Comparative tolerability of sedative agents in head-injured adults

Are GABAergic drugs beneficial in providing neuroprotection after traumatic brain injuries? A comprehensive literature review of preclinical studies

Traumatic brain injuries (TBI) caused by physical impact to the brain can adversely impact the welfare and well-being of the affected individuals. One of the leading causes of mortality and dysfunction in the world, TBI is a major public health problem facing the human community. Drugs that target GABAergic neurotransmission are commonly used for sedation in clinical TBI yet their potential to cause neuroprotection is unclear. In this paper, I have performed a rigorous literature review of the neuroprotective effects of drugs that increase GABAergic currents based on the results reported in preclinical literature. The drugs covered in this review include the following: propofol, benzodiazepines, barbiturates, isoflurane, and other drugs that are agonists of GABA_A receptors. A careful review of numerous preclinical studies reveals that these drugs fail to produce any neuroprotection after a primary impact to the brain. In numerous circumstances, they could be detrimental to neuroprotection by increasing the size of the contusional brain tissue and by severely interfering with behavioral and functional recovery. Therefore, anesthetic agents that work by enhancing the effect of neurotransmitter GABA should be administered with caution of TBI patients until a clear and concrete picture of their neuroprotective efficacy emerges in the clinical literature.

Comparison of Midazolam and Propofol Infusion to Suppress Stress Response in Patients With Severe TBII: A Prospective, Randomized Controlled Trial

Objective

The stress response following traumatic brain injury (TBI) is a preventable cause of secondary brain injury. This can be prevented using sedation in the intensive care unit (ICU). To date, the choice of sedative agent for preventing stress response is not well-studied in literature.

Methods

This prospective randomized controlled trial included 60 patients with severe TBI admitted to ICU. The patients were randomized into 2 study groups according to the choice of sedation: propofol (group I) and midazolam infusion (group II). The serum cortisol was measured as the primary outcome at admission to ICU and 48 hours following sedation infusion. The baseline Glasgow coma scale, hemodynamic, optic nerve sheath diameter (ONSD), and computed tomography scan findings were noted at admission. Glasgow outcome scale (GOS) was measured as a neurological outcome at discharge from ICU.

Results

There was a statistically significant reduction in serum cortisol level in both the study groups (Δ cortisol, p-value=134.91 (50.5,208.2), 0.00 and 118.8 (42.6,160.4), 0.00, in group I and II, respectively). Serum cortisol levels were comparable among both groups at baseline and 48 hours. Similarly, there was a statistically significant difference in ONSD in both groups, but there was no difference in ONSD value between the groups at 48 hours. The GOS was also similar in both groups at discharge from ICU.

Conclusion

The study demonstrated a similar reduction in serum cortisol levels following 48 hours of propofol or midazolam infusion in patients with severe TBI.

Early sedation in traumatic brain injury: a multicentre international observational study

Objectives: We aimed to investigate the use of sedation in patients with severe traumatic brain injury (TBI), focusing on the choice of sedative agent, dose, duration, and their association with clinical outcomes. Design: Multinational, multicentre, retrospective observational study. Settings: 14 trauma centres in Europe, Australia and the United Kingdom. Participants: A total of 262 adult patients with severe TBI and intracranial pressure monitoring. Main outcome measures: We described how sedative agents were used in this population. The primary outcome was 60-day mortality according to the use of different sedative agents. Secondary outcomes included intensive care unit and hospital length of stay, and the Extended Glasgow Outcome Scale at hospital discharge. Results: Propofol and midazolam were the most commonly used sedatives. Propofol was more common than midazolam as first line therapy (35.4% v 25.6% respectively). Patients treated with propofol had similar Acute Physiology and Chronic Health Evaluation (APACHE) II and International Mission for Prognosis and Analysis of Clinical Trials in Traumatic Brain Injury (IMPACT) scores to patients treated with midazolam, but lower Injury Severity Score (ISS) (median, 26 [IQR, 22-38] v 34 [IQR, 26-44]; P = 0.001). The use of propofol was more common in heavier patients, and midazolam use was strongly associated with opioid co-administration (OR, 12.9; 95% CI, 3.47-47.95; P < 0.001). Sixty-day mortality and hospital mortality were predicted by a higher IMPACT score (P < 0.001) and a higher ISS (P < 0.001), but, after adjustment, were not related to the choice of sedative agent. Conclusions: Propofol was used more often than midazolam, and large doses were common for both sedatives. The first choice was highly variable, was affected by injury severity, and was not independently associated with 60-day mortality.

