BJA
Correspondence
Declaration of interest None declared. M. R. Nadelson R. D. Sanders M. S. Avidan* St Louis, MO, USA *E-mail: [email protected]
doi:10.1093/bja/aeu476
Immediate postoperative pain can also be predicted by pupillary pain index in children Editor—We have read with great interest the article by Boselli and colleagues1 regarding the usefulness of a new analgesia/ nociception index (ANI). The idea of effectively predicting late postoperative pain during the intraoperative period, when the anaesthetist can still manage analgesic drugs to avoid patients’ awakening in pain, is universally interesting. The article’s authors found an improved correlation between pre-extubation ANI and postoperative visual analogue scale (VAS) compared with the correlation between postextubation ANI and postoperative VAS that these authors had obtained in a previous work.2 Pupillometry has been postulated as an alternative to ANI for the assessment of postoperative pain and assesses the pupillary dilation response to a stimulus in the operative site.3 4
345
Downloaded from http://bja.oxfordjournals.org/ at Pennsylvania State University on May 25, 2015
1 Nadelson MR, Sanders RD, Avidan MS. Perioperative cognitive trajectory in adults. Br J Anaesth 2014; 112: 440–51 2 Pearse RM, Holt PJ, Grocott MP. Managing perioperative risk in patients undergoing elective non-cardiac surgery. Br Med J 2011; 343: d5759 3 Guay J. General anaesthesia does not contribute to long-term postoperative cognitive dysfunction in adults: a meta-analysis. Indian J Anaesth 2011; 55: 358–63 4 Strøm C, Rasmussen LS, Sieber FE. Should general anaesthesia be avoided in the elderly? Anaesthesia 2014; 69(Suppl 1): 35 –44 5 Sauer AM, Nathoe HM, Hendrikse J, et al. Cognitive outcomes 7.5 years after angioplasty compared with off-pump coronary bypass surgery. Ann Thorac Surg 2013; 96: 1294–300 6 Selnes OA. Invited commentary. Ann Thorac Surg 2013; 96: 1300– 1 7 Chan MT, Cheng BC, Lee TM, Gin T, Group CT. BIS-guided anesthesia decreases postoperative delirium and cognitive decline. J Neurosurg Anesthesiol 2013; 25: 33 –42 8 Ballard C, Jones E, Gauge N, et al. Optimised anaesthesia to reduce post operative cognitive decline (POCD) in older patients undergoing elective surgery, a randomised controlled trial. PLoS One 2012; 7: e37410 9 Radtke FM, Franck M, Lendner J, Kru¨ger S, Wernecke KD, Spies CD. Monitoring depth of anaesthesia in a randomized trial decreases the rate of postoperative delirium but not postoperative cognitive dysfunction. Br J Anaesth 2013; 110(Suppl 1): i98–105 10 Sieber FE, Zakriya KJ, Gottschalk A, et al. Sedation depth during spinal anesthesia and the development of postoperative delirium in elderly patients undergoing hip fracture repair. Mayo Clin Proc 2010; 85: 18–26 11 Prasad V, Vandross A, Toomey C, et al. A decade of reversal: an analysis of 146 contradicted medical practices. Mayo Clin Proc 2013; 88: 790–8
However, this approach is difficult to perform in younger paediatric patients, who will barely tolerate pupillometry performance and will not bear any further manipulation of the surgical wound. For this reason, we decided to use an approach similar to that of Bosselli and colleagues1’ but with the pupillary pain index (PPI). The PPI consists in measuring the changes in pupillary dilation in response to a continuously increasing electric stimulus discharge until 13% of pupillary variation is reached. When a change .13% of the pupil size is detected, the stimulus stops and PPI is calculated by the device. Each electrical stimulation level lasts 1 s, and the increasing stimulus intensity varies from 10 to 60 mA in steps of 10 mA, assigning scores from 1 (when pupillary dilation is ,5% despite maximal tetanic stimulation intensity) to 10 (when pupillary dilation rises above 13% with the 10 mA). The lower the score, the greater the impregnation of opioid receptors. This examination is not appropriate for awake children, so we decided to do it immediately before extubation, with minimal alveolar concentration values between 0.5 and 0.8, corresponding to a bispectral index .50. Our hypothesis was the same as that of Boselli and colleagues’; the score obtained would be predictive of the level of analgesia expected in the immediate postoperative period. We performed a retrospective and observational study with data recorded after balanced (sevoflurane –fenatnyl) anaesthesia. Ethical approval for this study (Ethical Committee HULP-Code PI-1217) was provided by the Ethical Committee of Clinical Research of Madrid La Paz University Hospital, Madrid, Spain. An infrared portable pupillary algesimeter (Algiscan IDMed, Marseille, France) was used to obtain a PPI score immediately before tracheal extubation. Ten minutes after extubation, upon arrival in the postanaesthesia recovery unit, the VAS score (if the patient was co-operative) and/or a Spanish observational pain scale score (LLANTO scale)5 were assessed and recorded. Twenty children were included. They were scheduled for several surgical procedures, including general, trauma and otorhinolaryngology surgery. The median age was 3.5 years. The average intraoperative fentanyl dose employed was 4 mg kg21. In this group of patients, PPI presented a statistically significant correlation (r¼0.62, P¼0.0038) with the LLANTO scale but not with VAS (r¼0.05, P¼1.5). The PPI is a very simple way to measure the nociception/ analgesia balance, and it can be employed even in very young children when they are still under residual anaesthesia. The PPI could be correlated only with the LLANTO scale, because VAS is a subjective scale influenced by many psychological factors, especially in children. An ANI monitor may be influenced by these psychological factors to a more important extent than pupillometry. The measurement of PPI immediately before extubation after sevoflurane –fentanyl anaesthesia was significantly associated with the observational pain intensity measurement upon arrival in the postanaesthesia care unit. The measurement of PPI under these circumstances can be predictive for immediate postoperative pain in a simple and effective way
BJA
Correspondence
to assist physicians in optimizing acute pain management in young children.
Declaration of interest None declared. D. Ly-Liu* F. Reinoso-Barbero Madrid, Spain *E-mail: [email protected]
doi:10.1093/bja/aeu473
Use of analgesia monitors to optimize the management of immediate postoperative pain Reply from the authors Editor—We read with great interest the letter by Ly-Liu and Reinoso-Barbero in response to our publication.1 Similar to what we previously observed in adult patients using Analgesia/Nociception Index (ANI), the authors observed a significant correlation between the Pupillary Pain Index (PPI) and a behavioural paediatric pain scale (LLANTO scale) in children undergoing general anaesthesia using sevoflurane and remifentanil. This relationship was not observed with the PPI and Verbal Analogue Scale (VAS) pain scores, mostly because the VAS may be influenced by many factors other than pain in awake children, but also because young children may not use the VAS adequately. Monitoring analgesia is a new and very challenging concept and developing tools for the prediction of immediate postoperative pain may have an important impact in clinical practice. Indeed, it as been shown in a recent study that severe pain still occurs in 20–40% of patients, including patients undergoing so-called minor surgical procedures (appendectomy, tonsillectomy, etc.).2 In this perspective, the use of
346
Declaration of interest None declared. E. Boselli Lyon, France E-mail: [email protected] 1 Boselli E, Bouvet L, Be´gou G, et al. Prediction of immediate postoperative pain using the analgesia/nociception index: a prospective observational study. Br J Anaesth 2014; 112: 715–21 2 Gerbershagen HJ, Aduckathil S, van Wijck AJ, Peelen LM, Kalkman CJ, Meissner W. Pain intensity on the first day after surgery: a prospective cohort study comparing 179 surgical procedures. Anesthesiology 2013; 118: 934–44
doi:10.1093/bja/aeu477
Predictability of stroke volume variation Editor—I read with great interest the study of Guinot and colleagues1 regarding predictability of the respiratory variation of stroke volume, which showed that monitoring stroke volume may provide more reliable information than cardiac output concerning the effect of fluid infusion. Surely, this study would help us to guide fluid management, particularly in the subset of patients who have a significantly higher baseline heart rate, for example, patients in hypovolaemic shock? However, the authors have failed to mention whether they took into consideration the ventilatory and other confounding factors affecting stroke volume variation (SVV) in their study population. Studies have shown that respiratory variations in stroke volume and its derivatives are affected by respiratory rate,
