Pulmonary hypertension as a risk factor for death in patients with sickle cell disease.
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Anemia, Sickle Cell↗
Biomedical subjects
Jerry A Krishnan
Publications and source records attributed to Jerry A Krishnan.
A prospective, controlled trial of a protocol-based strategy to discontinue mechanical ventilation.
Weaning protocols can improve outcomes, but their efficacy may vary with patient and staff characteristics. In this prospective, controlled trial, we compared protocol-based weaning to usual, physician-directed weaning in a closed medical intensive care unit (ICU) with high physician staffing levels and structured, system-based rounds. Adult patients requiring mechanical ventilation for more than 24 hours were assigned to usual care (UC) or protocol weaning based on their hospital identification number. Patients assigned to UC (n=145) were managed at their physicians' discretion. Patients assigned to protocol (n=154) underwent daily screening and a spontaneous breathing trial by respiratory and nursing staff without physician intervention. There were no significant baseline differences in patient characteristics between groups. The proportion of patients (protocol vs. UC) who successfully discontinued mechanical ventilation (74.7% vs. 75.2%, p=0.92), duration of mechanical ventilation (median [interquartile range]: 60.4 hours [28.6-167.0 hours] vs. 68.0 hours [27.1-169.3 hours], p=0.61), ICU (25.3% vs. 28.3%) and hospital mortality (36.4% vs. 33.1%), ICU length of stay (115 vs. 146 hours), and rates of reinstituting mechanical ventilation (10.3% vs. 9.0%) was similar. We conclude that protocol-directed weaning may be unnecessary in a closed ICU with generous physician staffing and structured rounds.
Adult↗
Methods and issues in conducting a community-based environmental randomized trial.
The environment is suspected to play an important role in the prevalence and severity of asthma in inner-city children. This paper describes the implementation and baseline data of an inner-city community-based participatory research clinical trial designed to test the effectiveness of a pollutant and allergen control strategy on children's asthma morbidity. Participants were 100 elementary-school-aged children with asthma, graduates of a school-based asthma education program in East Baltimore. The intervention for half of the randomly assigned families consisted of environmental control education, allergen-proof encasements, pest extermination, and a HEPA air cleaner at the beginning of the study. Controls received the same at the end of the study. Participants visited a clinic for questionnaires, allergy skin testing, spirometry, and blood sample at baseline and 12 months. Home environments, NO(2), O(3), airborne particulates, and allergens were evaluated at baseline and at 6 and 12 months. Asthma morbidity and adherence was assessed quarterly. Collaboration with the community proved very beneficial in creating a study design and procedures acceptable to an inner-city community.
Air Pollution, Indoor↗
Emotional quality-of-life and outcomes in adolescents with asthma.
OBJECTIVE: Examine the association between emotional quality-of-life (QOL) and asthma morbidity in adolescents with asthma. STUDY DESIGN: Cross-sectional survey of 185 adolescents with asthma 11 to 17 years of age cared for in three managed care organizations (MCOs) in the United States. The asthma-specific Pediatric Asthma Quality of Life Questionnaire (PAQLQ) and a short version of the generic Child Health and Illness Profile-Adolescent Edition (CHIP-AE) were used to assess emotional QOL. Asthma morbidity measures were: asthma control, emergency department (ED) visits, hospitalizations, doctor visits for worsening asthma, and missed school because of asthma. RESULTS: Of the adolescents surveyed, 45% reported feeling depressed, 41% had ED visits, and 30% missed >or=1 day of school because of asthma. Poorer asthma-specific emotional QOL was associated with poorer control of asthma symptoms ( P < .0001), missed school (OR 7.1, P < .05), and doctor visits for worsened asthma (OR = 7.0, P < .05). CONCLUSIONS: Emotional symptoms related to asthma are common in adolescents with persistent asthma and asthma-specific QOL is related to increased asthma morbidity, healthcare use, and school absenteeism. Adolescents with high morbidity from asthma exhibit poorer QOL. Therefore, the evaluation of asthma-specific emotional QOL should be included in the assessment of adolescents with asthma.
