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Niall D Ferguson

Publications and source records attributed to Niall D Ferguson.

22 records · Page 2Linked to original sources

Screening of ARDS patients using standardized ventilator settings: influence on enrollment in a clinical trial.

OBJECTIVES: The American-European consensus conference (AECC) definition for acute respiratory distress syndrome (ARDS) requires a PaO(2)/F(I)O(2)< or =200 mmHg, regardless of ventilator settings. We report the results of using standardized ventilator settings to screen and enroll ARDS patients in a clinical trial of high-frequency oscillatory ventilation (HFOV), including the impact on study enrollment, and potential effects on study outcome. DESIGN: Prospective cohort study. SETTING: Intensive care units in two teaching hospitals. PARTICIPANTS. A consecutive sample of 41 patients with early ARDS by AECC criteria (baseline PaO(2)/F(I)O(2)< or =200) who met all other inclusion/exclusion criteria for the HFOV trial. INTERVENTIONS: Patients were placed on standardized ventilator settings (tidal volume 7-8 ml/kg, PEEP 10 cmH(2)O, F(I)O(2) 1.0), and the PaO(2)/F(I)O(2) was reassessed after 30 min. RESULTS: Seventeen patients (41.5%) had PaO(2)/F(I)O(2) ratios that remained < or =200 mmHg [Persistent ARDS; PaO(2)/F(I)O(2)=94+/-36 (mean+/-SD)] and went on to inclusion in the HFOV study; however, in 24 patients (58.5%) the PaO(2)/F(I)O(2) was >200 mmHg [Transient ARDS; PaO(2)/F(I)O(2)=310+/-74] and these patients were ineligible for the HFOV study. The ICU mortality was significantly greater (52.9 vs 12.5%; p=0.01) in the Persistent ARDS patients. CONCLUSIONS: The use of these standardized ventilatory significantly impacted the PaO(2)/F(I)O(2) ratio and therefore the ARDS prevalence and trial enrollment. These results have effects on the evaluation of the current ARDS literature and conduct of clinical trials in ARDS and hence consideration should be given to the use of standardized ventilatory settings in future ARDS trials.

Bias↗

High values of the pulmonary artery wedge pressure in patients with acute lung injury and acute respiratory distress syndrome.

OBJECTIVE: To determine the incidence and severity of pulmonary artery wedge pressure (PAWP) elevation in patients with ALI/ARDS. In addition, to examine the effects of clinical variables on the presence of a high PAWP (>18 mmHg) and the effect of an elevated PAWP on mortality. DESIGN AND PATIENTS: Post hoc analysis of 120 patients with or at high risk of ARDS, enrolled in a randomized controlled trial of pressure- and volume-limited ventilation. Patients with or at high risk of congestive heart failure were excluded from the original study. SETTING: Eight tertiary intensive care units. MEASUREMENTS AND RESULTS: Pulmonary artery catheters were inserted at the discretion of the attending physician, and PAWP was collected every 8 h when present. Of 120 subjects 71 (59%) had a pulmonary artery catheter (44 at randomization, 27 later). The mean maximum PAWP reading among patients was 22.5 mmHg (95% CI 21.2-23.8) and mean median was 16.6 mmHg (95% CI 15.6-17.5). Patients who met standard criteria for ARDS were more likely to develop a high PAWP. In a multivariate stepwise logistic regression model a persistently elevated PAWP (median >18 mmHg) was a strong predictor of mortality after correction for baseline differences (OR estimate 6.82; 95% CI 1.66-37.81). CONCLUSIONS: We conclude that in this group of patients a PAWP higher than 18 mmHg is common. Mandating a PAWP of 18 mmHg or less may negatively impact clinical trials in which ARDS is an inclusion/exclusion criteria or an endpoint.

APACHE↗

New therapies for adults with acute lung injury. High-frequency oscillatory ventilation.

High-frequency oscillatory ventilation seems theoretically ideal for the treatment of patients with ARDS, allowing adequate oxygenation and ventilation to be maintained without causing further damage to the already injured lung. High-frequency oscillating ventilation also seems a sound strategy for improving oxygenation in patients who are no longer responding to conventional mechanical ventilation. Currently, HFOV should be used in the adult ICU as one of many ancillary therapies available for the treatment of extremely ill, hypoxemic patients with ARDS. Future research may define the role of HFOV as a more routine strategy for preventing VALI in this patient population.

Adult↗