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Dive into the research topics where Simon J Mackenzie is active.

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Featured researches published by Simon J Mackenzie.


JAMA Internal Medicine | 2015

Increased Hospital-Based Physical Rehabilitation and Information Provision After Intensive Care Unit Discharge: The RECOVER Randomized Clinical Trial

Timothy S. Walsh; Lisa Salisbury; Judith Merriweather; Julia Boyd; David M Griffith; Guro Huby; Susanne Kean; Simon J Mackenzie; Ashma Krishan; Stephanie Lewis; Gordon Murray; John Forbes; Joel Smith; Janice Rattray; Alastair M. Hull; Pamela Ramsay

IMPORTANCE Critical illness results in disability and reduced health-related quality of life (HRQOL), but the optimum timing and components of rehabilitation are uncertain. OBJECTIVE To evaluate the effect of increasing physical and nutritional rehabilitation plus information delivered during the post-intensive care unit (ICU) acute hospital stay by dedicated rehabilitation assistants on subsequent mobility, HRQOL, and prevalent disabilities. DESIGN, SETTING, AND PARTICIPANTS A parallel group, randomized clinical trial with blinded outcome assessment at 2 hospitals in Edinburgh, Scotland, of 240 patients discharged from the ICU between December 1, 2010, and January 31, 2013, who required at least 48 hours of mechanical ventilation. Analysis for the primary outcome and other 3-month outcomes was performed between June and August 2013; for the 6- and 12-month outcomes and the health economic evaluation, between March and April 2014. INTERVENTIONS During the post-ICU hospital stay, both groups received physiotherapy and dietetic, occupational, and speech/language therapy, but patients in the intervention group received rehabilitation that typically increased the frequency of mobility and exercise therapies 2- to 3-fold, increased dietetic assessment and treatment, used individualized goal setting, and provided greater illness-specific information. Intervention group therapy was coordinated and delivered by a dedicated rehabilitation practitioner. MAIN OUTCOMES AND MEASURES The Rivermead Mobility Index (RMI) (range 0-15) at 3 months; higher scores indicate greater mobility. Secondary outcomes included HRQOL, psychological outcomes, self-reported symptoms, patient experience, and cost-effectiveness during a 12-month follow-up (completed in February 2014). RESULTS Median RMI at randomization was 3 (interquartile range [IQR], 1-6) and at 3 months was 13 (IQR, 10-14) for the intervention and usual care groups (mean difference, -0.2 [95% CI, -1.3 to 0.9; P = .71]). The HRQOL scores were unchanged by the intervention (mean difference in the Physical Component Summary score, -0.1 [95% CI, -3.3 to 3.1; P = .96]; and in the Mental Component Summary score, 0.2 [95% CI, -3.4 to 3.8; P = .91]). No differences were found for self-reported symptoms of fatigue, pain, appetite, joint stiffness, or breathlessness. Levels of anxiety, depression, and posttraumatic stress were similar, as were hand grip strength and the timed Up & Go test. No differences were found at the 6- or 12-month follow-up for any outcome measures. However, patients in the intervention group reported greater satisfaction with physiotherapy, nutritional support, coordination of care, and information provision. CONCLUSIONS AND RELEVANCE Post-ICU hospital-based rehabilitation, including increased physical and nutritional therapy plus information provision, did not improve physical recovery or HRQOL, but improved patient satisfaction with many aspects of recovery. TRIAL REGISTRATION isrctn.com Identifier: ISRCTN09412438.


Vox Sanguinis | 2003

Red cell transfusion practice following the transfusion requirements in critical care (TRICC) study: prospective observational cohort study in a large UK intensive care unit

S. S. Chohan; Fiona McArdle; D.B.L. McClelland; Simon J Mackenzie; Timothy S. Walsh

Background and Objectives The Transfusion Requirements In Critical Care (TRICC) study found that critically ill patients tolerate a restrictive haemoglobin transfusion threshold. We investigated red‐cell transfusion practice since publication of the TRICC study in a large Scottish teaching hospital intensive care unit (ICU).


