General overview of findings
This study consolidated a general guide for acute postoperative pain management following podiatric day surgery in Australia based on the severity of pain. The majority of panellists agreed acute postoperative pain management for podiatric surgery should be based on type and/or extent of surgery, osseous involvement with or without internal fixation, and patient factors such as age, comorbidities, or drug interactions or sensitivities. Therefore, it was prudent to classify the prescribing approach according to pain severity as this would incorporate the various factors that influence pain. In general, the intensity of pain has been thought to correspond to the magnitude of surgical injury and type of surgery, with bony procedures being more painful than soft-tissue procedures, as the periosteum has the lowest pain threshold of the deep somatic structures [14, 22]. Hence, it can be expected that more involved soft tissue dissection and osseous surgery corresponded with increased pain levels.
The main findings of this study were in line with the general recommendations found in the literature. While the exact combination of analgesic drugs used could not be determined from this survey due to the numerous combinations possible, the panellists’ responses demonstrated a pattern that reflected a stepwise approach to pain management, with an escalation to stronger analgesics with increasing pain levels, as well as a recommendation for utilising multimodal therapy for these larger procedures that require more extensive dissection. There was also majority view that oral opioids such as paracetamol plus codeine, oxycodone, tapentadol, or tramadol should be reserved for breakthrough pain at all pain severity levels (Tables 2, 3 and 4). A combination of long-acting local anaesthetic mixed with a corticosteroid like dexamethasone, was agreed on for general use in a preoperative or intraoperative setting (Table 5).
Multimodal analgesia for acute postoperative pain
It is widely accepted that acute postoperative pain management should employ a multimodal approach, but there is little consensus with regards to the specific combinations of analgesics used in specific situations [12]. Multimodal treatment has been shown to provide superior pain relief, and a reduction in opioid dependence and opioid related adverse events [5, 7, 12, 23, 24]. The combined drug synergy effects that block generation and perception of pain at several different stages in the pain pathway has been reported to be necessary for effective pain control [7, 12]. Several studies have reported on optimal pain management strategies through multimodal analgesia for elective foot and ankle surgeries with the use of the paracetamol, NSAIDs, opioids, and α2δ-ligands, and regional anaesthesia [5, 7, 12]. There was also indication from this study that multimodal therapy should be adopted for acute postoperative pain management, however, this could not be fleshed out further than identifying the most commonly accepted and prescribed analgesics. This was in part due to the large number of potential drug combinations being unfeasible to include in a single survey round.
Stepwise approach to acute postoperative pain management
This study supports a stepwise approach to acute postoperative pain management after podiatric surgery. A majority of panellists voted in favour of non-opioids and against opioids for mild acute postoperative pain (Fig. 1). This suggests paracetamol, paracetamol SR, and/or a COX-2 inhibitor be prescribed as first-line treatment for mild acute postoperative pain, while a non-selective NSAID and opioid combination product may be used with discretion. For moderate acute postoperative pain, paracetamol, a COX-2 inhibitor, opioid combination product, and/or tapentadol IR were suggested as the first-line options, while the other drug options were found to be neither appropriate nor inappropriate (Fig. 2). This could be attributed to the fact that moderate pain is a middle ground where titrating the right amount of analgesia can be difficult; that is, inadequate analgesia could negatively impact the patient’s pain experience and recovery, while overprescribing increases the risk of the patient experiencing unwanted adverse effects. For severe acute postoperative pain, this study suggested paracetamol, a COX-2 inhibitor, and oral opioids such as combination products, oxycodone, tramadol, tapentadol, or sublingual buprenorphine should be considered as first-line treatment, with greater consensus for opioids at this level of pain (Fig. 3).
It should be clarified that the panellists are not recommending that patients are prescribed all of the medications deemed appropriate for use at the specified pain levels, but rather that a selection of these medications that are deemed appropriate should be made while taking into account safe doses, a patient’s existing list of medications, as well as other patient factors.
