Gastric tonometry after subarachnoid hemorrhage

The proteomic and metabolomic signatures of isolated and polytrauma traumatic brain injury

BACKGROUND

The interactions of polytrauma, shock, and traumatic brain injury (TBI) on thromboinflammatory responses remain unclear and warrant investigation as we strive towards personalized medicine in trauma. We hypothesized that comprehensive omics characterization of plasma would identify unique metabolic and thromboinflammatory pathways following TBI.

METHODS

Patients were categorized as TBI vs Non-TBI, and stratified into Polytrauma or minimally injured. Discovery 'omics was employed to quantify the top differently expressed proteins and metabolites of TBI and Non-TBI patient groups.

RESULTS

TBI compared to Non-TBI showed gene enrichment in coagulation/complement cascades and neuronal markers. TBI was associated with elevation in glycolytic metabolites and conjugated bile acids. Division into isolated TBI vs polytrauma showed further distinction of proteomic and metabolomic signatures.

CONCLUSION

Identified mediators involving in neural inflammation, blood brain barrier disruption, and bile acid building leading to TBI associated coagulopathy offer suggestions for follow up mechanistic studies to target personalized interventions.

Nutritional and Bioenergetic Considerations in Critically Ill Patients with Acute Neurological Injury

The brain, due to intensive cellular processes and maintenance of electrochemical gradients, is heavily dependent on a constant supply of energy. Brain injury, and critical illness in general, induces a state of increased metabolism and catabolism, which has been proven to lead to poor outcomes. Of all the biochemical interventions undertaken in the ICU, providing nutritional support is perhaps one of the most undervalued, but potentially among the safest, and most effective interventions. Adequate provisions of calories and protein have been shown to improve patient outcomes, and guidelines for the nutritional support of the critically ill patient are reviewed. However, there are no such specific guidelines for the critically ill patient with neurological injury. Patients with primary or secondary neurological disorders are frequently undernourished, while data suggest this population would benefit from early and adequate nutritional support, although comprehensive clinical evidence is lacking. We review the joint recommendations from the Society for Critical Care Medicine and the American Society for Parenteral and Enteral Nutrition, as they pertain to neurocritical care, and assess the recommendations for addressing nutrition in this patient population.

Splanchnic ischemia and gut permeability after acute brain injury secondary to intracranial hemorrhage

INTRODUCTION

Splanchnic ischemia (SI) and increased gut permeability (GP) have been described in acute brain injury (ABI), although their incidence and relation to the type and severity of injury are uncertain. The aim of this study was to evaluate the incidence of both abnormalities in a series of patients with severe ABI secondary to intracranial hemorrhage (ICH) managed with a resuscitation protocol pursuing adequate cerebral and systemic hemodynamics.

METHODS

Eight patients with severe ABI secondary to ICH were admitted to the ICU and were mechanically ventilated and monitored with intracranial pressure measurement, jugular bulb venous oxygen saturation, arterial lactate concentration and gastric tonometry. All patients were managed actively to maintain adequate blood and cerebral perfusion pressures with a protocol based on aggressive fluid resuscitation prior to vasoactive drugs administration. GP was assessed using the lactulose/mannitol test (LMT). Values were recorded during the first 7 days of hospital stay.

RESULTS

Arterial lactate concentration was within the normal range (1.9 +/- 0.5 mmol/l) in all patients. Upon admission, the mean pCO(2) gap was 8.2 +/- 4.3 mmHg (1.09 +/- 0.57 kPa) with an intramucosal pH of 7.4 +/- 0.1. All patients had an abnormal LMT (0.066 +/- 0.055) compared with 19 healthy volunteers (0.025 +/- 0.004) (p < 0.05, Mann Whitney test).

CONCLUSION

Splanchnic ischemia is uncommon among patients with acute brain injury secondary to intracranial hemorrhage, provided they are adequately resuscitated with a protocol based mainly on fluids to achieve an adequate CPP. Gut hyperpermeability is commonly present, despite the absence of splanchnic ischemia.

