Fiona Sampson

Noninvasive Ventilation in Acute Cardiogenic Pulmonary Edema

BACKGROUND Noninvasive ventilation (continuous positive airway pressure [CPAP] or noninvasive intermittent positive-pressure ventilation [NIPPV]) appears to be of benefit in the immediate treatment of patients with acute cardiogenic pulmonary edema and may reduce mortality. We conducted a study to determine whether noninvasive ventilation reduces mortality and whether there are important differences in outcome associated with the method of treatment (CPAP or NIPPV). METHODS In a multicenter, open, prospective, randomized, controlled trial, patients were assigned to standard oxygen therapy, CPAP (5 to 15 cm of water), or NIPPV (inspiratory pressure, 8 to 20 cm of water; expiratory pressure, 4 to 10 cm of water). The primary end point for the comparison between noninvasive ventilation and standard oxygen therapy was death within 7 days after the initiation of treatment, and the primary end point for the comparison between NIPPV and CPAP was death or intubation within 7 days. RESULTS A total of 1069 patients (mean [+/-SD] age, 77.7+/-9.7 years; female sex, 56.9%) were assigned to standard oxygen therapy (367 patients), CPAP (346 patients), or NIPPV (356 patients). There was no significant difference in 7-day mortality between patients receiving standard oxygen therapy (9.8%) and those undergoing noninvasive ventilation (9.5%, P=0.87). There was no significant difference in the combined end point of death or intubation within 7 days between the two groups of patients undergoing noninvasive ventilation (11.7% for CPAP and 11.1% for NIPPV, P=0.81). As compared with standard oxygen therapy, noninvasive ventilation was associated with greater mean improvements at 1 hour after the beginning of treatment in patient-reported dyspnea (treatment difference, 0.7 on a visual-analogue scale ranging from 1 to 10; 95% confidence interval [CI], 0.2 to 1.3; P=0.008), heart rate (treatment difference, 4 beats per minute; 95% CI, 1 to 6; P=0.004), acidosis (treatment difference, pH 0.03; 95% CI, 0.02 to 0.04; P<0.001), and hypercapnia (treatment difference, 0.7 kPa [5.2 mm Hg]; 95% CI, 0.4 to 0.9; P<0.001). There were no treatment-related adverse events. CONCLUSIONS In patients with acute cardiogenic pulmonary edema, noninvasive ventilation induces a more rapid improvement in respiratory distress and metabolic disturbance than does standard oxygen therapy but has no effect on short-term mortality. (Current Controlled Trials number, ISRCTN07448447.)

Systematic review and meta-analysis of the diagnostic accuracy of ultrasonography for deep vein thrombosis

BackgroundUltrasound (US) has largely replaced contrast venography as the definitive diagnostic test for deep vein thrombosis (DVT). We aimed to derive a definitive estimate of the diagnostic accuracy of US for clinically suspected DVT and identify study-level factors that might predict accuracy.MethodsWe undertook a systematic review, meta-analysis and meta-regression of diagnostic cohort studies that compared US to contrast venography in patients with suspected DVT. We searched Medline, EMBASE, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, Database of Reviews of Effectiveness, the ACP Journal Club, and citation lists (1966 to April 2004). Random effects meta-analysis was used to derive pooled estimates of sensitivity and specificity. Random effects meta-regression was used to identify study-level covariates that predicted diagnostic performance.ResultsWe identified 100 cohorts comparing US to venography in patients with suspected DVT. Overall sensitivity for proximal DVT (95% confidence interval) was 94.2% (93.2 to 95.0), for distal DVT was 63.5% (59.8 to 67.0), and specificity was 93.8% (93.1 to 94.4). Duplex US had pooled sensitivity of 96.5% (95.1 to 97.6) for proximal DVT, 71.2% (64.6 to 77.2) for distal DVT and specificity of 94.0% (92.8 to 95.1). Triplex US had pooled sensitivity of 96.4% (94.4 to 97.1%) for proximal DVT, 75.2% (67.7 to 81.6) for distal DVT and specificity of 94.3% (92.5 to 95.8). Compression US alone had pooled sensitivity of 93.8 % (92.0 to 95.3%) for proximal DVT, 56.8% (49.0 to 66.4) for distal DVT and specificity of 97.8% (97.0 to 98.4). Sensitivity was higher in more recently published studies and in cohorts with higher prevalence of DVT and more proximal DVT, and was lower in cohorts that reported interpretation by a radiologist. Specificity was higher in cohorts that excluded patients with previous DVT. No studies were identified that compared repeat US to venography in all patients. Repeat US appears to have a positive yield of 1.3%, with 89% of these being confirmed by venography.ConclusionCombined colour-doppler US techniques have optimal sensitivity, while compression US has optimal specificity for DVT. However, all estimates are subject to substantial unexplained heterogeneity. The role of repeat scanning is very uncertain and based upon limited data.

