Post-operative atelectasis - a randomised trial investigating a ventilatory strategy and low oxygen fraction during recovery.

BACKGROUND: Atelectasis is common during and after general anaesthesia. We hypothesized that a ventilation strategy with a combination of 1) continuous positive airway pressure (CPAP) or positive end-expiratory pressure (PEEP) and 2) a reduced end-expiratory oxygen concentration during recovery would reduce post-operative atelectasis. METHODS: Sixty patients were randomized into two groups. During anaesthesia induction, inspiratory oxygen fraction (FIO2) was 1.0, and depending on weight, CPAP 6, 7 or 8 cmH2O was applied in both groups via facemask. During maintenance of anaesthesia, a laryngeal mask airway (LMA) was used, and PEEP was 6-8 cmH2O in both groups. Before removal of the LMA, FIO2 was set to 0.3 in the intervention group and 1.0 in the control group. Atelectasis was studied by computed tomography (CT) approximately 14 min post-operatively. RESULTS: In one patient in the group given an FIO2 of 0.3 before removal of the LMA a CT scan could not be performed so the patient was excluded. The area of atelectasis was 5.5, 0-16.9 cm(2) (median and range), and 6.8, 0-27.5 cm(2) in the groups given FIO2 0.3 or FIO2 1.0 before removal of the LMA, a difference that was not statistically significant (P = 0.48). Post-hoc analysis showed dependence of atelectasis on smoking (despite all were clinically lung healthy) and American Society of Anesthesiologists class (P = 0.038 and 0.015, respectively). CONCLUSION: Inducing anaesthesia with CPAP/PEEP and FIO2 1.0 and deliberately reducing FIO2 during recovery before removal of the LMA did not reduce post-operative atelectasis compared with FIO2 1.0 before removal of the LMA.

Relation between renal function, presentation, use of therapies and in-hospital complications in acute coronary syndrome: data from the SWEDEHEART register.

OBJECTIVE: To examine clinical characteristics, presenting symptoms, use of therapy and in-hospital complications in relation to renal function in patients with myocardial infarction (MI). DESIGN: Observational study. SETTING: Nationwide coronary care unit registry between 2003-2006 in Sweden. SUBJECTS: Consecutive MI patients with available creatinine (n = 57,477). RESULTS: Glomerular filtration rate was estimated with the Modification of Diet in Renal Disease Study formula. With declining renal function patients were older, had more co-morbidities and more often used cardio-protective medication on admission. Compared to patients with normal renal function, fewer with renal failure presented with chest pain (90% vs. 67%, P < 0.001), Killip I (89% vs. 58%, P < 0.001) and ST-elevation myocardial infarction (STEMI) (41% vs. 22%, P < 0.001). In a logistic regression model lower renal function was independently associated with a less frequent use of anticoagulant and revascularization in non-ST-elevation MI. The likelihood of receiving reperfusion therapy for STEMI was similar in patients with normal-to-moderate renal dysfunction, but decreased in severe renal dysfunction or renal failure. Reperfusion therapy shifted from primary percutaneous coronary intervention in 71% of patients with normal renal function to fibrinolysis in 58% of those with renal failure. Renal function was associated with a higher rate of complications and an exponential increase in in-hospital mortality from 2.5% to 24.2% across the renal function groups. CONCLUSION: Renal insufficiency influences the presentation and reduces the likelihood of receiving treatment according to current guidelines. Short-term prognosis remains poor.

Expansion of small-diameter abdominal aortic aneurysms is not reflected by the release of inflammatory mediators IL-6, MMP-9 and CRP in plasma.

OBJECTIVES: The aim of this study was to evaluate a possible correlation between plasma levels of interleukin-6 (IL-6), metalloproteinase-9 (MMP-9) and C-reactive protein (CRP) and the expansion of small abdominal aortic aneurysms (AAAs). DESIGN: Patients were selected from a prospective randomised clinical trial and categorised in two groups, in which one group received active treatment (azithromycin) and the other received placebo. No statistical difference in the expansion rate of AAAs between the groups was found and the two groups were considered as one cohort in the present study. MATERIAL AND METHODS: In this study, 213 patients with AAAs between 35 and 49 mm were followed-up with ultrasound examination every 6th month. Blood samples were taken on two occasions (6 months apart). IL-6 and MMP-9 were analysed on one occasion using Quantikine analysing kits (R&D Systems, Inc., USA). CRP was analysed using sensitive-CRP method. RESULTS: Levels of IL-6, MMP-9 and CRP did not correlate with AAA expansion. Neither was there any correlation between statin medication and changes in MMP-9 levels over the 6-month period. Patients on statins had a lower expansion rate than those not taking statins: 0.16 versus 0.25 cm per year. CONCLUSION: No correlation was found between levels of circulating IL-6, MMP-9, CRP and the expansion of small-diameter AAAs, indicating no clinical use of these markers in AAA surveillance.