Early-phase pharmacokinetics of enteral and parenteral nimodipine in patients with acute subarachnoid haemorrhage - a pilot study

OBJECTIVE

The pharmacokinetics of nimodipine following enteral administration in the early phase after subarachnoid haemorrhage (SAH) has not been described. If a sufficient absorption could be achieved with enterally administered nimodipine, this would be more feasible dosage form and result in a significant reduction in pharmaceutical costs given that the parenteral formulation of nimodipine currently used is tenfold more expensive than the enteral formulation.

METHODS

This was a pilot study in which 17 patients with aneurysmal SAH were randomly assigned to receive nimodipine within 24 h after initial bleeding either as an 60 mg tablet/suspension at 4-h intervals, or as a continuous intravenous infusion of 2 mg/h. Serum nimodipine concentrations were measured during the 4 h following the first dose, and at 24 and 72 h on a validated gas chromatography mass spectrometer (GC-MS).

RESULTS

Nimodipine AUC values (expressed in mug min/ml) were lower in the eight SAH patients receiving enteral nimodipine [AUC(0-4) range: 0.13-5.4 (median: 0.32); AUC(24-28) range: 0.16-6.1 (0.71); AUC(72-76) range: 0.47-20.6 (1.9)] than in the nine patients receiving a continuous intravenous infusion of nimodipine [AUC(0-4) range: 2.4-4.9 (3.4), p=0.059; AUC(24-28) range: 4.7-10.3 (7.3), p=0.001; AUC(72-76) range: 3.4-8.6 (6.9), p=0.001]. In three of five good-grade SAH patients receiving nimodipine tablets the AUC values were comparable to those of the intravenous administration, but in two good-grade patients with tablets and in all three poor-grade (Hunt&Hess, grade IV) SAH patients receiving the suspension, the rate and extent of nimodipine absorption was negligible.

CONCLUSION

This pilot study indicates that the rate and extent of nimodipine absorption following enteral administration in some acute SAH patients could be negligible, and this may particularly be the case in patients with a decreased level of consciousness.

Gastric tonometry and monitoring gastrointestinal perfusion: using research to support nursing practice

The principles and physiological underpinnings of gastric tonometry are reviewed. Tonometric variables, including the PtCO2, pHi and CO2 gap, are described and critiqued as measurements of gastrointestinal perfusion. Increases in gastrointestinal CO2 unrelated to gastrointestinal hypoperfusion are discussed within different clinical contexts. The technical limitations of gastric tonometry, including procedural errors and PtCO2 measurement are discussed in relation to the accuracy of tonometric measurements. Tonometric measurement using semi-continuous air tonometry is introduced as a strategy to minimize technical limitations.

Resource Use After Subarachnoid Hemorrhage: Comparison Between Endovascular and Surgical Treatment

OBJECTIVE

The aim of this study was to compare resource use after endovascular treatment and surgical clipping of ruptured intracranial aneurysms.

METHODS

The study population consisted of patients with aneurysmal subarachnoid hemorrhage who were actively treated in Kuopio University Hospital. The baseline patients' characteristics were obtained from the institution's aneurysm registry. Variables indicating resource use in the intensive care unit (ICU) were obtained from the ICU patient data management system. The Therapeutic Intervention Scoring System was used to measure the intensity of treatment in the ICU. All care days in the ICU and in the hospital and all Therapeutic Intervention Scoring System points that were accumulated during the 12-month follow-up period were calculated. Outcomes were assessed according to the Glasgow Outcome Scale.

RESULTS

The study population consisted of 68 patients who underwent endovascular treatment and 103 patients who had surgery. The median lengths of stay in the ICU (1.7 versus 1.8 d) and the hospital (14.0 versus 15.0 d), as well as the accumulated Therapeutic Intervention Scoring System points (56 versus 55), among patients who underwent endovascular or surgical treatment were similar (P = NS for all). The modality of treatment did not influence the number of ICU or hospital patient days or the intensity of ICU treatment, regardless of the patient's preoperative clinical status.

CONCLUSION

The modality of treatment of patients with subarachnoid hemorrhage does not seem to affect resource use. Endovascular and surgical treatment are likely to require a similar amount of ICU resources in the year after initial treatment.