Downloaded from http://bja.oxfordjournals.org/ at Pennsylvania State University on May 25, 2015
1 Boselli E, Bouvet L, Be´gou G, et al. Prediction of immediate postoperative pain using the analgesia/nociception index: a prospective observational study. Br J Anaesth 2014; 112: 715–21 2 Boselli E, Daniela-Ionescu M, Be´gou G, et al. Prospective observational study of the non-invasive assessment of immediate postoperative pain using the analgesia/nociception index (ANI). Br J Anaesth 2013; 111: 453– 9 3 Migeon A, Desgranges FP, Chassard D, et al. Pupillary reflex dilatation and analgesia nociception index monitoring to assess the effectiveness of regional anesthesia in children anesthetised with sevoflurane. Paediatr Anaesth 2013; 23: 1160–5 4 Barvais L, Engelman E, Eba JM, Coussaert E, Cantraine F, Kenny GN. Effect site concentrations of remifentanil and pupil response to noxious stimulation. Br J Anaesth 2003; 91: 347– 52 5 Reinoso-Barbero F, Lahoz Ramo´n AI, Dura´n Fuente MP, Campo Garcı´a G, Castro Parga LE. Escala LLANTO: instrumento espan˜ol de medicio´n del dolor agudo en la edad preescolar. An Pediatr (Barc) 2011; 74: 10 –4
analgesia monitors such as the ANI or PPI may provide useful information to physicians to optimize the management of immediate postoperative pain. It is postulated that ANI or PPI values immediately before extubation may be highly predictive of acute pain within the following minutes, thus the administration of a prophylactic dose of opioid may provide a reduction in pain scores at arrival in the post-anaesthetic care unit. This, however, remains to be demonstrated in prospective studies. For us, use of the ANI presents an advantage over the PPI since it allows for continuous analgesia monitoring directly from the patient monitor, whereas the PPI requires measuring the changes in pupil dilation in response to increasing electric stimulations. Moreover, in cephalic procedures such as ear– nose –throat surgery, the use of a device placed over the face is not possible. Nevertheless, the authors should be commended for performing this study in young children in an effort to optimize postoperative analgesia. Prospective studies comparing various monitors such as the ANI and PPI are urgently needed in both adults and children to determine the clinical benefit of analgesia monitoring in routine practice for acute postoperative pain management.
Correspondence
Declaration of interest None declared. M. R. Nadelson R. D. Sanders M. S. Avidan* St Louis, MO, USA *E-mail: [email protected]
doi:10.1093/bja/aeu476
Immediate postoperative pain can also be predicted by pupillary pain index in children Editor—We have read with great interest the article by Boselli and colleagues1 regarding the usefulness of a new analgesia/ nociception index (ANI). The idea of effectively predicting late postoperative pain during the intraoperative period, when the anaesthetist can still manage analgesic drugs to avoid patients’ awakening in pain, is universally interesting. The article’s authors found an improved correlation between pre-extubation ANI and postoperative visual analogue scale (VAS) compared with the correlation between postextubation ANI and postoperative VAS that these authors had obtained in a previous work.2 Pupillometry has been postulated as an alternative to ANI for the assessment of postoperative pain and assesses the pupillary dilation response to a stimulus in the operative site.3 4
345
Downloaded from http://bja.oxfordjournals.org/ at Pennsylvania State University on May 25, 2015
1 Nadelson MR, Sanders RD, Avidan MS. Perioperative cognitive trajectory in adults. Br J Anaesth 2014; 112: 440–51 2 Pearse RM, Holt PJ, Grocott MP. Managing perioperative risk in patients undergoing elective non-cardiac surgery. Br Med J 2011; 343: d5759 3 Guay J. General anaesthesia does not contribute to long-term postoperative cognitive dysfunction in adults: a meta-analysis. Indian J Anaesth 2011; 55: 358–63 4 Strøm C, Rasmussen LS, Sieber FE. Should general anaesthesia be avoided in the elderly? Anaesthesia 2014; 69(Suppl 1): 35 –44 5 Sauer AM, Nathoe HM, Hendrikse J, et al. Cognitive outcomes 7.5 years after angioplasty compared with off-pump coronary bypass surgery. Ann Thorac Surg 