Perioperative head injury management in the multiply injured trauma patient

Ultrasonic Assessment of Optic Nerve Sheath to Detect Increased Intracranial Pressure

Purpose

Increased intracranial pressure (ICP) is one of the prevalent symptoms of trauma, especially traumatic headache, which requires quick action for the diagnosis and treatment. The optic nerve sheath diameter (ONSD) is a newly proposed technique for the detection of an increase in ICP. The aim of this study was to assess the efficacy of this new diagnostic method in patients with increased ICP induced by trauma.

Methods

This prospective study was conducted between December 2016 and February 2017. The patients with traumatic headache and who had been diagnosed with increased ICP using clinical signs and computed tomography scan were compared to the voluntary healthy group. In each patient, measurements were performed employing ultrasound three times on each eye in an axial region, and the mean of these sizes was obtained as the ONSD.

Results

A total of 112 participants were examined. The mean ONSD measurement of the patients and the voluntary healthy group was 6.01 ± 0.76 and 3.41 ± 0.56 mm in the right eye, 6.11 ± 0.75 and 3.39 ± 0.54 mm in the left eye, and 6.06 ± 0.75 and 4.02 ± 1.07 mm in both sides, respectively. The ONSD in the right and left sides had high and significant correlation in the patients (r = 0.929, P < 0.000) and voluntary healthy (r = 0.630, P < 0.000) group. The mean ONSD of one of the patients was 6.24 ± 0.56 mm, and in another patient with no clinical sign of increased ICP, the mean ONSD was 4.61 ± 0.09 mm.

Conclusions

Ultrasound performed on the diaphragm of the optic nerve with acceptable sensitivity can detect patients with an increase in ICP and can be efficacious in expediting the action needed to reduce ICP. Due to the sensitivity and specificity of the ultrasound and high accuracy of the diameter of optic nerve sheath in detecting increase in ICP, as well as considering the fact that ultrasound is a noninvasive and available technique; it can be performed at the patient's bedside.

Optic nerve sonography: A noninvasive means of detecting raised intracranial pressure in a resource-limited setting

Objective:

The aim was to assess the use of optic nerve sonography (ONS) as a quick, noninvasive diagnostic test tool for detecting raised the intracranial pressure (ICP).

Materials and Methods:

A prospective blinded observational study was conducted at Obafemi Awolowo University Teaching Hospitals Complex (OAUTHC), Ile-Ife, Nigeria. The study population consisted of 160 adult patients referred to the radiology department for cranial computed tomography (CT) scan. There were 80 subjects and 80 controls. Optic nerve sheath diameter (ONSD) was measured by a radiologist using a 7.5 Megahertz ultrasound probe while cranial CT was reviewed by other radiologists blinded to the ONSD.

Results:

Sixty-nine subjects (86.3%) had intracranial space occupying lesions (SOL) with cranial CT confirmed features of increased ICP, mean binocular ONSD of 5.7 ± 0.59 mm while 11 (13.7%) had intracranial SOL without any cranial CT evidence of increased ICP, mean binocular ONSD of 4.8 ± 0.39 mm. The difference of mean ONSD of the two groups was statistically significant (P = 0.0001). The controls had a mean binocular ONSD of 4.5 ± 0.22 mm and the difference in mean binocular ONSD for subjects with raised ICP and the controls were also statistically significant (P = 0.0001). A cut-off value of 5.2 mm (sensitivity 81.2% [95% confidence interval (CI): 69.9–89.6], specificity 100% [95% CI: 71.5–100]) was obtained from the receiver operator characteristics curve as the mean binocular ONSD that best predicts raised ICP confirmed by at least a sign on cranial CT.

Conclusions:

Optic nerve sonography can differentiate between normal and elevated ICP and may serve as a useful screening tool in resource-limited practice.

Ocular ultrasound to detect intracranial hypertension in trauma patients

BACKGROUND

Increases in intracranial pressure (ICP) after head trauma require a rapid recognition to allow for adequate treatments. The aim of this study was to determine whether dilation of the optic nerve sheath, as detected by ocular ultrasound at the bedside, could reliably identify increases in ICP assessed with an intraparenchymal probe in adult head trauma patients.

METHODS

Eleven head trauma injured adult patients admitted to the intensive care unit with a Glasgow Coma Scale score ≤8, with cerebral contusion confirmed by computed tomography scan, and that required invasive ICP monitoring, were enrolled in the study. ICP values ≤20 mm Hg were considered as normal. Patients with acute or chronic ocular lesion were excluded. Ten nontrauma intensive care unit patients, with no ICP monitoring, were enrolled as control group. Invasive arterial pressure was monitored, and optic nerve sheath diameter (ONSD) was assessed by ocular ultrasound in all the patients.

