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Published on: August 19, 2020
Surgical pleth index in children younger than 24 months of age: a randomized double-blinded trial
J Harju1, M-L Kalliomäki2, H Leppikangas2
1Department of Anaesthesia, Tampere University Hospital, PL2000, Tampere 33521, Finland jarkko.harju@fimnet.fi.
Insights
The Surgical Pleth Index (SPI) shows some reactivity to anesthesia and surgical stimuli in infants, but its usefulness is limited by small changes and high variability. Nerve blocks can blunt this response.
Area of Science:
- Pediatric Anesthesiology
- Pain Management
- Autonomic Nervous System Monitoring
Background:
- The Surgical Pleth Index (SPI) measures intraoperative nociception, but its utility in young children is not well-established.
- Autonomic nervous system development in infants may affect SPI reliability compared to older children.
Purpose of the Study:
- To evaluate the usability and reactivity of the Surgical Pleth Index (SPI) in children younger than two years undergoing elective surgery.
- To assess the impact of ilioinguinal and iliohypogastric nerve blocks on SPI measurements in this age group.
Main Methods:
- Thirty infants (<2 years) were randomized into two groups: saline followed by ropivacaine, or nerve block followed by saline.
- SPI was recorded blinded during intubation, incision, and signs of inadequate anti-nociception.
- Ultrasound-guided ilioinguinal and iliohypogastric nerve blocks were administered.
Main Results:
- SPI significantly increased after intubation and incision in the saline group, but not significantly in the block group.
- Increased SPI was observed during clinically apparent inadequate anti-nociception.
- Significant inter-individual variability in SPI measurements was noted.
Conclusions:
- The SPI demonstrates reactivity to intubation and surgical stimuli in young children, though the response is modest.
- Marked inter-individual variability limits the clinical interpretation of SPI in this population.
- Ilioinguinal and iliohypogastric nerve blocks appear to blunt the SPI response.
Background:
The surgical pleth index (SPI) is a measurement of intraoperative nociception. Evidence of its usability in children is limited. Given that the autonomic nervous system is still developing during the first years of life, the performance of the SPI on small children cannot be concluded from studies carried out in older age groups.
Methods:
Thirty children aged <2 yr, planned for elective open inguinal hernia repair or open correction of undescended testicle, were recruited. The children were randomized into two groups; the saline group received ultrasound-guided saline injection in the ilioinguinal and iliohypogastric nerve region before surgery and ropivacaine after surgery, whereas the block group received the injections in the opposite order. The SPI was recorded blinded and was analysed at the time points of intubation, incision, and when signs of inadequate anti-nociception were observed.
Results:
There was a significant increase in the SPI after intubation (P=0.019) and after incision in the saline group (P=0.048), but not at the time of surgical incision in the block group (P=0.177). An increase in the SPI was also seen at times of clinically apparent inadequate anti-nociception (P=0.008). The between-patient variability of the SPI was large.
Conclusions:
The SPI is reactive in small children after intubation and after surgical stimuli, but the reactivity of the SPI is rather small, and there is marked inter-individual variability in reactions. The reactivity is blunted by the use of ilioinguinal and iliohypogastric nerve block.
Clinical Trial Registration:
NCT02045810.