2013; 96: 1294–300 6 Selnes OA. Invited commentary. Ann Thorac Surg 2013; 96: 1300– 1 7 Chan MT, Cheng BC, Lee TM, Gin T, Group CT. BIS-guided anesthesia decreases postoperative delirium and cognitive decline. J Neurosurg Anesthesiol 2013; 25: 33 –42 8 Ballard C, Jones E, Gauge N, et al. Optimised anaesthesia to reduce post operative cognitive decline (POCD) in older patients undergoing elective surgery, a randomised controlled trial. PLoS One 2012; 7: e37410 9 Radtke FM, Franck M, Lendner J, Kru¨ger S, Wernecke KD, Spies CD. Monitoring depth of anaesthesia in a randomized trial decreases the rate of postoperative delirium but not postoperative cognitive dysfunction. Br J Anaesth 2013; 110(Suppl 1): i98–105 10 Sieber FE, Zakriya KJ, Gottschalk A, et al. Sedation depth during spinal anesthesia and the development of postoperative delirium in elderly patients undergoing hip fracture repair. Mayo Clin Proc 2010; 85: 18–26 11 Prasad V, Vandross A, Toomey C, et al. A decade of reversal: an analysis of 146 contradicted medical practices. Mayo Clin Proc 2013; 88: 790–8
However, this approach is difficult to perform in younger paediatric patients, who will barely tolerate pupillometry performance and will not bear any further manipulation of the surgical wound. For this reason, we decided to use an approach similar to that of Bosselli and colleagues1’ but with the pupillary pain index (PPI). The PPI consists in measuring the changes in pupillary dilation in response to a continuously increasing electric stimulus discharge until 13% of pupillary variation is reached. When a change .13% of the pupil size is detected, the stimulus stops and PPI is calculated by the device. Each electrical stimulation level lasts 1 s, and the increasing stimulus intensity varies from 10 to 60 mA in steps of 10 mA, assigning scores from 1 (when pupillary dilation is ,5% despite maximal tetanic stimulation intensity) to 10 (when pupillary dilation rises above 13% with the 10 mA). The lower the score, the greater the impregnation of opioid receptors. This examination is not appropriate for awake children, so we decided to do it immediately before extubation, with minimal alveolar concentration values between 0.5 and 0.8, corresponding to a bispectral index .50. Our hypothesis was the same as that of Boselli and colleagues’; the score obtained would be predictive of the level of analgesia expected in the immediate postoperative period. We performed a retrospective and observational study with data recorded after balanced (sevoflurane –fenatnyl) anaesthesia. Ethical approval for this study (Ethical Committee HULP-Code PI-1217) was provided by the Ethical Committee of Clinical Research of Madrid La Paz University Hospital, Madrid, Spain. An infrared portable pupillary algesimeter (Algiscan IDMed, Marseille, France) was used to obtain a PPI score immediately before tracheal extubation. Ten minutes after extubation, upon arrival in the postanaesthesia recovery unit, the VAS score (if the patient was co-operative) and/or a Spanish observational pain scale score (LLANTO scale)5 were assessed and recorded. Twenty children were included. They were scheduled for several surgical procedures, including general, trauma and otorhinolaryngology surgery. The median age was 3.5 years. The average intraoperative fentanyl dose employed was 4 mg kg21. In this group of patients, PPI presented a statistically significant correlation (r¼0.62, P¼0.0038) with the LLANTO scale but not with VAS (r¼0.05, P¼1.5). The PPI is a very simple way to measure the nociception/ analgesia balance, and it can be employed even in very young children when they are still under residual anaesthesia. The PPI could be correlated only with the LLANTO scale, because VAS is a subjective scale influenced by many psychological factors, especially in children. An ANI monitor may be influenced by these psychological factors to a more important extent than pupillometry. The measurement of PPI immediately before extubation after sevoflurane –fentanyl anaesthesia was significantly associated with the observational pain intensity measurement upon arrival in the postanaesthesia care unit. The measurement of PPI under these circumstances can be predictive for immediate postoperative pain in a simple and effective way
BJA
Correspondence
to assist physicians in optimizing acute pain management in young children.
