PubMed Health⌕ Search

Biomedical subjects

D J Cook

Publications and source records attributed to D J Cook.

At least 199 records · Page 11Linked to original sources
PubMed1995

Discrimination and abuse experienced by general internists in Canada.

OBJECTIVE: To identify the frequency of psychological and emotional abuse, gender discrimination, verbal sexual harassment, physical sexual harassment, physical assault, and homophobia experienced by general internists. DESIGN: Cross-sectional survey. SETTING: Canadian general internal medicine practices. RESULTS: The overall response rate was 70.6% (984/1,393); the 501 respondents who classified themselves as general internists were studied. Three-fourths of the internists experienced psychological and emotional abuse at the hands of patients, and 38% of the women and 26% of the men experienced physical assault by patients. The majority of the female internists experienced gender discrimination by patients (67%) and by physician peers (56%). Forty-five percent of the women experienced verbal sexual harassment by patients, and 22% experienced physical sexual harassment by patients. The male internists experienced verbal sexual harassment from nurses slightly more often than the female internists did (19% vs 13%, p > 0.05). Verbal sexual harassment by male colleagues was reported by 35% of the female internists, and physical sexual harassment was reported by 11%. Approximately 40% of general internists reported homophobic remarks by both health care team members and patients. CONCLUSIONS: Abuse, discrimination, and homophobia are prevalent in the internal medicine workplace. A direct, progressive, multidisciplinary approach is necessary to label and address these problems.

Adult↗
PubMed1995

Cerebral blood flow during cardiac operations: comparison of Kety-Schmidt and xenon-133 clearance methods.

This study simultaneously compared the standard Kety-Schmidt and the modified xenon-133 (133Xe) clearance techniques for measuring cerebral blood flow (CBF) and cerebral metabolic rate for oxygen (CMRO2) during cardiac operations. The validity of the CBF method is important because our management of the patient during cardiopulmonary bypass (CPB) is based, in part, on our understanding of the cerebral hemodynamics during CPB. In 20 patients undergoing coronary artery bypass grafting, CBF and CMRO2 were determined by both methods. Measurements were made before onset of CPB and once during CPB. Ten patients underwent CPB with systemic normothermia (37 degrees C) and 10 with systemic hypothermia (27 degrees C). Anesthesia consisted of fentanyl and midazolam. CPB pump flows were kept at 2.2 to 2.4 L.min-1.m-2 and alpha-stat pH management was used. Xenon-133 clearance significantly underestimated CBF and CMRO2 relative to the Kety-Schmidt technique before CPB and at both bypass temperatures. Values obtained by 133Xe clearance were approximately 50% of that measured by the Kety-Schmidt method. The modified 133Xe technique as typically used during cardiac operations does not appear to measure CBF accurately; this leads to corresponding errors in CMRO2 calculations. Determination of CMRO2 and cerebral autoregulatory function during cardiac operations appears to be more appropriate if based on the more direct Kety-Schmidt technique. Accordingly, our management of CPB with respect to cerebral perfusion as it has been determined by the modified 133Xe clearance method may require reassessment.

Blood Gas Analysis↗
PubMed1995

Cardiopulmonary bypass temperature, hematocrit, and cerebral oxygen delivery in humans.

BACKGROUND: The neurologic effects of warm heart operations is a subject of popular interest. The purpose of this study was to examine the adequacy of cerebral oxygenation during normothermic cardiopulmonary bypass and better define the relationship between hematocrit, temperature, and brain oxygen delivery. METHODS: Cerebral blood flow, metabolic rate, and oxygen delivery were measured in 60 patients randomized to normothermic (37 degrees C) or hypothermic (27 degrees C) cardiopulmonary bypass. The nitrous oxide saturation technique of Kety and Schmidt was used for cerebral blood flow determinations. Both temperature groups underwent moderate (31%) hemodilution. RESULTS: During normothermic cardiopulmonary bypass, cerebral blood flow increased secondary to hemodilution and decreased cerebral vascular resistance; a normal matching of oxygen demand and delivery was maintained. During hypothermic bypass, hemodilution and hypothermia had essentially equal, opposing effects on cerebral vascular resistance and blood flow. With hypothermia, brain oxygen demand and delivery were both reduced but not closely coupled. CONCLUSIONS: From the standpoint of global cerebral perfusion and oxygenation, our data support the practice of "warm" heart operations. It clarifies the marked influence of hematocrit on cerebral blood flow and delineates the interaction of temperature and hematocrit on cerebral oxygen delivery. It also suggests that additional investigation to better define "temperature-appropriate" hemodilution during cardiopulmonary bypass is indicated.

