Summary

Neither opioids nor an opioid-free multimodal pain management strategy were shown to be superior in controlling pain in paediatric patients having undergone arthroscopic knee surgery.

Abstract

Introduction

The opioid epidemic is a prevalent and growing challenge faced by physicians as legal prescriptions account for a non-negligible proportion of the incidence of opioid use disorder. However, there is a paucity of literature regarding the avoidance of opioids for pain control in arthroscopic surgery for paediatric patients. This widespread issue can start to be addressed through the application of alternative methods such as a multimodal pain management strategy.

Aim

The purpose of this retrospective case-control study is to quantitatively evaluate the current use of opioids postoperatively within the recovery room and as exit prescriptions in paediatric patients undergoing arthroscopic knee surgery as well as to compare the effectiveness of opioids and non-opioid medications in terms of pain management.

Methods

Charts of patients having undergone arthroscopic knee surgery between 2014 and 2018 were reviewed at a tertiary academic paediatric hospital. Inclusion criteria were patients between the ages of 4 and 18 years old who underwent arthroscopic knee surgery. Exclusion criteria were patients who had mental illnesses, cognitive deficiencies, or concomitant surgery.

Relevant data were extracted from patients’ charts. Opioid doses were converted to morphine equivalence and adjusted for weight for statistical analysis. Pain was assessed based on the Visual Analog Scale (VAS) in the recovery room and reassessed after discharge via telephone follow-up.

Using SPSS version 24, differences between both groups were analyzed through student t-tests and correlations were calculated between variables.

Results

Our study population consisted of 211 patients. 152 were followed up with where 123 had described their pain as “controlled” (PC) and 29 described it as “uncontrolled” (PU) at a median of 2 days.

Age, weight, and VAS discharge scores differed significantly between the two groups. The PC group had a mean age of 15.97 ± 1.50 compared to 15.17 ± 2.32 for the PU group (p-value = 0.024). The PC group weighed on average 68.74 ± 16.72 kg compared to 60.47 ± 14.85 kg (p-value = 0.016). As well, there seemed to be an inverse relationship where the PC group had higher VAS discharge scores (3.42 ± 1.89) compared to the PU group (2.58 ±1.98) (p-value = 0.044). Another statistically significant finding existed where 26 (89.7%) of the PU group were given regional and/or multimodal anesthesia compared to just 80 (65.0%) of the PC group (p-value = 0.009). As well, a trend was found where the PC group was prescribed a lower morphine equivalent mean dose (0.097 ± 0.045 mg/kg) compared to the PU group (0.115 ± 0.047 mg/kg) (p-value = 0.065).

A moderate correlation was found between mg/kg morphine equivalent prescribed in PACU and VAS PACU scores (r = 0.473, p-value < 0.001). A weaker correlation was noted between mg/kg morphine equivalent prescribed in PACU and VAS discharge scores (r = 0.304, p-value < 0.001). Another weak correlation existed between VAS PACU and VAS discharge scores (r = 0.341, p-value < 0.001).

Regression analysis confirmed that tourniquet use (OR = 2.93, 95% CI = 1.01 – 8.52, p-value = 0.049) and higher VAS discharge scores (OR = 1.34, 95% CI = 1.01 – 1.79, p-value = 0.046) were associated with increased pain control at follow-up whereas regional and/or multimodal anesthesia use (OR = 0.19, 95% CI = 0 – 8.11, p-value = 0.043) was associated with decreased pain control at follow-up.

Conclusion

Currently, opioids seem to be used in greater quantities for patients that experience greater post-operative pain. This is possibly associated with a reaction by physicians to prescribe higher opioid doses instead of favoring a comprehensive multimodal approach when faced with a patient complaining of pain. The results suggest that higher doses of opioids following surgery might not be associated with improved postoperative pain management. However, non-opioid analgesics have not shown a significant correlation with pain control either. Further research is warranted into an opioid-free multimodal pain management strategy targeting better postoperative pain control without the risk of initiating opioid use disorder.