Declaration of interest None declared. D. Ly-Liu* F. Reinoso-Barbero Madrid, Spain *E-mail: [email protected]
doi:10.1093/bja/aeu473
Use of analgesia monitors to optimize the management of immediate postoperative pain Reply from the authors Editor—We read with great interest the letter by Ly-Liu and Reinoso-Barbero in response to our publication.1 Similar to what we previously observed in adult patients using Analgesia/Nociception Index (ANI), the authors observed a significant correlation between the Pupillary Pain Index (PPI) and a behavioural paediatric pain scale (LLANTO scale) in children undergoing general anaesthesia using sevoflurane and remifentanil. This relationship was not observed with the PPI and Verbal Analogue Scale (VAS) pain scores, mostly because the VAS may be influenced by many factors other than pain in awake children, but also because young children may not use the VAS adequately. Monitoring analgesia is a new and very challenging concept and developing tools for the prediction of immediate postoperative pain may have an important impact in clinical practice. Indeed, it as been shown in a recent study that severe pain still occurs in 20–40% of patients, including patients undergoing so-called minor surgical procedures (appendectomy, tonsillectomy, etc.).2 In this perspective, the use of
346
Declaration of interest None declared. E. Boselli Lyon, France E-mail: [email protected] 1 Boselli E, Bouvet L, Be´gou G, et al. Prediction of immediate postoperative pain using the analgesia/nociception index: a prospective observational study. Br J Anaesth 2014; 112: 715–21 2 Gerbershagen HJ, Aduckathil S, van Wijck AJ, Peelen LM, Kalkman CJ, Meissner W. Pain intensity on the first day after surgery: a prospective cohort study comparing 179 surgical procedures. Anesthesiology 2013; 118: 934–44
doi:10.1093/bja/aeu477
Predictability of stroke volume variation Editor—I read with great interest the study of Guinot and colleagues1 regarding predictability of the respiratory variation of stroke volume, which showed that monitoring stroke volume may provide more reliable information than cardiac output concerning the effect of fluid infusion. Surely, this study would help us to guide fluid management, particularly in the subset of patients who have a significantly higher baseline heart rate, for example, patients in hypovolaemic shock? However, the authors have failed to mention whether they took into consideration the ventilatory and other confounding factors affecting stroke volume variation (SVV) in their study population. Studies have shown that respiratory variations in stroke volume and its derivatives are affected by respiratory rate,
Downloaded from http://bja.oxfordjournals.org/ at Pennsylvania State University on May 25, 2015
1 Boselli E, Bouvet L, Be´gou G, et al. Prediction of immediate postoperative pain using the analgesia/nociception index: a prospective observational study. Br J Anaesth 2014; 112: 715–21 2 Boselli E, Daniela-Ionescu M, Be´gou G, et al. Prospective observational study of the non-invasive assessment of immediate postoperative pain using the analgesia/nociception index (ANI). Br J Anaesth 2013; 111: 453– 9 3 Migeon A, Desgranges FP, Chassard D, et al. Pupillary reflex dilatation and analgesia nociception index monitoring to assess the effectiveness of regional anesthesia in children anesthetised with sevoflurane. Paediatr Anaesth 2013; 23: 1160–5 4 Barvais L, Engelman E, Eba JM, Coussaert E, Cantraine F, Kenny GN. Effect site concentrations of remifentanil and pupil response to noxious stimulation. Br J Anaesth 2003; 91: 347– 52 5 Reinoso-Barbero F, Lahoz Ramo´n AI, Dura´n Fuente MP, Campo Garcı´a G, Castro Parga LE. Escala LLANTO: instrumento espan˜ol de medicio´n del dolor agudo en la edad preescolar. An Pediatr (Barc) 2011; 74: 10 –4
analgesia monitors such as the ANI or PPI may provide useful information to physicians to optimize the management of immediate postoperative pain. It is postulated that ANI or PPI values immediately before extubation may be highly predictive of acute pain within the following minutes, thus the administration of a prophylactic dose of opioid may provide a reduction in pain scores at arrival in the post-anaesthetic care unit. This, however, remains to be demonstrated in prospective studies. For us, use of the ANI presents an advantage over the PPI since it allows for continuous analgesia monitoring directly from the patient monitor, whereas the PPI requires measuring the changes in pupil dilation in response to increasing electric stimulations. Moreover, in cephalic procedures such as ear– nose –throat surgery, the use of a device placed over the face is not possible. Nevertheless, the authors should be commended for performing this study in young children in an effort to optimize postoperative analgesia. Prospective studies comparing various monitors such as the ANI and PPI are urgently needed in both adults and children to determine the clinical benefit of analgesia monitoring in routine practice for acute postoperative pain management.
