Risk factors for drug-resistant bacterial pneumonia in older patients hospitalized with pneumonia in a Chinese population.

BACKGROUND: The relationship between healthcare-associated pneumonia (HCAP) and resistant bacteria is unclear. The aim of this study was to identify the risk factors for pneumonia caused by drug-resistant bacteria (DRB). METHODS: A prospective cohort study was conducted at a tertiary teaching hospital in Hong Kong. Consecutive older patients (aged ≥65 years) were hospitalized with pneumonia from January 2004 to June 2005. DRB comprised methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, extended-spectrum ß-lactamase (ESBL) producing Enterobacteriaceae and Acinetobacter baumannii. RESULTS: The entire cohort consisted of 1176 older patients. Of 472 (40.1%) patients with etiological diagnosis established, bacterial pneumonia was found in 354 (30.1%) cases. DRB were isolated in 48 patients: P. aeruginosa (41), MRSA (5) and ESBL producing enteric bacilli (3). Co-infection with P. aeruginosa and MRSA was found in one patient. The prevalence of DRB in culture-positive pneumonia was 20.1% (48/239). Patients with DRB were more likely to have limitation in activities of daily living, bronchiectasis, dementia, severe pneumonia, recent hospitalization and recent antibiotic use. Logistic regression revealed that bronchiectasis [relative risk (RR) 14.12, P = 0.002], recent hospitalization (RR 4.89, P < 0.001) and severe pneumonia (RR 2.42, P = 0.010) were independent predictors of drug-resistant bacterial pneumonia. CONCLUSION: Recent hospitalization is the only risk factor for HCAP which is shown to be associated with DRB. Nursing home residence is not a risk factor. The concept of HCAP may not be totally applicable in Hong Kong where the prevalence of drug-resistant pathogens in pneumonia is low.

Influenza virus load in hospitalised patients.

1. Hospitalised patients with severe influenza have persistently high viral loads, for whom a different therapeutic approach may be needed. 2. Active screening of influenza infection should be performed in all high-risk patients hospitalised with febrile respiratory illness. Early diagnosis and treatment to suppress the high viral load may maximise clinical benefit. 3. For late presenting high risk patients with severe symptoms, their viral load may remain high, and initiation of antiviral treatment may still be worthwhile. 4. More stringent infection control measures, including strict droplet precautions and preferably isolation for an extended period of time may be necessary owing to prolonged viral shedding. 5. Randomised, controlled trials are indicated to address timing and dosage of treatment for severe influenza infection.

Capsule endoscopy in acute upper gastrointestinal hemorrhage: a prospective cohort study.

BACKGROUND AND STUDY AIMS: Capsule endoscopy may play a role in the evaluation of patients presenting with acute upper gastrointestinal hemorrhage in the emergency department. PATIENTS AND METHODS: We evaluated adults with acute upper gastrointestinal hemorrhage presenting to the emergency departments of two academic centers. Patients ingested a wireless video capsule, which was followed immediately by a nasogastric tube aspiration and later by esophagogastroduodenoscopy (EGD). We compared capsule endoscopy with nasogastric tube aspiration for determination of the presence of blood, and with EGD for discrimination of the source of bleeding, identification of peptic/inflammatory lesions, safety, and patient satisfaction. RESULTS: The study enrolled 49 patients (32 men, 17 women; mean age 58.3 ±â€†19 years), but three patients did not complete the capsule endoscopy and five were intolerant of the nasogastric tube. Blood was detected in the upper gastrointestinal tract significantly more often by capsule endoscopy (15 /18 [83.3 %]) than by nasogastric tube aspiration (6 /18 [33.3 %]; P = 0.035). There was no significant difference in the identification of peptic/inflammatory lesions between capsule endoscopy (27 /40 [67.5 %]) and EGD (35 /40 [87.5 %]; P = 0.10, OR 0.39 95 %CI 0.11 - 1.15). Capsule endoscopy reached the duodenum in 45 /46 patients (98 %). One patient (2.2 %) had self-limited shortness of breath and one (2.2 %) had coughing on capsule ingestion. CONCLUSIONS: In an emergency department setting, capsule endoscopy appears feasible and safe in people presenting with acute upper gastrointestinal hemorrhage. Capsule endoscopy identifies gross blood in the upper gastrointestinal tract, including the duodenum, significantly more often than nasogastric tube aspiration and identifies inflammatory lesions, as well as EGD. Capsule endoscopy may facilitate patient triage and earlier endoscopy, but should not be considered a substitute for EGD.

