Recurrent sinopulmonary infection and impaired antibody response to bacterial capsular polysaccharide antigen in children with selective IgG-subclass deficiency

We studied 20 children with recurrent sinopulmonary infections and serum IgG levels within the normal range, who had selective IgG-subclass deficiency. Twelve of the children were IgG2 deficient, five were IgG3 deficient, and three were deficient in both IgG2 and IgG3. IgA deficiency was present in 3 of the 20 patients. In the children with IgG2 deficiency, serum antibody concentrations to the capsular polysaccharide of Hemophilus influenzae type B (Hib) were significantly lower than those in age-matched controls, both before and after immunization with the Hib capsular polysaccharide antigen, which elicits antibody predominantly of the IgG2 subclass. In contrast, their serum antibody titers to the tetanus and diphtheria toxoid protein antigens, which elicit antibody predominantly of the IgG1 subclass, were normal in comparison with those of age-matched controls. These results suggest that impairment of the antibody response to specific microbial antigens predisposes patients with selective IgG-subclass deficiencies to recurrent infections. Thus, as an aid in determining therapy, children with recurrent infections and normal total serum IgG should be evaluated for this condition.

Protocol weaning of mechanical ventilation in medical and surgical patients by respiratory care practitioners and nurses: effect on weaning time and incidence of ventilator-associated pneumonia

STUDY OBJECTIVES

(1) To determine the effect of a single ventilator management protocol (VMP) used in medical and surgical ICUs on the duration of mechanical ventilation. (2) To determine the effect of a VMP on the incidence of ventilator-associated pneumonia (VAP).

DESIGN

Prospective, randomized, controlled study.

SETTING

: University medical center.

PATIENTS

Three hundred eighty-five patients receiving mechanical ventilation between June 1997 and May 1998.

INTERVENTIONS

A respiratory care practitioner- and registered nurse-driven VMP.

RESULTS

Intervention and control groups were comparable with respect to age, sex, severity of illness and injury, and duration of respiratory failure at the time of randomization. The duration of mechanical ventilation for patients was decreased from a median of 124 h for the control group to 68 h in the VMP group (p = 0.0001). Thirty-one total instances of VAP were noted. Twelve patients in the surgical control group had VAP, compared with 5 in the surgical VMP group (p = 0.061). The impact of the VMP on VAP frequency was less for medical patients. Mortality and ventilator discontinuation failure rates were similar between control and VMP groups.

CONCLUSIONS

A VMP designed for multidisciplinary use was effective in reducing duration of mechanical ventilatory support without any adverse effects on patient outcome. The VMP was also associated with a decrease in incidence of VAP in trauma patients. These results, in conjunction with prior studies, suggest that VMPs are highly effective means of improving care, even in university ICUs.

Prevention of hospital-associated pneumonia and ventilator-associated pneumonia

OBJECTIVE

To synthesize the available clinical data for the prevention of hospital-associated pneumonia (HAP) and ventilator-associated pneumonia (VAP) into a practical guideline for clinicians.

DATA SOURCE

A Medline database and references from identified articles were used to perform a literature search relating to the prevention of HAP/VAP.

CONCLUSIONS

There is convincing evidence to suggest that specific interventions can be employed to prevent HAP/VAP. The evidence-based interventions focus on the prevention of aerodigestive tract colonization (avoidance of unnecessary antibiotics and stress ulcer prophylaxis, use of sucralfate for stress ulcer prophylaxis, chlorhexidine oral rinse, selective digestive decontamination, short-course parenteral prophylactic antibiotics in high-risk patients) and the prevention of aspiration of contaminated secretions (preferred oral intubation, appropriate intensive care unit staffing, avoidance of tracheal intubation with the use of mask ventilation, application of weaning protocols and optimal use of sedation to shorten the duration of mechanical ventilation, semirecumbent positioning, minimization of gastric distension, subglottic suctioning, avoidance of ventilator circuit changes/manipulation, routine drainage of ventilator circuit condensate). Clinicians caring for patients at risk for HAP/VAP should promote the development and application of local programs encompassing these interventions based on local resource availability, occurrence rates of HAP/VAP, and the prevalence of infection due to antibiotic-resistant bacteria (Pseudomonas aeruginosa, Acinetobacter species, and methicillin-resistant Staphylococcus aureus).