The accuracy of MRI in diagnosis of suspected deep vein thrombosis: systematic review and meta-analysis

Magnetic resonance imaging (MRI) may be used to diagnose deep vein thrombosis (DVT) in patients for whom ultrasound examination is inappropriate or unfeasible. We undertook a systematic review of the literature and meta-analysis to estimate the diagnostic accuracy of MRI for DVT. We searched databases of medical literature and citation lists of retrieved articles. We selected studies that compared MRI with a reference standard in patients with suspected DVT or suspected pulmonary embolus, or high-risk asymptomatic patients. Data were analysed by random effects meta-analysis. We included 14 articles in the meta-analysis. Most compared MRI with venography in patients with clinically suspected DVT. The pooled estimate of sensitivity was 91.5% (95% CI: 87.5–94.5%) and the pooled estimate of specificity was 94.8% (95% CI: 92.6–96.5%). Sensitivity for proximal DVT was higher than sensitivity for distal DVT (93.9% versus 62.1%). However, pooled estimates should be interpreted with caution as estimates of both sensitivity and specificity were subject to significant heterogeneity (P<0.001). Individual studies reported sensitivity ranging from zero to 100%, while specificity ranged from 43 to 100%. MRI has equivalent sensitivity and specificity to ultrasound for diagnosis of DVT, but has been evaluated in many fewer studies, using a variety of different techniques.

A multicentre randomised controlled trial of the use of continuous positive airway pressure and non-invasive positive pressure ventilation in the early treatment of patients presenting to the emergency department with severe acute cardiogenic pulmonary oedema: the 3CPO trial.