Absenteeism↗
Relationship of physician estimate of underlying asthma severity to asthma outcomes.
BACKGROUND: Implementation of national guidelines for the treatment of asthma requires physician estimates of patients' underlying asthma severity. Asthma severity is commonly assigned based on respiratory symptoms. OBJECTIVE: To evaluate the relationship of guideline-based physician assessments to asthma control. METHODS: Data were collected by survey as part of a cohort study of adults with asthma. Physicians estimated the underlying severity of their patients' asthma as mild, moderate, or severe. We evaluated the relationship of these estimates to (1) general health status, asthma symptoms, and patient-reported emergency department (ED) visits and hospitalizations in the previous year and (2) outcomes in the following year. RESULTS: A total of 3,468 adults with asthma had physicians who completed assessments of their severity. Physician evaluation of severity was significantly associated with the patient's recent general health status, asthma symptom control, ED visits, and hospitalizations (P < .001 for all). Future outcomes, including hospitalizations and ED visits for asthma, increased with increasing severity rating (hospitalizations: 5% [mild] vs 11% [moderate] vs 19% [severe]; ED visits: 15% [mild] vs 22% [moderate] vs 32% [severe]; P < .001 for all). CONCLUSION: This study provides evidence of the validity of physician assessments of patients' underlying asthma severity using the strategy recommended by national guidelines.
Adult↗
Low caloric intake is associated with nosocomial bloodstream infections in patients in the medical intensive care unit.
OBJECTIVE: To determine whether caloric intake is associated with risk of nosocomial bloodstream infection in critically ill medical patients. DESIGN: Prospective cohort study. SETTING: Urban, academic medical intensive care unit. PATIENTS: Patients were 138 adult patients who did not take food by mouth for > or =96 hrs after medical intensive care unit admission. MEASUREMENTS: Daily caloric intake was recorded for each patient. Participants subsequently were grouped into one of four categories of caloric intake: <25%, 25-49%, 50-74%, and > or =75% of average daily recommended calories based on the American College of Chest Physicians guidelines. Simplified Acute Physiology Score II and serum albumin were measured on medical intensive care unit admission. Serum glucose (average value and maximum value each day) and route of feeding (enteral, parenteral, or both) were collected daily. Nosocomial bloodstream infections were identified by infection control surveillance methods. MAIN RESULTS: The overall mean (+/-sd) daily caloric intake for all study participants was 49.4 +/- 29.3% of American College of Chest Physicians guidelines. Nosocomial bloodstream infection occurred in 31 (22.4%) participants. Bivariate Cox analysis revealed that receiving > or =25% of recommended calories compared with <25% was associated with significantly lower risk of bloodstream infection (relative hazard, 0.24; 95% confidence interval, 0.10-0.60). Simplified Acute Physiology Score II also was associated with risk of nosocomial bloodstream infection (relative hazard, 1.27; 95% confidence interval, 1.01-1.60). Average daily serum glucose, admission serum albumin, time to initiating nutritional support, and route of nutrition did not affect risk of bloodstream infection. After adjustment for Simplified Acute Physiology Score II in a multivariable analysis, receiving > or =25% of recommended calories was associated with a significantly lower risk of bloodstream infection (relative hazard, 0.27; 95% confidence interval, 0.11-0.68). CONCLUSIONS: In the context of reducing risk of nosocomial bloodstream infections, failing to provide > or =25% of the recommended calories may be harmful. Higher caloric goals may be necessary to achieve other clinically important outcomes.
Cohort Studies↗
Maternal depressive symptoms and adherence to therapy in inner-city children with asthma.