Body Temperature↗
PubMed1995

Enteral nutrition in the critically ill patient: a prospective survey.

OBJECTIVES: To describe current enteral nutrition-prescribing practices for critically ill patients, and to identify factors associated with initiation of, and tolerance to, enteral nutrition. DESIGN: A prospective, cohort study. SETTING: Two tertiary care medical-surgical intensive care units (ICU) in Ontario, Canada. PATIENTS: We enrolled 99 consecutive patients who were expected to stay in the ICU for > 3 days and who were unable to tolerate oral nutrition. We followed patients for 21 days or until they tolerated enteral nutrition, tolerated oral nutrition, were discharged from the ICU, or died. MEASUREMENTS AND MAIN RESULTS: We recorded time elapsed from ICU admission to initiation and tolerance of enteral feedings, and examined factors associated with these events. We defined tolerance as receiving 90% of estimated daily energy requirements for > 48 hrs without gastrointestinal dysfunction (i.e., high gastric residuals, vomiting, diarrhea, abdominal distention). Seventy-three (74%) of 99 patients were started on enteral feedings an average 3.1 days (range 1 to 18) after ICU admission. Of 26 patients never started on enteral nutrition, three (12.5%) patients eventually tolerated oral nutrition, 14 (54.0%) patients were discharged from the ICU, and seven (27.0%) patients died. Reasons for not initiating enteral nutrition included absence of bowel sounds (27.0%), high nasogastric drainage (16.9%), contraindication to enteral nutrition (16.7%), tolerance of oral nutrition (6.8%), and no apparent reason (5.1%). Abdominal surgery, use of vasoactive drugs, and admission to one hospital made initiation of enteral nutrition less likely, whereas presence of bowel sounds and admission to the other hospital made initiation of enteral nutrition more likely. Thirty-five (42.9%) of 73 patients started on enteral nutrition achieved tolerance of the regimen. The average time from ICU admission to tolerance of feedings was 5.8 days (range 1 to 14). Once started on enteral nutrition, the most common reasons for decreasing or discontinuing feedings included high gastric residuals (51.0%), mechanical feeding tube problems (15.4%), medical or surgical procedures (5.4%), and vomiting (5.1%). Use of paralytic agents and the presence of high gastric residuals were associated with intolerance. Of 38 patients who did not achieve tolerance, 20 (52.6%) patients were discharged from the ICU, eight (21.0%) patients died, and eight (21.0%) patients eventually tolerated oral nutrition. CONCLUSIONS: Enteral nutrition is not started in all eligible ICU patients. Approximately half of those patients receiving enteral nutrition achieved tolerance of the regimen. Gastrointestinal dysfunction causing intolerance to enteral nutrition is a common reason for not starting, or discontinuing, feedings.

Critical Illness↗
PubMed1995

Corticosteroid treatment for sepsis: a critical appraisal and meta-analysis of the literature.

OBJECTIVE: To determine the effect of corticosteroid therapy on morbidity and mortality in patients with sepsis. DATA SOURCES: We searched for published and unpublished research using MEDLINE, EMBASE, and the Science Citation Index, manual searching of Index Medicus, citation review of relevant primary and review articles, personal files, and contact with primary investigators. STUDY SELECTION: From a pool of 124 potentially relevant articles, duplicate independent review identified nine relevant, randomized, controlled trials of corticosteroid therapy in sepsis and septic shock among critically ill adults. DATA EXTRACTION: In duplicate, independently, we abstracted key data on population, intervention, outcome, and methodologic quality of the randomized controlled trials. DATA SYNTHESIS: Corticosteroids appear to increase mortality in patients with overwhelming infection (relative risk 1.13, 95% confidence interval 0.99 to 1.29), and have no beneficial effect in the subgroup of patients with septic shock (relative risk 1.07, 95% confidence interval 0.91 to 1.26). Studies with the highest methodologic quality scores also suggest a trend toward increased mortality overall (relative risk 1.10, 95% confidence interval 0.94 to 1.29). A similar trend was observed for patients with septic shock (relative risk 1.12, 95% confidence interval 0.95 to 1.32). No difference in secondary infection rates was demonstrated in corticosteroid-treated patients with sepsis or septic shock. However, there was a trend toward increased mortality from secondary infections in patients receiving corticosteroids (relative risk 1.70, 95% confidence interval 0.70 to 4.12). The occurrence rate of gastrointestinal bleeding was increased slightly in the treatment group (relative risk 1.17, 95% confidence interval 0.79 to 1.73). CONCLUSIONS: Current evidence provides no support for the use of corticosteroids in patients with sepsis or septic shock, and suggests that their use may be harmful. These trials underscore the need for future methodologically rigorous trials evaluating new immune-modulating therapies in well-defined critically ill patients with overwhelming infection.

