of which had not been attributed to an active infection other than atypical mycobacterial disease; or the presence of one or more symptoms indicative of pulmonary disease coupled with exclusion of other illnesses with similar symptoms and signs. RESULTS: Thirty-five patients were HIV positive. Fever was the only clinical symptom more commonly seen in HIV-infected patients with NTM than non-HIV-infected patients. Sixty-six percent of all patients with AIDS were infected by Mycobacterium xenopi. Chest radiographs of AIDS patients showed a tendency for predominance of interstitial infiltrate and rarity of fibronodular disease. No specific radiographic pattern was observed for any particular organism. Adenopathy was not a feature of uncommon pulmonary NTM in AIDS, and it should suggest an alternate diagnosis. In two patients, NTM isolation from respiratory specimens preceded dissemination. Six of 8 AIDS patients treated for pulmonary NTM remained alive at the end of the study compared with only 4 of 15 patients who were not treated for pulmonary NTM (p<0.05). CONCLUSIONS: Uncommon NTM isolated from respiratory specimens ought to be considered as serious pathogens in the presence of clinical and radiographic manifestations unexplained by other pathologic processes. Colonization with NTM could precede dissemination. Treatment of uncommon pulmonary NTM disease could possibly confer a survival benefit in AIDS patients.

AIDS-Related Opportunistic Infections↗

PubMed1996

Outcome of AIDS patients requiring mechanical ventilation predicted by recursive partitioning.

Mechanical ventilatory support (VS) is often required for patients with AIDS. Patients, and/or their surrogates often ask the likely outcome of this intervention. To answer this question, we have developed a classification tree using clinical data from 71 patients with AIDS identified from the discharge abstracts of two hospitals between January 1990 and September 1994. These data were obtained at the time of hospital admission prior to any treatment and before VS was initiated. Survival was defined as discharge from the hospital that occurred in 13 of 72 admissions reviewed. A classification tree was developed by binary recursive partitioning. The output of the resulting tree was adjusted to produce a positive predictive value for death of 100% (95% confidence interval [95% CI], 94 to 100%) and a sensitivity and specificity of 98% (95% CI, 91 to 100%) and 100% (95% CI, 74 to 100%), respectively. The negative predictive value was 92% (95% CI, 64 to 100%). The tree predicted that patients with lactate dehydrogenase (LDH) levels less than 1,176 IU/L survived until hospital discharge, unless they had a positive blood culture, active tuberculosis prior to VS, a blood CD4 count less than 12 cells per cubic millimeter, or creatinine and hemoglobin values that were either above 2.4 mg/dL or less than 8.5 mg/dL, respectively. The remainder of the patients with an LDH level above 1,176 IU/L in this study died before hospital discharge. The classification tree requires prospective validation before it can be used as a predictive instrument. Nevertheless, this approach can be used to develop a concise summary of the local outcome experience of this circumstance in a manner that could be conveyed to patients and/or their surrogates.

Acquired Immunodeficiency Syndrome↗

PubMedDate not supplied

The utility of neural network in the diagnosis of Cheyne-Stokes respiration.

The aim of this study was to design a diagnostic model to identify patients with Cheyne-Stokes respiration (CSR-CSA) based on indices of oximetric spectral analysis. A retrospective analysis of oximetric recordings of 213 sleep studies conducted over a one-year period at a Veterans Affairs medical facility was performed. A probabilistic neural network (PNN) was developed from salient features of the oximetric spectral analysis, desaturation events and the delta index. A fivefold cross-validation was used to assess the accuracy of the neural network in identifying CSR-CSA. When compared to overnight polysomnography, the PNN achieved a sensitivity of 100% (95% confidence interval [CI] 85%-100%) and a specificity of 99% (95% 97%-100%) with a corresponding area under the curve of 99% (95% CI 99%-100%). When combined with overnight pulse oximetry, PNN offers an accurate and easily applicable tool to detect CSR-CSA.

Cheyne-Stokes Respiration↗