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Effects of the neurological wake-up test on clinical examination, intracranial pressure, brain metabolism and brain tissue oxygenation in severely brain-injured patients.

Helbok R, Kurtz P, Schmidt MJ, Stuart MR, Fernandez L, Connolly SE, Lee K, Schmutzhard E, Mayer SA, Claassen J, Badjatia N - Crit Care (2012)

Bottom Line: Daily interruption of sedation (IS) has been implemented in 30 to 40% of intensive care units worldwide and may improve outcome in medical intensive care patients.Little is known about the benefit of IS in acutely brain-injured patients.This prospective observational study was performed in a neuroscience intensive care unit in a tertiary-care academic center.

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ABSTRACT

Introduction: Daily interruption of sedation (IS) has been implemented in 30 to 40% of intensive care units worldwide and may improve outcome in medical intensive care patients. Little is known about the benefit of IS in acutely brain-injured patients.

Methods: This prospective observational study was performed in a neuroscience intensive care unit in a tertiary-care academic center. Twenty consecutive severely brain-injured patients with multimodal neuromonitoring were analyzed for levels of brain lactate, pyruvate and glucose, intracranial pressure (ICP), cerebral perfusion pressure (CPP) and brain tissue oxygen tension (PbtO2) during IS trials.

Results: Of the 82 trial days, 54 IS-trials were performed as interruption of sedation and analgesics were not considered safe on 28 days (34%). An increase in the FOUR Score (Full Outline of UnResponsiveness score) was observed in 50% of IS-trials by a median of three (two to four) points. Detection of a new neurologic deficit occurred in one trial (2%), and in one-third of IS-trials the trial had to be stopped due to an ICP-crisis (> 20 mmHg), agitation or systemic desaturation. In IS-trials that had to be aborted, a significant increase in ICP and decrease in PbtO2 (P < 0.05), including 67% with critical values of PbtO2 < 20 mmHg, a tendency to brain metabolic distress (P < 0.07) was observed.

Conclusions: Interruption of sedation revealed new relevant clinical information in only one trial and a large number of trials could not be performed or had to be stopped due to safety issues. Weighing pros and cons of IS-trials in patients with acute brain injury seems important as related side effects may overcome the clinical benefit.

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Clinical and hemodynamic changes during is-trials. Panel A shows median increase of GCS (empty circle) and the Four score (filled circle) during the IS-trial. Panel B-F gives average time course of cardiopulmonary, cerebrovascular parameters and ICP (y-axis) at baseline (time = 0) during the trial (grey square) and over 2 hours following restart of sedation and analgesics (x-axis) in patients where the trial was completed (empty square) and aborted (filled square). P-value is given for significant differences of time points (Panel A) or differences of parameters over time (Panel B-F) (** = P < 0.001, * = P < 0.05). On Panel B-F error bars represent means and one standard error of n = 54 individual trials. CPP, cerebral perfusion pressure; HR, heart rate; ICP, intracranial pressure; MAP, mean arterial pressure; RR, respiratory rate.
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Figure 1: Clinical and hemodynamic changes during is-trials. Panel A shows median increase of GCS (empty circle) and the Four score (filled circle) during the IS-trial. Panel B-F gives average time course of cardiopulmonary, cerebrovascular parameters and ICP (y-axis) at baseline (time = 0) during the trial (grey square) and over 2 hours following restart of sedation and analgesics (x-axis) in patients where the trial was completed (empty square) and aborted (filled square). P-value is given for significant differences of time points (Panel A) or differences of parameters over time (Panel B-F) (** = P < 0.001, * = P < 0.05). On Panel B-F error bars represent means and one standard error of n = 54 individual trials. CPP, cerebral perfusion pressure; HR, heart rate; ICP, intracranial pressure; MAP, mean arterial pressure; RR, respiratory rate.

Mentions: Thirty-six IS-trials (67%) were fully completed and one-third of all trials (n = 18, 33%; 12/20 patients) had to be aborted due to ICP crisis (n = 9, 50%), agitation (n = 4, 22%), systemic desaturation (n = 2, 11%) or a combination of all (n = 3, 17%). Trial failure was not associated with a specific disease entity or a specific time period after brain injury. Detection of a new neurologic deficit occurred in one trial (2%). In this patient an increase in brain lactate and slight decrease in brain glucose (to 1 mmol/L) was noted hours before the IS-trial was performed. At the trial start, patients received a median of two drugs (IQR, 2 to -3) including a combination of dexmedetomidine (n = 45, median = 1 μg/kg/h, 0.7 to 1.0 μg/kg/h), midazolam (n = 8, median dose = 1 mg/kg/h, 1 to 7 mg/kg/h), propofol (n = 43, median dose = 30 μg/kg/h, 25 to 40 μg/kg/h), and fentanyl (n = 30, median = 28 μg/h, 25 to 50 μg/h). The median time off sedation, including all trials, was 35 minutes (30 to 40 minutes). An increase in the FOUR Score (Full Outline of UnResponsiveness score) was observed in 50% of IS-trials by three (two to four) points (P < 0.05) (Figure 1A).