Adrenal Cortex Hormones↗
PubMed1995

Multiple organ dysfunction score: a reliable descriptor of a complex clinical outcome.

OBJECTIVE: To develop an objective scale to measure the severity of the multiple organ dysfunction syndrome as an outcome in critical illness. DESIGN: Systematic literature review; prospective cohort study. SETTING: Surgical intensive care unit (ICU) of a tertiary-level teaching hospital. PATIENTS: All patients (n = 692) admitted for > 24 hrs between May 1988 and March 1990. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Computerized database review of MEDLINE identified clinical studies of multiple organ failure that were published between 1969 and 1993. Variables from these studies were evaluated for construct and content validity to identify optimal descriptors of organ dysfunction. Clinical and laboratory data were collected daily to evaluate the performance of these variables individually and in aggregate as an organ dysfunction score. Seven systems defined the multiple organ dysfunction syndrome in more than half of the 30 published reports reviewed. Descriptors meeting criteria for construct and content validity could be identified for five of these seven systems: a) the respiratory system (Po2/FIO2 ratio); b) the renal system (serum creatinine concentration); c) the hepatic system (serum bilirubin concentration); d) the hematologic system (platelet count); and e) the central nervous system (Glasgow Coma Scale). In the absence of an adequate descriptor of cardiovascular dysfunction, we developed a new variable, the pressure-adjusted heart rate, which is calculated as the product of the heart rate and the ratio of central venous pressure to mean arterial pressure. These candidate descriptors of organ dysfunction were then evaluated for criterion validity (ICU mortality rate) using the clinical database. From the first half of the database (the development set), intervals for the most abnormal value of each variable were constructed on a scale from 0 to 4 so that a value of 0 represented essentially normal function and was associated with an ICU mortality rate of < 5%, whereas a value of 4 represented marked functional derangement and an ICU mortality rate of > or = 50%. These intervals were then tested on the second half of the data set (the validation set). Maximal scores for each variable were summed to yield a Multiple Organ Dysfunction Score (maximum of 24). This score correlated in a graded fashion with the ICU mortality rate, both when applied on the first day of ICU admission as a prognostic indicator and when calculated over the ICU stay as an outcome measure. For the latter, ICU mortality was approximately 25% at 9 to 12 points, 50% at 13 to 16 points, 75% at 17 to 20 points, and 100% at levels of > 20 points. The score showed excellent discrimination, as reflected in areas under the receiver operating characteristic curve of 0.936 in the development set and 0.928 in the validation set. The incremental increase in scores over the course of the ICU stay (calculated as the difference between maximal scores and those scores obtained on the first day [i.e., the delta Multiple Organ Dysfunction Score]) also demonstrated a strong correlation with the ICU mortality rate. In a logistic regression model, this incremental increase in scores accounted for more of the explanatory power than admission severity indices. CONCLUSIONS: This multiple organ dysfunction score, constructed using simple physiologic measures of dysfunction in six organ systems, mirrors organ dysfunction as the intensivist sees it and correlates strongly with the ultimate risk of ICU mortality and hospital mortality. The variable, delta Multiple Organ Dysfunction Score, reflects organ dysfunction developing during the ICU stay, which therefore is potentially amenable to therapeutic manipulation. (ABSTRACT TRUNCATED)

Humans↗
PubMed1995

Chest physical therapy management of patients with cystic fibrosis. A meta-analysis.

The purpose of this overview is to quantitatively assess the conflicting body of literature concerning the efficacy of physical therapy modalities for clearing bronchial secretions in the treatment of patients with cystic fibrosis (CF). The modalities examined included positive expiratory pressure (PEP) mask, forced expiratory technique (FET), exercise (EX), autogenic drainage (AD), and standard physical therapy (STD), consisting of postural drainage, percussion, and vibration. Computerized searches of the MEDLINE and Cumulative Index for Nursing and Allied Health databases were performed for the years from 1966 to 1993. The authors of relevant papers were contacted for unpublished information. Studies were considered relevant if they met the following criteria: randomized trials in patients with a definite diagnosis of CF; an intervention of any combination of PEP, FET, STD, AD, or EX; and an outcome of FEV1, sputum weight, or sputum clearance. A review of 456 citations yielded 65 potentially relevant trials and 8 review articles; of these, 35 met the inclusion criteria and were incorporated into the overview. These studies evaluated different combinations of physical therapy modalities; therefore, we performed seven separate meta-analyses comparing the independent techniques using the pooled effect size technique. Standard physical therapy resulted in a significantly greater sputum expectoration than no treatment (effect size of 0.61 SD units, p < 0.0001). The combination of standard therapy with EX with associated with a statistically significant increase in FEV1 over STD alone (effect size of 0.48 SD units, p = 0.04). No other differences between physical therapy modalities were found.