CONTEXT: Little is known about how depressive symptoms in mothers affects illness management in inner-city children with asthma. OBJECTIVE: Our goal was to determine how maternal depressive symptoms influence child medication adherence, impact of the child's asthma on the mother, and maternal attitudes and beliefs. METHODS: Baseline and 6-month surveys were administered to 177 mothers of young minority children with asthma in inner-city Baltimore, MD and Washington, DC. Medication adherence, disruptiveness of asthma, and select attitudes toward illness and asthma therapy were measured. Six-month data (N = 158) were used to prospectively evaluate long-term symptom control and emergency department use. Independent variables included asthma morbidity, age, depressive symptoms, and other psychosocial data. RESULTS: No difference in child asthma morbidity was observed between mothers high and low in depressive symptoms. However, mothers with high depressive symptoms reported significantly more problems with their child using inhalers properly (odds ratio [OR]: 5.0; 95% confidence interval [CI]: 1.3-18.9) and forgetting doses (OR: 4.2; 95% CI: 1.4-12.4). Depressive symptoms were also associated with greater emotional distress and interference with daily activities caused by the child's asthma, along with less confidence in asthma medications, ability to control asthma symptoms, and self-efficacy to cope with acute asthma episodes. In addition, depressed mothers reported less understanding about their child's medications and use (OR: 7.7; 95% CI: 1.7-35.9). Baseline asthma morbidity, maternal depression scores, and family income were independently associated with asthma symptoms 6 months later, whereas medication adherence was not predictive of subsequent asthma morbidity or emergency department use. CONCLUSIONS: Maternal depressive symptoms were not associated with child asthma morbidity but were associated with a constellation of beliefs and attitudes that may significantly influence adherence to asthma medications and illness management. Identifying and addressing poor psychological adjustment in mothers is important when developing a child's asthma treatment and may facilitate parent-provider communication, medication adherence, and asthma management among inner-city children.
Adult↗
Accuracy of CT in the diagnosis of pulmonary embolism: a systematic literature review.
OBJECTIVE: We sought to summarize systematically the published evidence describing the accuracy of contrast-enhanced helical CT for diagnosing pulmonary embolism. MATERIALS AND METHODS: We selected all systematic reviews published before December 2003 that evaluated the accuracy of CT angiography for the diagnosis of pulmonary embolism. We also selected all prospective studies from the same time period in the primary literature in which all subjects underwent both CT and conventional angiography, the latter being considered the reference standard. Articles were identified through a computerized MEDLINE search and by other means. The quality and content of each article were evaluated independently by pairs of researchers. RESULTS: Six systematic reviews and eight primary studies were selected. The combined sensitivities of CT for detecting pulmonary embolism ranged from 66% to 93% across the systematic reviews and the combined specificities ranged from 89% to 97%. Only one of the reviews reported a combined sensitivity of greater than 90%. Among the eight primary studies, the sensitivities ranged from 45% to 100% and specificities ranged from 78% to 100%. Only three of the eight primary studies reported a sensitivity greater than 90%. None of the primary studies used scanners with four or more detectors. CONCLUSION: A systematic literature review revealed a wide range of reported sensitivities, only a minority of which exceeded 90%. Pooled estimates of sensitivity and specificity reported by systematic literature reviews should be interpreted with caution because of potential selection bias and heterogeneity in the reviewed studies. Accuracy studies of recent generations of MDCT scanners are not yet available despite the current dissemination of this technology.
Humans↗
Differences in sleep-induced hypoxia between A/J and DBA/2J mouse strains.
