Benha Medical Journal

CLINICAL TRIAL
Year
: 2018  |  Volume : 35  |  Issue : 1  |  Page : 20--23

Nebulized fentanyl: is it effective in pediatric postoperative analgesia?


Hani I Taman, Hisham M Sheere, Hosam I Elsaid Saber 
 Faculty of Medicine, Mansoura University Children Hospital, Mansoura University, Mansoura, Egypt

Correspondence Address:
Hani I Taman
Faculty of Medicine, Mansoura University Children Hospital, Mansoura University, 10 Gehan Street, Mansoura, 35511
Egypt

Abstract

Background Postoperative pain management in pediatric patients is challenging. Intravenous (IV) fentanyl appears to be an appropriate solution; however, nebulized fentanyl could be a new, promising, noninvasive method for systemic fentanyl administration with less side effects in pediatric patients. Patients and methods A total of 40 pediatric patients who underwent lower abdominal surgery under general anesthesia were classified into two groups − group IV received 1 µg/kg IV fentanyl and group N received 2 µg/kg nebulized fentanyl. Observations were made with regard to pain relief by the FLACC score and sedation by the Ramsay score. Hemodynamics and other side-effects such as vomiting, bradychardia, hypotension, and pruritus were also recorded. Results Although FLACC changes were observed in lesser than 10 min after initiation of drug administration in group IV when compared with group N, incidence of side-effects in group IV was higher when compared with group N. The rapidity of onset of fentanyl’s analgesic effect was faster in group IV followed by group N. No differences were found between the two groups with regard to the Ramsay score. Conclusion We found that 2 µg/kg nebulized fentanyl has equal analgesic effects with less side-effects compared with 1 µg/kg IV fentanyl but with slower onset of action.



How to cite this article:
Taman HI, Sheere HM, Elsaid Saber HI. Nebulized fentanyl: is it effective in pediatric postoperative analgesia?.Benha Med J 2018;35:20-23


How to cite this URL:
Taman HI, Sheere HM, Elsaid Saber HI. Nebulized fentanyl: is it effective in pediatric postoperative analgesia?. Benha Med J [serial online] 2018 [cited 2018 Jun 19 ];35:20-23
Available from: http://www.bmfj.eg.net/text.asp?2018/35/1/20/226408


Full Text



 Introduction



Postoperative pain management in pediatric patients is challenging. Intravenous (IV) fentanyl appears to be an appropriate solution for this, but many anesthesiologists are concerned about using IV fentanyl as it is associated with high incidence of respiratory depression, bradychardia, and hypotension [1].

Fentanyl is a highly lipophilic agent [2], and it can be administered through noninvasive routes (intranasal, transdermal, rectal, etc.) [3], in addition to conventional IV or epidural routes, which is an added advantage. Intranasal fentanyl at a dose of 2 µg/kg provides effective analgesia for pediatric patients with orthopedic trauma [4],[5], and it could be a new promising noninvasive method for systemic fentanyl administration in pediatric patients [1].

Singh et al. [1], and Bartfield et al. [6] reported results on using fentanyl nebulization, and found that fentanyl nebulization was as effective as IV fentanyl in postoperative pain relief after abdominal surgery and in patients with abdominal pain in emergency departments, especially in adults.

This study hypothesized that the analgesic effects of nebulized fentanyl (2 µg/kg) may be as effective as IV fentanyl (1 µg/kg) with less side-effects for postoperative pain relief in pediatric patients.

The main aim of this study was to compare the analgesic effect, sedative effect, and side-effects of nebulized fentanyl (2 µg/kg) with standard IV fentanyl (1 µg/kg) in postoperative pain relief in pediatric patients undergoing lower abdominal surgery.

 Patients and methods



This prospective, double-blind, randomized, comparative clinical trial was conducted by the Department of Anesthesia in collaboration with the Department of Pediatric Surgery at Mansoura University Children Hospital from December 2013 after obtaining approval from the local Ethics Committee of our university. An informed written consent was obtained from the guardians of all patients included in the study. Patients of either sex between 3 and 6 years of age scheduled for lower abdominal surgery under general anesthesia were included in this study.

Patients with active respiratory tract infection, congenital anomalies, congenital cardiac, hepatic, and renal insufficiencies, coagulation disorders, or hypersensitivity to opioids were excluded from this study.

There were two study groups: the IV fentanyl group (IV) and the nebulized group (N). Patients were operated for 60–90 min under general anesthesia with IV 15 mg/kg paracetamol as the only analgesic drug. On arrival of the patient into the postoperative care unit, a paramedic who was blinded to the drug alternately allocated patients included in the study with computer assistance into the two groups (IV and N, respectively). Fentanyl solution was prepared by a second paramedic − 4 ml for IV and 5 ml for nebulization − for patients in the respective groups. The quantity was 1 ml higher for the nebulization group to compensate for the loss of the drug through the venturi mask during nebulization in the upper airway.

All the patients enrolled in our study received the labeled drug by IV or nebulization routes, whenever the patient complained of pain for the first time, with an FLACC score of higher than 4 in post-anesthesia care unit (PCU).

The IV dose of fentanyl was given as 1 µg/kg in IV solution for group IV and was nil in the nebulization solution for group N. In addition, fentanyl was given as 2 µg/kg in nebulized solution for group N and was nil in the IV solution for group IV.