Evaluation of clinical judgment in the identification and treatment of nosocomial pneumonia in ventilated patients

To evaluate the accuracy of clinical judgment in the diagnosis and treatment of nosocomial pneumonia in ventilated patients, we studied 84 patients suspected of having nosocomial pneumonia because of the presence of a new pulmonary infiltrate and purulent tracheal secretions. We prospectively evaluated the accuracy of diagnostic predictions and therapeutic plans independently formulated by a team of physicians aware of all clinical, radiologic and laboratory data, including the results of Gram-stained bronchial aspirates. Definite (n = 51) or probable (n = 33) diagnoses could be established in all patients by strict histopathologic and/or bacteriologic criteria. Only 27/84 patients were diagnosed as having pneumonia. Organisms responsible for pneumonias were identified by quantitative cultures of samples obtained using a protected specimen brush or pleural fluid cultures. Four hundred eight predictions were made for the 84 studied patients. Clinical diagnoses for patients subsequently diagnosed as having pneumonia were accurate in 81/131 cases (62 percent). Furthermore, only 43/131 (33 percent) therapeutic plans proposed for these patients represented effective therapy. Common causes of inappropriate treatment included failure to diagnose pneumonia (50 plans), failure to effectively treat highly resistant organisms (21 plans), and failure to treat all organisms in cases of polymicrobial pneumonia (14 plans). Therapeutic plans formulated for patients without pneumonia included the unnecessary use of antibiotics in 45/277 cases (16 percent). These findings indicate that the use of clinical criteria alone does not permit the accurate diagnosis of nosocomial pneumonia in ventilated patients, and commonly results in inappropriate or inadequate antibiotic therapy for these patients.

Transfusion and postoperative pneumonia in coronary artery bypass graft surgery: effect of the length of storage of transfused red cells

BACKGROUND

Various bioactive substances are released from white cell (WBC) granules into red cell (RBC) components in a time-dependent manner during blood storage. Some of these substances may have immunosuppressive effects and may contribute to transfusion-induced immunomodulation. RBCs transfused after prolonged storage may be associated with a higher incidence of postoperative infections than fresh RBCs. This hypothesis does not seem to have been investigated in a clinical study.

STUDY DESIGN AND METHODS

The records of 416 consecutive patients undergoing coronary artery bypass graft operations at the Massachusetts General Hospital were reviewed. The association between the length of storage of the transfused RBCs, as well as the number of units of non-WBC-reduced allogeneic RBCs and/or platelets transfused, and the occurrence of postoperative pneumonia was calculated by logistic regression analyses adjusting for the effects of confounding factors. Among these were the numbers of days of intubation, days of impaired consciousness, and units of RBCs transfused.

RESULTS

By Centers for Disease Control and Prevention criteria, pneumonia developed in 54 patients (13.0%). Among 269 patients given RBCs, the risk of pneumonia increased by 1 percent per day of increase in the mean storage time of the transfused RBCs (p<0.005). In an analysis of all patients, the risk of pneumonia increased by 5 percent per unit of non-WBC-reduced allogeneic RBCs and/or platelets received (p = 0.0584).

CONCLUSION

After adjustment for the effects of the risk factors for pneumonia and the number of transfused RBCs, an association was observed between the length of storage of transfused RBCs and the development of postoperative pneumonia. This association should be investigated further in future studies of the outcomes of blood transfusion.

Medical and neurological complications of ischemic stroke: experience from the RANTTAS trial. RANTTAS Investigators

BACKGROUND AND PURPOSE

Medical and neurological complications after acute ischemic stroke may adversely impact outcome and in some cases may be preventable. Limited data exist regarding the frequency of such complications occurring in the first days after the ictus and the relationship of these complications to outcome. Our objective was to identify the types, severity, and frequency of medical and neurological complications following acute ischemic stroke and to determine their role in mortality and functional outcome.

METHODS

Rates of serious (life-threatening) and nonserious medical and neurological complications and mortality were derived from the placebo limb of the Randomized Trial of Tirilazad Mesylate in Acute Stroke (RANTTAS) database (n=279). Complications were correlated with clinical outcome using logistic regression techniques.

RESULTS

Of all patients, 95% had at least one complication. The most common serious medical complication was pneumonia (5%), and the most common serious neurological complication was new cerebral infarction or extension of the admission infarction (5%). The 3-month mortality was 14%; 51% of these deaths were attributed primarily to medical complications. Outcome was significantly worse in patients with serious medical complications, after adjustment for baseline imbalances, as measured by the Barthel Index (odds ratio [OR], 6.1; 95% confidence interval [CI], 2.5 to 15.1) and by the Glasgow Outcome Scale (OR, 11.6; 95% CI, 4.3 to 30.9). After death was discounted, serious medical complications were associated with severe disability at 3 months as determined by the Glasgow Outcome Scale (OR, 4.4; 95% CI, 1.3 to 14.8).

CONCLUSIONS

Medical complications that follow ischemic stroke not only influence mortality but may influence functional outcome.