OBJECTIVES To determine whether non-invasive ventilation reduces mortality and whether there are important differences in outcome by treatment modality. DESIGN Multicentre open prospective randomised controlled trial. SETTING Patients presenting with severe acute cardiogenic pulmonary oedema in 26 emergency departments in the UK. PARTICIPANTS Inclusion criteria were age > 16 years, clinical diagnosis of acute cardiogenic pulmonary oedema, pulmonary oedema on chest radiograph, respiratory rate > 20 breaths per minute, and arterial hydrogen ion concentration > 45 nmol/l (pH < 7.35). INTERVENTIONS Patients were randomised to standard oxygen therapy, continuous positive airway pressure (CPAP) (5-15 cmH2O) or non-invasive positive pressure ventilation (NIPPV) (inspiratory pressure 8-20 cmH2O, expiratory pressure 4-10 cmH2O) on a 1:1:1 basis for a minimum of 2 hours. MAIN OUTCOME MEASURES The primary end point for the comparison between NIPPV or CPAP and standard therapy was 7-day mortality. The composite primary end point for the comparison of NIPPV and CPAP was 7-day mortality and tracheal intubation rate. Secondary end points were breathlessness, physiological variables, intubation rate, length of hospital stay and critical care admission rate. Economic evaluation took the form of a cost-utility analysis, taken from an NHS (and personal social services) perspective. RESULTS In total, 1069 patients [mean age 78 (SD 10) years; 43% male] were recruited to standard therapy (n = 367), CPAP [n = 346; mean 10 (SD 4) cmH2O] or NIPPV [n = 356; mean 14 (SD 5)/7 (SD 2) cmH2O]. There was no difference in 7-day mortality for standard oxygen therapy (9.8%) and non-invasive ventilation (9.5%; p = 0.87). The combined end point of 7-day death and intubation rate was similar, irrespective of non-invasive ventilation modality (CPAP 11.7% versus NIPPV 11.1%; p = 0.81). Compared with standard therapy, non-invasive ventilation was associated with greater reductions (treatment difference, 95% confidence intervals) in breathlessness (visual analogue scale score 0.7, 0.2-1.3; p = 0.008) and heart rate (4/min, 1-6; p = 0.004) and improvement in acidosis (pH 0.03, 0.02-0.04; p < 0.001) and hypercapnia (0.7 kPa, 0.4-0.9; p < 0.001) at 1 hour. There were no treatment-related adverse events or differences in other secondary outcomes such as myocardial infarction rate, length of hospital stay, critical care admission rate and requirement for endotracheal intubation. Economic evaluation showed that mean costs and QALYs up to 6 months were 3023 pounds and 0.202 for standard therapy, 3224 pounds and 0.213 for CPAP, and 3208 pounds and 0.210 for NIPPV. Modelling of lifetime costs and QALYs produced values of 15,764 pounds and 1.597 for standard therapy, 17,525 pounds and 1.841 for CPAP, and 17,021 pounds and 1.707 for NIPPV. These results suggest that both CPAP and NIPPV accrue more QALYs but at higher cost than standard therapy. However, these estimates are subject to substantial uncertainty. CONCLUSIONS Non-invasive ventilatory support delivered by either CPAP or NIPPV safely provides earlier improvement and resolution of breathlessness, respiratory distress and metabolic abnormality. However, this does not translate into improved short- or longer-term survival. We recommend that CPAP or NIPPV should be considered as adjunctive therapy in patients with severe acute cardiogenic pulmonary oedema in the presence of severe respiratory distress or when there is a failure to improve with pharmacological therapy. TRIAL REGISTRATION Current Controlled Trials ISRCTN07448447.

Diagnostic value of CT for deep vein thrombosis: results of a systematic review and meta-analysis ☆

AIM To estimate the sensitivity and specificity of computed tomography (CT) for the diagnosis of deep vein thrombosis (DVT) in patients with suspected DVT and pulmonary embolus (PE). MATERIALS AND METHODS A search of the medical literature and citation lists was undertaken, and selected studies comparing CT to a reference standard in patients with suspected DVT or PE were retrieved. Data were analysed by random effects meta-analysis. RESULTS Thirteen articles were included in the meta-analysis. Most compared CT to ultrasound in patients with clinically suspected PE. The sensitivity ranged from 71-100%, while specificity ranged from 93-100%. The pooled estimate of sensitivity was 95.9% (95% CI 93 to 97.8%) and the pooled estimate of specificity was 95.2% (93.6 to 96.5%). However, pooled estimates should be interpreted with caution as these were subject to significant heterogeneity (p=0.025 and p<0.001, respectively). Most studies only appeared to report proximal DVT. Too few data were available to estimate sensitivity for distal DVT. CONCLUSIONS CT has a similar sensitivity and specificity to ultrasound in patients with suspected PE where investigation of suspected DVT is required. There is insufficient research to determine the diagnostic accuracy of CT in patients with suspected DVT alone.

How should continuity of care in primary health care be assessed

Recent changes in the organisation of primary health care have increased the range of professionals that patients may encounter, leading to renewed interest in the importance of continuity of care. To assess whether organisational changes have had an impact on continuity, it is necessary to define and measure the term. Researchers seeking to assess continuity face many conceptual and practical difficulties. This article argues that it is important to distinguish between three distinct but related concepts: longitudinal continuity from a minimum number of health professionals, caring relationships between patients and professionals, and well-coordinated care between professionals. An evaluation of Advanced Access as a case study is used to illustrate how researchers need to make several value judgements in operationalising longitudinal continuity. These include whether continuity should be measured from the perspective of patient, doctor, or healthcare system, the types of professionals and consultations that should be considered, the time period to be assessed, the measure to be used, and also practical considerations about data collection. It is argued that decisions about these issues should be based on an underlying hypothesis about why continuity may be important in the particular context. Distinguishing between longitudinal continuity, patient-professional relationships, and coordinated care makes it possible to examine interactions between these different concepts, and to examine relationships with outcomes such as patient satisfaction and quality of care. It will also give greater clarity to debates about whether new models of primary care reduce continuity.