In obstructive sleep apnea, hypoxic ventilatory sensitivity may affect the degree of hypoxic stress and sleep disruption that occurs in response to upper airway obstruction. We induced (1) sleep-induced hypoxia (SIH) or (2) sleep fragmentation (SF) without hypoxia for 5 days (12-hour light/dark cycle) in two inbred mouse strains with low (A/J) and high (DBA/2J) hypoxic ventilatory sensitivities. During SIH, the time to arousal (26.4 +/- 1.1 vs. 21.3 +/- 1.5 seconds, p<0.025) and the severity of hypoxic exposure (nadir FIO2: 11.5 +/- 0.4 vs. 13.6 +/- 0.1%, p<0.002) was greater in A/J than DBA/2J mice. Furthermore, A/J mice had a greater frequency of hypoxic events (640 +/- 29 vs. 368 +/- 33 events per 24 hours, p<0.001) and total sleep time (47.5 +/- 2.8% vs. 26.5 +/- 2.4% per 24 hours, p<0.0001) during SIH than DBA/2J mice. In contrast, the event characteristics and total sleep time during SF were the same in both strains. Furthermore, in the light phase, both strains showed a longer (p<0.01) time to arousal during SIH and SF compared with the dark phase. We conclude that genetic background can influence respiratory events and sleep architecture during SIH and that the arousal threshold is subject to circadian variation. Our data imply that individuals with low hypoxic sensitivity may be at a greater risk for hypoxia-related complications of obstructive sleep apnea.
Animals↗
Low-intensity warfarin therapy for the prevention of recurrent venous thromboembolism.
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Anticoagulants↗
In-hospital mortality following acute exacerbations of chronic obstructive pulmonary disease.
BACKGROUND: Acute exacerbations of chronic obstructive pulmonary disease (COPD) are a frequent cause of hospitalization in the United States. Previous studies of selected populations of patients with COPD have estimated in-hospital mortality to range from 4% to 30%. Our objective was to obtain a generalizable estimate of in-hospital mortality from acute exacerbation of COPD in the United States and to identify predictors of in-hospital mortality using administrative data. METHODS: We performed a cross-sectional study utilizing the 1996 Nationwide Inpatient Sample, a data set of all hospitalizations from a 20% sample of nonfederal US hospitals. The study population included 71 130 patients aged 40 years or older with an acute exacerbation of COPD at hospital discharge. The primary outcome assessed was in-hospital mortality. RESULTS: In-hospital mortality for patients with an acute exacerbation of COPD was 2.5%. Multivariable analyses identified older age, male sex, higher income, nonroutine admission sources, and more comorbid conditions as independent risk factors for in-hospital mortality. CONCLUSIONS: Mortality during hospitalization in this nationwide sample of patients with acute exacerbations of COPD was lower than that of previous studies of select populations. This estimate should provide optimism to both clinicians and patients regarding prognoses from COPD exacerbations requiring hospitalization. Our results indicate that the use of administrative data can help to identify subsets of patients with acute exacerbations of COPD that are at higher risk of in-hospital mortality.
Acute Disease↗
Lower physician estimate of underlying asthma severity leads to undertreatment.
BACKGROUND: Asthma undertreatment has been linked to poor outcomes. National guidelines recommend that physicians classify asthma severity based on pretreatment symptoms and titrate care as the disease changes in the individual patient. This study evaluated the extent to which the physician estimate of underlying severity affects a patient's asthma care. METHODS: Data used were collected from a cohort of adults with asthma enrolled in managed care. Eligible patients were adults enrolled in managed care with medical encounters coded for asthma. Physicians were eligible if they were main asthma providers. The patient survey covered demographics, symptoms, asthma treatment, and self-management knowledge. Physicians were asked to assess the underlying severity of their patients' asthma. RESULTS: There were 4005 patients with asthma with physician estimates of underlying severity. Of the patients, 70.1% were female (mean age, 44.8 years) and 83.5% were white. Most patients' current asthma symptoms were moderate (39.4%) and severe (50.1%). Most physician estimates of underlying severity were mild (44.6%) and moderate (44.5%). Among those patients reporting moderate symptoms, daily inhaled corticosteroid use was reported in 35.2% when physician estimates were mild, 53.0% when moderate, and 68.1% when severe (P =.001). Rates of peak flowmeter ownership, allergy testing, and self-management knowledge tracked similarly with physician estimates of underlying severity. CONCLUSIONS: Physician estimates of underlying asthma severity appear to determine asthma care. For patients with inadequate symptom control, lower physician estimates of underlying severity were associated with care that is less consistent with national guidelines. To improve the quality of asthma care, physicians need to update treatment based on their patients' current symptoms and adapt care accordingly.