Level of sedation in critically ill adult patients: a protocol for a systematic review with meta-analysis and trial sequential analysis

INTRODUCTION

It is standard of care to provide sedation to critically ill patients to reduce anxiety, discomfort and promote tolerance of mechanical ventilation. Given that sedatives can have differing effects based on a variety of patient and pharmacological characteristics, treatment approaches are largely based on targeting the level of sedation. The benefits of differing levels of sedation must be balanced against potential adverse effects including haemodynamic instability, causing delirium, delaying awakening and prolonging the time of mechanical ventilation and intensive care stay. This systematic review with meta-analysis aims to investigate the current evidence and compare the effects of differing sedation levels in adult critically ill patients.

METHODS AND ANALYSES

We will conduct a systematic review based on searches of preidentified major medical databases (eg, MEDLINE, EMBASE, CENTRAL) and clinical trial registries from their inception onwards to identify trials meeting inclusion criteria. We will include randomised clinical trials comparing any degree of sedation with no sedation and lighter sedation with deeper sedation for critically ill patients admitted to the intensive care unit. We will include aggregate data meta-analyses and trial sequential analyses. Risk of bias will be assessed with domains based on the Cochrane risk of bias tool. An eight-step procedure will be used to assess if the thresholds for clinical significance are crossed, and the certainty of the evidence will be assessed using Grades of Recommendations, Assessment, Development and Evaluation.

ETHICS AND DISSEMINATION

No formal approval or review of ethics is required as individual patient data will not be included. This systematic review has the potential to highlight (1) whether one should believe sedation to be beneficial, harmful or neither in critically ill adults; (2) the existing knowledge gaps and (3) whether the recommendations from guidelines and daily clinical practice are supported by current evidence. These results will be disseminated through publication in a peer-reviewed journal.

Effect of Dezocine on Hemodynamic Indexes of Postoperative Patients With Traumatic Brain Injury (TBI)---A Pilot Study

Background: Due to pain and other stimuli, patients with traumatic brain injury (TBI) after surgery show excited Sympathetic Nervous system, increased intracranial pressure, brain tissue swelling, intracranial hemorrhage, or reduced cerebral perfusion pressure, seriously threatening the life and prognosis of patients. The effect of dezocine on postoperative analgesia after TBI remains largely undetermined.

Objective: In the present study, we aimed to investigate the efficacy and safety of dezocine in postoperative sedative and analgesic therapy for a craniocerebral injury.

Methods: The patients were randomly divided into two groups (n = 40) as follows: dezocine group (Group A) and control group (Group B). Electrocardiography (ECG), heart rate (HR), blood pressure, and oxygen saturation (SpO₂) were routinely monitored after postoperative return to the ward. Both groups were initially injected with 5 mg·kg⁻¹·h⁻¹ propofol to maintain sedation, and the dose was adjusted according to the patient’s condition. Vital signs of patients were recorded at T1 (the base value when arriving at the ward), T2 (before the sedative agent was used) and T3 (use of dezocine or 0.9% saline solution for 8 h), T4 (use for 1 day), T5 (use for 3 days), T6 (termination of dezocine or 0.9% saline solution for 1 day), and T7 (termination for 3 days), and mean arterial pressure (MAP) and HR values were also recorded. The total amount of propofol, total fluid inflow, blood loss, and urine output were recorded within 24 h. The number of coughs of each patient was recorded within 1 day after entry, and the incidence of adverse events, such as insufficient oxygenation (SaO₂ reduced by about 5% from the base value), hypotension, bradycardia, laryngospasm, bronchospasm, and so on, was assessed.

Results: Compared with the control group (group B), the hemodynamics of the dezocine group (group A) was more stable, there were significant differences in MAP and HR (p < 0.05), and the stress response was milder. The total amount of propofol, total fluid inflow, blood loss, and urine volume of the dezocine group were significantly improved compared with the control group (p < 0.05). Moreover, the incidence of adverse events, such as cough, in the dezocine group was significantly reduced compared with the control group (p < 0.05).

Conclusions: Dezocine, as a drug with a strong analgesic effect and obvious sedative effect, was suitable for craniocervical surgery, and it could significantly improve the stability of airway and hemodynamics in TBI patients during anesthesia recovery.

Posttraumatic midazolam administration does not influence brain damage after experimental traumatic brain injury

BACKGROUND

The benzodiazepine midazolam is a γ-aminobutyric acid (GABA)-A receptor agonist frequently used for sedation or stress control in patients suffering from traumatic brain injury (TBI). However, experimental studies on benzodiazepines have reported divergent results, raising concerns about its widespread use in patients. Some studies indicate that benzodiazepine-mediated potentiation of GABAergic neurotransmission is detrimental in brain-injured animals. However, other experimental investigations demonstrate neuroprotective effects, especially in pretreatment paradigms. This study investigated whether single-bolus midazolam administration influences secondary brain damage post-TBI.

