pain mangement lecture for 3rd year mbbs
DESCRIPTION
surgery and alliedTRANSCRIPT
Pain control and postoperative analgesia
DR.NADIR MEHMOOD
Asst professor
Department ofSurgery, RMC
Objectives• Define pain and its types.• Explain the physiology of pain• Explain pain as the “fifth vital sign”• Enumerate factors influencing pain• Enlist pain control strategies• Elaborate rules for pharmacotherapy• Introduce some pharmacological approaches to treating
pain. • Algorithms for pain management• Describe nursing interventions for pain control• Enumerate complementary (non pharmacological
therapies used to control pain)
“Pain is a Sensory and Emotional experience,
associated with actual or potential tissue
damage or described in terms of such
damage”
(IASP)
Definition of pain?
Pain Types• NOCICEPTIVE PAIN
– results from ongoing activation of mechanical, thermal, or chemical nociceptors
– typically opioid-responsive– eg. pain related to mechanical instability
• NEUROPATHIC PAIN
– spontaneous or evoked pain that occurs in the absence of ongoing tissue damage,Dysfunction of the nervous system
– Abnormality in the processing of sensations– Associated with medical conditions rather than tissue damage
– typically opioid-resistant***– eg. pain secondary to nerve root injury
• Phantom Pain
Phantom Pain
• Occurs after the loss of a body part from amputation
• Patient “feels” pain in the amputated part for years after the amputation has occurred
• May be controlled
Accessed 11 February 2009 fromhttp://www.pc.rhul.ac.uk/staff/J.Zanker/PS1061/L6/phantom.gif
Time-based classification of pain
• Acute: short-term; usually due to nociception (tissue damage); resolves with healing.
• In back pain, Acute = < 4 wks Sub-acute = 4-12 weeks
Chronic = > 12 weeks• Chronic pain: pain lasting > 3-6 months
• Persisting pain (NHMRC: acute pain guidelines)
“pain is whatever the experiencing person says it is,
existing whenever he says it does.” (McCaffery & Pasero, 1989).
“It is not the responsibility of clients to prove that they are in pain; it is the physician’s responsibility to believe them.” (Crisp & Taylor, 2005).
Factors Influencing Pain• Age• Gender• Culture• Meaning of pain• Attention• Anxiety• Fatigue• Previous experience• Coping style• Family and social support
Causes of Acute Pain Post-operative
Burns
Trauma
Infective / Inflammatory conditions
Ischaemic pain
Visceral pain
Obstetric - Labor
Causes of Post-Operative Pain
Incisional skin and subcutaneous tissue Deep cutting, coagulation, trauma Positional nerve compression, traction & bed sore. IV site needle trauma, extravasation, venous irritation Tubes drains, nasogastric tube, ETT Respiratory from ETT, coughing, deep breathing Rehab physiotherapy, movement, ambulation Surgical complication of surgery Others cast, dressing too tight, urinary retention
Causes of Chronic Pain
Cancer pain Cancer related From cancer therapy Cancer unrelated
Non-cancer Nociceptive Neuropathic Idiopathic
Basics of Pain Management
• 1st step: is the good pain assessment.
• Pain medications must be taken:
when the pain is first perceived.
• Doses of opioids are increased:
with the patient’s report of pain
• Adjuvant medications are used for:
opioid non-responsive & neuropathic pain.
• Non-pharmacologic approaches are always a part of any pain management protocol.
The “Costs” of Uncontrolled Pain Stress response Hypothalamo-Pituitary-Adrenal axis:
Disturbed cytokine cascade. Impairment of immune function. Increased catabolism. Negative nitrogen balance.
Pain Chronicity. Cardiovascular Respiratory GIT Neuro-psychiatric Impairment of mobility, Gait disturbances.
Physiological effects of Pain• Increased catabolic demands: poor wound healing,
weakness, muscle breakdown• Decreased limb movement: increased risk of DVT/PE• Respiratory effects: shallow breathing, tachypnea,
cough suppression increasing risk of pneumonia and atelectasis
• Increased sodium and water retention (renal)• Decreased gastrointestinal mobility• Tachycardia and elevated blood pressure
Psychological effects of Pain
• Negative emotions: anxiety, depression• Sleep deprivation• Existential suffering: may lead to patients
seeking active end of life.
Immunological effects of Pain
• Decrease natural killer cell counts• Effects on other lymphocytes not yet defined.
The ‘fifth’ Vital Sign
• Assessed in all patients
• Patient/client right to appropriate assessment and management of pain
Acute Pain Management
Goal
• To provide patients with a level of pain control that allows them to actively participate in recovery– This level will be individual to each patient
• To minimize nausea and vomiting• To minimize other side effects of analgesics– Sedation– Ileus– Weakness– Hypotension
Why all this is vital??