Cystic Fibrosis↗
PubMed1995

Sonographic measurement of renal enlargement in children with acute pyelonephritis and time needed for resolution: implications for renal growth assessment.

OBJECTIVE: Failure of a kidney to grow satisfactorily in childhood is evidence of renal disease. Because kidneys may enlarge during an episode of acute pyelonephritis, concomitant renal length measurements cannot be used as baselines for growth assessment. This study was designed to determine the degree of renal enlargement in children with acute pyelonephritis and the time the enlargement takes to resolve after treatment is started to find the optimum time for obtaining baseline measurements. SUBJECTS AND METHODS: In a cohort study, 180 children younger than 5 years old with their first proven acute urinary tract infection, with or without pyelonephritis, had renal scintigraphy and sonography within 15 days of starting treatment. The presence of cortical defects on scintigrams indicated pyelonephritis. The lengths of kidneys with and without scintigraphic defects (i.e., with and without pyelonephritis) were compared, adjusting for age and sex, and the length of kidneys with defects was related to time elapsed between the start of treatment and sonography. RESULTS: Ninety-nine kidneys (28%) in 77 children (43%) had scintigraphic defects. Kidneys with defects were an average of 3.2 mm longer than kidneys without defects. Length and time interval between treatment and sonography in kidneys with defects correlated negatively, with mean length approaching that of kidneys without defects by 10-11 days. CONCLUSION: Kidneys with acute pyelonephritis initially increase in length but return to normal on average by the 11th day of treatment. If poor renal growth is used as an indication of renal disease, sonography should be delayed or repeated at least 2 weeks after the start of treatment to determine the length of the uninflamed kidney.

Acute Disease↗
PubMed1995

Stress ulcer prophylaxis: gastrointestinal bleeding and nosocomial pneumonia. Best evidence synthesis.

PURPOSE: To examine the effect of stress ulcer prophylaxis on gastrointestinal bleeding, pneumonia, and mortality. METHODS: Computerized search of published and unpublished research, bibliographies, pharmaceutical and personal files and abstract reports. Independent review of 257 articles identified 71 relevant randomized trials for inclusion. We made independent, duplicate assessment of the methodologic quality, population, intervention and outcomes of each trial. RESULTS: This overview demonstrates that prophylaxis with histamine-2-receptor antagonists decreases the incidence of overt gastrointestinal bleeding (odds ratio 0.29 [95% CI 0.17-0.45]) and clinically important bleeding (odds ratio 0.35 [95% CI 0.15-0.76]). There is a trend to decreased overt bleeding when antacids are compared with no therapy (odds ratio 0.35 [95% CI 0.08-1.33]). Although sucralfate, antacids, and histamine-2-receptor antagonists are equivalent in reducing clinically important bleeding, sucralfate decreases the incidence of nosocomial pneumonia compared with antacids and/or histamine-2-receptor antagonists (odds ratio 0.50 [95% CI 0.21-0.79]). Sucralfate is associated with lower mortality relative to antacids (odds ratio 0.70 [95% CI 0.52-0.94]), and relative to histamine-2-receptor antagonists (odds ratio 0.71 [95% CI 0.49-1.04]). CONCLUSIONS: All stress ulcer prophylactic agents appear to be effective in decreasing bleeding. Prophylaxis with sucralfate is associated with a lower rate of nosocomial pneumonia and mortality, providing strong evidence for use of this agent in clinical practice.

Anti-Ulcer Agents↗
PubMed1995

Gastric alkalinization, pneumonia, and systemic infections: the controversy.