METHODS

Two different midazolam dosages (0.5 and 5 mg/kg BW), a combination of midazolam and its competitive antagonist flumazenil, or vehicle solution (NaCl 0.9%) was injected intravenously to mice 24 h after experimental TBI induced by controlled cortical impact. Mice were evaluated for neurological and motor deficits using a 15-point neuroscore and the rotarod test. Histopathological brain damage and mRNA expression of inflammatory marker genes were analyzed using quantitative polymerase chain reaction three days after insult.

RESULTS

Histological brain damage was not affected by posttraumatic midazolam administration. Midazolam impaired functional recovery, and this effect could not be counteracted by administering the midazolam antagonist flumazenil. An increase in IL-1β mRNA levels due to postinjury application of midazolam was reversible by flumazenil administration. However, other inflammatory parameters were not affected.

CONCLUSIONS

This study merely reports minor effects of a postinjury midazolam application. Further studies focusing on a time-dependent analysis of posttraumatic benzodiazepine administration are required.

Anesthetic management of unruptured intracranial aneurysms: a qualitative systematic review

Intracranial aneurysms (IA) occur in 3-5% of the general population and may require surgical or endovascular obliteration if the patient is symptomatic or has an increased risk of rupture. These procedures carry an inherent risk of neurological complications, and the outcome can be influenced by the physiological and pharmacological effects of the administered anesthetics. Despite the critical role of anesthetic agents, however, there are no current studies to systematically assess the intraoperative anesthetic risks, benefits, and outcome effects in this population. In this systematic review of the literature, we carefully examine the existing evidence on the risks and benefits of common anesthetic agents during IA obliteration, their physiological and clinical characteristics, and effects on neurological outcome. The initial search strategy captured a total of 287 published studies. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, 28 studies were included in the final report. Our data showed that both volatile and intravenous anesthetics are commonly employed, without evidence that either is superior. Although no specific anesthetic regimens are promoted, their unique neurological, cardiovascular, and physiological properties may be critical to the outcome in vulnerable patients. In particular, patients at risk for perioperative ischemia may benefit from timely administration of anesthetic agents with neuroprotective properties and optimization of their physiological parameters. Further studies are warranted to examine if these anesthetic regimens can reduce the risk of neurological injury and improve the overall outcome in these patients.

Association Between Processed Electroencephalogram-Based Objectively Measured Depth of Sedation and Cerebrovascular Response: A Systematic Scoping Overview of the Human and Animal Literature

Background: Current understanding of the impact that sedative agents have on neurovascular coupling, cerebral blood flow (CBF) and cerebrovascular response remains uncertain. One confounding factor regarding the impact of sedative agents is the depth of sedation, which is often determined at the bedside using clinical examination scoring systems. Such systems do not objectively account for sedation depth at the neurovascular level. As the depth of sedation can impact CBF and cerebral metabolism, the need for objective assessments of sedation depth is key. This is particularly the case in traumatic brain injury (TBI), where emerging literature suggests that cerebrovascular dysfunction dominates the burden of physiological dysfunction. Processed electroencephalogram (EEG) entropy measures are one possible solution to objectively quantify depth of sedation. Such measures are widely employed within anesthesia and are easy to employ at the bedside. However, the association between such EEG measures and cerebrovascular response remains unclear. Thus, to improve our understanding of the relationship between objectively measured depth of sedation and cerebrovascular response, we performed a scoping review of the literature.

Methods: A systematically conduced scoping review of the existing literature on objectively measured sedation depth and CBF/cerebrovascular response was performed, search multiple databases from inception to November 2020. All available literature was reviewed to assess the association between objective sedation depth [as measured through processed electroencephalogram (EEG)] and CBF/cerebral autoregulation.

Results: A total of 13 articles, 12 on adult humans and 1 on animal models, were identified. Initiation of sedation was found to decrease processed EEG entropy and CBF/cerebrovascular response measures. However, after this initial drop in values there is a wide range of responses in CBF seen. There were limited statistically reproduceable associations between processed EEG and CBF/cerebrovascular response. The literature body remains heterogeneous in both pathological states studied and sedative agent utilized, limiting the strength of conclusions that can be made.

Conclusions: Conclusions about sedation depth, neurovascular coupling, CBF, and cerebrovascular response are limited. Much further work is required to outline the impact of sedation on neurovascular coupling.

Tier-three therapies for refractory intracranial hypertension in adult head trauma

Refractory intracranial hypertension after traumatic brain injury (TBI) is defined as recurrent increase of intracranial pressure (ICP) above 20-22 mmHg for sustained period of time (10-15 min), despite conventional therapies, such as osmotic therapy, cerebral spinal fluid drainage and mild hyperventilation. As such, more aggressive treatments should be taken into consideration. In particular, therapeutic hypothermia, barbiturates administration and decompressive craniectomy are considered as tier-three or "salvage" interventions, as they have shown to be able to control refractory hypertension, but are also associated with an increased risk of significant side effects. The aim of this review is therefore to describe the evidence supporting the use of these tier-three therapies in the management of refractory intracranial hypertension in TBI patients.

