What can we do to prevent PPOU?

In this step, Dr Jane Quinlan, Consultant in Anaesthesia and Pain Medicine at Oxford University Hospitals Trust and Honorary Senior Clinical Lecturer at the University of Oxford, outlines what practical steps can be taken to reduce the risk of this complication happening to your patients.

Hospital clinicians who prescribe discharge opioids have to balance two important concepts:

Firstly, we must give the patient enough analgesia to make a good functional recovery. This will vary according to the procedure: a patient having a knee replacement will need opioids for longer than a patient having a hernia repair, for example.

It will also depend on how much opioid a patient has needed in hospital: if no opioids were needed in the 24 hours before discharge, then the patient should not be sent home with opioids.

Secondly, there is a risk of giving too much opioid on discharge so that opioids are left, unused, in the community leading to diversion, accidental overdose or continued use (PPOU).

Risk Factors for PPOU

Some of these risk factors may be modifiable, and in Week 3 you will discover how to address them practically.

Safer Principles of Postoperative Opioid Prescribing

Steps of analgesia

Acute pain gets better with healing, so we give most analgesia after surgery, then go down the analgesic steps as pain settles. This concept is referred to as the reverse pain ladder.

Strong opioids for postoperative pain must be short-acting and used only as necessary (also called pro re nata or PRN) before mobilisation or activity (see Function below).

There is no place for long-acting (modified-release) opioids in the management of acute postoperative pain.

The diagram above shows a three-step approach to weaning analgesia over time as pain decreases. In the course of normal recovery, and as pain improves, patients would be expected to ‘step down’ the ladder from left to right, stopping opioids first. Depending on the severity of postoperative pain, on discharge from hospital a patient may be started on the top step, step 3. They should be prescribed a higher potency immediate-release opioid (eg morphine or oxycodone) for a limited period, along with regular simple analgesics (paracetamol and if not contra-indicated, a non-steroidal anti-inflammatory drug – NSAID). The next step down, step 2, utilises either lower potency opioids (e.g. codeine, dihydrocodeine or tramadol) or less frequent/lower doses of a high-potency opioid (you will explore whether this makes a difference in Step 2.9). Again, these should be in combination with simple analgesics. As pain improves, opioids can be weaned off completely on step 1 with the patient continuing with paracetamol (plus NSAID) until no longer required. A larger, screen-readable version is available to download below.

Assessment

Function

Functional Activity Scale

FAS-A No limitation: the patient is able to undertake the activity without limitation due to pain

FAS-B Mild limitation: the patient is able to undertake the activity, but experiences moderate to severe pain

FAS-C Significant limitation: the patient is unable to complete the activity due to pain or pain treatment-related adverse effects

Expectations

Reduction and risk management

The amount and duration of discharge opioids given are important: the risk of PPOU is higher if patients are given larger quantities or longer courses of opioids.

Best clinical practice

Identify patients pre-operatively who have a higher risk of PPOU:

• already on long-term opioids
• anxiety or depression
• unrealistic expectations of a pain-free recovery

Educate patients on:

• pain expectations
• multimodal analgesia
• analgesic weaning
• safe storage
• safe disposal

Limit discharge opioids:

• depending on procedure
• depending on patient use in past 24 hours
• typically to less than a week
• avoid repeat prescriptions of opioids after discharge
• avoid modified-release opioids

You will explore these principles, and the supporting evidence which backs their implementation, in greater detail over the next two weeks.