Utility of M-mode ultrasound for pupillary assessment in patients with traumatic brain injury

Abstract

Background Pupillary assessment is an important index to evaluate changes in the conditions of patients with traumatic brain injury (TBI). This study assessed the utility of M-mode ultrasound as a non-invasive bedside assessment to evaluate pupillary light reflex (PLR) sensitivity in patients with TBI. Methods This is a prospective observational study of patients with TBI. Patients were divided into brisk, sluggish, or absent groups based on their PLR sensitivity. M-mode ultrasound was performed according to standard operation guidelines using a standardized light stimulus.Pupillary diameter (PD) and PLR sensitivity were recorded. At the same time, the pupil was examined by M-mode ultrasound, and the diameter and pupillary contraction time (PCT) were measured at rest, ipsilateral opposite PLR, and contralateral opposite PLR. Results A total of 150 participants were included. In the briskgroup, during the ipsilaterallight reflex, the left and right PCTs were 0.09 ± 0.02s and 0.10 ± 0.09s, respectively, and the pupillary diameter variation rates (PDVRs) were 0.36 ± 0.10 and 0.35 ± 0.09. In the sluggish group, during the ipsilateral light reflex, the left and right PCTs were 0.20 ± 0.05s and 0.19 ±0.03s, respectively. PDVRs were 0.18 ± 0.07 and 0.19 ± 0.11, respectively. In the brisk group, the cut-off value of PDVR of ipsilateral PLR was 0.205, AUC value was 0.957, and sensitivity and specificity were 95.3% and 90.8%, the cut-off value of PDVR of contralateral PLR was 0.146, AUC value was 0.962, and sensitivity and specificity were 95.3% and 86.2%. Conclusions This study demonstrated the usefulness of M-mode ultrasound for quantitative evaluation of pupillary changes. It is a simple, rapid, and objective method that can accurately monitor PD and sensitivity to light reflex, especially in patients with eyelid edema or TBI, where pupils cannot be examined visually.

Feasibility of USG‐Guided Objective Initial Assessment of Pupillary Size and Pupillary Reflexes Versus Clinical Examination in Patients With Altered Mental Status

“…The "limits of agreement" (Δmean AE 2SD) between clinical and USG examination for left and right pupils at rest, during D stim and C stim , that range from À0.17 AE 2 Â 0.60 mm (1.03 mm, À1.37 mm) to 0.15 AE 2 Â 0.58 mm (1.31 mm, À1.01 mm), were found clinically important measurements according to pupil gauge(mm) chart. 9 Hence, these two methods are not essentially equivalent (Table 4).…”

“…4 Point of care ultrasound assessed pupil in previous studies. [5][6][7][8][9] However, literature regarding the use of B-mode ultrasound as an objective assessment tool during neurological examination has not been studied. 6,9 We propose to study the feasibility of ultrasoundguided objective assessment of pupillary size and reflex as an adjunct to neurological assessment in patients with altered mental status.…”

“…[5][6][7][8][9] However, literature regarding the use of B-mode ultrasound as an objective assessment tool during neurological examination has not been studied. 6,9 We propose to study the feasibility of ultrasoundguided objective assessment of pupillary size and reflex as an adjunct to neurological assessment in patients with altered mental status. Since clinical examination is being used since a long time for pupillary examination in emergency settings and resource-limited settings, we studied the agreement of pupillary size between clinical and USG methods of pupillary light reflex (PLR) examination.…”

“…Point of care ultrasound (POCUS) has been used to assess common acute ocular pathologies such as retinal detachment, lens dislocation, and globe rupture including vascular lesions which can be identified using Doppler 4 . Point of care ultrasound assessed pupil in previous studies 5–9 . However, literature regarding the use of B‐mode ultrasound as an objective assessment tool during neurological examination has not been studied 6,9 .…”