Women younger than 65 years with diabetes mellitus are a high-risk group after myocardial infarction: a report from the Swedish Register of Information and Knowledge about Swedish Heart Intensive Care Admission (RIKS-HIA).

OBJECTIVE: To analyse gender differences in prognosis, risk factors and evidence-based treatment in patients with diabetes and myocardial infarction. METHODS: Mortality in 1995-2002 was analysed in 70 882 Swedish patients (age <80) with a first registry-recorded acute myocardial infarction stratified by gender and age. Owing to gender differences in mortality, specifically characterising patients below the age of 65 years, a more detailed analysis was performed within this cohort of 25 555 patients. In this group, 5786 (23%) were women and 4473 (18%) had diabetes. Differences in clinical and other parameters were adjusted for using a propensity score model. RESULTS: Long-term mortality in diabetic patients aged <65 years was significantly higher in women than men (RR 1.34; 95% CI 1.16 to 1.55). Compared with diabetic men, women had an increased risk factor burden (hypertension 49 vs 43%; RR 1.12; 95% CI 1.05 to 1.20; heart failure 10 vs 8%; RR 1.25; 95% CI 1.03 to 1.53). Diabetic women aged <65 years were less frequently treated with intravenous beta-blockade during the acute hospital phase and with angiotensin-converting enzyme inhibitors at hospital discharge. However, this under-use was not associated with the mortality differences, nor was female gender by itself. CONCLUSION: Women below 65 years of age with diabetes have a poorer outcome than men after a myocardial infarction. This relates to an increased risk factor burden. It is suggested that greater awareness of this situation and improved prevention have the potential to improve what is an unfavourable situation for these women.

Blood glucose in acute stroke, different therapeutic targets for diabetic and non-diabetic patients?

OBJECTIVES: To study the impact of blood glucose concentrations on early stroke mortality in diabetic and non-diabetic stroke patients, and to identify the optimal blood glucose concentration for each patient category. MATERIAL AND METHODS: A representative sample of 81 diabetic and 366 non-diabetic stroke patients was studied. Logistic regression analyses were performed in order to estimate the impact of blood glucose concentrations on admission and during hospital stay and other clinical parameters on 30-day case-fatality. Receiver operating characteristic curves were used to predict case-fatality by blood glucose. RESULTS: Blood glucose, body temperature and level of consciousness were independently related to early stroke mortality in diabetic and non-diabetic patients. The mean blood glucose concentration had a greater impact on 30-day case-fatality than the admission blood glucose, particularly in diabetic patients. A mean blood glucose concentration above 10.3 mmol/l predicted 30-day case-fatality in diabetic patients. The corresponding value was 6.3 mmol/l in non-diabetic patients. CONCLUSION: Improved blood glucose control has a potential to reduce early stroke mortality. The optimal glucose concentration seems to be higher in diabetic than in non-diabetic patients.

Association between environmental risk factors and campylobacter infections in Sweden.

Campylobacter sp. is the most common cause of acute bacterial gastroenteritis in Sweden and the incidence has been increasing. Case-control studies to identify risk factors have been conducted in several countries, but much remains unexplained. The geographical distribution of campylobacter infections varies substantially, and many environmental factors may influence the observed pattern. Geographical Information Systems (GIS) offer an opportunity to use routinely available surveillance data to explore associations between potential environmental risk factors showing a geographical pattern and disease incidence, complementing traditional approaches for investigating risk factors for disease. We investigated associations between campylobacter incidence and environmental factors related to water and livestock in Sweden. Poisson regression was used to estimate the strength of the associations. Positive associations were found between campylobacter incidence and average water-pipe length per person, ruminant density, and a negative association with the percentage of the population receiving water from a public water supply. This indicates that drinking water and contamination from livestock may be important factors in explaining sporadic human campylobacteriosis in Sweden, and that contamination occurring in the water distribution system might be more important than previously considered.

A one-year study of foodborne illnesses in the municipality of Uppsala, Sweden.

Surveillance was enhanced and a retrospective interview study performed in 1998-99 to determine incidence, causes, and costs of foodborne illnesses in Uppsala, Sweden. Sixty-eight percent of the detected foodborne illness incidents were single cases, and 32% were outbreaks. Most (85%) of the incidents came to the attention of the municipal authorities through telephone calls from affected persons. Calicivirus, Campylobacter spp., and Staphyloccocus aureus were the most common etiological agents; meat, meat products, and mixed dishes were the most implicated food categories. The incidence of foodborne illness was estimated to be 38 cases per 1,000 inhabitants per year. The estimated average costs per illness were 2,164 Swedish Krona (SEK) ($246) to society and 500 SEK ($57) to the patient. The annual cost of foodborne illnesses in Sweden was estimated to be 1,082 million SEK ($123 million).

