This article, will discuss how to assess and manage acute pain in critically ill patients.

Pain ‘is a complex subjective phenomenon associated with actual or potential tissue damage’ (Prevost 2009).

Pain should be predicted in all patients and every action should be questioned for its possibility to cause pain or discomfort to the patient. Anticipation of pain allows alternative strategies to be considered or pre-emptive analgesics given (Mallet et al. 2013).

Acute Pain v Chronic Pain

Pain can be:

• Acute –  pain that occurs during the expected period of healing and lasts for less than 12 weeks; or
• Chronic – pain that continues afterthe expected period of healing and lasts for more than 12 weeks in duration.

(Department of Health and Social Care 2010)

The pain in most critically ill patients is considered as acute because it usually has an identified cause. For example, it may be associated with a procedure during the patient’s stay on the ward or postoperatively (Prevost 2009).

Common Causes of Pain

Critically ill patients are particularly vulnerable to pain and discomfort due to the severity of their health conditions and diagnostic and treatment interventions, such as:

• Incisions
• Surgery
• Trauma
• Cannulation
• Catheterisation
• Airway suctioning
• Endotracheal tubes
• Non-invasive ventilating devices
• Drains/drain removal
• Wounds/dressing changes
• Physical therapy
• Prolonged immobility
• Constipation
• Sleep deprivation
• Disturbances such as awakening and manipulation for repositioning
• Patient’s inability to report pain

Critically ill patients should be assessed for pain on a regular basis and the frequency of assessment should be patient-specific and adjusted according to their risk.

However, health professionals often underestimate patients’ pain and this is one of the main reason for inadequate pain management (Hamill-Ruth & Marohn 1999; Watt-Watson et al. 2001).

Possible Barriers to Adequate Pain Management

• Fears that the patients will become addicted to opiates
• Patients’ reluctance to request analgesia
• Patients’ inability to request analgesia
• Lack of regular and frequent assessment of pain and pain-relief interventions.
• A belief that pain is not harmful but a ‘normal’ response to surgery.
• Inadequate patient education
• Lack of understanding of the need to titrate analgesics to meet patients’ needs

(Macintyre & Schug 2007)

Effects of Untreated or Unmanaged Pain

Untreated pain can pose serious consequences for the already compromised, critically ill patient and can affect most body systems (Prevost 2009). Untreated pain could have the following effects:

• Respiratory: decreased respiratory effort, sputum retention and pneumonia.
• Cardiovascular: hypotension, tachycardia, increased peripheral vascular resistance and pulmonary embolism.
• Gastrointestinal: decreased gastric emptying and gut motility, leading to ileus and reduced function.
• Urinary retention.
• Immune system: pain can cause suppression of immune function predisposing to infection.
• Metabolic: reduced anabolic hormone, leading to increased protein breakdown, hyperglycaemia, impaired wound healing and increased muscle breakdown.
• Musculoskeletal: pain can lead to muscle spasm, muscle wasting and immobility.
• Psychological: pain can cause fear, anxiety, helplessness, sleep deprivation, all leading to increased pain.
• Central nervous system: untreated pain can lead to chronic pain due to central sensitisation.

( Macintyre & Schug 2007)

Pain Assessment in the Critically Ill Patient

Careful consideration needs to be given to the assessment method chosen for critically ill patients because they are often unable to participate in the pain assessment process.

Below are some methods of assessing pain in critically ill patients:

Patients’ Self-Report (Numeric Rating Scale)

This is considered the most reliable method of pain assessment.

This method is 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, for example, 0-10 (where 0 = pain-free and 10 = worst pain you can imagine), can still be used if the patient is able to point to the scale or nod at simple commands (Mallet et al. 2013).

Behavioural Pain Scale (BPS)

The behavioural pain scale was developed to allow a more quantifiable assessment of pain (Payen et al. 2001) in patients who cannot self-report pain and are unable to be assessed with the numeric rating scale.

As many critically ill patients are unable to cooperate with a numeric rating scale they may require an alternative assessment. The BPS involves looking for pain-related behaviours and physiological indicators in order to plan treatment, such as:

Behavioural indicators:

• Facial grimacing
• Limb flexion
• Ventilator dyssynchrony

Physiological indicators:

• Hypertension
• Tachycardia
• Tachyphoea
• Lacrimation

(Jocabi et al. 2002)

However, physiological signs alone are a poor assessment of pain in the critically ill. That is because these signs are often present regardless of pain.

Therefore, pain assessment should be sure to include observations of behaviours and physiological signs, with any change in the physiological indicators after administering analgesics to be monitored (Jocabi et al. 2002).

Management of Pain

When pain is indicated in the patient, follow the WHO analgesic ladder (WHO 1990) and take into account the patient’s co-morbidities and your institution’s usual selection of analgesics.

An analgesic regimen tailored specifically to the patient will take into account:

1. The patient’s pain levels
2. Appropriate analgesics for the patient
3. Documentation of each step of the care and assessment provided to the patient (this helps to provide an accurate record, monitor effectiveness of treatment and also facilitates continuity of care).

(Mallet et al. 2013)

Conclusion

Effective pain management is an important element of the nurses’ role. The effects of inadequate pain management are significant and can lead to delayed healing and prolonged recovery. The nurse, therefore, must be competent in pain assessment methods/tools and be able to administer and evaluate pain management techniques.