Omar Bouamra

Dr. Omar Bouamra

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Research Focus & Metrics

Academic Career Length

22Years (2005-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 October 2005 in The Lancet
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Journal Article
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HPHc Patel
Hc Patel
OBOmar Bouamra
Omar Bouamra
MWM Woodford
M Woodford
AKAt King
At King
DYDw Yates
Dw Yates
FLFe Lecky
Fe Lecky

17 July 2017 in Journal of Cardiothoracic Surgery
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Journal Article
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MKMaziar Khorsandi
Maziar Khorsandi
SDScott Dougherty
Scott Dougherty
OBOmar Bouamra
Omar Bouamra
VPVasudev Pai
Vasudev Pai
PCPhilip Curry
Philip Curry
VZVipin Zamvar
Vipin Zamvar
Postcardiotomy cardiogenic shock (PCCS) refractory to inotropic support and intra-aortic balloon pump (IABP) occurs rarely but is almost universally fatal without mechanical circulatory support. In this systematic review and meta-analysis we looked at the evidence behind the use of veno-arterial extra-corporeal membrane oxygenation (VA ECMO) in refractory PCCS from a patient survival rate and determinants of outcome viewpoint. A systematic review was performed in January 2017 using PubMed (with no defined time period) using the keywords “postcardiotomy”, “cardiogenic shock”, “extracorporeal membrane oxygenation” and “cardiac surgery”. We excluded papers pertaining to ECMO following paediatric cardiac surgery, medical causes of cardiogenic shock, as well as case reports, review articles, expert opinions, and letters to the editor. Once the studies were collated, a meta-analysis was performed on the proportion of survivors in those papers that met the inclusion criteria. Meta-regression was performed for the most commonly reported adverse prognostic indicators (API). We identified 24 studies and a cumulative pool of 1926 patients from 1992 to 2016. We tabulated the demographic data, including the strengths and weaknesses for each of the studies, outcomes of VA ECMO for refractory PCCS, complications, and APIs. All the studies were retrospective cohort studies. Meta-analysis of the moderately heterogeneous data (95% CI 0.29 to 0.34, p < 0.01, I 2 = 60%) revealed overall survival rate to hospital discharge of 30.8%. Some of the commonly reported APIs were advanced age (>70 years, 95% CI −0.057 to 0.001, P = 0.058), and long ECMO support (95% CI −0.068 to 0.166, P = 0.412). Postoperative renal failure, high EuroSCORE (>20%), diabetes mellitus, obesity, rising lactate whilst on ECMO, gastrointestinal complications had also been reported. Haemodynamic support with VA ECMO provides a survival benefit with reasonable intermediate and long-term outcomes. Many studies had reported advanced age, renal failure and prolonged VA ECMO support as the most likely APIs for VA ECMO in PCCS. EuroSCORE can be utilized to anticipate the need for prophylactic perioperative VA ECMO in the high-risk category. APIs can be used to aid decision-making regarding both the institution and weaning of ECMO for refractory PCCS.