A One-Day Prospective National Observational Study on Sedation-Analgesia of Patients with Brain Injury in French Intensive Care Units: The SEDA-BIP-ICU (Sedation-Analgesia in Brain Injury Patient in ICU) Study

BACKGROUND

Sedation/analgesia is a daily challenge faced by intensivists managing patients with brain injury (BI) in intensive care units (ICUs). The optimization of sedation in patients with BI presents particular challenges. A choice must be made between the potential benefit of a rapid clinical evaluation and the potential exacerbation of intracranial hypertension in patients with impaired cerebral compliance. In the ICU, a pragmatic approach to the use of sedation/analgesia, including the optimal titration, management of multiple drugs, and use of any type of brain monitor, is needed. Our research question was as follows: the aim of the study is to identify what is the current daily practice regarding sedation/analgesia in the management of patients with BI in the ICU in France?

METHODS

This study was composed of two parts. The first part was a descriptive survey of sedation practices and characteristics in 30 French ICUs and 27 academic hospitals specializing in care for patients with BI. This first step validates ICU participation in data collection regarding sedation-analgesia practices. The second part was a 1-day prospective cross-sectional snapshot of all characteristics and prescriptions of patients with BI.

RESULTS

On the study day, among the 246 patients with BI, 106 (43%) had a brain monitoring device and 74 patients (30%) were sedated. Thirty-nine of the sedated patients (53%) suffered from intracranial hypertension, 14 patients (19%) suffered from agitation and delirium, and 7 patients (9%) were sedated because of respiratory failure. Fourteen patients (19%) no longer had a formal indication for sedation. In 60% of the sedated patients, the sedatives were titrated by nurses based on sedation scales. The Richmond Agitation Sedation Scale was used in 80% of the patients, and the Behavioral Pain Scale was used in 92%. The common sedatives and opioids used were midazolam (58.1%), propofol (40.5%), and sufentanil (67.5%). The cerebral monitoring devices available in the participating ICUs were transcranial Doppler ultrasound (100%), intracranial and intraventricular pressure monitoring (93.3%), and brain tissue oxygenation (60%). Cerebral monitoring by one or more monitoring devices was performed in 62% of the sedated patients. This proportion increased to 74% in the subgroup of patients with intracranial hypertension, with multimodal cerebral monitoring in 43.6%. The doses of midazolam and sufentanil were lower in sedated patients managed based on a sedation/analgesia scale.

CONCLUSIONS

Midazolam and sufentanil are frequently used, often in combination, in French ICUs instead of alternative drugs. In our study, cerebral monitoring was performed in more than 60% of the sedated patients, although that proportion is still insufficient. Future efforts should stress the use of multiple monitoring modes and adherence to the indications for sedation to improve care of patients with BI. Our study suggests that the use of sedation and analgesia scales by nurses involved in the management of patients with BI could decrease the dosages of midazolam and sufentanil administered. Updated guidelines are needed for the management of sedation/analgesia in patients with BI.

Brain Herniation and Intracranial Hypertension

This article introduces the basic concepts of intracranial physiology and pressure dynamics. It also includes discussion of signs and symptoms and examination and radiographic findings of patients with acute cerebral herniation as a result of increased as well as decreased intracranial pressure. Current best practices regarding medical and surgical treatments and approaches to management of intracranial hypertension as well as future directions are reviewed. Lastly, there is discussion of some of the implications of critical medical illness (sepsis, liver failure, and renal failure) and treatments thereof on causation or worsening of cerebral edema, intracranial hypertension, and cerebral herniation.

Is jugular bulb oximetry monitoring associated with outcome in out of hospital cardiac arrest patients?

Cerebral protection against secondary hypoxic-ischemic brain injury is a key priority area in post-resuscitation intensive care management in survivors of cardiac arrest. Nevertheless, the current understanding of the incidence, diagnosis and its’ impact on neurological outcome remains undetermined. The aim of this study was to evaluate jugular bulb oximetry as a potential monitoring modality to detect the incidences of desaturation episodes during post-cardiac arrest intensive care management and to evaluate their subsequent impact on neurological outcome. We conducted a prospective, observational study in unconscious adult patients admitted to the intensive care unit who had successful resuscitation following out of hospital cardiac arrest of presumed cardiac causes. All the patients were treated as per European Resuscitation Council 2015 guidelines and they received jugular bulb catheter. Jugular bulb oximetry measurements were performed at six hourly intervals. The neurological outcomes were evaluated on 90th day after the cardiac arrest by cerebral performance categories scale. Forty patients met the eligibility criteria. Measurements of jugular venous oxygen saturation were performed for 438 times. Altogether, we found 2 incidences of jugular bulb oxygen saturation less than 50% (2/438; 0.46%), and 4 incidences when it was less than 55% (4/438; 0.91%). The study detected an association between SjVO₂ and CO₂ (r = 0.26), each 1 kPa increase in CO₂ led to an increase in SjvO₂ by 3.4% + / − 0.67 (p < 0.0001). There was no association between SjvO₂ and PaO₂ or SjvO₂ and MAP. We observed a statistically significant higher mean SjvO₂ (8.82% + / − 2.05, p < 0.0001) in unfavorable outcome group. The episodes of brain hypoxia detected by jugular bulb oxygen saturation were rare during post-resuscitation intensive care management in out of hospital cardiac arrest patients. Therefore, this modality of monitoring may not yield any additional information towards prevention of secondary hypoxic ischemic brain injury in post cardiac arrest survivors. Other factors contributing towards high jugular venous saturation needs to be considered.