Open-access colonoscopy: outcomes of referrals from the emergency department.

AIM: The study investigated the diagnostic outcome of colonoscopy referrals from the emergency department (ED) via an open-access system. METHOD: A retrospective cohort study over two years was performed on all patients under 65 years referred for open-access colonoscopy by the ED in a hospital with an annual ED attendance of 140,000. Patient characteristics and presenting symptoms were retrieved. Waiting times from presentation to colonoscopy were recorded. RESULTS: Over a 2-year period, 266 patients were referred, of whom 37 defaulted, leaving 229 patients who had a colonoscopy. The mean age was 48.3 ± 11.3 (SD) and the female/male ratio was 229/125. The most frequent presenting symptoms included: rectal bleeding (n = 142, 62%), change of bowel habit (n = 47, 20.5%) and abdominal pain (n = 40, 17.5%). The median waiting time from presentation to colonoscopy was 17 (range 1-69) days. A positive colonoscopic finding was recorded in 45.4%, including colorectal cancer in 12 (5.2%). CONCLUSION: The rate of a positive diagnoses from the ED-based colonoscopy referral service was comparable to that of the general Hong Kong population. This approach may help to reduce the waiting time for colonoscopy in a specialist colorectal clinic.

Circulating nucleic acid analysis: diagnostic applications for acute pathologies.

Much research interest has been shown in recent years for the development of molecular diagnostic strategies based on the analysis of DNA/RNA molecules that are present in the plasma/serum of human subjects. Reported applications include the diagnosis, prognostication or monitoring of malignancies and pregnancy-associated complications. While researchers have speculated that cell death is a potential mechanism that leads to the release of DNA/RNA into the circulation, studies have demonstrated that indeed increased amounts of plasma DNA and RNA could be detected in patients sustaining acute traumatic injuries. The degree of plasma DNA elevation correlated with the severity of injury. Similarly, plasma DNA concentrations have been shown to correlate with indices of prognostic significance in patients with acute stroke. It is expected that new diagnostic markers based on plasma RNA detection could be developed for the evaluation of acute pathologies.

Thin-section CT in patients with severe acute respiratory syndrome following hospital discharge: preliminary experience.

PURPOSE: To report the initial experience regarding thin-section computed tomographic (CT) findings in patients with severe acute respiratory syndrome (SARS) who improved clinically after treatment. MATERIALS AND METHODS: Twenty-four patients (10 men, 14 women; mean age, 39 years; age range, 23-70 years) with confirmed SARS underwent follow-up thin-section CT of the thorax. The scans were obtained on average 36.5 days after hospital admission and were analyzed for parenchymal abnormality (ground-glass opacification, consolidation, or interstitial thickening) and evidence of fibrosis (parenchymal band, traction bronchiectasis, irregular interfaces). Patients were assigned to group 1 (with CT evidence of fibrosis) and group 2 (without CT evidence of fibrosis) for analysis. Patient demographics, length of hospital stay, rate of intensive care unit admission, peak lactate dehydrogenase level, pulsed intravenous methylprednisolone therapy, and peak opacification on chest radiographs were compared between the two groups. RESULTS: Parenchymal abnormality was found in 96% (23 of 24) of patients and ranged from residual ground-glass opacification and interstitial thickening in group 2 (nine of 24, 38%) to fibrosis in group 1 (15 of 24, 62%). Patients in group 1 were older (mean age, 45 vs 30.3 years), had a higher rate of intensive care unit admission (27% [four of 15] vs 11% [one of nine]), more requirement for pulsed intravenous methylprednisolone (87%, [13 of 15] vs 67% [six of nine]), higher peak lactate dehydrogenase level (438.9 vs 355.6 U/L), and higher peak opacification on chest radiographs (estimated area, 14% vs 11%) than patients in group 2. CONCLUSION: Pulmonary fibrosis may develop early in patients with SARS who have been discharged after treatment. Patients who are older and have more severe disease during treatment are more likely to develop thin-section CT findings of fibrosis.