Clinical spectrum and transmission characteristics of infection with Norwalk-like virus: findings from a large community outbreak in Sweden.

A large foodborne outbreak caused by Norwalk-like virus (NLV) among children and staff at 30 day care centers provided an opportunity to study symptomatology and attack rates among patients in different age groups, as well as secondary transmission rates in centers and households. A retrospective cohort study of 775 subjects from 13 randomly chosen centers was performed. Diarrhea was more common in adults than in children (P=.001), whereas the reverse was noted with regard to vomiting (P=.003). The primary attack rate was 27% (142 of 524 subjects): 54% of adults versus 19% of children (P<.001). The mean incubation time for foodborne cases of infection was 34 hours. The secondary attack rate was 17%. Risk factors for spread into households were the primary case being a child (relative risk [RR], 3.8; 95% confidence interval [CI], 1.9-7.6) and vomiting (RR, 2.4; 95% CI, 1.0-5.5). The incubation time for person-to-person transmission was approximated by a mean serial interval of 52 hours. This is the first reported outbreak of NLV infection in which secondary transmission into households by individuals has been studied.

A population-based, case-control study of Taenia solium taeniasis and cysticercosis.

A two-phase study was conducted in a rural community in Honduras, to evaluate the association between neurocysticercosis (NCC) diagnosed by computed tomography (CT), epilepsy, seropositivity for antibodies to the cysticerci of Taenia solium [determined by enzyme-linked-immunoelectrotransfer-blot (EITB) assays], intestinal infection with this parasite, and various epidemiological factors. Of the 480 individuals studied in the first phase, 17% were seropositive and 2.5% supplied faecal samples which contained T. solium eggs. In the second phase, 148 individuals (74 of the seropositive subjects from the first phase and 74 matched controls from the seronegatives) underwent CT and neurological examinations. The CT results appeared normal in 110 (74%) of the 148, showed anatomical abnormality in seven (5%), and active or calcified lesions compatible with NCC in 31 (23% of the seropositives and 19% of the seronegatives). Only five of the latter had neurological symptoms (two being epileptics) and only five lived in households in which intestinal taeniasis had been detected. Subject age was significantly associated with NCC-compatible lesions but all the other factors investigated, including seropositivity, showed no significant association with the CT findings. The overall sensitivity of the EITB assays was found to be 55%. Taken together, the present results indicate that, even though it is a valuable tool in determining transmission levels in sero-epidemiological studies, the EITB assay should not be used to predict the existence of NCC or to estimate the prevalence of NCC. The results do provide further evidence that taeniasis and cysticercosis are widely prevalent in Honduras, and indicate that much larger studies of hyper-endemic communities may be necessary if the factors associated with the transmission of T. solium are to be elucidated.

Near absence of vancomycin-resistant enterococci but high carriage rates of quinolone-resistant ampicillin-resistant enterococci among hospitalized patients and nonhospitalized individuals in Sweden.

Rates of colonization with enterococci with acquired resistance to vancomycin (vancomycin-resistant enterococci [VRE]) and ampicillin (ampicillin-resistant enterococci [ARE]) were determined by using fecal samples from 670 nonhospitalized individuals and 841 patients in 27 major hospitals. Of the hospitalized patients, 181 (21.5%) were carriers of ARE and 9 (1.1%) were carriers of VRE. In univariate analyses, length of hospital stay (odds ratio [OR], 4.6; 95% confidence interval [CI], 2.5 to 8.9) and antimicrobial therapy (OR, 4.7; 95% CI, 3.3 to 6.7) were associated with ARE colonization, as were prior treatment with penicillins (OR, 3.1; 95% CI, 1.8 to 5. 5), cephalosporins (OR, 2.9; 95% CI, 1.7 to 5.0), or quinolones (OR, 2.7; 95% CI, 1.5 to 4.7). In logistic regression analysis, antimicrobial therapy for at least 5 days was independently associated with ARE carriage (adjusted OR, 3.8; 95% CI, 2.6 to 5.4). Over 90% of the ARE isolates were fluoroquinolone resistant, whereas 14% of the ampicillin-susceptible Enterococcus faecium isolates were fluoroquinolone resistant. ARE carriage rates correlated with the use of fluoroquinolones (P = 0.04) but not with the use of ampicillin (P = 0.68) or cephalosporins (P = 0.40). All nine VRE isolates were E. faecium vanB and were found in one hospital. Seven of these isolates were related according to their types as determined by pulsed-field gel electrophoresis. Among the nonhospitalized individuals, the ARE carriage rate was lower (6%; P < 0.05), and only one person, who had recently returned from Africa, harbored VRE (E. faecium vanA). The absence of VRE colonization in nonhospitalized individuals reflects an epidemiological situation in Sweden radically different from that in countries in continental Europe where glycopeptides have been widely used for nonmedical purposes.