Effect of sedative agent selection on morbidity, mortality and length of stay in patients with increase in intracranial pressure

BACKGROUND

To identify the effects of sedative agent selection on morbidity, mortality, and length of stay in patients with suspected increase in intracranial pressure. Recent trends and developments have resulted in changes to medications that were previously utilized as pharmacological adjuncts in the sedation and intubation of patients with suspected increases in intracranial pressure. Medications that were previously considered contraindicated are now being used with increasing regularity without demonstrated safety and effectiveness. The primary objective of this study is to evaluate and compare the use of Ketamine as an induction agent for patients with increased intracranial pressure. The secondary objective was to evaluate and compare the use of Etomidate, Midazolam, and Ketamine in patients with increased intracranial pressure.

METHODS

We conducted a retrospective chart review of patients transported to our facility with evidence of intracranial hypertension that were intubated before trauma center arrival. Patients were identified during a 22-month period from January 2014 to October 2015. Goals were to evaluate the impact of sedative agent selection on morbidity, mortality, and length of stay.

RESULTS

During the review 148 patients were identified as meeting inclusion criteria, 52 were excluded due to incomplete data. Of those the patients primarily received; Etomidate, Ketamine, and Midazolam. Patients in the Ketamine group were found to have a lower mortality rate after injury stratification.

CONCLUSION

Patients with intracranial hypertension should not be excluded from receiving Ketamine during intubation out of concern for worsening outcomes.

Optimizing sedation in patients with acute brain injury

Daily interruption of sedative therapy and limitation of deep sedation have been shown in several randomized trials to reduce the duration of mechanical ventilation and hospital length of stay, and to improve the outcome of critically ill patients. However, patients with severe acute brain injury (ABI; including subjects with coma after traumatic brain injury, ischaemic/haemorrhagic stroke, cardiac arrest, status epilepticus) were excluded from these studies. Therefore, whether the new paradigm of minimal sedation can be translated to the neuro-ICU (NICU) is unclear. In patients with ABI, sedation has ‘general’ indications (control of anxiety, pain, discomfort, agitation, facilitation of mechanical ventilation) and ‘neuro-specific’ indications (reduction of cerebral metabolic demand, improved brain tolerance to ischaemia). Sedation also is an essential therapeutic component of intracranial pressure therapy, targeted temperature management and seizure control. Given the lack of large trials which have evaluated clinically relevant endpoints, sedative selection depends on the effect of each agent on cerebral and systemic haemodynamics. Titration and withdrawal of sedation in the NICU setting has to be balanced between the risk that interrupting sedation might exacerbate brain injury (e.g. intracranial pressure elevation) and the potential benefits of enhanced neurological function and reduced complications. In this review, we provide a concise summary of cerebral physiologic effects of sedatives and analgesics, the advantages/disadvantages of each agent, the comparative effects of standard sedatives (propofol and midazolam) and the emerging role of alternative drugs (ketamine). We suggest a pragmatic approach for the use of sedation-analgesia in the NICU, focusing on some practical aspects, including optimal titration and management of sedation withdrawal according to ABI severity.

Pharmacological interventions in traumatic brain injury: Can we rely on systematic reviews for evidence?

INTRODUCTION

Providing current, reliable and evidence based information for clinicians and researchers in a synthesised and summarised way can be challenging particularly in the area of traumatic brain injury where a vast number of reviews exists. These reviews vary in their methodological quality and are scattered across varying sources. In this paper, we present an overview of systematic reviews that evaluate the pharmacological interventions in traumatic brain injury (TBI). By doing this, we aim to evaluate the existing evidence for improved outcomes in TBI with pharmacological interventions, and to identify gaps in the literature to inform future research.

METHODS

We searched the Neurotrauma Evidence Map on systematic reviews relating to pharmacological interventions for managing TBI in acute phase. Two reviewers independently screened search results and appraised each systematic review using the validated AMSTAR tool and extracted data from the review.