Adult↗
Outpatient therapy with low molecular weight heparin for the treatment of venous thromboembolism: a review of efficacy, safety, and costs.
PURPOSE: To summarize the evidence comparing the efficacy, safety, and costs of outpatient and inpatient treatment of venous thromboembolism. METHODS: We searched the literature through March 2002 for studies comparing outpatient and inpatient treatment of venous thromboembolism with low molecular weight heparin or unfractionated heparin, and for studies addressing the costs of low molecular weight heparin use in any setting. We included studies with comparison groups or decision analyses. RESULTS: Eight studies (three randomized trials and five cohort studies) compared outpatient use of low molecular weight heparin with inpatient use of unfractionated heparin in 3762 patients. The incidence of recurrent deep venous thrombosis was similar in the two groups (median, 4% [range, 0% to 7%] vs. 6% [range, 0% to 9%]), as was major bleeding (median, 0.5% [range, 0% to 2%] vs. 1% [range, 0% to 2%]). Use of low molecular weight heparin was associated with shorter hospitalization (median, 2.7 days [range, 0.03 to 5.1 days] vs. 6.5 days [range, 4 to 9.6 days]) and lower costs (median difference, 1600 dollars). Comparisons of outpatient and in-hospital use of low molecular weight heparin reported no difference in outcomes, but there were savings in hospitalization costs. Low molecular weight heparin was also found to be more cost saving and cost-effective than unfractionated heparin, with savings of 0% to 64% (median, 57%). CONCLUSION: The evidence indicates that outpatient treatment of deep venous thrombosis with low molecular weight heparin is likely to be efficacious, safe, and cost-effective.
Ambulatory Care↗
Nebulized beta2-agonist use in high-risk inner-city adults with asthma.
Nebulizer use has been linked to worse asthma outcomes, but the precise reason(s) for this relationship is not known. We assessed the frequency of nebulized beta2-agonist use in high-risk inner-city adults with asthma and compared asthma self-management practices according to nebulizer use in this population. This was a cross-sectional study conducted over 6 weeks from July to August 2000. A convenience sample (N=50) was recruited from an inner-city emergency department (ED). Adults (age > or = 18 years) were eligible if they had a physician diagnosis of acute asthma exacerbation. Data regarding asthma symptoms, acute care utilization, use of nebulized beta2-agonist for symptom relief, and indicators of asthma self-management (physician for asthma care, use of controller medications, current cigarette smoking, and substance use) were collected by an interviewer-administered survey. Nebulized beta2-agonist use was reported by 54.0% of patients during the 30 days before their ED visit. Nebulizer users reported more severe asthma symptoms (96.3% vs. 73.9% with moderate or severe persistent asthma, p=0.02) than nonusers. Nebulizer users were more likely to have a physician for asthma care (85.2% vs. 56.5%, p=0.02), have more frequent care from their physicians in the past 12 months (e.g., >3 visits: 59.3% vs. 30.4%, p=0.02), and notify their physician during their asthma exacerbation (39.1% vs. 7.7%, p=0.04). Compared with nonusers, nebulizer users reported better care across other indicators of care, though differences between groups were not significant. After accounting for symptom severity, results were largely unchanged. If these findings are confirmed in other studies with larger numbers of patients, we conclude that the relationship between nebulizer use and higher asthma morbidity largely represents preferential use of nebulizers by patients with more symptomatic disease.
Administration, Inhalation↗
Caloric intake in medical ICU patients: consistency of care with guidelines and relationship to clinical outcomes.