Opioids for breakthrough pain
Opioids have often been reported to be used as rescue analgesics used at higher levels of pain or for breakthrough pain. This study results recommend oral opioids such as codeine, oxycodone, tapentadol, or tramadol be reserved for breakthrough pain at all levels. While these drugs may be considered inappropriate for milder pain levels, they should still be considered when necessary, and conversely, while these drugs may be deemed appropriate for more severe pain, they may not necessarily be required. This mirrors the view in the literature that opioids be used as rescue analgesics and only as required due to their potential undesirable effects that could impede recovery [5]. It should also be noted that at all pain levels in this study, a COX-2 inhibitor was found to be highly appropriate, while a non-selective NSAID was generally found to be neither appropriate nor inappropriate.
Non-selective NSAIDs and COX-2 inhibitors
NSAIDs are commonly used as first-line medications to treat postoperative pain and inflammation. Wang and colleagues proposed the combination of paracetamol and conventional NSAID or COX-2 inhibitors should be used whenever possible [5]. Contrary to this, Kohring and Orgain recommended non-selective NSAIDs and COX-2 inhibitors be used for postoperative pain management after soft tissue procedures, but not for procedures that require bone healing [7]. There is level III evidence to corroborate that short-term, low-dose use of NSAIDs and COX-2 inhibitors may have an inhibitory effect on bony healing, but not on soft tissue healing [7, 25]. Other studies on the effects of NSAIDs on bone healing concluded that in the absence of robust clinical or scientific evidence, clinicians should treat NSAIDs as a risk factor for bone healing impairment, and their administration should be avoided in high risk patients [26, 27].
The results from this study align more closely with that of Wang and colleagues. It was agreed an oral COX-2 inhibitor was appropriate for acute postoperative pain management at all pain levels by an overwhelming majority of the panellists. This could be attributed to the fact that inhibition of COX-1 results in platelet dysfunction and gastrointestinal toxicity, and COX-2 inhibitors have little or no effect on COX-1 at therapeutic doses, thus providing anti-inflammatory and analgesic actions with a reduced risk of these unwanted COX-1 side effects [7, 28]. It should be noted, however, that COX-2 inhibitors are still associated with adverse effects, including but not limited to gastrointestinal adverse effects [28]. In contrast, a non-selective NSAID was found to be neither appropriate nor inappropriate by the majority in all but the severe pain level, where the vote was tied between being appropriate and neither appropriate nor inappropriate. While a non-selective NSAID may pose a greater risk to platelet and gastrointestinal function compared to COX-2 inhibitors, it still offers the benefits of analgesia, accessibility, low cost, and non-addictive properties that provide a suitable pain management option for the carefully chosen patient.
Opioid prescribing practice and concerns
Prescribing opioids for acute pain management in foot and ankle surgery is highly varied and without formal recommendation. The literature has few guidelines for opioid-prescribing practices, with only anecdotal suggestions offered, and because physicians cannot accurately predict how much analgesia a patient will require, opioids tend to be overprescribed [9, 10, 15, 23, 29,30,31]. Similarly, this study had a lack of a definitive consensus on prescribing opioid analgesics for moderate acute postoperative pain, however, the consensus to use opioids at more severe pain levels in this study is reflective of the literature. These include a level II prospective observational cohort study that proposed patients who had hindfoot, ankle, or osseous procedures required more opioids [9], as well as the study by Chan et al. that found fewer opioids were required postoperatively for percutaneous foot and ankle surgery due to the smaller incisions and minimal disruption to surrounding soft tissue [31].
There was agreement from panellists that oral opioids should be prescribed for a shorter duration for soft tissue procedures compared to osseous procedures. This can most likely be attributed to the opioid prescription concerns raised by the majority of panellists (Table 6). The addictive potential and side-effect profile associated with opioids are widely recognised in the literature; consequently, the increase in accidental death and high health care costs reported with opioid abuse has created a need for alternative methods of pain control, as well as legislation restricting opioid prescriptions [7, 23, 29, 32].