Macrophage engulfment of apoptotic neutrophils contributes to the resolution of acute pulmonary inflammation in vivo

For resolution of inflammation to occur, it is necessary both to limit leukocyte influx and to clear now redundant cells from the tissues. Recent evidence from in vitro studies suggests that clearance may be an active process, accomplished in part by macrophage engulfment of intact cells that have undergone programmed cell death or apoptosis. However, the kinetics of these events and their association with the resolution of acute inflammatory responses in vivo remain to be elucidated. To investigate these events, we examined an animal model of acute, limited, neutrophilic pulmonary inflammation. Cells were obtained by bronchoalveolar lavage (BAL) of rats at various time points after intratracheal administration of lipopolysaccharide (LPS). Apoptotic neutrophils were rarely seen in BAL from control animals but were detected after neutrophil influx had occurred in response to LPS challenge. Macrophage engulfment of these cells was identified at light microscopy and confirmed at electron microscopy. The proportion of macrophages that had engulfed apoptotic neutrophils was maximal 24 h after LPS challenge and declined thereafter as total neutrophil numbers fell. During the resolution phase, the alveolar macrophages became positive for peroxidase, indicating the presence of neutrophil granule contents in their cytoplasm. These observations demonstrate that apoptosis of leukocytes indeed occurs during the course of an acute inflammatory response in vivo and that the emergence of apoptotic neutrophils and macrophage engulfment of these cells are temporally correlated with the resolution of acute inflammation.

Local and systemic inflammation in patients with chronic obstructive pulmonary disease: soluble tumor necrosis factor receptors are increased in sputum

Chronic obstructive pulmonary disease (COPD) is characterized by significant chronic inflammation in the pulmonary compartment as well as in the circulation. This study aimed to elucidate the relationship between local and systemic inflammation in smoking-induced COPD by assessing levels of soluble (s) tumor necrosis factor (TNF) receptors, TNF-alpha, and interleukin-8 (IL-8) in induced sputum and in plasma. Sputum induction was performed in 18 subjects with COPD (FEV(1) 56% predicted) and 17 healthy smokers (FEV(1) 99% predicted). Patients with COPD showed significantly higher percentages of neutrophils and levels of sTNF-R55 and IL-8 in sputum as compared with control subjects, whereas sputum sTNF-R75 levels tended to be higher in COPD. Sputum TNF-alpha levels were similar in both groups. When comparing sTNF receptors in sputum and plasma, no direct correlations were found despite elevation of circulating sTNF-R75 levels in patients with COPD. In addition, sputum sTNF receptors were inversely related to the FEV(1) in patients with COPD, whereas circulating sTNF receptors were not, suggesting different regulation of inflammation in the pulmonary and systemic compartment. When subjects were divided according to their current smoking status, levels of sTNF-R55, sTNF-R75, and IL-8 in sputum were significantly elevated in ex-smoking versus currently smoking patients with COPD, suggesting ongoing inflammation in airways and circulation of patients with COPD after smoking cessation.

Neutrophil-dependent acute lung injury. Requirement for P-selectin (GMP-140)

Rapid translocation of P-selectin (GMP-140) from cytoplasmic granules to the cell membrane of endothelial cells promotes adhesive interactions with neutrophils which, when activated, damage the endothelium. The role of P-selectin in lung vascular endothelial injury in rats after systemic activation of complement by intravenous infusion of cobra venom factor has been assessed. Within 5-10 min after cobra venom factor infusion, the pulmonary vasculature demonstrated immunohistochemical expression of an epitope that reacts with anti-human P-selectin. Monoclonal antibody to human P-selectin blocked in vitro adherence of rat or human platelets (activated with thrombin) to neutrophils and was demonstrated to react with thrombin-activated rat platelets. The antibody did not react with rat neutrophils. In vivo, the antibody had strongly protective effects against cobra venom factor-induced pulmonary vascular injury as determined by permeability changes and hemorrhage. In parallel, lung myeloperoxidase content was greatly reduced and, by transmission electron microscopy, there was markedly diminished adherence of neutrophils to the pulmonary vascular endothelium and much diminished injury of endothelial cells, as defined by hemorrhage. These data indicate that anti-human P-selectin reacts with a pulmonary vascular antigen in rats and that this antigen is essential for the full expression of lung injury.

Therapy with gastric acidity inhibitors increases the risk of acute gastroenteritis and community-acquired pneumonia in children

OBJECTIVE

Gastric acidity (GA) inhibitors, including histamine-2 receptor antagonists (H2 blockers) and proton pump inhibitors (PPIs), are the mainstay of gastroesophageal reflux disease (GERD) treatment. A prolonged GA inhibitor-induced hypochlorhydria has been suggested as a risk factor for severe gastrointestinal infections. In addition, a number of papers and a meta-analysis have shown an increased risk of pneumonia in H2-blocker-treated intensive care patients. More recently, an increased risk of community-acquired pneumonia associated with GA inhibitor treatment has been reported in a large cohort of adult patients. These findings are particularly relevant to pediatricians today because so many children receive some sort of GA-blocking agent to treat GERD. To test the hypothesis that GA suppression could be associated with an increased risk of acute gastroenteritis and pneumonia in children treated with GA inhibitors, we conducted a multicenter, prospective study.

