Comparación de la eficacia del pentobarbital y el tiopental en el control de la hipertensión intracraneal refractaria. Resultados preliminares en una serie de 20 pacientes

Burst Suppression for ICP Control

BACKGROUND

The goal of our study was to perform a systematic review of the literature to determine the effect that burst suppression has on intracranial pressure (ICP) control.

METHODS

All articles from MEDLINE, BIOSIS, EMBASE, Global Health, Scopus, Cochrane Library, the International Clinical Trials Registry Platform (inception to January 2015), reference lists of relevant articles, and gray literature were searched. The strength of evidence was adjudicated using both the Oxford and the Grading of Recommendation Assessment Development and Education (GRADE) methodology.

RESULTS

Seven articles were considered for review. A total of 108 patients were studied, all receiving burst suppression therapy. Two studies failed to document a decrease in ICP with burst suppression therapy. There were reports of severe hypotension and increased infection rates with barbiturate-based therapy. Etomidate-based suppressive therapy was linked to severe renal dysfunction.

CONCLUSIONS

There currently exists both Oxford level 2b and GRADE C evidence to support that achieving burst suppression reduces ICP, and also has no effect on ICP, in severe traumatic brain injury. The literature suggests burst suppression therapy may be useful for ICP reduction in certain cases, although these situations are currently unclear. In addition, the impact on patient functional outcome is unclear. Further prospective study is warranted.

Acute management of acquired brain injury part II: an evidence-based review of pharmacological interventions

PRIMARY OBJECTIVE

To review the research literature on pharmacological interventions used in the acute phase of acquired brain injury (ABI) to manage ICP and improve neural recovery.

MAIN OUTCOMES

A literature search of multiple databases (CINAHL, EMBASE, MEDLINE and PSYCHINFO) and hand searched articles covering the years 1980-2008 was performed. Peer reviewed articles were assessed for methodological quality using the PEDro scoring system for randomized controlled trials (RCTs) and the Downs and Black tool for RCTs and non-randomized trials. Levels of evidence were assigned and recommendations were made.

RESULTS

In total, 11 pharmacological interventions used in the acute management of ABI were evaluated. These included propofol, barbiturates, opioids, midazolam, mannitol, hypertonic saline, corticosteroids, progesterone, bradykinin antagonists, dimethyl sulphoxide and cannabinoids. Of these interventions, corticosteroids were found to be contraindicated and cannabinoids were reported as ineffective. The other nine interventions demonstrated some benefit for treatment of acute ABI. However, rarely did these benefits result in improved long-term patient outcomes.

CONCLUSIONS

Substantial research has been devoted to evaluating the use of pharmacological interventions in the acute management of ABI. However, much of this research has focused on the application of individual interventions in small single-site trials. Future research will need to establish larger patient samples to evaluate the benefits of combined interventions within specific patient populations.

Effect of barbiturate coma on adrenal response in patients with traumatic brain injury

INTRODUCTION

Barbiturate coma is the second tier measure recommended by guidelines to treat post-traumatic refractory intracranial pressure. Systemic hypotension is its most important side effect. Recent evidence suggests that low-dose corticosteroid therapy may be used in a subset of patients with traumatic brain injury (TBI) to avoid hypotension. We evaluated adrenal function in TBI patients undergoing barbiturate coma, as treatment of their refractory intracranial hypertension.

MATERIALS AND METHODS

We prospectively studied 40 patients with moderate to severe TBI. Group A (17 patients) were treated with barbiturate coma. Group B (23 patients) presented intracranial hypertension controlled with first tier measures, and acted as a control. Adrenal function was evaluated by using the high-dose corticotropin stimulation test within 24 h after brain injury and after barbiturate coma induction.

RESULTS

Within 24 h after TBI, adrenal function was similar in both groups. Once barbiturate coma was induced, patients in group A treated with barbiturate coma presented a higher incidence of adrenal insufficiency compared with the control group B (53% vs 22%, p=0.03). Patients treated with barbiturates, who developed adrenal impairment, required higher doses of norepinephrine to maintain cerebral perfusion pressure than patients treated with barbiturates without adrenal impairment (1.07+/-1.04 microg/kg/min vs 0.31+/-0.32 mug/kg/min, p=0.03).

CONCLUSIONS

Patients with TBI treated with barbiturate coma are at higher risk of developing adrenal insufficiency. This subset of patients presented higher requirements of vasoactive support to avoid hypotension. In these patients corticosteroid therapy may have potential therapeutic implications to treat hemodynamic instability.