1 June 2013 in Journal of Trauma and Acute Care Surgery
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Journal Article
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SBStevan R. Fcem Bruijns
Stevan R. Fcem Bruijns
HGHenry R. Fcem Guly
Henry R. Fcem Guly
OBOmar Bouamra
Omar Bouamra
FLFiona Lecky
Fiona Lecky
WLWallis A. Lee
Wallis A. Lee
BACKGROUND Systolic blood pressure (SBP), heart rate (HR), and respiratory rate are poor predictors of trauma outcome. We postulate that HR/SBP (shock index [SI]) and novel new markers SI × age (SIA), SBP / age (BPAI), maximum HR (220 − age) − HR (minpulse [MP]), and HR / maximum HR (pulse max index [PMI]) are better predictors of 48-hour mortality compared with traditional vital signs. METHODS Data were extracted from the Trauma Audit and Research Network database. Exclusions included any head or spine injury and prehospital intubation or cardiac arrest. Area under receiver operator characteristic curve (AUROC) was determined for 48-hour mortality for all variables and age. A threshold for each marker was derived using the specificity (rule-in) cutoffs at both 90% and 95% from the receiver operator characteristic curve. Positive likelihood ratios were described for each marker’s derived threshold. RESULTS Vital signs, markers, and age were all significantly associated with 48-hour mortality (p < 0.001). HR, SBP, and respiratory rate fared worst overall (AUROC = 0.69, 0.66, and 0.66, respectively). SIA, MP, PMI, BPAI, and SI were significantly (p < 0.05) better than age at predicting 48-hour mortality (AUROC = 0.79, 0.77, 0.77, 0.74, 0.73, and 0.68, respectively; AUROC for age = 0.68). Thresholds derived for these five markers were values 55 or greater, 44 or less, 70% or greater, 1.5 or less, and 0.9 or greater, respectively, each with a specificity of 95% for 48-hour mortality (positive likelihood ratios were 8.4, 6.1, 6.7, 6.6, and 7.5, respectively). The likelihood of death in 48 hours was 8.4 times more likely if SIA was greater than 55 than if it was lower. CONCLUSION Older age seems to be significantly associated with early mortality. Newer markers, especially those combining traditional vital signs with age (SIA, BPAI, MP, and PMI), may contribute to better trauma triage of patients with blunt injuries than traditional vital signs. LEVEL OF EVIDENCE Prognostic/epidemiologic study, level III.

3 August 2009 in BMC Emergency Medicine
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Journal Article
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PPPablo Perel
Pablo Perel
IRIan Roberts
Ian Roberts
OBOmar Bouamra
Omar Bouamra
MWMaralyn Woodford
Maralyn Woodford
JMJane Mooney
Jane Mooney
FLFiona Lecky
Fiona Lecky
Intracranial bleeding (IB) is a common and serious consequence of traumatic brain injury (TBI). IB can be classified according to the location into: epidural haemorrhage (EDH) subdural haemorrhage (SDH) intraparenchymal haemorrhage (IPH) and subarachnoid haemorrhage (SAH). Studies involving repeated CT scanning of TBI patients have found that IB can develop or expand in the 48 hours after injury. If IB enlarges after hospital admission and larger bleeds have a worse prognosis, this would provide a therapeutic rationale for treatments to prevent increase in the extent of bleeding. We analysed data from the Trauma Audit & Research Network (TARN), a large European trauma registry, to evaluate the association between the size of IB and mortality in patients with TBI. We analysed 13,962 patients presenting to TARN participating hospitals between 2001 and 2008 with a Glasgow Coma Score (GCS) less than 15 at presentation or any head injury with Abbreviated Injury Scale (AIS) severity code 3 and above. The extent of intracranial bleeding was determined by the AIS code. Potential confounders were age, presenting Glasgow Coma Score, mechanism of injury, presence and nature of other brain injuries, and presence of extra-cranial injuries. The outcomes were in-hospital mortality and haematoma evacuation. We conducted a multivariable logistic regression analysis to evaluate the independent effect of large and small size of IB, in comparison with no bleeding, on patient outcomes. We also conducted a multivariable logistic regression analysis to assess the independent effect on mortality of large IB in comparison with small IB. Almost 46% of patients had at some type of IB. Subdural haemorrhages were present in 30% of the patients, with epidural and intraparenchymal present in approximately 22% each. After adjusting for potential confounders, we found that large IB, wherever located, was associated with increased mortality in comparison with no bleeding. We also found that large IB was associated with an increased risk of mortality in comparison with small IB. The odds ratio for mortality for large SDH, IPH and EDH, in comparison with small bleeds, were: 3.41 (95% CI: 2.68-4.33), 3.47 (95% CI: 2.26-5.33) and 2.86 (95% CI: 1.86-4.38) respectively. Large EDH, SDH and IPH are associated with a substantially higher probability of hospital mortality in comparison with small IB. However, the limitations of our data, such as the large proportion of missing data and lack of data on other confounding factors, such as localization of the bleeding, make the results of this report only explanatory. Future studies should also evaluate the effect of IB size on functional outcomes.