METHODS

The study was performed by expert pediatric gastroenterologists from 4 pediatric gastroenterology centers. Children (aged 4-36 months) consecutively referred for common GERD-related symptoms (for example, regurgitation and vomiting, feeding problems, effortless vomiting, choking), from December 2003 to March 2004, were considered eligible for the study. Exclusion criteria were a history of GA inhibitors therapy in the previous 4 months, Helicobacter pylori infection, diabetes, chronic lung or heart diseases, cystic fibrosis, immunodeficiency, food allergy, congenital motility gastrointestinal disorders, neuromuscular diseases, or malnutrition. Control subjects were recruited from healthy children visiting the centers for routine examinations. The diagnosis of GERD was confirmed in all patients by standard criteria. GA inhibitors (10 mg/kg ranitidine per day in 50 children or 1 mg/kg omeprazole per day in 50 children) were prescribed by the physicians for 2 months. All enrolled children were evaluated during a 4-month follow-up. The end point was the number of patients presenting with acute gastroenteritis or community-acquired pneumonia during a 4-month follow-up study period.

RESULTS

We obtained data in 186 subjects: 95 healthy controls and 91 GA-inhibitor users (47 on ranitidine and 44 on omeprazole). The 2 groups were comparable for age, gender, weight, length, and incidence of acute gastroenteritis and pneumonia in the 4 months before enrollment. Rate of subjects presenting with acute gastroenteritis and community-acquired pneumonia was significantly increased in patients treated with GA inhibitors compared with healthy controls during the 4-month follow-up period. In the GA inhibitor-treated group, the rate of subjects presenting with acute gastroenteritis and community-acquired pneumonia was increased when comparing the 4 months before and after enrollment. No differences were observed between H2 blocker and PPI users in acute gastroenteritis and pneumonia incidence in the previous 4 months and during the follow-up period. On the contrary, in healthy controls, the incidence of acute gastroenteritis and pneumonia remained stable.

CONCLUSIONS

This is the first prospective study performed in pediatric patients showing that the use of GA inhibitors was associated with an increased risk of acute gastroenteritis and community-acquired pneumonia in GERD-affected children. It could be interesting to underline that we observed an increased incidence of intestinal and respiratory infection in otherwise healthy children taking GA inhibitors for GERD treatment. On the contrary, the majority of the previous data showed that the patients most at risk for pneumonia were those with significant comorbid illnesses such as diabetes or immunodeficiency, and this points to the importance of GA suppression as a major risk factor for infections. In addition, this effect seems to be sustained even after the end of therapy. The results of our study are attributable to many factors, including direct inhibitory effect of GA inhibitors on leukocyte functions and qualitative and quantitative gastrointestinal microflora modification. Additional studies are necessary to investigate the mechanisms of the increased risk of infections in children treated with GA inhibitors, and prophylactic measures could be considered in preventing them.

Risk factors for pneumonia and other lower respiratory tract infections in elderly residents of long-term care facilities

BACKGROUND

Little is known about the risk factors, outcome, and impact of pneumonia and other lower respiratory tract infections (LRTIs) in residents of long-term care facilities.

OBJECTIVE

To determine the risk factors and the effect of these infections on functional status and clinical course.

METHODS

Active surveillance for these infections was conducted for 475 residents in 5 nursing homes from July 1, 1993, through June 30, 1996. Information regarding potential risk factors for these infections, functional status, transfers to hospital, and death was also obtained.

RESULTS

Two hundred seventy-two episodes of pneumonia and other LRTIs occurred in 170 residents during 228 757 days of surveillance for an incidence of 1.2 episodes per 1000 resident-days. Multivariable analysis revealed that older age (odds ratio [OR], 1.7; 95% confidence interval [CI], 1.1-2.6 per 10-year interval; P = .01), male sex (OR, 1.9; 95% CI, 1.1-3.5; P = .03), swallowing difficulty (OR, 2.0; 95% CI, 1.2-3.3; P = .01), and the inability to take oral medications (OR, 8.3; 95% CI, 1.4-50.3; P = .02) were significant risk factors for pneumonia; receipt of influenza vaccine (OR, 0.4; 95% CI, 0.3-0.5; P = .01) was protective. Age (OR, 1.6 [95% CI, 1.0-2.5] per 10-year interval; P = .05) and immobility (OR, 2.6; 95% CI, 1.8-3.8; P = .01) were significant risk factors for other LRTIs, and influenza vaccination was protective (OR, 0.3; 95% CI, 0.2-0.4; P = .01). Residents with pneumonia (OR, 0.7; 95% CI, 0.3-1.4; P = .31) or with other LRTIs (OR, 0.5; 95% CI, 0.2-1.1; P = .43) were no more likely to have a deterioration in functional status than individuals in whom infection did not develop.