BACKGROUND: Gastric alkalinization has been suspected as a cause of pneumonia in critically ill patients. Although meta-analysis of the available data confirms an association between the administration of antacids/H2-antagonists and the risk of pneumonia, controversy remains whether stress ulcer prophylaxis with sucralfate reduces the risk of pneumonia. We hypothesized that the conflicting study results may be due to differences in patient population and general treatment regimens. RISK FACTORS: Microbiological studies have shown that a gastric pH > 4 is crucial for overgrowth of gastric gram-negative but not gram-positive bacteria. Sucralfate mainly influences the growth of gram-negative bacteria. Thus, in patient groups with a high frequency of gram-positive pneumonia, preservation of gastric acidity does not influence the pneumonia rate. Since 40-60% of critically ill patients show gastric pH values > 4 even without administration of acid-neutralizing agents, an increased risk of nosocomial pneumonia with antacids/H2-antagonists can only be expected if these agents substantially increase the frequency of patients with gastric pH > 4. No influence of stress ulcer prophylaxis on the pneumonia rate can be expected in patients on enteral nutrition, especially if administered continuously. In non-ventilated patients or in those with a short duration of ventilation no significant influence of stress ulcer prophylaxis on nosocomial pneumonia rate can be expected. The same is true for patient groups where regurgitation of gastric content is prevented, e.g. head-up position in neurosurgical patients. Furthermore, in patient groups with primary lung injury nosocomial pneumonia occurs due to specific pathomechanisms, e.g. lung contusion or inhalation injury. Based on these factors we have developed a scoring system and have performed a regression analysis between the sum of the risk scores and the odds ratio of nosocomial pneumonia of all available stress ulcer studies dealing with nosocomial pneumonia. RESULTS: A highly significant correlation (p < 0.0001) could be demonstrated between the sum of the risk score and the odds ratio for pneumonia. An increased risk of nosocomial pneumonia due to stress ulcer prophylaxis with antacids/H2-antagonists occurred in patient groups with a risk score of > or = 2. CONCLUSIONS: This analysis supports the hypothesis that gastric alkalinization significantly increases the risk of nosocomial pneumonia in long-term ventilated patients. However, this analysis also shows that only specific subgroups of patients benefit from acid-independent stress ulcer prophylaxis relative to nosocomial pneumonia. Furthermore, recent experimental and clinical studies support the hypothesis that gastric alkalinization may increase the risk of systemic infections and that sucralfate may have significant protective effects.

Acid-Base Equilibrium↗
PubMed1995

The aetiology, consequences and prevention of barotrauma: a critical review of the literature.

PURPOSE: To review critically the literature on pulmonary barotrauma in mechanically ventilated patients. METHODS: Data sources included MEDLINE and citation lists of relevant articles. Articles investigating the aetiology or prevention of pulmonary barotrauma were critically evaluated according to published guidelines. RESULTS: Experimental animal studies and observational clinical studies consistently demonstrate that the high airway pressures and large tidal volumes associated with conventional modes of mechanical ventilation are major contributors to lung injury. Animal studies establish the correct temporal relationship and demonstrate a biological gradient. Observational clinical studies demonstrate an increased risk of barotrauma in the setting of acute lung injury. The results of three case series and two small randomised clinical trials indicate that a pressure-limited ventilation strategy aimed to reduce barotrauma may improve outcomes in patients with acute lung injury. CONCLUSIONS: Pulmonary barotrauma is a clinically important phenomenon that may delay the healing of injured lungs and lead to the development, or the exacerbation, of ARDS. Risk factors for barotrauma include high peak airway pressures, large tidal volumes and acute lung injury. Resolution of the role for pressure-limited ventilation in ARDS prevention and treatment requires a large-scale randomised clinical trial.

Airway Resistance↗
PubMed1995

Changing demographics in renal transplant recipients: the 30 year Cleveland Clinic experience.

While it does appear that the most recent era of transplantation has not resulted in significant improvement in long-term allograft function, this appears to be due, at least in part, to the transplantation of increasing numbers of high-risk patients. It is noted that the improved results accomplished over prior eras of transplantation have been maintained despite the inclusion of these high-risk patients. Patients currently undergoing transplantation are more likely to be older, diabetic, obese or African American. All of these subgroups have poorer patient survival in the most recent transplant era and thus, death with a functioning graft has become a significant contributor to graft loss. Recipients were more likely to receive kidneys from cadaveric donors in the most recent era and within the live-donor groups, sibling donation has decreased. Hopefully, the recent trend of increased live-donor transplants (especially living, unrelated transplants) will continue. Cadaveric recipients were at higher risk for posttransplant ATN which, for the first time in the current era, had a significant adverse impact on graft survival. Long-term survival appeared to be associated with particular characteristics (optimal age at transplantation, optimal donor age, live donor, etc.), and can be achieved despite known risk factors, such as rejection or delayed graft function.

Adolescent↗