management of pain

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Management of Pain

Dr U I Hapuarachchi

Department of Surgery01/07/2009



Learning objectives At the end of this lecture, you should be

able to demonstrate the;

Classification of pain

Advantages of relief of pain

WFSA & WHO Pain ladder Treatment options available

Side effects of the options mentioned

Management of common side effects



Content Definition of Pain

Types of pain Advantages of relief of pain

Assessment of Pain

Pharmacological interventions Regional techniques

Therapeutic adjuncts



Definition

An unpleasant sensory & emotional

experience resulting from a stimuluscausing, or likely to cause, tissuedamage (nociception), or expressed interms of that damage



Advantages of pain relief Humanitarian reasons

Reduced cardiovascular complications Reduced respiratory complications

Reduced gastro-intestinal effects

Less salt/water retention Less impairment of sleep/mental function

Early hospital discharge

Economical



Classification Pathophysiology

Nociceptive or Neuropathic

Onset

Acute or Chronic

Etiology Postoperative or Cancer

Affected area

Headache or Low back pain



ClassificationNociceptive pain-

Originates in the presence of normal painpathways

Noxious stimuli stimulate peripheral receptors& messages relayed via the dorsal horn to

higher brain centres to warn of impending orongoing tissue damage



ClassificationNeuropathic pain-

Occurs when there abnormal activation of pain pathways as result of damage ordysfunction within the nervous system itself

Sometimes pain persists despite healing of

the damaged tissues

Pain persisting >3 months – Chronic Pain



Classification Acute pain-

Caused by noxious stimulation due to injury, adisease process or the abnormal function of muscle or viscera

Usually nociceptive

Typically associated with a neuroendocrinestress



ClassificationChronic pain-

Pain that persists beyond the usual course of

an acute disease or after a reasonable time forhealing to occur ( 01 to 06 months )

Nociceptive, neuropathic or mixed

Psychological mechanisms or environmentalfactors play major role

Often have attenuated or absentneuroendocrine stress response

Have prominent sleep & mood disturbances



Assessment of Pain Visual Analogue Scale

0_______________________________10No pain 10 cm line Worst pain

experienced

Numerical Scale

0__ 1__ 2__3__ 4__5__ 6__7__8__9__10No pain 10 cm line Worst pain

experienced



Assessment of Pain Descriptive Scale

No pain - mild - moderate - severe - excruciating

McGill Pain Questionnaire

Check list of words describing symptoms

Psychological questionnaires for analysis of personality & pain



Assessment of Pain

Wong-Baker FACES Pain Rating Scale

Is used in children



Management of Post operative

Pain

Multimodal Approach

According to the WFSA ladder

Systemic analgesics

Regional techniques



WFSA Pain Ladder



Systemic analgesics

Opioids – Morphine, pethidine, fentanyl,

remifentanyl,

NSAIDs – Diclofenac sodium, ibuprofen,

ketorolac

Others – Paracetamol, Tramadol



Opioids

Strong analgesic for moderate to severepain

Can be given as im, iv, sc, oral, Patientcontrolled analgesia (PCA), transdermal,spinal/epidural

PCA – bolus dose, lockout interval

+/- background infusion



PCA Pump



Opioids

Dose

Morphine –

0.1 mg/kg Pethidine – 1 mg/kg

Fentanyl – 1-3 µg/kg

Remifentanyl – 0.025-0.1 µg/kg/min



Opioids

Respiratory depression

Hypotension

Tachy / bradycardia

Sedation

Euphoria / dysphoria

Nausea / vomiting Uriticaria

Urine retention



Opioids

Respiratory depression

If RR < 10 /min – Awaken the patient

If RR < 8 /min – O2 via face mask

Naloxone 40 µg iv boluses

Urticaria

Chlopheniramine 5-10 mg

Naloxone 40 µg iv



Opioids

Nausea & vomiting

Promethazine -12.5-25 mg im / iv

Metoclopramide – 5-10 mg slow iv / im

Ondansetrone – 4-8 mg iv

Urine retention

General measures

catheterization



NSAIDs

Can be given as oral, suppositories, iv

Potent analgesic for mild to moderate

pain

Can cause renal toxicity

Precipitate bronchial asthma Peptic ulceration

Fluid retention



NSAIDs

Dose

Diclofenac sodium – 1 mg/kg tds (maximum -3 mg/kg/day) - > 1 yr

Ibuprofen – 5-10 mg/kg tds



Other drugs

Paracetamol

Analgesic for mild to moderate pain

Liver damage in overdose

Can be given as oral, suppositories, iv

Dose – 20 mg/kg & then 15 mg/kg 4 hrly

Maximum dose – 90 mg/kg



Other drugs

Tramadol

Has opioid & non-opioid mechanism of action

Has less respiratory depression, constipation,euphoria than other opioids

Causes nausea, dizziness, dry mouth

Increased S/E in conjunction with otheropioids

Can be given as oral, slow iv / im

50-100 mg 4 hrly



Regional techniques

Epidural – Continuous infusion / boluses

PCEA, Caudal

Nerve plexus blocks – Supraclavicular,

axillary, lumber plexus

Individual nerve blocks – median, ulnar,

sciatic, femoral

Intra-pleural analgesia

Infiltration



Regional techniques



Regional techniques

Less stress response

Less bleeding

Better organ perfusion

Better gut motility

Less DVT

Motor block

CVS instability – Hypotension

Urine retention with spinal/epidural opioids



Regional techniques

Epidural / PCEA – 0.125 –0.1% Bupivacaine

+ /- opioidOther blocks – 0.25-0.5% Bupivacaine

PCEA – better pain relief less overdose



Regional techniques

Hypotension

Rapid iv fluid infusion Vasoconstrictors – ephedrine 5-10 mg iv

Inform the Pain relief team



Management of NeuropathicPain

Pharmacological interventions

Antidepressants – Block presynaptic reuptake of serotonin,

norephinephrine or both

Anticonvulsants-Block voltage gated sodium channels & can

suppress spontaneous neural discharges




Pharmacological interventions

NeurolepticsBlock dopaminergic receptors in mesolimbic sites

Corticosteroids

Has anti-inflammatory & analgesic actions

α2 Adrenergic agonists

Activate descending inhibitory pathways in thedorsal horn





Psychological interventionsCognitive therapy, Behavioral therapy, Biofeedback,

Relaxation techniques & Hypnosis

Physical therapyHeat & cold therapy, Exercise



Cognitive therapy





AcupuctureIn chronic pain – chronic musculosketal

disorders & headache

Electrical stimulation

TENS, Spinal cord stimulation, Intracerebral

stimulation



TENS



WHO Pain Ladder



References

Management of Acute pain

National Guidelines-Anaesthesiology, Ministry of Healthcare & nutrition, Sri Lanka. Pg70-91

Atkinson RS, Rushman GB, Davies NJH. Acute painLee’s Synopsis of Anaesthesia 11 th Edition Chapter 26

Kirk RM, Ribbans WJ. Management of Post-operative pain

Clinical Surgery in General-RCS Course Manual 4 th Edition

Pg 357-369 http://www.frca.co.uk

Resources>Clinical Anaesthesia>Acute pain

Morgan GE, Mikhail MS, Murray MJ. Pain Management

Clinical Anaesthesiology 4 th

Edition Pg 359-411

http://www.frca.co.uk/

http://www.frca.co.uk/



Thank you

management of pain

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