CONCLUSIONS

Swallowing difficulty and lack of influenza vaccination are important, modifiable risks for pneumonia and other LRTIs in elderly residents of long-term care facilities. Our findings challenge the commonly held belief that pneumonia leads to long-term decline in functional status in this population.

Time course of cigarette smoke-induced pulmonary inflammation in mice

Inflammation of the airways and lung parenchyma plays a major role in the pathogenesis of chronic obstructive pulmonary disease. In the present study a murine model of tobacco smoke-induced emphysema was used to investigate the time course of airway and pulmonary inflammatory response, with a special emphasis on pulmonary dendritic cell (DC) populations. Groups of mice were exposed to either cigarette smoke or to control air for up to 24 weeks. In response to cigarette smoke, inflammatory cells (i.e. neutrophils, macrophages and lymphocytes) progressively accumulated both in the airways and lung parenchyma of mice. Furthermore, a clear infiltration of DCs was observed in airways (10-fold increase) and lung parenchyma (1.5-fold increase) of cigarette-exposed mice at 24 weeks. Flow cytometric analysis of bronchoalveolar lavage (BAL) DCs of smoke-exposed mice showed upregulation of major histocompatability complex II molecules and costimulatory molecules CD40 and CD86, compared with BAL DCs of air-exposed mice. Morphometric analysis of lung histology demonstrated a significant increase in mean linear intercept and alveolar wall destruction after 24 weeks of smoke exposure. In conclusion, the time course of the changes in inflammatory and dendritic cells in both bronchoalveolar lavage and the pulmonary compartment of cigarette smoke-exposed mice was carefully characterised.

Case-control study of the role of nutritional rickets in the risk of developing pneumonia in Ethiopian children

BACKGROUND

Pneumonia is the most important cause of morbidity and mortality in children aged under 5 years worldwide. Studies in developing countries have suggested an association between nutritional rickets and pneumonia. Since both nutritional rickets and pneumonia are common in Ethiopia, we did a case-control study to determine the role of nutritional rickets in the development of pneumonia.

METHODS

Cases were children younger than 5 years admitted to the Ethio-Swedish Children's Hospital during a 5-year period with a diagnosis of pneumonia (n = 521), but data were incomplete for 21 of these and they were not included. Controls (n = 500) were matched for admission within 3 months of cases and age within 3 months and had no evidence of pneumonia. Nutritional, demographic, and clinical and radiographic data for rickets and pneumonia were collected. Matched odd ratios and logistic regression were used to test the significance of the association of rickets and pneumonia.

FINDINGS

Rickets was present in 210 of 500 cases compared with 20 of 500 controls (odds ratio 22.11). There were significant differences between cases and controls for family size, birth order, crowding, and months of exclusive breastfeeding (p < 0.05). After correction for these confounding factors by logistic regression, there was still a 13-fold higher incidence of rickets among children with pneumonia than among controls (13.37 [95% CI 8.08-24.22], p < 0.001).

INTERPRETATION

Vitamin D or calcium deficiency may be important predisposing factors for pneumonia in children aged under 5 years in developing countries. Efforts to prevent vitamin D deficiency or calcium supplementation may result in significant reductions in morbidity and mortality from pneumonia in these children.

Primary intramedullary femur fixation in multiple trauma patients with associated lung contusion--a cause of posttraumatic ARDS?

We investigated whether primary (< 24 hours) intramedullary stabilization of femoral shaft fractures in multiple trauma patients with severe thoracic injury might be associated with an increased incidence of adult respiratory distress syndrome (ARDS). A total of 766 patients with multiple trauma admitted to Hannover Medical School between January 1, 1982, and December 31, 1991, were investigated retrospectively. Of these, 106 patients met the inclusion criteria: Injury Severity Score > 18, femoral midshaft fracture treated by intramedullary nailing, primary admission or referral within 8 hours after injury, and no death from head injury or hemorrhagic shock. Two groups were differentiated according to the presence or absence of chest trauma (severe chest trauma = AIS thorax > or =, group T; no severe chest trauma = AIS thorax < 2, group N). Selection of subgroups according to the time of femur stabilization was group I < 24 hours after trauma, group II > 24 hours after trauma. Injury Severity Scores in the four groups were TI: 29.4 (n = 24); TII 31.4 (n = 26); NI 20.1 (n = 33); NII 25.4 (n = 23). In patients without thoracic trauma the ICU time (NI: 7.3 days; NII: 18.0 days) and intubation time (NI: 5.5 days; NII: 11.0 days) were lower in the patients treated primarily (p < 0.05). In patients with severe chest trauma there was a higher incidence of posttraumatic ARDS (33% versus 7.7%) and mortality (21% versus 4%) when early intramedullary femoral nailing was done. In the absence of severe chest trauma primary intramedullary femoral nailing is beneficial.(ABSTRACT TRUNCATED AT 250 WORDS)

