Persistent post-surgical pain (PPP) reduced by high-quality management of acute pain extended to sub-acute pain at home

Acute pain service (APS), accelerated recovery programme (ACC), or extended pain-care at home

Most hospitals in the Nordic countries are supposed to have an anaesthesiologist-based acute pain service (APS), making epidural-infusion, peripheral nerve-infusion, and intravenous opioid patient-controlled-analgesia (PCA) safe and effective procedures on surgical wards during the first few days after major surgery [4]. Partly in order to save money on the hospital budget, patients are often discharged early after surgery, leaving the patients to struggle with severe acute pain at home. Hospitals, especially in Denmark, have transformed the APS to an accelerated recovery programme (ACC), a “fast-track” for patients out of the hospital after surgery [4]. When this is part of a well-planned regimen with focus on pain-relief, mobilization, early oral nutrition, and multimodal support, this can be beneficial for the patient. But there is a risk that during the first few days at home after an ultra-short stay in the hospital with full attention from an APS or an ACC, self-management at home becomes painful and difficult. For patients who are at risk for PPP, this period is most likely very important for the final result: burdensome PPP or recovery to good health, as Tiippana et al. have documented [3].

The post-thoracotomy period is notoriously painful and problematic because the effort of deep-breathing and coughing provokes severe pain. The risk of having persistent post-surgical pain (PPP) after 6 months, with deleterious consequences for the patients’ health-related quality of life, can be as high as 67% [5].

Tiippana et al. chose this ideal operation for studying interventions that may reduce this high risk of PPP [3].

Extended APS-follow-up of pain management at home decreases risk of PPP

Tiippana et al. had the APS follow their three intervention groups (two groups having NSAIDs and I.V. morphine-PCA, and a group having Patient-Controlled-Epidural-Analgesia (PCEA)) with high quality pain management for a mean of 8 days in hospital and also after discharge from the hospital, for as long as there was pain that needed special attention. The control group of patients, treated with standard “usualcare” (thoracic epidural without PCEA) and no special focus on helping patients with pain at home, were discharged from the hospital already 5 days after surgery.

An important finding is that the three intervention groups, who all had extended high quality pain management at home, had a much reduced PPP, only 3%, compared with the control group’s 24% 6 months after surgery [3].

Acute post-thoracotomy pain at rest (in bed) can be relieved by NSAIDs and I.V.-PCA-morphine

Tiippana et al. [3] studied valdecoxib and its I.V. pro-drug parecoxib (by infusion for 44h after surgery), oral diclofenac and diclofenac I.V. (infusion for 44h after surgery), both in combinations with morphine I.V.-PCA. They could demonstrate that these regimens were satisfactory for relieving pain and discomfort when the patients were restedinbed. There were no differences between the specific COX-II-inhibitor valdecoxib and the COX-I and (mostly) COX-II inhibitor diclofenac.

Individually optimized thoracic epidural analgesia provides best dynamic pain relief

The routine for post-thoracotomy pain reliefisthoracic epidural analgesia also in the Finnish capital [3]. They (as we) have not been impressed by thoracic paravertebral block, even when the surgeon placesthe paravertebral block-catheter under directvision towards the end of the thoracotomy [3,6]. They confirm the very important observation that epidural analgesia must be tailored and optimized for each individual patient, by PCEA or adjusted by the ward nurses, in order to achieve the best possible reduction of pain provoked by deep breathing and forceful coughing (dynamic pain) [3,7,8].

An epidural infusion that is not followed closely and adjusted appropriately by well-trained nurses on the surgical wards, and by the APS as needed, can be a disappointing experience for the patients, especially when there is not sufficient focus on transition from epidural analgesia to systemic analgesics [9].

The high risk of PPP after thoracotomy is reduced by high-quality management of acute pain in hospital and sub-acute pain at home

Several studies have documented a reduced risk of PPP after thoracotomy when patients had adequate epidural analgesia [2,5]. The present study from Helsinki, documents clearly, again, that unless epidural analgesia is optimized for each patient, and the patients are followed up with adequate pain management at home, epidural analgesia does not have the same profound effect on persistent post-surgical pain [3]. In fact, the patients who had NSAIDs+morphine-PCA had significantly lower PPP than the control group of patients having standard treatment with epidural “as usual” without extended follow-up after discharge [3].