Patients were nebulized by a standard venturi mask with a nebulization chamber at a constant flow rate of oxygen, 4–6 l/min for 8 min.

Patients who were not relieved of pain even after 15 min from start of the study received 15 mg/kg IV paracetamol and were excluded from the study.

Patients were assessed for pain by the FLACC score [7] (face, leg, activity, cry and consolability) and sedation by the Ramsay sedation scale [8] (1 − anxious/restless or both; 2 − cooperative, oriented and tranquil, and responding to command; 3 − brisk response to stimulus; 4 − sluggish response to stimulus; and 5 − no response to any stimulus). Incidence of vomiting (forceful expulsion of gastric content), pruritus, retention of urine, and mean arterial pressure, respiratory rate, and heart rate were also recorded.

The above-mentioned parameters were observed continuously, and data were recorded initially at the time of drug administration, at 10, 20, 30, and 45 min after administration, and then at 60, 90, and 120 min after administration of fentanyl by either route until completion of study by a resident doctor blinded to the groups.

On the basis of these data, in our pilot study, the mean FLACC score in the IV group 30 min after administration of the placebo solution was 2.8 with a SD of 0.447. An a priori power analysis showed that we needed to include 17 children in each group to detect 20% reduction in the median FLACC scores at 30 min after nebulization of fentanyl with an alpha error of 0.05 and a power of 90%. We included 15% extra children to compensate for dropouts during recruitment and for the abnormal distribution of the FLACC score.

Data obtained were statistically analyzed using SPSS software, version 18 (SPSS Inc., Chicago, Illinois, USA). Data were first tested for normality by the Klomogorov–Smirnov test. Normally distributed continuous data were analyzed using student’s t-test. Non-normally distributed continuous and ordinal data were analyzed using the Mann–Whitey U-test. Categorical data were analyzed by χ2 or Fisher’s exact test as appropriate. The results are presented as means (SD) or as numbers and % of patients as appropriate. A P value less than 0.05 was considered statistically significant.

 Results



Overall, 40 consecutive patients were enrolled to the present study. They were randomized into two groups (groups IV and N) with 20 patients in each group. Both groups were similar in terms of age, sex distribution, and body weight of patients ([Table 1]).{Table 1}

Statistically significant mean FLACC change was observed 10 min after initiation of drug administration, and it was lower in group IV when compared with group N. The FLACC score showed no significant differences throughout the rest of the study ([Table 2]).{Table 2}

The Ramsay score of patients were comparable and was not statistically significant between the two groups ([Table 3]).{Table 3}

Incidence of vomiting and pruritus in group IV was higher when compared with group N. The incidence of urinary retention showed no statistical significance between the two groups ([Table 4]).{Table 4}

The rapidity of onset of the analgesic effect was faster in group IV when compared with group N ([Table 5]).{Table 5}

Although respiratory rate changes were insignificant between the studied groups, heart rate and mean arterial pressure were significantly lower in group IV when compared with group N at 10 min after initiation of drug administration. ([Figure 1],[Figure 2],[Figure 3], respectively).{Figure 1}{Figure 2}{Figure 3}

 Discussion



Pediatric postoperative pain management has developed rapidly accompanying the development of new drugs. However, children have remained undertreated for postoperative pain because of the difficulty in pain assessment and apprehension regarding cardiorespiratory depression [8].

IV opioids remain the gold standard for the management of pain, but unfortunately they may be associated with side-effects and IV access may be lost during transfer or because of agitation; insertion of IV access in this condition seems to be difficult, especially in children, and therefore searching for alternative routes for opioid administration may be important.

This study was conducted on pediatric patients admitted for lower abdominal operation under general anesthesia. At the onset of pain, patients were given either IV or nebulized fentanyl.

In this study, the onset of analgesia was rapid in the control group (IV) than in the other two groups (nebulized groups), and this is in agreement with the finding of Sing and colleagues who studied IV fentanyl versus nebulized fentanyl in adult patients and also with study by Kissin [9] who found that maximum serum concentration of fentanyl after intranasal administration is reached at 13 min, whereas maximum serum concentration of fentanyl after IV administration is reached after 2–3 min. In another study, Mather and colleagues reported that the therapeutic level of fentanyl in blood after inhalation is as rapid as IV fentanyl dosing, which is opposite to the results of the present study.

The FLACC score was lower in the control group when compared with FI and FII and was lower in group FII when compared with FI after 10 min, and this can be explained by the rapid rise in plasma concentrations in the IV control group and increased dose in group FII; however, after 20 min, the quality of analgesia was equal in all groups (no significant difference).

The incidence of side-effects (pruritus, nausea, decreased heart rate) increased in the control (IV) group compared with the nebulized groups; this also can be explained by the rapid rise in plasma concentrations of fentanyl in IV group, and this is in agreement with the results of the study conducted by Singh et al. [1].

There were no major side-effects such as hypoxia and respiratory depression in all groups, and this correlates with the findings of Singh et al. [1], Higgin et al. [10], and Worsely et al. [11].

From this study, we can conclude that 2 µg/kg nebulized fentanyl is effective in the management of postoperative pain in pediatric patients undergoing lower abdominal surgery with less side-effects compared with 1 µg/kg IV fentanyl. Another important point is that nebulized fentanyl provides an alternative simple route for effective postoperative analgesia in pediatric patients with delayed onset and less side-effects in comparison with traditional IV routes.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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