Air pollution and hospital admissions for respiratory disease

Several recent studies have reported associations between short-term changes in air pollution and respiratory hospital admissions. Most of those studies analyzed locations where there was a high correlation between airborne particles and sulfur dioxide (SO2), and between all air pollutants and temperature. Here, I seek to replicate the previous findings in a location where SO2 concentrations were trivial, and the correlation between both airborne particles and ozone with temperature was considerably lower than in previous studies. I constructed daily counts of admissions to all hospitals in Spokane, WA, for respiratory disease (International Classification of Diseases, 9th revision, codes 460-519) for persons age 65 years and older. I computed average daily concentrations of airborne particles whose diameter is 10 microns or less (PM10) and ozone (O3) from all monitors in each city, and I obtained daily average temperature and humidity from the U.S. weather service. SO2 concentrations in Spokane were so low that monitoring was discontinued. I regressed daily respiratory admission counts on temperature, humidity, day of the week indicators, and air pollution. I used a Poisson regression analysis and removed long wavelength patterns using a nonparametric smooth function of day of study. I dealt with a possible U-shaped dependence of admissions on temperature and/or humidity by using nonparametric smooth functions of weather variables as well. I then examined sensitivity analyses to control for weather. Both PM10 and ozone were associated with increased risk of respiratory hospital admissions [relative risk (RR) = 1.085; 95% confidence interval (CI) = 1.036-1.136 for a 50-microgram per m3 increase in PM10, and RR = 1.244; 95% CI = 1.002-1.544 for a 50-microgram per m3 increase in peak-hour ozone]. The PM10 association was insensitive to alternative methods of control for weather, including exclusion of extreme temperature days and control for temperature on multiple days. The ozone results were more sensitive to the approach for weather control. The magnitude of the PM10 effect in this location, where SO2 was essentially not present, and where the correlation between PM10 and temperature was close to zero, was similar to that reported in other locations in the eastern United States and Europe, where confounding by weather and SO2 is a more substantial concern.

Risk factors for pneumonia in the elderly

PURPOSE

To investigate the prevalence of certain chronic conditions among the elderly and to estimate the relative risk for pneumonia associated with each condition.

PATIENTS AND METHODS

Medical records of all inhabitants aged 60 years or more (4,175 persons) in one township (population 24,716) in Finland were reviewed, seeking 15 chronic conditions. Which patients had pneumonia in the same population was prospectively ascertained over a period of 3 years (185 patients).

RESULTS

Hypertension was the most frequent chronic condition (36.4%) in the study population. Other common conditions were heart disease (23.7%, with chronic compensated heart failure in 96.3% of these), other cardiovascular disease (13.1%), and diabetes (13.1%). The prevalence of any other condition was less than 5%. The following conditions were significantly more common among pneumonia patients than among control subjects: heart disease (38.4% versus 23.0%), lung disease (13.0% versus 3.8%), bronchial asthma (11.9% versus 3.1%), immunosuppressive therapy (2.7% versus 0.8%), alcoholism (2.2% versus 0.3%), and institutionalization (8.6% versus 3.9%). By multivariate logistic regression analysis, independent risk factors for pneumonia were alcoholism (relative risk [RR] = 9.0, confidence interval [CI] = 5.1 to 16.2), bronchial asthma (RR = 4.2, CI = 3.3 to 5.4), immunosuppressive therapy (RR = 3.1, CI = 1.9 to 5.1), lung disease (RR = 3.0, CI = 2.3 to 3.9), heart disease (RR = 1.9, CI = 1.7 to 2.3), institutionalization (RR = 1.8, CI = 1.4 to 2.4), and age (70 years or more versus 60 to 69 years; RR = 1.5, CI = 1.3 to 1.7). One third of the study population and 57% of the pneumonia patients had one or more of these risk factors. Diabetes, chronic pyelonephritis, and malignancies of sites other than the lungs were not associated with increased risk for pneumonia.

CONCLUSION

We found which elderly persons have an increased risk for pneumonia. Although the highest relative risk was associated with alcoholism, that condition was rare in this elderly population. Chronic obstructive lung diseases were more common and were also associated with a high relative risk. Heart disease had the highest public health impact because it was very common among the elderly and increased the risk of contracting pneumonia almost twofold; it also increased the risk of pneumonia-related death. These population-based data confirm and extend previous findings derived from selected patient groups and are useful for designing cost-effective pneumonia prevention programs.

