Nebulised recombinant activated factor VII (rFVIIa) does not attenuate the haemorrhagic effects of blast lung injury.

INTRODUCTION: Primary blast lung injury causes intrapulmonary haemorrhage. A number of case reports have suggested the efficacy of recombinant activated factor VII (rFVIIa) in the treatment of diffuse alveolar haemorrhage from a range of medical causes, but its efficacy in blast lung is unknown. The aim of this study was to investigate whether nebulised rFVIIa attenuates the haemorrhagic effects of blast lung injury in an animal model. METHODS: Terminally anaesthetised rabbits subjected to blast lung injury were randomised to receive either rFVIIa or placebo via a nebuliser. The primary outcome was the level of blood iron-transferrin complex, a marker of the extent of blast lung injury, analysed using low temperature electron paramagnetic resonance spectroscopy. RESULTS: Blast exposure led to a significant fall in iron-bound transferrin in both groups of animals (p<0.001), which remained depressed during the study. There were no significant differences in iron-transferrin between the rFVIIa and placebo treatment groups over the duration of the study (p=0.081), and there was no trend towards elevated iron-transferrin in the rFVIIa-treated group once drug treatment had started. There was suggestive evidence of systemic absorption of rFVIIa given via the inhaled route. CONCLUSION: A single dose of nebulised rFVIIa did not attenuate pulmonary haemorrhage in a rabbit model of blast lung injury. As there was some evidence of systemic absorption, the inhaled route does not avoid the concern about potential thromboembolic complications from administration of rFVIIa.

Paediatric traumatic cardiac arrest: a Delphi study to establish consensus on definition and management.

AIMS: Paediatric traumatic cardiac arrest (TCA) is associated with low survival and poor outcomes. The mechanisms that underlie TCA are different from medical cardiac arrest; the approach to treatment of TCA may therefore also need to differ to optimise outcomes. The aim of this study was to explore the opinion of subject matter experts regarding the diagnosis and treatment of paediatric TCA, and to reach consensus on how best to manage this group of patients. METHODS: An online Delphi study was conducted over three rounds, with the aim of achieving consensus (defined as 70% agreement) on statements related to the diagnosis and management of paediatric TCA. Participants were invited from paediatric and adult emergency medicine, paediatric anaesthetics, paediatric ICU and paediatric surgery, as well as Paediatric Major Trauma Centre leads and representatives from the Resuscitation Council UK. Statements were informed by literature reviews and were based on elements of APLS resuscitation algorithms as well as some concepts used in the management of adult TCA; they ranged from confirmation of cardiac arrest to the indications for thoracotomy. RESULTS: 73 experts completed all three rounds between June and November 2016. Consensus was reached on 14 statements regarding the diagnosis and management of paediatric TCA; oxygenation and ventilatory support, along with rapid volume replacement with warmed blood, improve survival. The duration of cardiac arrest and the lack of a response to intervention, along with cardiac standstill on ultrasound, help to guide the decision to terminate resuscitation. CONCLUSION: This study has given a consensus-based framework to guide protocol development in the management of paediatric TCA, though further work is required in other key areas including its acceptability to clinicians.

The role of neutrophil gelatinase-associated lipocalin (NGAL) in the detection of blast lung injury in a military population.

PURPOSE: To study the relationship between serum neutrophil gelatinase-associated lipocalin (NGAL) and military blast and gunshot wound (GSW) to establish whether potential exists for NGAL as a biomarker for blast lung injury (BLI). METHOD: Patients from the intensive care unit (ICU) of the Role 3 Medical Treatment Facility at Camp Bastion, Helmand Province, Afghanistan were studied over a five month period commencing in 2012. Age, mechanism, trauma injury severity score (TRISS) and serum NGAL were recorded on ICU admission (NGAL1). Serum NGAL (NGAL2) and PaO2/FiO2 ratio (P/F ratio2) were recorded at 24h. RESULTS: 33 patients were injured by blast and 23 by GSW. NGAL1 inversely correlated with TRISS (p=0.020), pH (p=0.002) and P/F ratio 2 (p=0.009) overall. When data was stratified into blast and GSW, NGAL1 also inversely correlated with P/F ratio 2 in the blast injured group (p=0.008) but not GSW group (p=0.27). CONCLUSION: Raised NGAL correlated with increased severity of injury (worse survival probability i.e. TRISS and low pH) in both patient groups. There was an inverse correlation between admission NGAL and a marker of blast lung injury (low P/F ratio) at 24h in blast injured group but not GSW group that warrants further investigation.

Blast lung injury.

Blast lung injury is an increasing problem for UK forces in Afghanistan, but is not a new phenomenon, with evidence that it has been increasing in incidence over the last century. Management is conservative, but there are newer therapies that may play a role in the future management of this condition.

How accurately do novice surgeons place thoracic pedicle screws with the free hand technique?

STUDY DESIGN: Cadaver study. OBJECTIVE: To evaluate with direct observation the errors made when novice resident surgeons place thoracic pedicle screws. To determine how many specimens need to be instrumented to assure an improvement in accuracy to currently published levels. SUMMARY OF BACKGROUND DATA: Thoracic pedicle screw instrumentation has been shown to provide numerous benefits in spinal deformity surgery including 3 column fixation of the spinal elements, decreased need for thoracoplasty or anterior thoracic release and decreased operative time and blood loss. METHODS: Three orthopaedic residents inexperienced in pedicle screw placement received an introductory teaching session. Intact thoracic vertebral body specimens were harvested from 15 cadaver spines. Each vertebral body was mounted on a clear Plexiglas frame with only the posterior surface anatomy visible to the surgeon. Each resident surgeon instrumented 5 thoracic spines verbalizing all perceived pedicle wall violations as they occurred. An observer recorded the accuracy of the gearshift probe, flexible probe, tap, and screw placement. Critically perforated screws were defined as a greater than 2 mm breach of the pedicle wall. RESULTS: Two hundred ninety-seven pedicles in 149 intact vertebral body specimens were instrumented. Eighty-five (29%) screws were not fully within the pedicle. Sixty-three (74%) were noncritical violations and 22 (26%) were critical violations. There were 18 (21%) screw violations not perceived by the surgeon to be outside the pedicle. There was a decrease in the proportion of total screw violations by the third cadaver (P < 0.001) and in critical screw violations by the fourth cadaver (P = 0.01). CONCLUSION: Novice resident surgeons placing thoracic pedicle screws in cadavers were able to significantly improve by the fourth cadaver to accuracy levels documented in the literature. Surgeons in training shouldpractice these skills in the laboratory before proceeding to the operating room.