Scheduled medicines list for podiatric surgeons
The secondary aim of this study was to generate consensus on improvements to the current list of scheduled medicines available to podiatric surgeons in Australia, particularly for acute postoperative pain management. The panellists agree that podiatric surgeons in Australia should have access to a higher oral oxycodone dose strength and duration of course than the current allowance as outlined in Table 7. The results demonstrated the majority of panellists were advocates for access to other opioid alternatives such as oral tramadol, oral tapentadol, or sublingual buprenorphine; other non-opioid alternatives such as gabapentin, pregabalin, or ketamine; and additional anti-emetic medications.
One of the more contentious topics was the consensus for podiatric surgeons to have access to an open formulary with further specialist input, to achieve optimal pain management. The surgeon is logically the healthcare practitioner best equipped to understand the patient’s need for pain control given their close involvement throughout the patient’s surgical journey, while the pain specialists bring their in-depth knowledge and expertise on pain management to the table. Not only would this recommendation allow the surgeon to assume responsibility with continuity of care, at the same time it also promotes interdisciplinary involvement in acute postoperative pain management when other specialist input is obtained. This is advantageous to both patient and practitioner as the benefits of more immediate and complete facilitation of care with these safety precautions and tailored analgesia outweigh the risk of adverse events and potential delays with treatment. It is, however, imperative prescribers seeking to obtain access to a wider range of medications have appropriate training, so as to ensure the principles of safe prescribing are adhered to at all times.
Psychosocial factors and previous success or failure
Finally, other factors beyond drug efficacy and side-effects need to be considered when prescribing for acute postoperative pain. Panellists recommended that psychosocial factors and previous success or failure with certain analgesics should guide choice of drug and dosing regimen (Table 8). A salient point made by Kohring and Orgain was that clinical judgement should always be applied to adjust, omit, or substitute appropriate medications, doses, intervals, and durations to ensure safe and optimal care [7].
Strengths, limitations, and future studies
The strength of this Delphi study was that it afforded an avenue to guide group opinion from experts within their fields toward a final decision with the benefit of panellist anonymity, which has been proposed to reduce the effects of conformity to the dominant view and the bandwagon effect [16, 17]. Moreover, it was a useful platform to initiate discussion on topics of controversy or that have a lack of clarity, such as opioid prescribing and additional endorsement rights for podiatric surgeons.
Several limitations accompany the methodology and analysis of this study. Due to time constraints, creation of this study’s initial open-ended survey was limited to questions developed by the investigators, without the use of phone interviews and face-to-face conversations. One of the major limitations of this research method included a lack of a cut-off for consensus. The literature suggests variation in the level of consensus reported, with some studies defining a consensus level of 75 to 80%, while others omitted a defined cut-off [18]. Nevertheless, due to the explorative nature of the study, the authors felt that the results would be better captured by demonstrating the majority vote, instead of excluding statements that fail to meet an arbitrary cut-off. There was also the potential for researcher or subject bias and a lack of strong evidence to support its reliability [16, 21]. That is, if these same surveys were proposed to a different panel, there could be a possibility for different outcomes [16, 21]. Another potential weakness of this study is the participating panellists and their potential conflicts of interest; specifically, the number of participating podiatric surgeons outweighed the number of anaesthetists involved, and thus, could be considered to have skewed the results. While the results show the majority vote for each Delphi statement, they do not illustrate whether the anaesthetists concurred with the views of podiatric surgeons. The exclusion of direct and/or indirect patient contribution to this study could also be considered a limitation, given the era of patient centred care and shared decision making.
Goodman stated the final judgement should always consider the distribution of responses and be aware that the group’s agreement may not be as significant as it appears [17]. Future studies may consider a panellist group consisting of equal numbers of podiatric surgeons and anaesthetists, and clearly delineate an algorithm for the combination of drugs and their dosing regimen for acute postoperative pain management according to each severity level. The use of an independent researcher, who is not involved in the data analyses, to conduct focus groups and phone or face-to-face interviews to develop the first round survey questions, may improve the rigour of this type of mix-methods study.