Intravenous thrombolysis plus hypothermia for acute treatment of ischemic stroke (ICTuS-L): final results

BACKGROUND AND PURPOSE

Induced hypothermia is a promising neuroprotective therapy. We studied the feasibility and safety of hypothermia and thrombolysis after acute ischemic stroke.

METHODS

Intravenous Thrombolysis Plus Hypothermia for Acute Treatment of Ischemic Stroke (ICTuS-L) was a randomized, multicenter trial of hypothermia and intravenous tissue plasminogen activator in patients treated within 6 hours after ischemic stroke. Enrollment was stratified to the treatment time windows 0 to 3 and 3 to 6 hours. Patients presenting within 3 hours of symptom onset received standard dose intravenous alteplase and were randomized to undergo 24 hours of endovascular cooling to 33°C followed by 12 hours of controlled rewarming or normothermia treatment. Patients presenting between 3 and 6 hours were randomized twice: to receive tissue plasminogen activator or not and to receive hypothermia or not. Results- In total, 59 patients were enrolled. One patient was enrolled but not treated when pneumonia was discovered just before treatment. All 44 patients enrolled within 3 hours and 4 of 14 patients enrolled between 3 to 6 hours received tissue plasminogen activator. Overall, 28 patients randomized to receive hypothermia (HY) and 30 to normothermia (NT). Baseline demographics and risk factors were similar between groups. Mean age was 65.5±12.1 years and baseline National Institutes of Health Stroke Scale score was 14.0±5.0; 32 (55%) were male. Cooling was achieved in all patients except 2 in whom there were technical difficulties. The median time to target temperature after catheter placement was 67 minutes (Quartile 1 57.3 to Quartile 3 99.4). At 3 months, 18% of patients treated with hypothermia had a modified Rankin Scale score of 0 or 1 versus 24% in the normothermia groups (nonsignificant). Symptomatic intracranial hemorrhage occurred in 4 patients (68); all were treated with tissue plasminogen activator <3 hours (1 received hypothermia). Six patients in the hypothermia and 5 in the normothermia groups died within 90 days (nonsignificant). Pneumonia occurred in 14 patients in the hypothermia and in 3 of the normothermia groups (P=0.001). The pneumonia rate did not significantly adversely affect 3 month modified Rankin Scale score (P=0.32).

CONCLUSIONS

This study demonstrates the feasibility and preliminary safety of combining endovascular hypothermia after stroke with intravenous thrombolysis. Pneumonia was more frequent after hypothermia, but further studies are needed to determine its effect on patient outcome and whether it can be prevented. A definitive efficacy trial is necessary to evaluate the efficacy of therapeutic hypothermia for acute stroke.

Bacterial infections in adult patients with the acquired immune deficiency syndrome (AIDS) and AIDS-related complex

Sixty-four episodes of bacterial infection were identified over a 44-month period in 16 of 28 patients with the acquired immune deficiency syndrome (AIDS) and 14 of 31 patients with AIDS-related complex. Nineteen of the 30 infected patients were parenteral drug abusers, 10 were from Caribbean Islands and had no identified risk factor, and one was a homosexual male. Fourteen patients had 21 episodes of community-acquired pneumonia: Streptococcus pneumoniae (10), Haemophilus influenzae (three), other Haemophilus species (three), group B beta-hemolytic streptococci (one), Staphylococcus aureus (one), Branhamella catarrhalis (one), Legionella pneumophila (one), and Mycoplasma pneumoniae (one). Seven patients had eight episodes of nosocomial pneumonia caused by gram-negative bacilli. Twenty-five episodes of community-acquired bacteremia and nine episodes of nosocomial bacteremia were associated with specific sites of infection. Other infections included meningitis (two), urinary tract infection (one), and abscesses involving subcutaneous and deep tissues (12). Sixteen patients had recurrent infections; 11 of these had or eventually had AIDS. Community-acquired bacterial infections in patients with AIDS or AIDS-related complex are common and may be recurrent but have low fatality rates. In comparison, nosocomial bacterial infections occur primarily in patients with AIDS and have high fatality rates.

Predictors of postoperative pulmonary complications following abdominal surgery

STUDY OBJECTIVE

To determine how risk factors could be combined to best predict the development of a postoperative pulmonary complication (PPC) following abdominal surgery.

DESIGN

Prospective model-building study. Logistic regression models were developed using significant risk factors identified in the univariate analysis.

SETTING

Four midwestern hospitals.

PATIENTS

Convenience sample of 400 patients who underwent abdominal surgical procedures between January 1993 and August 1995.