RESULTS

Head trauma patients without intracranial hypertension had ONSD values, assessed by ultrasound, equivalent to those measured in control patients (5.52 mm ± 0.36 mm vs. 5.51 mm ± 0.32 mm). ONSD, instead, significantly increased to 7.0 mm ± 0.58 mm, when ICP rose in value to >20 mm Hg (p < 0.0001 vs. normal ICP and control). ONSD values were significantly correlated to ICP values (r = 0.74, p < 0.001).

CONCLUSIONS

When ICP was higher than 20 mm Hg, the ONSD diameter increased, whereas when the ICP was below 20 mm Hg, the ONSD returned to values equivalent to those assessed in control nontrauma patients. Accordingly, ocular ultrasound may be considered as a good alternative for a rapid indirect evaluation of head trauma patients' ICP.

Prehospital hypocapnia and poor outcome after severe traumatic brain injury

BACKGROUND

The Brain Trauma Foundation (BTF) Guidelines for prehospital management of traumatic brain injury (TBI) recommend a goal end-tidal carbon dioxide of 30 mm Hg to 35 mm Hg in patients without signs of herniation.

METHODS

We examined prehospital concordance with BTF Guidelines, selected demographic and physiologic variables and outcomes for 100 consecutive admissions to a well-established Level I regional trauma center. All patients had blunt TBI with Glasgow Coma Score < or = 8 without signs of herniation. All were transported by helicopter by flight paramedics experienced with BTF Guidelines and the continuous wave form capnometer. Patients resumed spontaneous ventilation after intubation.

RESULTS

Concordance (prehospital end-tidal carbon dioxide > 29 mm Hg) was achieved in 65 of 100 cases. Mortality was 29% (19 of 65) among those in whom guideline levels were achieved prehospital and 46% (16 of 35) in those in whom guideline levels were not achieved prehospital (odds ratio, 0.49; p = 0.10). The "achieved" group was younger (p = 0.02), with higher calculated probability of survival (p = 0.01). Intracranial pressure was maintained under intensive care within acceptable limits in the hospital in both groups but was significantly higher in the "not achieved" group (p = 0.05).

CONCLUSIONS

Our data, though not statistically significant, suggest that patients who are harder to keep within the guidelines in the field are more likely to die, because of more severe TBI or complication by other factors such as age or injury severity. Whether increased awareness of this phenomenon can improve outcomes is unknown but suggests an approach to future education and research.

Optic nerve sonography in the diagnostic evaluation of adult brain injury

INTRODUCTION

The optic nerve sheath diameter (ONSD) may be increased in brain-injured patients, especially children, with intracranial hypertension. We investigated whether measurements of ONSD correlated with simultaneous noninvasive and invasive measurements of the intracranial pressure (ICP) in brain-injured adults.

METHODS

Seventy-six critical care patients (58 males; 47 +/- 18 years old) were included in the study. Fifty patients suffered from brain injury, whereas 26 had no intracranial pathology and served as control individuals. Initially, brain-injured patients were evaluated clinically (Glasgow Coma Scale) and using a semiquantitative (I to VI) neuroimaging scale (Marshall Scale). Thereafter, the patients were divided into those with moderate (Marshall Scale = I and Glasgow Coma Scale > 8 [n = 18]) and severe (Marshall Scale = II to VI and Glasgow Coma Scale < or =8 [n = 32]) brain injury. All patients underwent noninvasive measurement of the ICP (estimated ICP) by transcranial Doppler sonography, and synchronous ONSD measurements by optic nerve sonography. Finally, invasive ICP measurement using an intraparenchymal catheter was performed in patients with severe brain injury.

RESULTS

ONSD and estimated ICP were both significantly increased (6.1 +/- 0.7 mm and 26.2 +/- 8.7 mmHg, respectively; P < 0.0001) in patients with severe brain injury as compared with patients with moderate brain injury (4.2 +/- 1.2 mm and 12.0 +/- 3.6 mmHg) and compared with control individuals (3.6 +/- 0.6 mm and 10.3 +/- 3.1 mmHg). Furthermore, in patients with severe brain injury the ONSD measurements were strongly correlated with estimated ICP values (r = 0.80, P < 0.0001) as well as with the neuroimaging scale results (r = 0.82, P < 0.001). In the patients with severe brain injury, ONSD measurements correlated with invasive ICP values (r = 0.68, P = 0.002). The best cut-off value of ONSD for predicting elevated ICP was 5.7 mm (sensitivity = 74.1% and specificity = 100%).

CONCLUSION

ONSD measurements correlate with noninvasive and invasive measurements of the ICP, and with head computed tomography scan findings in brain-injured adults. Hence, optic nerve sonography may serve as an additional diagnostic tool that could alert clinicians to the presence of elevated ICP, whenever invasive ICP evaluation is contraindicated and/or is not available. This trial is International Standard Randomised Controlled Trial Number registered (ISRCTN 91941687).