Assessment of post operative pain: A first step towards effective post operative pain management

Acute pain after surgery is inevitable because of the associated trauma to many pain-sensitive structures. Role of pain is to provide alarming signal about tissue damage, but in case of the surgical incisions, such alarm is scarcely needed. Instead of being a useful tool, post operative pain can impair the hematologic, immune, hormonal, cardiac, and respiratory systems. Pain also limits mobility, interfere with sleep and rest, and contribute to agitation, psychosis, aggressive behaviour, and delirium. Hence, effective management of postoperative pain not only reduces patient suffering but also reduces morbidity which facilitates rapid recovery and early discharge from hospital, leading to reduced hospital costs.

Negative effects of pain

Short term negative effects of acute pain include: 

• Emotional and physical suffering for the patient
• Sleep disturbance (with negative impact on mood and mobilisation)
• Cardiovascular side effects (such as hypertension and tachycardia)
• Increased oxygen consumption (with negative impact in the case of coronary artery disease)
• Impaired bowel movement (untreated pain may be an important cause of impaired bowel movement or post operative nausea and vomiting)
• Negative effects on respiratory function (leading to atelectasis, retention of secretions and pneumonia)
• Delays mobilisation and promotes thromboembolism (effect of postoperative pain on mobilisation is one of the major causes for delayed mobilisation)

Long term negative effects of acute pain:

• Severe acute pain is a risk factor for the development of chronic pain
• There is a risk of behavioural changes in children for a prolonged period (up to 1 year) after surgical pain

Effective pain management has become an integral part of modern surgical practice. Unfortunately, patients are often under medicated and do not have effective pain relief. Numerous factors appear to influence under treatment. Healthcare providers tightly control analgesics to avoid contributing to drug dependency and/or having to deal with drug-induced adverse effects. They may also underestimate the amount of pain a patient is experiencing and overestimate the effectiveness of analgesics they are administering.

Assessment of pain is a vital element in effective postoperative pain management as it may help the healthcare providers to estimate the intensity of pain felt by the patient. Specific pain assessment scales are used to quantify pain. The intensity of pain should therefore be assessed as far as possible by the patient as long as he/she is able to communicate and express what pain feels like.

Tools for assessment of pain are available which includes Faces pain assessment tool, VAS (Visual analogue scale), Verbal rating scale (VRS) and numerical rating scale (NRS). The choice of tool depends on the communicability of the patients. For patients with weaker communication, the faces pain assessment is easier while with communicable patients, other pain scales provide accurate assessment.

Effective pain management can be made using this tools e.g. for mild to moderate pain, paracetamol and NSAIDs are suitable. However, for moderate to sever pain opioids are required.

Thus, assessment of post operative pain is valuable for providing effective analgesia without increasing risk of adverse events.