Increased plasma free cyclic-AMP levels following major trauma and their relevance to the immune response.

BACKGROUND: Following injury, neutrophil mobilisation is an important element of the immune response. The ideal features of an agent responsible for this mobilisation would include the ability to mobilise neutrophils without activating them, and rapid reversibility. This study investigates the hypothesis that raised levels of plasma adrenaline following trauma act via cyclic adenosine monophosphate (cAMP) to mobilise neutrophils, and measures the amount of cAMP extruded from cells into the plasma following injury. METHODS: 20-ml samples of venous blood were drawn from 34 trauma patients within 3 h of injury and divided between three sample tubes: (1) ethylene diamine tetra-acetic acid anticoagulant (EDTA) for full blood count; (2) cooled EDTA for cAMP levels; and (3) cooled lithium heparin for catecholamines. The latter two tubes were immediately centrifuged at low temperature and the supernatant plasma deep frozen pending analysis. Adrenaline was measured using high pressure liquid chromatography (HPLC) and cAMP measured by an enzyme immunoassay technique. RESULTS: 34 patients, six of whom had sustained minor trauma (ISS 1-8), 12 moderate trauma (ISS 9-15) and 16, major trauma (ISS 16 and above) were studied. Median age was 39 years (range 16-77) and 30 patients were male. Plasma adrenaline levels were available for 28 of the patients. Plasma free cAMP levels were significantly raised in patients with major trauma (P < 0.006). There were positive correlations between the plasma levels of cAMP and adrenaline (rho 0.660, P = 0.011), adrenaline and neutrophil count (rho 0.654, P = 0.01) and cAMP and neutrophil count (rho 0.508, P = 0.013). CONCLUSIONS: Evidence is presented of the possible inter-relationships between neutrophil counts, adrenaline levels and cAMP levels following injury, supporting the proposition that neutrophil mobilisation pathways are activated early via beta-adrenergic stimulation.

Early role of neutrophil L-selectin in posttraumatic acute lung injury.

OBJECTIVE: To investigate whether early numerical and functional changes in circulating neutrophils and expression of neutrophil L-selectin and soluble L-selectin are related to the subsequent development of posttraumatic acute lung injury (ALI), the systemic inflammatory response syndrome, sepsis, and organ failure. DESIGN: Prospective study of whole blood and plasma samples to assess numerical and functional changes in circulating neutrophils and in soluble L-selectin. SETTING: The emergency department of a university hospital. PATIENTS: A total of 147 patients admitted to the resuscitation room after trauma were compared with 69 control subjects. Ten patients developed ALI. LABORATORY ANALYSIS: Flow cytometry of whole blood and ELISA of plasma. RESULTS: Total leukocyte and neutrophil counts, expression of L-selectin, and the ratio of neutrophil to plasma L-selectin increased with injury and were highest in those who developed ALI. Soluble L-selectin decreased with injury severity and was lowest in those who developed ALI. CONCLUSIONS: Early changes in the average expression of L-selectin per cell do not correlate with the development of subsequent posttraumatic ALI. However, the development of ALI is related to the total expression of L-selectin in the neutrophil mass, and the most striking association is in those with lower concentrations of plasma L-selectin.