Multivariate projection method to investigate inflammation associated with secondary insults and outcome after human traumatic brain injury: a pilot study.

BACKGROUND: Neuroinflammation has been proposed as a possible mechanism of brain damage after traumatic brain injury (TBI), but no consensus has been reached on the most relevant molecules. Furthermore, secondary insults occurring after TBI contribute to worsen neurological outcome in addition to the primary injury. We hypothesized that after TBI, a specific pattern of cytokines is related to secondary insults and outcome. METHODS: A prospective observational clinical study was performed. Secondary insults by computerized multimodality monitoring system and systemic value of different cytokines were collected and analysed in the first week after intensive care unit admission. Neurological outcome was assessed at 6 months (GOSe). Multivariate projection technique was applied to analyse major sources of variation and collinearity within the cytokines dataset without a priori selecting potential relevant molecules. RESULTS: Twenty-nine severe traumatic brain injury patients undergoing intracranial pressure monitoring were studied. In this pilot study, we demonstrated that after TBI, patients who suffered of prolonged and severe secondary brain damage are characterised by a specific pattern of cytokines. Patients evolving to brain death exhibited higher levels of inflammatory mediators compared to both patients with favorable and unfavorable neurological outcome at 6 months. Raised ICP and low cerebral perfusion pressure occurred in 21 % of good monitoring time. Furthermore, the principal components selected by multivariate projection technique were powerful predictors of neurological outcome. CONCLUSIONS: The multivariate projection method represents a valuable methodology to study neuroinflammation pattern occurring after secondary brain damage in severe TBI patients, overcoming multiple putative interactions between mediators and avoiding any subjective selection of relevant molecules.

Effect of a lung protective strategy for organ donors on eligibility and availability of lungs for transplantation: a randomized controlled trial.

CONTEXT: Many potential donor lungs deteriorate between the time of brain death and evaluation for transplantation suitability, possibly because of the ventilatory strategy used after brain death. OBJECTIVE: To test whether a lung protective strategy increases the number of lungs available for transplantation. DESIGN, SETTING, AND PATIENTS: Multicenter randomized controlled trial of patients with beating hearts who were potential organ donors conducted at 12 European intensive care units from September 2004 to May 2009 in the Protective Ventilatory Strategy in Potential Lung Donors Study. Interventions Potential donors were randomized to the conventional ventilatory strategy (with tidal volumes of 10-12 mL/kg of predicted body weight, positive end-expiratory pressure [PEEP] of 3-5 cm H(2)O, apnea tests performed by disconnecting the ventilator, and open circuit for airway suction) or the protective ventilatory strategy (with tidal volumes of 6-8 mL/kg of predicted body weight, PEEP of 8-10 cm H(2)O, apnea tests performed by using continuous positive airway pressure, and closed circuit for airway suction). MAIN OUTCOME MEASURES: The number of organ donors meeting eligibility criteria for harvesting, number of lungs harvested, and 6-month survival of lung transplant recipients. RESULTS: The trial was stopped after enrolling 118 patients (59 in the conventional ventilatory strategy and 59 in the protective ventilatory strategy) because of termination of funding. The number of patients who met lung donor eligibility criteria after the 6-hour observation period was 32 (54%) in the conventional strategy vs 56 (95%) in the protective strategy (difference of 41% [95% confidence interval {CI}, 26.5% to 54.8%]; P <.001). The number of patients in whom lungs were harvested was 16 (27%) in the conventional strategy vs 32 (54%) in the protective strategy (difference of 27% [95% CI, 10.0% to 44.5%]; P = .004). Six-month survival rates did not differ between recipients who received lungs from donors ventilated with the conventional strategy compared with the protective strategy (11/16 [69%] vs 24/32 [75%], respectively; difference of 6% [95% CI, -22% to 32%]). CONCLUSION: Use of a lung protective strategy in potential organ donors with brain death increased the number of eligible and harvested lungs compared with a conventional strategy. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00260676.