14 May 2014 in Critical Care
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Journal Article
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CBCeri Elisabeth Battle
Ceri Elisabeth Battle
HHHayley Anne Hutchings
Hayley Anne Hutchings
SLSimon Lovett
Simon Lovett
OBOmar Bouamra
Omar Bouamra
SJSally Jones
Sally Jones
AEAdrian Evans
Adrian Evans
Introduction: Blunt chest wall trauma accounts for over 15% of all trauma admissions to Emergency Departments worldwide. Reported mortality rates vary between 4 and 60%. Management of this patient group is challenging as a result of the delayed on-set of complications. The aim of this study was to develop and validate a prognostic model that can be used to assist in the management of blunt chest wall trauma. Methods: There were two distinct phases to the overall study; the development and the validation phases. In the first study phase, the prognostic model was developed through the retrospective analysis of all blunt chest wall trauma patients (n = 274) presenting to the Emergency Department of a regional trauma centre in Wales (2009 to 2011). Multivariable logistic regression was used to develop the model and identify the significant predictors for the development of complications. The model’s accuracy and predictive capabilities were assessed. In the second study phase, external validation of the model was completed in a multi-centre prospective study (n = 237) in 2012. The model’s accuracy and predictive capabilities were re-assessed for the validation sample. A risk score was developed for use in the clinical setting. Results: Significant predictors of the development of complications were age, number of rib fractures, chronic lung disease, use of pre-injury anticoagulants and oxygen saturation levels. The final model demonstrated an excellent c-index of 0.96 (95% confidence intervals: 0.93 to 0.98). Conclusions: In our two phase study, we have developed and validated a prognostic model that can be used to assist in the management of blunt chest wall trauma patients. The final risk score provides the clinician with the probability of the development of complications for each individual patient.

1 April 2012
Verified
Journal Article
Closed access
RHRebecca M. Hasler
Rebecca M. Hasler
AEAristomenis K. Exadaktylos
Aristomenis K. Exadaktylos
OBOmar Bouamra
Omar Bouamra
LBLorin M. Benneker
Lorin M. Benneker
MCMike Clancy
Mike Clancy
FLFiona Lecky
Fiona Lecky
Patients with cervical spine injuries are a high-risk group, with the highest reported early mortality rate in spinal trauma. This cohort study investigated predictors for cervical spine injury in adult (≥ 16 years) major trauma patients using prospectively collected data of the Trauma Audit and Research Network from 1988 to 2009. Univariate and multivariate logistic regression analyses were used to determine predictors for cervical fractures/dislocations or cord injury. A total of 250,584 patients were analyzed. Median age was 47.2 years (interquartile range, 29.8-66.0) and Injury Severity Score 9 (interquartile range, 4-11); 60.2% were male. Six thousand eight hundred two patients (2.3%) sustained cervical fractures/dislocations alone. Two thousand sixty-nine (0.8%) sustained cervical cord injury with/without fractures/dislocations; 39.9% of fracture/dislocation and 25.8% of cord injury patients suffered injuries to other body regions. Age ≥ 65 years (odds ratio [OR], 1.45-1.92), males (females OR, 0.91; 95% CI, 0.86-0.96), Glasgow Coma Scale (GCS) score 2 m (OR, 2.74; 95% CI, 2.53-2.97) were predictive for fractures/dislocations. Age 2 m (OR, 2.24; 95% CI, 1.94-2.58) were predictors for cord injury. 3.5% of patients suffered cervical spine injury. Patients with a lowered GCS or systolic blood pressure, severe facial fractures, dangerous injury mechanism, male gender, and/or age ≥ 35 years are at increased risk. Contrary to common belief, head injury was not predictive for cervical spine involvement.