Therefore, I agree with the authors’ statement on the implications of their study that “High quality acute pain management and follow-up continuing after discharge could be more important than the analgesic method perse in preventing persistent post-thoracotomy pain” [3].

However, we must not forget that well-done and followed-up epidural analgesia does have several well-documented benefits on postoperative morbidity and mortality [10]. Many of these benefits from an optimal epidural service are in fact lost and the risk of rare but serious complications is increased when the epidural procedure and follow-up is less than optimal [10,11].

Cost-saving for the hospital by discharging the patients 3 days earlier after thoracotomy in the control group [3] were lost for the health-care budgets of society: Patients who end up with difficult to treat PPP, will cost society much more in health care provisions [12] than the few savings on the hospital budget from early discharge after surgery.

Some well-documented preoperative factors that increase risk of PPP

Experience has shown that patients with the following characteristics do have high risk of PPP [2]:

1. Pain in the area of planned surgery.

2. Having chronic pain anywhere in the body before surgery.

3. High level of life-stress.

4. Intense anxiety about outcome of surgery (“catastrophizing thoughts”).

5. Being female.

Factors that increase risk of PPP after surgery:

1. Severe acute pain during the first few days after surgery is also a well-documented risk factor [2].

2. Severe sub-acute pain after discharge from the hospital cannow be added [3].

What the peri-operative health care providers can do to reduce the risk of PPP

When some of these pre-operative risk factors are present, the patients should have regional anaesthesia when appropriate, continued into the postoperative phase as long as feasible.

Administer lidocaine intravenously before and during surgery, possibly a low dose ketamine infusion, administer pregabalin (or gabapentin) before and after surgery, and use high concentration nitrous oxide inhalation as part of general anaesthesia, when appropriate. For research behind these statements, see [2].

After surgery, an anaesthesiologist-based APS can reduce acute-pain, and it must be extended into the sub-acute pain phase at home, focusing on those patients with protracted pain [3]. This is a resource-demanding activity that is necessary if we want to give patients the best possible protection against PPP and the miserable health-related quality of life that follows with chronic pain [3]. However, chronic pain, whether caused by surgery or by other causes, is a costly health care problem [12]. Reducing the incidence of PPP from 24% in the control group to 3% as Tiippana and co-workers did [3], will save large health care costs for society. The practical difficulty with implementing this practice is that the cost and the savings are on different budgets [12].

Patients gain marked benefits from taking part in clinical research

Tiippana and co-workers’ observation that patients gain marked benefits from being part of a clinical outcome research project is important: The “context-sensitive therapeutic effect” is always present in randomized controlled trials. It is positive and lasts as long as patients get the extra attention from the research team [13]. This potent nonspecific effect can sometimes obscure a specific treatment effect [13]. To use patients who receive “treatment as usual” as control patients will eliminate this unspecific “context-sensitive-therapeutic effect” from the control group, resulting in a more sensitive study design [3].

Conclusions

Both patient-controlled epidural analgesia and NSAID+IV-PCA morphine provided sufficient analgesia with little persistent pain compared with the incidence of persistent pain in the Control group having standard epidural analgesia but no special follow-up after discharge [3]. High quality acute pain management and follow-up continuing after discharge could be more important than the analgesic method per se in preventing persistent post-thoracotomy pain [3]. In the acute phase the measurement of pain when coughing and the duration of pain after coughing could be easy measures to recognize patients having a higher risk for persistent post-thoracotomy pain [3].

Implications

To prevent persistent post-thoracotomy pain, the extended protocol for high quality pain management in hospital covering also the sub-acute phase at home, is clearly important [3]. This study also provides some evidence that there are safe and effective alternatives when thoracic epidural analgesia and paravertebral blocks are contraindicated due to risk of bleeding. Comparing patients having standard “as usual” care with the intervention patients provides information of the added value of being a study patient [3], and it can increase sensitivity of an intervention study. This important observation by Tiippana et al [3] deserves further consideration in future studies.