Effects of the neurological wake-up test on clinical examination, intracranial pressure, brain metabolism and brain tissue oxygenation in severely brain-injured patients.

Helbok R, Kurtz P, Schmidt MJ, Stuart MR, Fernandez L, Connolly SE, Lee K, Schmutzhard E, Mayer SA, Claassen J, Badjatia N - Crit Care (2012)

Clinical and hemodynamic changes during is-trials. Panel A shows median increase of GCS (empty circle) and the Four score (filled circle) during the IS-trial. Panel B-F gives average time course of cardiopulmonary, cerebrovascular parameters and ICP (y-axis) at baseline (time = 0) during the trial (grey square) and over 2 hours following restart of sedation and analgesics (x-axis) in patients where the trial was completed (empty square) and aborted (filled square). P-value is given for significant differences of time points (Panel A) or differences of parameters over time (Panel B-F) (** = P < 0.001, * = P < 0.05). On Panel B-F error bars represent means and one standard error of n = 54 individual trials. CPP, cerebral perfusion pressure; HR, heart rate; ICP, intracranial pressure; MAP, mean arterial pressure; RR, respiratory rate.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3672610&req=5

Figure 1: Clinical and hemodynamic changes during is-trials. Panel A shows median increase of GCS (empty circle) and the Four score (filled circle) during the IS-trial. Panel B-F gives average time course of cardiopulmonary, cerebrovascular parameters and ICP (y-axis) at baseline (time = 0) during the trial (grey square) and over 2 hours following restart of sedation and analgesics (x-axis) in patients where the trial was completed (empty square) and aborted (filled square). P-value is given for significant differences of time points (Panel A) or differences of parameters over time (Panel B-F) (** = P < 0.001, * = P < 0.05). On Panel B-F error bars represent means and one standard error of n = 54 individual trials. CPP, cerebral perfusion pressure; HR, heart rate; ICP, intracranial pressure; MAP, mean arterial pressure; RR, respiratory rate.
Mentions: Thirty-six IS-trials (67%) were fully completed and one-third of all trials (n = 18, 33%; 12/20 patients) had to be aborted due to ICP crisis (n = 9, 50%), agitation (n = 4, 22%), systemic desaturation (n = 2, 11%) or a combination of all (n = 3, 17%). Trial failure was not associated with a specific disease entity or a specific time period after brain injury. Detection of a new neurologic deficit occurred in one trial (2%). In this patient an increase in brain lactate and slight decrease in brain glucose (to 1 mmol/L) was noted hours before the IS-trial was performed. At the trial start, patients received a median of two drugs (IQR, 2 to -3) including a combination of dexmedetomidine (n = 45, median = 1 μg/kg/h, 0.7 to 1.0 μg/kg/h), midazolam (n = 8, median dose = 1 mg/kg/h, 1 to 7 mg/kg/h), propofol (n = 43, median dose = 30 μg/kg/h, 25 to 40 μg/kg/h), and fentanyl (n = 30, median = 28 μg/h, 25 to 50 μg/h). The median time off sedation, including all trials, was 35 minutes (30 to 40 minutes). An increase in the FOUR Score (Full Outline of UnResponsiveness score) was observed in 50% of IS-trials by three (two to four) points (P < 0.05) (Figure 1A).

Bottom Line: Daily interruption of sedation (IS) has been implemented in 30 to 40% of intensive care units worldwide and may improve outcome in medical intensive care patients.Little is known about the benefit of IS in acutely brain-injured patients.This prospective observational study was performed in a neuroscience intensive care unit in a tertiary-care academic center.

View Article: PubMed Central - HTML - PubMed

ABSTRACT

Introduction: Daily interruption of sedation (IS) has been implemented in 30 to 40% of intensive care units worldwide and may improve outcome in medical intensive care patients. Little is known about the benefit of IS in acutely brain-injured patients.

Methods: This prospective observational study was performed in a neuroscience intensive care unit in a tertiary-care academic center. Twenty consecutive severely brain-injured patients with multimodal neuromonitoring were analyzed for levels of brain lactate, pyruvate and glucose, intracranial pressure (ICP), cerebral perfusion pressure (CPP) and brain tissue oxygen tension (PbtO2) during IS trials.

Results: Of the 82 trial days, 54 IS-trials were performed as interruption of sedation and analgesics were not considered safe on 28 days (34%). An increase in the FOUR Score (Full Outline of UnResponsiveness score) was observed in 50% of IS-trials by a median of three (two to four) points. Detection of a new neurologic deficit occurred in one trial (2%), and in one-third of IS-trials the trial had to be stopped due to an ICP-crisis (> 20 mmHg), agitation or systemic desaturation. In IS-trials that had to be aborted, a significant increase in ICP and decrease in PbtO2 (P < 0.05), including 67% with critical values of PbtO2 < 20 mmHg, a tendency to brain metabolic distress (P < 0.07) was observed.

Conclusions: Interruption of sedation revealed new relevant clinical information in only one trial and a large number of trials could not be performed or had to be stopped due to safety issues. Weighing pros and cons of IS-trials in patients with acute brain injury seems important as related side effects may overcome the clinical benefit.

Show MeSH
Related in: MedlinePlus