Monitoring Pain

Macintyre and Schug (2007)

METHODS OF ASSESSING PAIN

The inability of health-care professionals to adequately assess pain is one of the primary reasons for inadequate pain management (Prevost 2009). The choice of methods used for assessment are predicted based on our knowledge of what pain is and how pain from an individual is converted to words or expressions perceived by others (Puntillo et al. 2009). Careful consideration needs to be given to the assessment tool chosen for the critically ill population because they are often unable to participate in the assessment process (Puntillo et al. 2009).

Patient’s Self-Report

This is considered the most reliable method of pain assessment (Puntillo et al. 2009). In the ICU population this method is still feasible and offered to patients who are able to communicate, even if not verbally (Puntillo et al. 2009). A numerical rating scale (NRS) with a standard scale of 1–10 can still be utilised if the patient is able to point to the scale or nod to simple commands. It has been reported that even patients with reduced cognitive ability are still able to self-report pain, with the added benefit that this method can be adapted to other variables such as nausea and vomiting (Macintyre and Schug 2007). Laminated charts containing an NRS, as well as an outline of a body that patients can point to locate their pain, are readily available.

Behavioural Tools

When the patient is not able to communicate at all, the use of a validated behavioural tool is recommended. Pain assessment using this method is based on behavioural and physiological indicators that guide the practitioner through pain assessment, management and decision-making process (Puntillo et al. 2009). Tools such as the pain assessment, intervention and notation algorithm (PAIN) and critical care pain observation tool (CPOT) prompt the following processes: assessment of pain-related behavioural and physiological indicators, identification of potential risks of opiate administration, and implementation and documentation of analgesic treatment (Puntillo et al. 2009; Gelinas et al. 2011).

Current Research

Other methods of pain assessment are currently raising interest and promoting further exploration. The bispectral monitor (BIS) is a non-invasive method using electromyographic (EMG) activity and. in some models. electroencephalographic (EEG) activity to quantify electrophysiological changes in the brain in response to pain (Gelinas et al. 2011).

Pain Intervention

The nurse plays a crucial role in the administration of analgesia. Although pharmacological methods are most frequently used, the nurse is uniquely located to give physical and psychological support in the management of pain (Prevost 2009). The mainstay of pharmacological interventions in critically ill patients are opiates, usually intravenous on the ICU (Prevost 2009; van Heerden 2009). Morphine is usually the drug of choice on the ICU because of its efficacy, low cost and availability, although it has some serious side effects in critically ill patients including reduced gut motility and prolonged effect due to its long half-life. Non-steroidal anti-inflammatory drugs (NSAIDs) are not frequently used in the critically ill population because of the potential side effects such as renal dysfunction, gastrointestinal haemorrhage and platelet inhibition leading to increased bleeding tendency (van Heerden 2009).

Monitoring the Patient with an Epidural

Epidural anaesthesia is viewed as the gold standard in pain relief because it is one of the most effective forms of pain relief (Chumbley and Thomas 2010). A catheter is inserted into the epidural space through the lumbar, thoracic or cervical vertebral processes, facilitating a continuous infusion (Fig 13.1) of opiate (usually fentanyl) and local (anaesthetic, usually bupivacaine), and facilitating a totally pain-free state (Chumbley and Thomas 2010). Advantages of an epidural include reduction in postoperative complications and reduced cardiovascular stress (Macintyre and Schug 2007).

Fig. 13.1 Epidural infusion pump.