Need for improved treatment of postoperative pain

Postoperative pain treatment continues to represent a significant clinical challenge. Recent surveys demonstrate that 75% of patients experience pain after surgery and up to 30% experience moderate to severe postoperative pain [1-3].

One approach for improving postoperative pain treatment is the introduction of hospital-based acute pain services such as those initially introduced in the USA and Germany in 1985 [4]. With such services followed an increased use of advanced pain treatment modalities such as regional blockade, epidural analgesia and patient controlled analgesia. However, improved pain relief per se could not be demonstrated to improve postoperative outcome, except that patient satisfaction rose and pulmonary complications became fewer [4]. Instead, it was suggested that improved patient outcomes could be obtained by integrating the work of acute pain services with multimodal rehabilitation programmes or fast-track surgery. It was subsequently demonstrated that a standardized pain treatment plan that was part of a fast-track set-up reduced the length of the stay and also the incidence of severe medical complications compared with a conventional postoperative rehabilitation programme [5, 6].

The Section of Acute Pain Management and Palliative Medicine (EASP) was established at Rigshospitalet, Copenhagen, a tertiary university hospital in Denmark. One of the Section’s main objectives is to introduce and implement multimodal postoperative analgesic and anti-emetic regimens and to integrate these with fast-track surgery programmes. Consequently, we initially conducted a cross sectional study to describe the current postoperative pain and nausea treatment at Rigshospitalet with a view to identifying improvement areas.

MATERIAL AND METHODS

This was a cross-sectional, observational and non-interventional study. The local Regional Ethics Committee was asked, but since the study was a quality assurance study, no approval was needed.

Through interviews with doctors and nurses at surgical departments, up to four of the major and most frequently performed types of surgery at the departments were identified. Furthermore, the nature of the standard postoperative pain and nausea treatment for each of these procedures was registered from interviews and from the electronic patient medication (EPM) record. Procedure-related information on pain management handed out to patients was collected as were staff guidelines on pain and nausea treatment.

Audits of three individual patient courses from each type of surgery were performed. Demographic data (gender, age and usual opioid consumption) were collected. Furthermore, data on any visual analogue scale (VAS) pain scores (at rest and during mobilization); analgesic treatment (opioids, paracetamol, nonsteroidal anti-inflammatory drugs (NSAIDs) and gabapentin) and nausea (incidence and anti-emetic treatment) were tracked and collected for the first three postoperative days (POD). This was based on patient and nurse records, pain score forms and EPM registration. Only written data material and data from the EPM were used; no patients were interviewed for the audit

Trial registration: not relevant.

RESULTS

The study was carried out at Rigshospitalet – a tertiary 1,100 bed hospital – from November 2009 to February 2010. Data from 121 patients, 60 female and 61 male, with a mean age of 56 (range 15–93) years, were included in the study. Patients represented 12 surgical departments and 44 surgical procedures (Table 1). Eighteen of the patients received opioid treatment prior to their hospital admission.

Pain

Few data on pain score were available at the surgical departments. For the first three PODs, no VAS-pain scores at rest were available for 55%, 71% and 84% of patients, respectively. Furthermore, no VAS-pain scores during mobilization were available for 80%, 87% and 89% of patients on POD 1-3, respectively (Figure 1 A). Consequently, it was not possible to collect reliable information on the quality of pain management.

Opioid treatment

Most patients (> 75%) patients received an opioid in the first three postoperative days. Seven different opioids were used at the surgical departments (Figure 1 B). Oxycodone (40%) was the most frequently used drug followed by morphine (39%).

Non-opioid analgesic treatment

The overwhelming majority of patients (97%) received paracetamol. However, according to the EPM, sufficient 24-hour treatment of 1 g every six hours was only given to 47%, 59% and 63% of the patients on POD 1-3, respectively.

A total of 53 patients (44%) received NSAID treatment during POD 1-3. Ibuprofen (51 patients) was the most frequently administered drug. However, according to the EPM, sufficient 24-hour treatment (defined as a minimum of 1,200 mg ibuprofen/24h), was only given to 57%, 85% and 65% of patients on POD 1-3, respectively.

Multimodal pain treatment with paracetamol ibuprofen and gabapentin.

Whereas most patients received analgesic treatment with paracetamol, relatively few patients were treated with a combination of non-opioid analgesics (Table 2).

Nausea

Approximately one out of five patients suffered from nausea during POD 1-3 (Table 3). However, only three departments (7%) presented a written guideline for nausea treatment. For the majority of the procedures (93%), an anti-emetic drug was prescribed as a part of the postoperative pain treatment plan in the EPM with ondansetron (88%) and metoclopramide (31%) as the most frequently administered drugs.

Pain treatment guideline

A standard, procedure-specific pain treatment plan was present in the EPM for 40 of 44 procedures.

