Rapid Sequence Intubation in Traumatic Brain-injured Adults

Diagnosis and management of elevated intracranial pressure in the emergency department

BACKGROUND

Elevated intracranial pressure is a devastating complication of catastrophic brain injury. Intracranial hypertension is commonly seen in neurologic injury secondary to traumatic brain injuries. Uncontrolled pressures can lead to permanent neurologic damage, but acute medical management is often overlooked when pursuing surgical management options that may not always be indicated.

DISCUSSION

Traumatic brain injury is the leading cause of death in patients with severe neurologic injury. Diagnosing elevated intracranial pressures is imperative in initiating prompt treatment to reduce secondary central nervous system injury, morbidity, and mortality. Although the initial injury to the brain is typically irreversible, intracranial pressure control can assist in salvaging the remaining brain tissue from additional damage. We will discuss the initial medical and surgical management of traumatic brain injury to prevent further neurologic deterioration and reduce mortality.

CONCLUSION

Recent literature has reported several methods to detect elevated intracranial pressure easily and studies describing multiple treatment modalities. These investigations suggest that early detection and timely treatment of intracranial hypertension are beneficial in reducing mortality.

Effects of intubation technique on intracranial pressure: a cadaveric study

Patients are at risk of increased intracranial pressure (ICP) during manipulation for endotracheal intubation. The aim of this cadaveric study was to quantify this relationship. Five fresh frozen adult cadaveric heads were used. The internal carotid artery (ICA) and internal jugular vein (IJV) were dissected bilaterally. All vessels were occluded on the right side. To mimic central venous pressures, the left IJV was cannulated and filled with water to maintain a pressure of approximately 7 cm H2O. The ICA cannula was attached to an oscillating water pump. Next, an ICP monitor was placed. Normophysiological volumes of water were infused to maintain normal ICP. Baseline ICP and IJV pressures were recorded. The heads were then placed in the sniffing position and in neutral position for nasal intubation, and finally an oral endotracheal tube was placed using standard head/neck maneuvers. The ICP was recorded. Mean baseline ICP was 13 mmHg (range 4-18 mmHg) and mean IJV pressure was 6 cm H2O. In the sniffing position, ICP increased in all specimens by a mean of 5 mmHg. In the neutral position, after intubation, the ICP increased in all specimens by a mean of 3 mmHg. Nasal intubation resulted in an increase in four of the five specimens. The mean increase in ICP with this maneuver was 2 mmHg. We present a cadaveric model of ICP measurement during neck manipulation using intracranial fluid dynamics. The ICP increased consistently. Following clinical studies, physicians involved in intubating patients with concern for raised ICP should change the technique to avoid complications.

Exogenous Ketones and Lactate as a Potential Therapeutic Intervention for Brain Injury and Neurodegenerative Conditions

Metabolic dysfunction is a ubiquitous underlying feature of many neurological conditions including acute traumatic brain injuries and chronic neurodegenerative conditions. A central problem in neurological patients, in particular those with traumatic brain injuries, is an impairment in the utilization of glucose, which is the predominant metabolic substrate in a normally functioning brain. In such patients, alternative substrates including ketone bodies and lactate become important metabolic candidates for maintaining brain function. While the potential neuroprotective benefits of ketosis have been recognized for up to almost a century, the majority of work has focused on the use of ketogenic diets to induce such a state, which is inappropriate in cases of acute disease due to the prolonged periods of time (i.e., weeks to months) required for the effects of a ketogenic diet to be seen. The following review seeks to explore the neuroprotective effects of exogenous ketone and lactate preparations, which have more recently become commercially available and are able to induce a deep ketogenic response in a fraction of the time. The rapid response of exogenous preparations makes their use as a therapeutic adjunct more feasible from a clinical perspective in both acute and chronic neurological conditions. Potentially, their ability to globally moderate long-term, occult brain dysfunction may also be relevant in reducing lifetime risks of certain neurodegenerative conditions. In particular, this review explores the association between traumatic brain injury and contusion-related dementia, assessing metabolic parallels and highlighting the potential role of exogenous ketone and lactate therapies.

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.

Rehabilitation effect of rTMS combined with cognitive training on cognitive impairment after traumatic brain injury

OBJECTIVE

To innvestigate the rehabilitation effects of repetitive transcranial magnetic stimulation (rTMS) combined with cognitive training on cognitive impairment in patients with traumatic brain injury (TBI) by using multimodal magnetic resonance imaging.

METHODS

Clinical data of 166 patients with cognitive impairment after TBI were retrospectively analyzed. The patients were assigned into an observation group and a control group according to different treatment methods, with 83 cases in each group. The observation group was given rTMS + cognitive training, and the control group was given cognitive training only. The changes in GCS score, the Cho/Cr, Cho/NAA and NAA/Cr ratios examined by MRSI, the score of cognitive impairment, the grading of cognitive impairment, and the changes in modified Barthel index were observed and compared between the two groups.

RESULTS

The GCS score, and the ratios of Cho/Cr, Cho/NAA and NAA/Cr after treatment were better than those before treatment in both groups and were lower in the observation group compared with the control group (all P<0.05). The score and grading of cognitive impairment as well as modified Barthel index after treatment were all significantly better in the observation group than in the control group (all P<0.05).

CONCLUSION

rTMS can improve the rehabilitation effect on cognitive impairment in patients after TBI and is recommended for clinical use.

Pharmacological Management of Severe Neuropathic Pain in a Case of Eosinophilic Meningitis Related to Angiostrongylus cantonensis

Angiostrongylus cantonensis, the rat lungworm, is the most common infectious cause of eosinophilic meningitis and can be fatal. The parasite can be found throughout Southeast Asia and Pacific Islands and the global distribution is expanding. We present the case of a fourteen-year-old female who had previously traveled to Hawaii and developed severe neuropathic pain related to A. cantonensis infection refractory to gabapentin and pregabalin monotherapy, who was eventually managed with an ultralow dose ketamine infusion, methadone, and serotonin-norepinephrine reuptake inhibitor.