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Relationship between pre-incision Pupillary Pain Index and post-incision heart rate and pupillary diameter variation
Nada Sabourdin1,2, Loïc Del Bove1, Nicolas Louvet1
1CHU Armand Trousseau, Département d'Anesthésie-Réanimation, DMU DREAM, GRC 29, APHP, Sorbonne Université, Paris, France.
Insights
The Pupillary Pain Index (PPI) can predict nociception in children undergoing anesthesia. A PPI below 3 may indicate no heart rate response to surgical incision, suggesting adequate analgesia.
Area of Science:
- Anesthesiology
- Pain Management
- Pediatric Surgery
Background:
- The Pupillary Pain Index (PPI) is a novel pupillometric tool for assessing analgesia levels during general anesthesia.
- Inadequate analgesia can lead to adverse hemodynamic responses to painful stimuli like skin incision.
Purpose of the Study:
- To explore the relationship between pre-incision PPI and heart rate increase after skin incision in pediatric patients.
- To evaluate the predictive capability of pre-incision PPI for pupillary and heart rate reactivity to surgical stimuli.
Main Methods:
- A prospective pilot study included children undergoing general anesthesia.
- Pupillary Pain Index was measured 2 minutes before skin incision.
- Maximal variations in heart rate (ΔHR) and pupillary diameter (ΔPD) post-incision were recorded and analyzed using Spearman correlation and ROC curve analysis.
Main Results:
- A moderate correlation was found between pre-incision PPI and ΔHR (rs=0.35, p=0.011) and ΔPD (rs=0.54, p<0.001).
- Receiver operating characteristic analysis showed good predictive performance for PPI regarding heart rate (AUC=0.90) and pupillary diameter (AUC=0.78) reactivity.
- A pre-incision PPI threshold of <3 accurately predicted the absence of heart rate reactivity (negative predictive value=1).
Conclusions:
- Pre-incision Pupillary Pain Index shows a moderate correlation with post-incision nociception in children.
- The PPI demonstrates strong predictive value for heart rate and pupillary diameter reactivity to skin incision.
- A pre-incision PPI value below 3 may reliably indicate a lack of heart rate response to incision, suggesting sufficient pain management.
Background:
The Pupillary Pain Index is a recent pupillometric index designed to assess the level of analgesia under general anesthesia in children and adults. If analgesia is inadequate, acute nociceptive stimuli such as skin incision may induce significant hemodynamic disturbances.
Aims:
Our aim was to investigate the potential relationship between pre-incision Pupillary Pain Index and heart rate increase following skin incision in children.
Methods:
This was a prospective, non-randomized, registered pilot study. We included children undergoing surgery under general anesthesia. Pupillary Pain Index was assessed 2 min before skin incision. Then, heart rate maximal variation (ΔHR ) and pupillary diameter maximal variation (ΔPD ) in the minute following incision were recorded. Spearman coefficient was calculated to characterize the relationship between Pupillary Pain Index and ΔHR or ΔPD . Using receiver operating characteristic curve analysis, we also studied the predictive value of pre-incision Pupillary Pain Index for heart rate and pupillary diameter reactivity.
Results:
53 patients were included (10 ± 4 years, 40 ± 19 kg). There was a modest correlation between pre-incision Pupillary Pain Index and ΔHR (Spearman rs = 0.35 [0.05-0.57], p = .011), and between pre-incision Pupillary Pain Index and ΔPD (Spearman rs = 0.54 [0.33-0.71], p < .001). Regarding the predictive value of Pupillary Pain Index for heart rate or pupillary diameter reactivity, the corresponding areas under the receiver operating characteristic curves were 0.90 [0.82-0.99] and 0.78 [0.65-0.93], respectively. A threshold of Pupillary Pain Index <3 predicted the absence of heart rate reactivity at incision with a good performance (negative predictive value = 1).
Conclusions:
In children, pre-incision Pupillary Pain Index was moderately correlated with post-incision nociception. Pre-incision Pupillary Pain Index had good predictive performances for heart rate or pupillary diameter reactivity to skin incision. Pre-incision Pupillary Pain Index <3 might predict the absence of heart rate reaction to incision.
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