STUDY OBJECTIVES: To assess the consistency of caloric intake with American College of Chest Physicians (ACCP) recommendations for critically ill patients and to evaluate the relationship of caloric intake with clinical outcomes. DESIGN: Prospective cohort study. SETTING: Adult ICUs at two teaching hospitals. PARTICIPANTS: Patients with an ICU length of stay of at least 96 h. MEASUREMENTS AND RESULTS: On ICU admission, severity of illness (ie, simplified acute physiology score II) and markers of nutritional status (ie, serum albumin level and body mass index) were recorded. The route of feeding (ie, enteral or parenteral), actual caloric intake (ie, percentage of ACCP recommendations: 0 to 32% [tertile I]; 33 to 65% [tertile II]; >/==" BORDER="0"> 66% [tertile III]), and evidence of GI intolerance (ie, gastric aspirate levels, >/==" BORDER="0"> 100 mL) were recorded daily. The following outcomes were assessed: status on hospital discharge (alive vs dead); spontaneous ventilation before ICU discharge (yes vs no); and ICU discharge without developing nosocomial sepsis (yes vs no). The average caloric intake among 187 participants was 50.6% of the ACCP targets and was similar in both hospitals. Caloric intake was inversely related to the mean number of gastric aspirates >/==" BORDER="0"> 100 mL/d (Spearman rho = -0.04; p = 0.06), but not to severity of illness, nutritional status, or route of feeding. After accounting for the number of gastric aspirates >/==" BORDER="0"> 100 mL, severity of illness, nutritional status, and route of feeding, tertile II of caloric intake (vs tertile I) was associated with a significantly greater likelihood of achieving spontaneous ventilation prior to ICU discharge. Tertile III of caloric intake (vs tertile I) was associated with a significantly lower likelihood of both hospital discharge alive and spontaneous ventilation prior to ICU discharge. CONCLUSIONS: Study participants were underfed relative to ACCP targets. These targets, however, may overestimate needs, since moderate caloric intake (ie, 33 to 65% of ACCP targets; approximately 9 to 18 kcal/kg per day) was associated with better outcomes than higher levels of caloric intake.
APACHE↗
Asthma in older patients: factors associated with hospitalization.
BACKGROUND: Although older adults (> or =65 years) with asthma have higher rates of hospitalization and death from asthma than younger adults, the reasons for this are not known. OBJECTIVES: To determine whether patterns of care were less favorable for older than younger adults with asthma and to assess whether patient characteristics such as symptom severity and comorbid illnesses explain the higher rate of hospitalization. METHODS: Prospective cohort study of 6590 adults with asthma in 15 managed care organizations in the United States. Participants completed a survey of demographics, symptoms, health status, comorbid illnesses, treatment, access to care, self-care knowledge, physician specialty, and health care use. RESULTS: Among 6590 adults with asthma, 554 (8%) were 65 years or older and 1942 (29%) were aged 18 to 34 years. Older patients were more likely than younger patients to be men, white, non-Hispanic, and less educated. At baseline, older patients reported a greater frequency of asthma-related symptoms, such as daily cough (36% vs 22%, P<.001) and wheezing (27% vs 22%, P<.002). They were also more likely to report comorbid conditions, such as sinusitis (50% vs 38%), heartburn (35% vs 23%), chronic bronchitis (43% vs 16%), emphysema (19% vs 1%), congestive heart failure (8% vs 1%), and history of smoking (54% vs 34%) (all P<.001). Care appeared to be better for the older patients compared with the younger, including more frequent use of inhaled corticosteroids, greater self-management knowledge, and fewer reported barriers to care. In the follow-up year, older patients were approximately twice as likely to be hospitalized (14%) than were younger patients (7%) (P<.001). In multivariate analysis, however, older age was not predictive of future hospitalization (odds ratio, 1.05; 95% confidence interval, 0.68-1.61), after adjustment for sex, ethnicity, education, baseline asthma symptoms, health status, comorbid illnesses, and tobacco use. Factors independently associated with hospitalization included being female, nonwhite, less educated, and less physically healthy, and more frequent asthma symptoms. CONCLUSIONS: Although the older adults with asthma had greater respiratory symptoms and more comorbidity than their younger counterparts, chronologic age was not an independent risk for hospitalization. Appropriate care for older adults with asthma should address asthma symptoms and other chronic conditions.
Adult↗
Indications for lung transplant referral: physician attitudes.
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Attitude of Health Personnel↗