However, a written, procedure-specific pain treatment guideline was available to staff in only 14% of the cases.

Patient information

In the handout and other written information aimed at patients about the postoperative period, only 16 of 44 procedures presented a specific goal for the pain treatment, e.g. that the patient should have low pain levels at rest and be able to move freely and/or cough.

DISCUSSION

This cross-sectional quality assurance study performed at a tertiary university hospital revealed several postoperative pain treatment issues with a potential for improvement. Data on the quality of postoperative pain management were scarce, written procedure-specific guidelines for pain management were few and the use of multimodal opioid-sparing pain treatment was suboptimal. This situation was mirrored in a the consumption of opioids by the majority of the patients who had a high incidence of nausea, an opioid-related side-effect. Although disappointing, especially at a university hospital, these issues are most likely of a more general nature not only limited to Rigshospitalet, and they have, indeed, been observed in multi-national surveys [1, 3].

We were unable to collect pain scores for the majority of the patients. An estimation of the effectiveness of the actual pain treatment was therefore impossible. Regular pain scoring of patients is a basic tool in postoperative pain care and is essential in order to improve and adjust treatment. Data on pain scores during mobilization are especially valuable, as high pain scores may keep patients from early mobilization and ambulation and thereby prolong convalescence [7, 8].

In contemporary evidence-based postoperative pain treatment, attenuation of pain is achieved by a combination of different analgesics affecting different pain mechanisms, e.g. nociceptive, neuropathic and inflammatory pain mechanisms [7]. Thus, an additive or even synergistic effect on pain can be achieved and pain during mobilization reduced. Another achievement from multimodal treatment is a reduction of opioid consumption and thereby also of its well-known side-effects [9]. This is well documented for drugs like NSAIDs [10, 11] and gabapentin [12, 13]. The present study showed that most patients were treated with paracetamol, but combinations of non-opioid analgesics were used in only 7% (paracetamol + NSAID + gabapentin) and 44% (paracetamol + NSAID) of the patients. We believe that this area holds an important potential for improvement.

Most patients needed treatment with opioids, and oxycodone was used as frequently as morphine. However, morphine is generally recommended as first-choice drug when opioid treatment is warranted [14], and there is no evidence that oxycodone is a superior drug compared with morphine. On the contrary, the prescription of morphine rather than e.g. oxycodone or fentanyl may be cost-saving, not only for the hospital, but also for society [14].

Our study was not designed to indicate which patient should have been treated with an opioid or not, but it does serve to demonstrate the frequent use of opioids; a use which may well be reflected in the relatively high incidence of nausea on POD 1-3. This, in turn, emphasizes the importance of an opioid-sparing pain treatment [13, 15]. It is also of concern that evidence-based guidelines for treatment of postoperative nausea and vomiting (PONV) were present for only a small minority of the procedures. In the majority of cases, PONV treatment was limited to one drug, e.g. ondansetron or metoclopramide, and administered at the discretion of the attending nurse on the ward. If evidence-based anti-emetic prophylaxis and therapy [16] were combined with guidelines to support clinical staff, important improvements would be achievable in this area. Furthermore, such changes would limit the use of metoclopramide, which has no evidence-based anti-emetic effect in the doses typically used (10 mg), and which has unwarranted side-effects at higher doses [17].

In fast-track surgery, it is highly important that patients are well informed and cooperative. Information about the planned pain treatment and any related goals may help patients to cooperate with the staff and thereby improve their pain management and outcome [18].

The results of this cross-sectional quality assurance study identify challenges that need to be met in daily clinical praxis at our hospitals. To handle these challenges, interdisciplinary collaboration is required between all involved staff in the course of the patients from admission to discharge. Furthermore, updated knowledge and education on pain treatment is needed. And, finally, the handling of these challenges requires the introduction of procedure-specific pain and nausea treatment plans that are based on best knowledge and incorporated into daily practice and which include concomitant monitoring of implementation and results [19]. Consequently, a coordinating project- and research unit working cross-sectionally and facilitating and promoting collaboration between a wide range of clinical staff is warranted.

In summary, the way forward includes organizational adaptation and represents a natural extension of the work of the traditional acute pain service. The objective of such work is to facilitate, develop, teach and implement updated, procedure-specific postoperative pain treatment plans at the hospital [19]. Such plans should be based on collection of data both before and after implementation in order to document results and make adjustments as required. Finally, plans should be incorporated with fast-track treatment programmes to achieve the full advantages of improved pain treatment.

Correspondence: Ole Mathiesen , Enhed for Akut Smertebehandling og Palliation 4114 Rigshospitalet, 2100 Copenhagen, Denmark. E-mail: olemat@dadlnet.dk

Accepted: 9 January 2012

Conflicts of interest:none