American Journal of Respiratory and Critical Care Medicine | 2009

C5a Mediates Peripheral Blood Neutrophil Dysfunction in Critically Ill Patients

Andrew Conway Morris; Kallirroi Kefala; Thomas S. Wilkinson; Kevin Dhaliwal; Lesley Farrell; Timothy S. Walsh; Simon J Mackenzie; Hamish Reid; Donald J. Davidson; Christopher Haslett; Adriano G. Rossi; Jean-Michel Sallenave; A. John Simpson

RATIONALE Critically ill patients are highly susceptible to hospital-acquired infection. Neutrophil function in critical illness remains poorly understood. OBJECTIVES To characterize and define mechanisms of peripheral blood neutrophil (PBN) dysfunction in critically ill patients. To determine whether the inflamed lung contributes additional phagocytic impairment. METHODS Prospective collection of blood and bronchoalveolar lavage fluid from patients with suspected ventilator-associated pneumonia and from age- and sex-matched volunteers; laboratory analysis of neutrophil functions. MEASUREMENTS AND MAIN RESULTS Seventy-two patients and 21 volunteers were included. Phagocytic capacity of PBNs was 36% lower in patients than in volunteers (P < 0.0001). From several biologically plausible candidates only activated complement was significantly associated with impaired PBN phagocytosis (P < 0.0001). Phagocytosis was negatively correlated with serum C3a and positively correlated with expression of C5a receptor type 1 (CD88) on PBNs. C5a recapitulated impaired PBN phagocytosis and significantly down-regulated CD88 expression in vitro. C5a-mediated phagocytic impairment was prevented by blocking either CD88 or phosphoinositide 3-kinase, and completely reversed by granulocyte-macrophage colony-stimulating factor. C5a also impaired killing of Pseudomonas aeruginosa by, and migration of, PBNs, indicating that effects were not restricted to phagocytosis. Bronchoalveolar lavage fluid leukocytes from patients also demonstrated significantly impaired function, and lavage supernatant reduced phagocytosis in healthy neutrophils by 43% (P = 0.0001). However, lavage fluid did not affect CD88 expression and lavage-mediated impairment of phagocytosis was not blocked by anti-CD88 antibody. CONCLUSIONS Critically ill patients have significant dysfunction of PBNs, which is mediated predominantly by activated complement. Further, profound complement-independent neutrophil dysfunction occurs in the inflamed lung.


Thorax | 2010

Diagnostic importance of pulmonary interleukin-1β and interleukin-8 in ventilator-associated pneumonia

Andrew Conway Morris; Kallirroi Kefala; Thomas S. Wilkinson; Olga Lucia Moncayo-Nieto; Kevin Dhaliwal; Lesley Farrell; Timothy S. Walsh; Simon J Mackenzie; David Swann; Peter Andrews; Niall Anderson; John R. W. Govan; Ian F. Laurenson; Hamish Reid; Donald J. Davidson; Christopher Haslett; Jean-Michel Sallenave; A. John Simpson

Background Ventilator-associated pneumonia (VAP) is the most commonly fatal nosocomial infection. Clinical diagnosis of VAP remains notoriously inaccurate. The hypothesis was tested that significantly augmented inflammatory markers distinguish VAP from conditions closely mimicking VAP. Methods A prospective, observational cohort study was carried out in two university hospital intensive care units recruiting 73 patients with clinically suspected VAP, and a semi-urban primary care practice recruiting a reference group of 21 age- and sex-matched volunteers. Growth of pathogens at >104 colony-forming units (cfu)/ml of bronchoalveolar lavage fluid (BALF) distinguished VAP from “non-VAP”. Inflammatory mediators were quantified in BALF and serum. Mediators showing significant differences between patients with and without VAP were analysed for diagnostic utility by receiver operator characteristic (ROC) curves. Results Seventy-two patients had recoverable lavage—24% had VAP. BALF interleukin-1β (IL-1β), IL-8, granulocyte colony-stimulating factor and macrophage inflammatory protein-1α were significantly higher in the VAP group (all p<0.005). Using a cut-off of 10 pg/ml, BALF IL-1β generated negative likelihood ratios for VAP of 0.09. In patients with BALF IL-1β <10 pg/ml the post-test probability of VAP was 2.8%. Using a cut-off value for IL-8 of 2 ng/ml, the positive likelihood ratio was 5.03. There was no difference in cytokine levels between patients with sterile BALF and those with growth of <104 cfu/ml. Conclusions BALF IL-1β and IL-8 are amongst the strongest markers yet identified for accurately demarcating VAP within the larger population of patients with suspected VAP. These findings have potential implications for reduction in unnecessary antibiotic use but require further validation in larger populations.


