Journal Information
Vol. 46. Issue 7.
Pages 415 (July 2022)
Letter to the Editor
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Quantitative pupillometry as a tool to predict post-cardiac arrest neurological outcome in target temperature patients
Pupilometría óptica cuantitativa como herramienta para predecir el pronóstico neurológico posparada cardiaca en pacientes con control de la temperatura
A. Blandino Ortiza,
Corresponding author

Corresponding author.
, J. Higuera Lucasa, C. Sorianoa, R. de Pabloa,b
a Servicio de Medicina Intensiva, Hospital Universitario Ramón y Cajal, Madrid, Spain
b Facultad de Medicina y Ciencias de la Salud, Universidad Alcalá de Henares, Alcalá de Henares, Madrid, Spain
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Dear Editor:

An expert consensus document has been published recently on the management of temperature control in patients after cardiac arrest.1 However, we believe that in the neuroprognosis and tools section—one of the newest and more practical methods to this end—quantitative pupillometry has been left out.

The lack of pupillary reactivity is one of the criteria with more specific weight to assess neurological prognosis although such an assessment using the standard method is largely subject to assessment and interpretation biases. Such non-minor errors associated with the assessment of pupillary reactivity have been explored in former studies, among them, the one conducted by Riker et al.2. They studied a sample of 55 patients with temperature monitoring during the post-cardiac arrest period and went on to perform a neurological assessment through pupillometry. Among the study results, patients with Neurological Pupil index (NPi) scores of 0 or <3 within the first 6 h were more prone to poor prognoses (86%) compared to those with NPi scores >3 (52%; P = .03). Without a doubt the best study conducted so far and with more scientific repercussion is the one conducted by Oddo et al.3. They analyzed over 450 patients with cardiac arrest in whom pupillary reactivity was assessed using the standard method vs quantitative pupillometry. Investigators found that, with pupillometry, all examinations with NPi scores ≤2 within the first 72 h after the cardiac arrest provided a 100% specificity to predict unfavorable neurological outcomes after 3 months according to the cerebral performance category (CPC) scale. As a matter of fact, when pupillometry was added to the bilateral lack of somatosensory evoked potentials (N-20) maximum sensitivity in all the tests run was achieved (58%) with similar specificity (100%).

In an even more complex scenario, Miroz et al.4 conducted an observational cohort study among patients treated with ECMO-VA due to cardiogenic shock or refractory cardiac arrest. These authors found that pupillometry revealed that an abnormal NPi (<3, at any time within 24 to 72 h) was 100% specific to predict 90-day mortality. However, NPi values = 0 when ECMO-VA support was initiated (N = 9) were 100% predictive of mortality.

The last clinical practice guidelines on the post-cardiac arrest syndrome5 emphasize that this tool is suitable to predict—in a more precise and reproducible way—the lack of corneal reflex compared to standard assessment.

Infrared pupillometry provides intensivists with an easily reproducible, non-invasive, precise, and quantitative tool for pupillary examination. Based on the current evidence available and our own experience, we believe that pupillometry should be added to the neurological examination armamentarium available and performed on a routine basis in device-capable centers to assess the neurological prognosis of patients after cardiac arrest under temperature monitoring.


This study had no funding whatsoever from government or private companies.

R. Ferrer Roca, J.C. Sánchez Salado, M. Chico Fernández, J.M. García Acuña, A. Lesmes Serrano, E. López de Sá, et al.
Management of temperature control in post-cardiac arrest care: an expert report.
Med Intensiva, 45 (2021), pp. 164-174
R.R. Riker, M.E. Sawyer, V.G. Fischman, T. May, C. Lord, A. Eldridge, et al.
Neurological pupil index and pupillary light reflex by pupillometry predict outcome early after cardiac arrest.
Neurocrit Care, 32 (2020), pp. 152-161
M. Oddo, C. Sandroni, G. Citerio, J.P. Miroz, J. Horn, M. Rundgren, et al.
Quantitative versus standard pupillary light reflex for early prognostication in comatose cardiac arrest patients: an international prospective multicenter double-blinded study.
Intensive Care Med, 44 (2018), pp. 2102-2111
J.P. Miroz, N. Ben-Hamouda, A. Bernini, F. Romagnosi, F. Bongiovanni, A. Roumy, et al.
Neurological pupil index for early prognostication after venoarterial extracorporeal membrane oxygenation.
Chest, 157 (2020), pp. 1167-1174
J.P. Nolan, C. Sandroni, B.W. Böttiger, A. Cariou, T. Cronberg, H. Friberg, et al.
European Resuscitation Council and European Society of Intensive Care Medicine guidelines 2021: post-resuscitation care.
Intensive Care Med, 47 (2021), pp. 369-421

Please cite this article as: Blandino Ortiz A, Higuera Lucas J, Soriano C, de Pablo R. Pupilometría óptica cuantitativa como herramienta para predecir el pronóstico neurológico posparada cardiaca en pacientes con control de la temperatura. Med Intensiva. 2022;46:415.

Copyright © 2021. Elsevier España, S.L.U. and SEMICYUC
Medicina Intensiva (English Edition)
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