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Correspondence  |   December 2015
In Reply
Author Notes
  • Assistance Publique - Hôpitaux de Paris, Hôpital Bichat-Claude Bernard, Paris Cedex, France (J.G.). jean.guglielminotti@bch.aphp.fr
  • (Accepted for publication August 25, 2015.)
    (Accepted for publication August 25, 2015.)×
Article Information
Correspondence
Correspondence   |   December 2015
In Reply
Anesthesiology 12 2015, Vol.123, 1481. doi:10.1097/ALN.0000000000000897
Anesthesiology 12 2015, Vol.123, 1481. doi:10.1097/ALN.0000000000000897
We thank Kla et al. for their interest and comments on our recent publication in Anesthesiology.1  They raise concerns about the generalizability of the results of our study conducted in young and healthy patients, considering (1) the prevalence of elderly or diabetic patients in surgical patients and (2) the pupillary autonomic dysfunction associated with these two conditions.
Elderly patients make up a significant proportion of the surgical population in the United States and worldwide. According to the Centers for Disease Control and Prevention, 37.4% of inpatient procedures were performed in patients older than 65 yr in 2010.2  However, it also indicates that almost two thirds of these procedures were performed in patients younger than 65 yr. The rates of diagnosed diabetes in the civilian population in 2010 were 1.7% between 0 and 44 yr and 12.2% between 45 and 64 yr.3  These numbers highlight that the pupillary dilatation reflex amplitude evoked by a standardized noxious test to predict movement response to surgical stimulation and individualized administration of general anesthesia could be used in a significant proportion of inpatient procedures.
Studies reporting pupillary autonomic dysfunction in elderly or diabetic patients have examined the changes in pupillary diameter elicited by light/darkness or by mydriatic/myotic eye drops.4,5  The effects of these two conditions on the changes in pupillary diameter elicited by noxious stimuli such as an electrical current have not yet been examined. The nature and characteristics of the stimuli used affect the amplitude of the pupillary response, and further investigations should examine the consequences of pupillary autonomic dysfunction on the pupillary dilatation reflex to pain in these populations.6 
Contrary to volatile agents and the minimum alveolar concentration, there is currently no available tool in the United States to predict the absence of response to noxious stimuli when using total intravenous anesthesia. Target-controlled infusions of hypnotic and opioid allowing real-time calculation of effect-site concentrations of both agents are available in Europe but not yet in the United States.7  This underscores the urgent need for further research in this area to help anesthesiologists in the administration of total intravenous anesthesia.
As indicated by Larson and Gupta8  in the accompanying editorial, our study should be viewed as a first step toward “real-time individualized intravenous anesthetics,” and “additional studies examining this pupillary test to predict nonmovement in a more diverse population” are warranted.
Competing Interests
The authors declare no competing interests.
Jean Guglielminotti, M.D., Ph.D., Dan Longrois, M.D., Ph.D. Assistance Publique - Hôpitaux de Paris, Hôpital Bichat-Claude Bernard, Paris Cedex, France (J.G.). jean.guglielminotti@bch.aphp.fr
References
Guglielminotti, J, Grillot, N, Paule, M, Mentré, F, Servin, F, Montravers, P, Longrois, D Prediction of movement to surgical stimulation by the pupillary dilatation reflex amplitude evoked by a standardized noxious test.. Anesthesiology. (2015). 122 985–93 [Article] [PubMed]
Centers for Disease Control and Prevention, Inpatient surgery 2010.. http://www.cdc.gov/nchs/fastats/inpatient-surgery.htm
Centers for Disease Control and Prevention, Rate per 100 of civilian, noninstitutionalized population with diagnosed diabetes, by age, United States, 1980–2011.. http://www.cdc.gov/diabetes/statistics/prev/national/figbyage.htm
Cahill, M, Eustace, P, de Jesus, V Pupillary autonomic denervation with increasing duration of diabetes mellitus.. Br J Ophthalmol. (2001). 85 1225–30 [Article] [PubMed]
Bitsios, P, Prettyman, R, Szabadi, E Changes in autonomic function with age: A study of pupillary kinetics in healthy young and old people.. Age Ageing. (1996). 25 432–8 [Article] [PubMed]
Larson, MD, Behrends, M Portable infrared pupillometry: A review.. Anesth Analg. (2015). 120 1242–53 [Article] [PubMed]
Egan, TD, Shafer, SL Target-controlled infusions for intravenous anesthetics: Surfing USA not!. Anesthesiology. (2003). 99 1039–41 [Article] [PubMed]
Larson, MD, Gupta, DK Pupillary reflex dilation to predict movement: A step forward toward real-time individualized intravenous anesthetics.. Anesthesiology. (2015). 122 961–3 [Article] [PubMed]