Comparing PCA and NAA is crucial in understanding how different pain management strategies impact patient outcomes, particularly LOS and postoperative pain, which this study aimed to uncover. Following propensity score matching for age, sex, and preoperative pain scores, demographic characteristics were similar between the PCA and non-PCA groups. Bernabei et al. noted that older patients were more likely to be undertreated for pain (
20). However, by matching for key demographic variables, our study minimized potential age-related biases.
In our study, the PCA group had higher postoperative pain scores and less postoperative pain relief compared to the non-PCA group. These findings align with a study conducted by Iddagoda et al., who also found worse pain control in their PCA group (
14). Their study showed that PCA was linked to worse postoperative physical function, longer hospital stays, and higher odds of needing support at discharge. Similarly, our study found a longer average LOS in PCA patients, suggesting PCA may be less effective in pain control and recovery.
Increased pain scores among patients receiving PCA may be influenced by a complex interplay of factors such as chronic pain, psychological distress, cognitive impairment, and preexisting opioid tolerance (
16,
21-
23). Future research should aim to stratify patients based on these risk factors to develop personalized PCA strategies and explore adjunctive therapies.
When comparing our study with that of Cho et al., who conducted a prospective study on multimodal pain control versus PCA in rotator cuff repair, both studies highlight PCA's limited effectiveness in pain management (
24). In their study, better pain control and earlier functional recovery were reflected in the multimodal pain control group, with significantly lower postoperative pain scores and fewer adverse effects reported. Duellman et al. compared the effects of multimodal preemptive analgesia versus PCA on postoperative outcomes following total joint arthroplasty (
25). On average, the preemptive analgesia group had shorter LOS. The PCA patients consumed significantly more IV morphine and experienced a threefold increase in postoperative nausea. Additionally, PCA patients were twice as likely to miss rehabilitation therapy sessions and nearly twice as likely to be discharged to an extended care facility. While our study did not examine rehabilitation or post-discharge disposition, an increase in LOS would likely negatively impact both. Lahtinen et al. compared the use of PCA versus NAA in patients undergoing TKA (
15). They found that opioid consumption and use of antiemetics during the first 24 hours post-surgery were similar in both groups. However, the PCA group had a significantly shorter LOS compared to the control group. In contrast, our study noted an increased LOS in patients who received PCA (
15). However, our study focused on patients who underwent upper or lower limb fracture repair as opposed to patients who exclusively underwent TKA, as in this study.
A Cochrane review by McNicol et al. evaluated the efficacy and safety of PCA versus non-PCA for postoperative pain management (
17). The review included 49 studies with 3,412 participants. It found that PCA significantly reduced pain intensity compared to non-PCA, with patients having lower VAS scores at 24 and 48 hours after surgery. The PCA also led to higher opioid consumption and greater patient satisfaction. However, no significant difference in hospital LOS was observed between the two techniques. Overall, the review concluded that PCA is an effective alternative to non-PCA, although the quality of the evidence was rated as moderate to low.
A study by Khan et al. evaluated whether PCA in a fast-track joint replacement program led to increased perioperative opioid consumption and longer LOS (
18). This double-blind, randomized controlled trial involved 80 patients undergoing elective TKA. Patients were randomized into PCA and non-PCA groups. The results showed no significant differences between the two groups in terms of opioid consumption, LOS, pain scores, or opioid-related side effects. While many studies in the literature report greater pain relief and shorter hospital stays among patients receiving PCA, others highlight potential drawbacks, including higher opioid consumption, prolonged hospital stays, or decreased postoperative pain relief. Some research suggests that despite these concerns, the benefits of PCA — particularly enhanced patient autonomy and, in certain cases, reduced LOS — make it a viable alternative to NAA (
8). However, several studies also found no significant differences in outcomes between PCA and NAA (
12,
24). These findings underscore the importance of considering both the type of surgery and individual patient characteristics when evaluating the efficacy of PCA for postoperative pain management.
Our retrospective analysis suggests a notable association between PCA use and increased LOS as well as higher postoperative pain scores when compared to exclusive NAA use, findings that diverge from some prior research outcomes. These discrepancies underscore the complexity of postoperative pain management and the influence of patient and procedural variability. Future research with larger samples or the use of a Bayesian approach using empirical priors is recommended to better estimate these relationships and produce more robust conclusions.
Current pain management protocols from prominent guidelines, such as those provided by the American Pain Society and the American Society of Anesthesiologists, emphasize the use of multimodal analgesia and individualized patient pain management strategies (
16). The PCA is commonly recommended for its ability to allow patient autonomy and timely analgesic administration, improving patient satisfaction. However, its impact on clinical outcomes such as LOS and pain control compared to NAA remains less clear when considering results from McNicol et al., and Khan et al. (
17,
18).
Despite our study's observational design limiting causative conclusions and the relatively small sample size, these findings contribute important preliminary evidence to an area of limited and unclear research. Considering the inconsistent findings in existing literature, our results highlight the necessity for larger-scale studies to rigorously evaluate the impact of PCA versus NAA on postoperative outcomes, ultimately refining clinical guidelines and enhancing patient care.
5.1. Conclusions
This retrospective analysis suggests an association between the use of PCA combined with NAA and longer LOS and higher postoperative pain scores when compared to exclusive NAA use in patients who underwent limb fracture repair. Older patients more often received pain medications than younger patients, regardless of the method of administration. Future studies should consider larger sample sizes or the use of a Bayesian approach to better estimate these relationships. The PCA may be applied based on clinical judgment when patients are expected to have higher pain scores and longer hospital stays. However, careful patient selection and monitoring are essential to optimize postoperative outcomes.