RESULTS

A total of 288 systematic reviews relating to TBI were available on the Neurotrauma Evidence Map at the time of this study. We identified 19 systematic reviews on pharmacological management for acute TBI with publications dates ranging from 1998 to 2014. The studies were of varying methodological quality, with a mean AMSTAR score of 7.78 (range 2-11].

CONCLUSION

The evidence from high quality systematic reviews show that there is currently insufficient evidence for the use of magnesium, monoaminergic and dopamine agonists, progesterone, aminosteroids, excitatory amino acid inhibitors, haemostatic and antifibrinolytic drugs in TBI. Anti-convulsants are only effective in reducing early seizures with no significant difference between phenytoin and leviteracetam. There is no difference between propofol and midazolam for sedation in TBI patients and ketamine may not cause increased ICP. Overviews of systematic review provide informative and powerful summaries of evidence based research.

Levels of F2-isoprostanes, F4-neuroprostanes, and total nitrate/nitrite in plasma and cerebrospinal fluid of patients with traumatic brain injury

Several events occurring during the secondary damage of traumatic brain injury (TBI) can cause oxidative stress. F(2)-isoprostanes (F(2)-IsoPs) and F(4)-neuroprostanes (F(4)-NPs) are specific lipid peroxidation markers generated from arachidonic acid and docosahexaenoic acid, respectively. In this study, we evaluated oxidative stress in patients with moderate and severe TBI. Since sedatives are routinely used to treat TBI patients and propofol has been considered an antioxidant, TBI patients were randomly treated with propofol or midazolam for 72 h postoperation. We postoperatively collected cerebrospinal fluid (CSF) and plasma from 15 TBI patients for 6-10 d and a single specimen of CSF or plasma from 11 controls. Compared with the controls, the TBI patients exhibited elevated levels of F(2)-IsoPs and F(4)-NPs in CSF throughout the postsurgery period regardless of the sedative used. Compared with the group of patients who received midazolam, those who received propofol exhibited markedly augmented levels of plasma F(2)-IsoPs, which were associated with higher F(4)-NPs levels and lower total nitrate/nitrite levels in CSF early in the postsurgery period. Furthermore, the higher CSF F(2)-IsoPs levels correlated with 6-month and 12-month worse outcomes, which were graded according to the Glasgow Outcome Scale. The results demonstrate enhanced oxidative damage in the brain of TBI patients and the association of higher CSF levels of F(2)-IsoPs with a poor outcome. Moreover, propofol treatment might promote lipid peroxidation in the circulation, despite possibly suppressing nitric oxide or peroxynitrite levels in CSF, because of the increased loading of the lipid components from the propofol infusion.

Ketamine does not increase intracranial pressure compared with opioids: meta-analysis of randomized controlled trials

BACKGROUND

Ketamine is traditionally avoided in sedation management of patients with risk of intracranial hypertension. However, results from many clinical trials contradict this concern. We critically analyzed the published data of the effects of ketamine on intracranial pressure (ICP) and other cerebral hemodynamics to determine whether ketamine was safe for patients with hemodynamic instability and brain injuries.

METHODS

We systematically searched the online databases of PubMed, Medline, Embase, Current Controlled Trials, and Cochrane Central (last search performed on January 15, 2014). Trial characteristics and outcomes were independently extracted by two assessors (Xin Wang, Xibing Ding). For continuous data, mean differences (MD) were formulated. If the P value of the chi-square test was >0.10 or I(2) <50%, a fixed-effects model was used; otherwise, the random effects model was adopted.

RESULTS

Five trials (n = 198) met the inclusion criteria. Using ICP levels within the first 24 h of ketamine administration as the main outcome, the use of ketamine leads to the same ICP levels as opioids [MD = 1.94; 95% confidence interval (95% CI), -2.35, 6.23; P = 0.38]. There were no significant differences in mean arterial pressure values between the two groups (MD = 0.99; 95% CI, -2.24, 4.22; P = 0.55). Ketamine administration was also comparable with opioids in the maintenance of cerebral perfusion pressure (MD = -1.07; 95% CI, -7.95, 5.8; P = 0.76).

CONCLUSIONS

The results of this study suggest that ketamine does not increase ICP compared with opioids. Ketamine provides good maintenance of hemodynamic status. Clinical application of ketamine should not be discouraged on the basis of ICP-related concerns.

Comparison of the safety and efficacy of propofol with midazolam for sedation of patients with severe traumatic brain injury: a meta-analysis

OBJECTIVE

To perform a meta-analysis to compare the safety and efficacy of propofol with midazolam for sedation of patients with severe traumatic brain injury.