MEASUREMENTS AND RESULTS

Multicriteria outcome for postoperative pulmonary complication used to collectively assess atelectasis and pneumonia. Twenty-three risk factors were assessed. Six risk factors were identified as independent by logistic regression: age > or = 60 years (adjusted odds ratio [Adj OR], 1.89); impaired preoperative cognitive function (Adj OR, 5.93); smoking history within the past 8 weeks (Adj OR, 2.27); body mass index > or = 27 (Adj OR, 2.82); history of cancer (Adj OR, 2.23); and incision site-upper abdominal or both upper/lower abdominal incision (Adj OR 2.30).

CONCLUSIONS

These results provide a framework for identifying patients at risk of developing a PPC following abdominal surgery. A reliable and valid risk index could be used clinically to guide preoperative and postoperative pulmonary care and target limited resources for patients at risk.

Pneumonia and urinary tract infection after acute ischaemic stroke: a tertiary analysis of the GAIN International trial

The third most common stroke complication is infection. We studied the rates of aspiration pneumonia and urinary tract infection (UTI), their risk factors and their effect on outcome in the 1455 Glycine Antagonist (Gavestinel) in Neuroprotection (GAIN) International patients with ischaemic stroke. Forward stepwise logistic regression and Cox proportional hazards modelling identified baseline factors that predicted events and the independent effect of events up to day 7 on poor stroke outcome at 3 months in patients alive at day 7, after correcting for prognostic factors. Higher baseline National Institute of Health Stroke Scale (NIHSS) and age, male gender, history of diabetes and stroke subtype predicted pneumonia, which occurred in 13.6% of patients. Female gender and higher baseline NIHSS and age predicted UTI, which occurred in 17.2% of patients. Pneumonia was associated with poor outcome by mortality (hazard ratio, 2.2; 95% confidence interval, 1.5-3.3), Barthel index (<60) (odds ratio, 3.8; 2.2-6.7), NIHSS (4.9; 1.7-14) and Rankin scale (>/=2) (3.4; 1.4-8.3). UTI was associated with Barthel index (1.9; 1.2-2.9), NIHSS (2.2; 1.2-4.0) and Rankin scale (3.1; 1.6-4.9). Pneumonia and UTI are independently associated with stroke poor outcome. Patients with identified risk factors must be closely monitored for infection.

Incidence, etiology, and outcome of nosocomial pneumonia in mechanically ventilated patients

This study assessed the incidence, etiology, and consequences of ventilator-associated pneumonia in 1,000 consecutive patients admitted in a medical-surgical intensive care unit (ICU). A total of 264 patients were submitted to mechanical ventilation (MV) for more than 48 hours. Fifty-eight (21.9 percent) patients developed a bacterial pneumonia after a mean of 7.9 days (range, 2 to 40 days) of MV. In addition, they were ten superinfections in nine patients, raising the mean incidence to 25.7 percent. Five patients developed secondary bacteremia, and another five had septic shock. Identification of the causative agent of pneumonia was possible in 47 episodes by means of highly specific techniques (telescoping plugged catheter, blood cultures, and/or necropsy). Thirteen (27.6 percent) of these cases were polymicrobial. The predominant pathogens isolated in the first episode of pneumonia were Gram-negative bacilli (62.6 percent), but a high incidence of Staphylococcus aureus infection (23.2 percent) was detected. Gram-negative bacilli represented 66.6 percent of the total organisms isolated in superinfections. The mortality rate in the pneumonia group was 42 percent; this percentage is similar to mortality rate among MV patients without pneumonia (37 percent). We conclude that nosocomial pneumonia is a frequent complication of MV in the medical-surgical ICU. Ventilator-associated pneumonia does not appear to increase fatality in critically ill patients with a high mortality rate (38 percent); however, it significantly prolongs the length of stay in the ICU for survivors.

Vitamin C and Infections

In the early literature, vitamin C deficiency was associated with pneumonia. After its identification, a number of studies investigated the effects of vitamin C on diverse infections. A total of 148 animal studies indicated that vitamin C may alleviate or prevent infections caused by bacteria, viruses, and protozoa. The most extensively studied human infection is the common cold. Vitamin C administration does not decrease the average incidence of colds in the general population, yet it halved the number of colds in physically active people. Regularly administered vitamin C has shortened the duration of colds, indicating a biological effect. However, the role of vitamin C in common cold treatment is unclear. Two controlled trials found a statistically significant dose-response, for the duration of common cold symptoms, with up to 6-8 g/day of vitamin C. Thus, the negative findings of some therapeutic common cold studies might be explained by the low doses of 3-4 g/day of vitamin C. Three controlled trials found that vitamin C prevented pneumonia. Two controlled trials found a treatment benefit of vitamin C for pneumonia patients. One controlled trial reported treatment benefits for tetanus patients. The effects of vitamin C against infections should be investigated further.