Pain: The word “pain” comes from the Latin “poena” meaning a fine, a penalty.
An unpleasant sensation that can range from mild, localized discomfort to agony. Pain has both physical and emotional components. The physical part of pain results from nerve stimulation.
Pain may be acute or chronic. Both is having different methods of pain relief. We will see both separately.
Methods of acute pain relief.
- NSAIDs (ibuprofen, diclofenac)
- Opioids and paracetamol combination
- Intramuscular and intravenous morphine
- Regional anesthesia
- Patient control analgesia (PCA)
- Psychological and behavioural techniques
Good nursing care
WHO analgesic ladder: below is the figure showing world health organization(WHO) analgesic ladder. Although this step wise management was developed for chronic pain but it is useful guide for acute pain as well.
By following this step ladder we start simply from paracetamol and goes on climbing the ladder till the patient feel himself free of pain. Patient may be on any rung of ladder at any time, but for pain of acute type we will tend to go down the ladder while the patient with chronic pain (malignancy) will tend to climb the ladder with time as the disease is progressive in nature.
Patient control analgesia (PCA): This is a technique in which narcotic analgesic is administered by the patient himself by intravenous injection or epiduraly. The patient is trained to give a bolus dose of the drug by pressing a control button on the machine. The method is popular with patient as they able to control their pain,and delay in administration of the dose is avoided.
Epidural analgesia: It is becoming gold standard now a days. In this technique a catheter is placed in to the epidural space and remain there for 4-5 days. Low concentration local anesthetics or opiates such as diamorphine can be given through this catheter, which provide very effective pain relief specially for lower abdominal surgeries.
Chronic pain management: Chronic pain can be because of malignancy or it can be caused by a benign disease.
Cancer pain management:
Most of the malignancies initially are painless but pain occurs either by excessive growth of the tumor causing stretch on the capsule of the organ or the infiltration of the nervous plexus. The most appropriate regimen for the control of malignant pain is WHO stepladder pattern which has already been discussed. There is no justification to avoid opiates for fear for addiction to control malignant pain.
Opioid resistant pain: some patients are either partially sensitive or insensitive to opioids. These patient are managed with alternative drugs or some other techniques which are briefly given below.
Bone pain: metastatic bone pain is best managed by radiotherapy. Generalized bone pain in malignancy may need systemic therapy with bisphosphonates . hormone therapy also have a role.
Liver capsule: this pain is partially opioid sensitive. Steroids are very helpful in this contest as they reduce the liver swelling and relieve capsule stretching.
Colic: If caused by constipation, it is usually relieved by laxatives. Colic from tumor obstruction may respond to antispasmodic drugs.
Meningeal pain/raised intracranial pressure: steroids have dramatic effect in this contest.
Nerve pain: The pain is usually caused by infiltration of the nerve/plexus by the tumor and is often opioid insensitive. Steroids are useful in nerve compression . nerve infiltration/destruction or irritation pain may respond to drugs that alter neurotransmission (low dose tricyclic antidepressants, anticonvulsants) when the life expectancy of the patient is limited and the diagnosis is certain then the neurolytics technique which are given below can be helpful to relieve the pain.
- Subcostal phenol injection for a rib metastasis.
- Celiac plexus block with alcohol for pancreatic, gastric or hepatic cancer. Image intensifier control is essential.
- Intrathecal neurolytic injection of hyperbaric phenol.
- Percutaneous anterolateral cordotomy divides spinothalmic ascending pain pathway.
- Alternative strategies include antipitutary hormones (tamoxifen), palliative therapy , steroids to reduce cerebral oedema, tricyclic antidepressants etc.
Pain management of benign diseases: The basic difference between pain management of benign and malignant disease is the use of narcotics. In benign disease the use of narcotics should be avoided as much as possible while in malignant disease narcotics are the mainstay of pain management. The following are the treatment option for chronic pain of benign disease.
- Local anesthetics and steroids injections
- Nerve stimulation procedures (TENS, Acupuncture)
- Nerve decompression (laminectomy, cordectomy)