MATERIALS AND METHODS

Studies were included in the meta-analysis if they met the following criteria: randomized controlled trial of sedative-hypnotic agents including propofol and midazolam; patients had severe traumatic brain injury; the primary outcome was the Glasgow Outcome Scale score; secondary outcomes included mortality, therapeutic failure, intracranial pressure, and cerebral perfusion pressure. The data were analyzed using software for meta-analysis.

RESULTS

Seven relevant studies were identified. Three of these studies were excluded: one was a single-arm study, one compared morphine and propofol, and for one the full text article could not be obtained. The remaining 4 studies were included in the meta-analysis. The results of the meta-analysis showed that propofol and midazolam have similar effects on the Glasgow Outcome Scale score, mortality, intracranial pressure, and cerebral perfusion pressure.

CONCLUSION

Our meta-analysis of 4 studies showed that there are no important differences between propofol and midazolam when administered to provide sedation for patients with severe traumatic brain injury. Further randomized, controlled trials comparing propofol with midazolam for sedation of such patients are needed.

The emerging use of ketamine for anesthesia and sedation in traumatic brain injuries

Traditionally, the use of ketamine for patients with traumatic brain injuries is contraindicated due to the concern of increasing intracranial pressure (ICP). These concerns, however, originated from early studies and case reports that were inadequately controlled and designed. Recently, the concern of using ketamine in these patients has been challenged by a number of published studies demonstrating that the use of ketamine was safe in these patients. This article reviews the current literature in regards to using ketamine in patients with traumatic brain injuries in different clinical settings associated with anesthesia, as well as reviews the potential mechanisms underlying the neuroprotective effects of ketamine. Studies examining the use of ketamine for induction, maintenance, and sedation in patients with TBI have had promising results. The use of ketamine in a controlled ventilation setting and in combination with other sedative agents has demonstrated no increase in ICP. The role of ketamine as a neuroprotective agent in humans remains inconclusive and adequately powered; randomized controlled trials performed in patients undergoing surgery for traumatic brain injury are necessary.

Sedation in traumatic brain injury

Several different classes of sedative agents are used in the management of patients with traumatic brain injury (TBI). These agents are used at induction of anaesthesia, to maintain sedation, to reduce elevated intracranial pressure, to terminate seizure activity and facilitate ventilation. The intent of their use is to prevent secondary brain injury by facilitating and optimising ventilation, reducing cerebral metabolic rate and reducing intracranial pressure. There is limited evidence available as to the best choice of sedative agents in TBI, with each agent having specific advantages and disadvantages. This review discusses these agents and offers evidence-based guidance as to the appropriate context in which each agent may be used. Propofol, benzodiazepines, narcotics, barbiturates, etomidate, ketamine, and dexmedetomidine are reviewed and compared.

Sedation for critically ill adults with severe traumatic brain injury: a systematic review of randomized controlled trials

OBJECTIVES

To summarize randomized controlled trials on the effects of sedative agents on neurologic outcome, mortality, intracranial pressure, cerebral perfusion pressure, and adverse drug events in critically ill adults with severe traumatic brain injury.

DATA SOURCES

PubMed, MEDLINE, EMBASE, the Cochrane Database, Google Scholar, two clinical trials registries, personal files, and reference lists of included articles.

STUDY SELECTION

Randomized controlled trials of propofol, ketamine, etomidate, and agents from the opioid, benzodiazepine, α-2 agonist, and antipsychotic drug classes for management of adult intensive care unit patients with severe traumatic brain injury.

DATA EXTRACTION

In duplicate and independently, two investigators extracted data and evaluated methodologic quality and results.

DATA SYNTHESIS

Among 1,892 citations, 13 randomized controlled trials enrolling 380 patients met inclusion criteria. Long-term sedation (≥24 hrs) was addressed in six studies, whereas a bolus dose, short infusion, or doubling of plasma drug concentration was investigated in remaining trials. Most trials did not describe baseline traumatic brain injury prognostic factors or important cointerventions. Eight trials possibly or definitely concealed allocation and six were blinded. Insufficient data exist regarding the effects of sedative agents on neurologic outcome or mortality. Although their effects are likely transient, bolus doses of opioids may increase intracranial pressure and decrease cerebral perfusion pressure. In one study, a long-term infusion of propofol vs. morphine was associated with a reduced requirement for intracranial pressure-lowering cointerventions and a lower intracranial pressure on the third day. Trials of propofol vs. midazolam and ketamine vs. sufentanil found no difference between agents in intracranial pressure and cerebral perfusion pressure.

CONCLUSIONS

This systematic review found no convincing evidence that one sedative agent is more efficacious than another for improvement of patient-centered outcomes, intracranial pressure, or cerebral perfusion pressure in critically ill adults with severe traumatic brain injury. High bolus doses of opioids, however, have potentially deleterious effects on intracranial pressure and cerebral perfusion pressure. Adequately powered, high-quality, randomized controlled trials are urgently warranted.