• Pain is a miserable experience• Pain increases sympathetic output– Increases myocardial oxygen demand– Increases BP, HR
• Pain limits mobility– Increases risk for DVT/PE– Increases risk for pneumonia, atelectasis
secondary to splinting
Principles of Assessment
• Assess and reassess• Use methods appropriate to cognitive status and context• Assess intensity, relief, mood, and side effects• Use verbal report whenever possible• Document in a visible place• Expect accountability• Include the family
Assessment
• Location• Intensity• Onset • Duration• Radiation• Exacerbation• Alleviation
Good assessment = Successful management
Pain Assessment
N
R
S
Pain Assessment Tools
• In Adults: Self Report Measurement Scales, such as Numerical Scales
Pain Assessment Tools
• In Pediatric Patients:– Physiologic and Behavioral Indicators of
Pain ( Infants, Toddlers, Nonverbal or Critically Ill Children)
– Face Scale (Age 3-10 yrs)– Visual Analogue Scales (Age 10-18)
• Subjective:• Pain Scores:
• Unidimentional Acute pain• VRS, VAS & NRS.• Facial expression.
• Multidimentional Chronic pain• McGill & Pain Inventory.
• Objective:– Behavioral: refusal to move, cough & deep breath– Physiological: PR, RR, ABP, sweatiness & dilated pupils– Neuro-endocrinal: RBS, Stress hormones
Pain Assessment
Numeric Rating Scale (NRS)
Visual Analogue Scale (VAS)
0 10
Pain Scores
Wong-Baker “Faces Scale”
Verbal scale
NoPain
Mild ModerateSeverePain
–Pharmacotherapy– Anesthetic approaches– Implantable devices– Neurostimulation approaches– Alternative approaches– Surgical approaches– Rehabilitative approaches– Lifestyle changes– Psychological approaches
Pain Control Strategies
Drug Strategies• Non Opioid Analgesics:– NSAA– NSAIDs
• Non-selective COX inhibitors• Selective COX-2 inhibitors
• Opioids– Weak Opioids.– Strong opioids.– Mixed agonist – antagonists
• Adjuvants– Antidepressants– Anticonvulsants– Substance P inhibitors– NMDA (N-methyl-D-aspartate receptor) inhibitors– LA– Drugs for Headache– Drugs for Bone pain– Others .
• Alternative medicine:– Acupuncture– TENS– Cupping– Chiropractice
• Physical Therapy– ice, heat, massage
• Exercise• Psychological therapy
– Cognitive-behavioral therapy– Relaxation techniques– Biofeedback– Hypnosis
Non-Drug Strategies
Routes of Administration
• PO• PR• IV • IM• Transdermal• Transmucosal• Epidural• Intrathecal
WHO step Ladder
1 mild
2 moderate
3 severe
Morphine
Hydromorphone
Methadone
Pethidine
Fentanyl
Oxycodone
± Adjuvants
Codeine
Hydrocodone
Oxycodone
Dihydrocodeine
Tramadol
± Adjuvants
ASA
Acetaminophen
NSAIDs
± Adjuvants
Pain
Step 1±Nonopioid± Adjuvant
Pain persisting or increasing
Step 2Opioid for mild to moderate pain
±Nonopioid ± Adjuvant
Pain persisting or increasing
Pain persisting or increasing
Step 3Opioid for moderate to severe pain
±Nonopioid ±Adjuvant
Invasive treatments
Opioid Delivery
Quality of Life
Modified WHO Analgesic Ladder
Proposed 4th Step
The WHOLadder
Deer, et al., 1999
How do we do it?
• Multimodal analgesia: Several analgesics with different mechanisms of action, each working at different sites in the nervous system
OPIOIDS Efficacy is limited by Side-Effects
• The harder we “push” with single mode analgesia, the greater the degree of side-effects
Analgesia
Side-effects
Multimodal Analgesia• Lower doses of each drug can be used therefore
minimizing side effects• With the multimodal analgesic approach there is additive
or even synergistic analgesia, while the side-effects profiles are different and of small degree (Pasero & Stannard, 2012).
Analgesia
Side-effects
Systemic Analgesia
• Opioids– Potent analgesics– Drug of choice for moderate to severe pain– Unfortunately, they are often the only drug
ordered– Side effects:
Epidural Infusions
• Used for major surgery ie. Oncologic surgery, thoracotomy
• Ideally placed pre-operatively and used in combination with a GA for surgery and continued ~ 2 days
• Usually patient is tolerating diet and ambulation to chair when epidural is D/C
• Advantages:
– Patients can titrate their own analgesia
– Improved:• Pain relief• Pulmonary function.
– Decreased:• Total daily dose.• Over sedation.• Postoperative complications.
Routes of Administrations - PCA
Miscellaneous Adjuvant Analgesics
• Pamidronate (Aredia)• Zoledronic acid (Zometa)• Strontium-89 (Metastron)• Calcitonin (Calcimar) Not in cancer ? arthritis• Capsaicin (Zostrix) scheduled in neuropathic pain• Clonidine (Catapres) all forms• Cannabinoid (Marinol)
Analgesics for Neuropathic Pain• Tricyclic antidepressants
– nortriptaline (1st choice)• Anticonvulsants
– Gabapentin, Carbamazepine, Pregaba• Local anesthetics
– Parenteral, oral, topical• Topical capsaicin• Opioids for selected patients
Multidisciplinary Pain Clinic Personnel
• Physicians
– Neurosurgeon– Orthopedic surgeon– Anesthesiologist– Neurologist– Physiatrist– Internal medicine– Psychiatrist– Addictionologist
• Nurses• Psychologists
• Physical Therapist• Occupational Therapist• Vocational counselor• Social worker• Dietician• Recreational staff• Administrative support staff
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