Cholesterol and coronary heart disease: screening and treatment.

Coronary heart disease (CHD) is a major cause of morbidity and mortality in the United Kingdom, accounting for just under one quarter of all deaths in 1995: 27% among men and 21% among women.1 Although many CHD deaths occur among elderly people, CHD accounts for 31% of male and 13% of female deaths within the 45–64 age group.

Feeling Fixed and its Contribution to Patient Satisfaction with Primary Angioplasty: A Qualitative Study

Background: Primary angioplasty is being used increasingly as an alternative to intravenous thrombolysis for patients with acute ST-elevation myocardial infarction. Aims: To explore positive and negative views of patient and carer experiences of undergoing primary angioplasty. Methods: We undertook semi-structured qualitative interviews (n = 16). We identified a thematic framework from transcripts then coded data according to themes identified. Results: Participants were extremely positive about their experiences of primary angioplasty. They were impressed by the speed and efficiency of the process and their quick recovery from feeling extremely ill. Participants expressed a high degree of confidence in the procedure and many spoke of being ‘fixed’ following resolution of their symptoms. This may have been engendered by witnessing the procedure take place as well as successful treatment of a potentially fatal heart attack. The speed of resolution and feeling of being fixed led some participants to question whether they had actually had a heart attack. Conclusions: The ‘high-tech’ efficient procedure of primary angioplasty and fast recovery contributes to high levels of patient satisfaction. The feeling of being fixed and lack of belief at having had a heart attack may have implications for uptake of rehabilitation and lifestyle changes following hospital discharge.

Cost-effectiveness of high-dose chemotherapy in first-line treatment of advanced multiple myeloma

The cost‐effectiveness of high‐dose chemotherapy in multiple myeloma was considered as part of a UK National Health Service Executive regional evidence‐based appraisal process. The use of high‐dose chemotherapy supported by autologous stem cell transplantation in patients under 65 years of age was shown to provide a marginal benefit of 0·7 life‐years over conventional chemotherapy. This corresponded to an incremental cost ‘per life‐year gained’ figure of approximately £15 000, based upon initial treatment costs and trial‐period data only. The use of high‐dose chemotherapy in the first‐line treatment of advanced multiple myeloma improves event‐free and overall survival and appears to be a cost‐effective treatment option.

Interventions to improve the management of pain in emergency departments: systematic review and narrative synthesis

Introduction Pain management in emergency departments (ED) is often inadequate despite the availability of effective analgesia, with many patients receiving insufficient and untimely analgesia. We conducted a systematic literature review to identify interventions that could improve pain management in the ED. Methods We systematically searched seven databases for studies reporting pain management outcomes after intervention to change professional practice to improve pain management in the ED, compared with pain management before or without intervention. Data was synthesised using principles of narrative synthesis. Results We identified 43 relevant studies, including 40 uncontrolled before-and-after studies. Interventions included implementation of guidelines and protocols, educational interventions, pain scoring tools and changes in nursing roles, with many multifaceted interventions incorporating two or more of these elements. Interventions aimed to improve assessment and documentation of pain, knowledge and awareness of pain management and reduce time to analgesia. Due to the high probability of bias in study design and significant variation between studies, it was not possible to estimate the overall effectiveness of interventions, or identify which had the greatest impact. Intervention to improve pain management was reported to have some positive impact in most studies, but these findings may be explained by limitations in study design. Conclusions Many interventions reported improvements in pain management, but current evidence is insufficient to recommend any for widespread adoption. In order to improve pain management we need to understand more about the theory underlying interventions, the context in which interventions work, and develop interventions based on this stronger theoretical understanding.