Neurologic Outcome of Posttraumatic Refractory Intracranial Hypertension Treated With External Lumbar Drainage

BACKGROUND

Refractory intracranial hypertension (ICH) to second level measures after severe traumatic brain injury (TBI) is associated with mortality up to 84% to 100%. The use of external lumbar drainage (ELD) has been described in these patients. We report our experience with the use of ELD in 17 cases of refractory ICH after severe TBI.

METHODS

In our Level 3 Intensive Care Unit (ICU) at a university hospital, ICH is treated according to a progressive approach following the Brain Trauma Foundation guidelines. When second level measures fail to control ICH, we use an ELD as a rescue therapy if basal cisterns are discernible. Outcome at ICU discharge and 6 months after injury were analyzed using Glasgow Outcome Scale (GOS).

RESULTS

Mean age was 32.5 +/- 13.3 years. ICH was reduced in all patients. ICP before ELD was 30.9 +/- 7.9 mm Hg and after ELD 14.1 +/- 5.9 mm Hg. Four patients (24%) had an ICH rebound after 5 days of ELD placement and died in the ICU. At 6 months after TBI, 13 patients (76%) presented a good outcome (GOS score of 4 and 5). No patient presented pupillary changes or cerebrospinal fluid infection during ELD use.

CONCLUSION

External lumbar drainage is an effective and safe procedure to treat refractory ICH when basal cisterns are discernible. Control of refractory ICH with ELD is associated with an important reduction of mortality and a good functional recovery at 6 months.

Barbiturates for acute traumatic brain injury

BACKGROUND

Raised intracranial pressure (ICP) is an important complication of severe brain injury, and is associated with a high mortality rate. Barbiturates are believed to reduce intracranial pressure by suppressing cerebral metabolism, thus reducing cerebral metabolic demands and cerebral blood volume. However, barbiturates also reduce blood pressure and therefore may adversely effect cerebral perfusion pressure.

OBJECTIVES

To assess the effects of barbiturates in reducing raised intracranial pressure, mortality and morbidity in people with acute traumatic brain injury. To quantify any side effects resulting from the use of barbiturates.

SEARCH STRATEGY

The review draws largely on the search strategy developed for the Cochrane Injuries Group as a whole. However, in addition the Cochrane Library was searched in December 1996 using the text terms "barbiturate*," "pentobarb*," "phenobarb*," "head," and "brain." An updated search was done in April 1999.

SELECTION CRITERIA

Randomised or quasi randomised trials of any one or more of the barbiturate class of drugs (amobarbital, barbital, hexobarbital, mephobarbital, methohexital, murexide, pentobarbital, phenobarbital, secobarbital, thiobarbiturate) where study participants had a clinically diagnosed acute traumatic brain injury of any severity.

DATA COLLECTION AND ANALYSIS

The reviewer extracted the data and assessed the quality of allocation concealment in the trials.

MAIN RESULTS

The pooled relative risk for death (barbiturate vs no barbiturate) was 1.09 (95%CI 0.81 to 1.47). The pooled effect of barbiturates on adverse neurological outcome, measured using the Glasgow Outcome Scale (death, persistent vegetative state or severe disability) was 1.15 (95% 0.81 to 1.64). Two studies examined the effect of barbiturate therapy on intracranial pressure. In the study by Eisenberger et al, a smaller proportion of patients in the barbiturate group had uncontrolled ICP (68% vs 83%). The relative risk for uncontrolled ICP was 0.81 (95%CI 0.62 to 1.06). Similarly, in the study by Ward et al, mean ICP was lower in the barbiturate treated group. Barbiturate therapy results in an increase in the occurrence of hypotension (RR=1.80 95%CI 1.19 to 2.70). For every four patients treated one will develop clinically significant hypotension. Mean body temperature was significantly lower in the barbiturate treated group. Schwartz et al compared pentobarbital with mannitol in the control of intracranial pressure. Pentobarbital was less effective than mannitol for control of raised ICP. 68% of patients in the pentobarbital treated group required a second drug for the treatment of raised intracranial pressure compared to 39% in the mannitol treated group (RR=1.75 95%CI 1.05 to 2.92). There was no substantial difference in mortality between the two study groups (RR=1.18 95%CI 0.73 to 1.92).

REVIEWER'S CONCLUSIONS

There is no evidence that barbiturate therapy in patients with acute severe head injury improves outcome. Barbiturate therapy results in a fall in blood pressure in 1 in 4 treated patients. The hypotensive effect of barbiturate therapy will offset any ICP lowering effect on cerebral perfusion pressure.