BMJ Open | 2012

A randomised controlled trial evaluating a rehabilitation complex intervention for patients following intensive care discharge: the RECOVER study

Timothy S. Walsh; Lisa Salisbury; Julia Boyd; Pamela Ramsay; Judith Merriweather; Guro Huby; John Forbes; Janice Z Rattray; David M Griffith; Simon J Mackenzie; Alastair M. Hull; Steff Lewis; Gordon Murray

Introduction Patients who survive an intensive care unit admission frequently suffer physical and psychological morbidity for many months after discharge. Current rehabilitation pathways are often fragmented and little is known about the optimum method of promoting recovery. Many patients suffer reduced quality of life. Methods and analysis The authors plan a multicentre randomised parallel group complex intervention trial with concealment of group allocation from outcome assessors. Patients who required more than 48 h of mechanical ventilation and are deemed fit for intensive care unit discharge will be eligible. Patients with primary neurological diagnoses will be excluded. Participants will be randomised into one of the two groups: the intervention group will receive standard ward-based care delivered by the NHS service with additional treatment by a specifically trained generic rehabilitation assistant during ward stay and via telephone contact after hospital discharge and the control group will receive standard ward-based care delivered by the current NHS service. The intervention group will also receive additional information about their critical illness and access to a critical care physician. The total duration of the intervention will be from randomisation to 3 months postrandomisation. The total duration of follow-up will be 12 months from randomisation for both groups. The primary outcome will be the Rivermead Mobility Index at 3 months. Secondary outcomes will include measures of physical and psychological morbidity and function, quality of life and survival over a 12-month period. A health economic evaluation will also be undertaken. Groups will be compared in relation to primary and secondary outcomes; quantitative analyses will be supplemented by focus groups with patients, carers and healthcare workers. Ethics and dissemination Consent will be obtained from patients and relatives according to patient capacity. Data will be analysed according to a predefined analysis plan. Trial registration The trial is registered as ISRCTN09412438 and funded by the Chief Scientist Office, Scotland.


Hepatology | 1998

The effect of N‐acetylcysteine on oxygen transport and uptake in patients with fulminant hepatic failure

Timothy S. Walsh; Patrick Hopton; Barbara J. Philips; Simon J Mackenzie; Alistair Lee


Chest | 1999

Hyperlactatemia and pulmonary lactate production in patients with fulminant hepatic failure

Timothy S. Walsh; Stuart A. McLellan; Simon J Mackenzie; Alistair Lee


Trials | 2014

A rehabilitation intervention to promote physical recovery following intensive care: a detailed description of construct development, rationale and content together with proposed taxonomy to capture processes in a randomised controlled trial.

Pamela Ramsay; Lisa Salisbury; Judith Merriweather; Guro Huby; Janice Rattray; Alastair M. Hull; Stephen Brett; Simon J Mackenzie; Gordon Murray; John Forbes; Timothy S. Walsh


Archive | 2015

Increased Hospital-Based Physical Rehabilitation and Information Provision After Intensive Care Unit Discharge

Timothy S. Walsh; Lisa Salisbury; Judith Merriweather; Julia Boyd; David M Griffith; Guro Huby; Susanne Kean; Simon J Mackenzie; Ashma Krishan; Stephanie Lewis; Gordon Murray; John Forbes; Joel Smith; Janice Rattray; Alastair M. Hull; Pamela Ramsay


Thorax | 2008

NEUTROPHILS FROM PATIENTS WITH VENTILATOR-ASSOCIATED PNEUMONIA: PRO-INFLAMMATORY AND CYTOTOXIC INTERACTIONS WITH ALVEOLAR EPITHELIUM

Hamish Reid; A. Conway Morris; Kallirroi Kefala; Thomas S. Wilkinson; Lesley Farrell; Timothy S. Walsh; Simon J Mackenzie; Jean-Michel Sallenave; Kev Dhaliwal; Christopher Haslett; A J Simpson

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Guro Huby

University of Edinburgh

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John Forbes

University of Limerick

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Julia Boyd

University of Edinburgh

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