Pain Assessment and Management in the Critically Ill Patient
Published: 04 August 2021
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 either:
Acute: Pain that occurs during the expected period of healing and lasts for less than 12 weeks, or
Chronic: Pain that continues after the expected period of healing and lasts for more than 12 weeks in duration.
(DoH UK 2010)
Pain in most critically ill patients is considered 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).
Causes of Pain in Critcally Ill Patients
Critically ill patients are particularly vulnerable to pain and discomfort due to the severity of their health conditions, as well as diagnostic and treatment interventions. Potential causes include:
Non-invasive ventilating devices
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. This is one of the main reasons for inadequate pain management (Hamill-Ruth & Marohn 1999; Watt-Watson et al. 2001).
Potential Barriers to Adequate Pain Management
Fear that the patients will become addicted to opiates
Reluctance or inability of patients to request analgesia
Lack of regular and frequent assessment of pain and pain-relief interventions
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)
The 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 may have the following effects:
Respiratory: Decreased respiratory effort, sputum retention and pneumonia
Gastrointestinal: Decreased gastric emptying and gut motility, leading to ileus and reduced function
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 and 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:
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:
(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 comorbidities and your organisation’s usual selection of analgesics.
An analgesic regimen tailored specifically to the patient will take into account:
The patient's pain levels
Appropriate analgesics for the patient
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)
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.
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