The role of the emergency pharmacist in trauma resuscitation

The clinical pharmacist in the emergency department is now commonly incorporated as a member of the emergency department trauma team. As such, the emergency pharmacist needs to have detailed knowledge of the pharmacotherapy of resuscitation and be able to apply the skills needed to function as a valuable member of this team. In addition to the traditional skills of the discipline of clinical pharmacy, the emergency pharmacist must be familiar with the intricacies of treating life-threatening injuries in an emergent setting and be able to anticipate the direction of the patient's care. The ability to provide valuable pharmacological interventions throughout the resuscitation and stabilization process requires familiarity with the process of resuscitation, including rapid sequence induction, analgesia and sedation, seizure prophylaxis, appropriate antibiotic and tetanus prophylaxis, intracranial pressure control, hemodynamic stabilization, and any other specific drug therapy that the clinical situation demands. This article discusses the aforementioned pharmacotherapeutic topics and describes the role of the Emergency Pharmacist on the ED trauma team.

Multicenter evaluation of propofol for head-injured patients in Taiwan

BACKGROUND

The present study was a multicenter, retrospective study which aimed to evaluate the efficacy of propofol, a new choice of pharmacotherapy in head-injured patients.

METHODS

Head-injured patients admitted to 3 hospitals during the period from January 2003 to December 2004 were included in this clinical trial. Data on patients' demographics, laboratory data, GCS score, ICP, CPP, concurrent medications, and therapeutic outcomes were collected.

RESULTS

Among the 104 patients included, only 44 were given propofol. The average age was 40.8 +/- 22 years for all patients, with 41.91 +/- 20.41 and 43.48 +/- 23.19 years for the propofol group and nonpropofol group, respectively (P=.097). There was no significant difference in baseline GCS score between the 2 groups (5.86 +/- 1.84 vs 5.66 +/- 1.59, P=.729). Mean ICP for the first 3 days in the ICU was 17.23 +/- 9.0 mm Hg in the propofol group and 33.19 +/- 32.56 in the nonpropofol group, respectively (P=.017). Mean CPP for the first 5 days in the ICU was 71.10 +/- 15.32 mm Hg in the propofol group and 43.20 +/- 29.92 mm Hg in the nonpropofol group (P<.001). A higher survival rate was found in the propofol group (81.8% vs 46.7%, P<.001).

CONCLUSIONS

The present study demonstrated that propofol improved the outcome in recovery phase of head-injured patients.

Ketamine for rapid sequence induction in patients with head injury in the emergency department

OBJECTIVE

To examine the evidence regarding the use of ketamine for induction of anaesthesia in patients with head injury in the ED.

METHOD

A literature review using the key words ketamine, head injury and intracranial pressure.

RESULTS

Advice from early literature guiding against the use of ketamine in head injury has been met with widespread acceptance, as reflected by current practice. That evidence is conflicting and inconclusive in regards to the safety of using ketamine in head injury. A review of the literature to date suggests that ketamine could be a safe and useful addition to our available treatment modalities. The key to this argument rests on specific pharmacological properties of ketamine, and their effects on the cerebral haemodynamics and cellular physiology of brain tissue that has been exposed to traumatic injury.

CONCLUSION

In the modern acute management of head-injured patients, ketamine might be a suitable agent for induction of anaesthesia, particularly in those patients with potential cardiovascular instability.

Managing head injured patients

PURPOSE OF REVIEW

In this article we aim to review the recent literature concerning the management of traumatic brain injury patients, summarize the main findings, and discuss the impact of these findings on clinical practice.

RECENT FINDINGS

Several authors have focused on the development of more reliable and informative tools to predict outcome in traumatic brain injury as well as refining the definition of cerebral ischemia in last year's literature. The validity of the current cerebral perfusion pressure management guidelines has also come under scrutiny. It appears that a one size fits all therapy is not a suitable approach for traumatic brain injury patients. An individualized approach, depending on the integrity of pressure autoregulation mechanisms, would be more advisable. Clinical trials investigating brain protective treatments in head injured patients have been disappointing so far. Increasing the homogeneity of patients entering brain protective studies might be an answer. Finally, the use of hyperoxia as well as factors contributing to secondary brain injury such as the occurrence of hyperthermia, with or without an infectious process, have been assessed in head injury patients.

SUMMARY

The key term for the management of traumatic brain injury patients in the early twenty-first century will clearly be 'individualized therapy'. The search of an ideal cerebral perfusion pressure target that would fit every head-injured patients is a utopia. More energy should be focused on the development of reliable tools for outcome prediction and outcome assessment for traumatic brain injured patients. That, and a better targeting of patients entering brain protective trials, should increase the likelihood of demonstrating a significant salvaging effect of a particular treatment in humans.