Analgesics for Field and Emergency Use

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Analgesics for Field and Emergency Use

• Dr. Ghiamat MD Anesthesiologist

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There is more to basic pre-hospital and
immediate medical treatment than basic life
support

• The standard pre-hospital and immediate medical
  treatment is focused on basic life support
• A Airway
• B Breathing
• C Circulation
• One further element of patient care must be
  addressed
• Pain management

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History of Inadequate Treatment

• Brutane, until recently, was the analgesic and
  sedative most often used
• total immobilization by several adults and a
  papoose via brute strength.
• Paris PM. Amer J Emerg Med 1989

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Reasons For Inadequate Analgesia/Sedation

• No ideal sedative.
• Fear of side effects.
• Fear of addiction.
• Inadequate training

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Analgesia

• Patient experiences relief from pain without
  sedation.

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The Spectrum of Sedation Patients may travel
quickly in either direction along this spectrum!
Analgesia Anxiolysis Hypnosis
Level of Consciousness
Conscious Sedation
Deep Sedation
General Anesthesia
Awake
Protective Reflexes
Potential Loss
Potential Loss
Present
Total Loss
Present
ED/Transport Mgmt
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Sedation Protocol
During Procedure
After Procedure
Before Procedure
Vital Signs
Baseline
Q 5 min.
Q 15 min.
Personnel 1 (Performs Procedure)
Consent H P

Personnel 2 (Monitors Patient)
Records meds. Dosages
Discharge Instructions

Continuous Pulse Oximetry


Emergency meds, O2 suction and airway equipment
available


Present
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KFSH Conscious Sedation Policy

• There must be a documented evaluation of the
  patients anesthetic risk prior to administration
  of conscious sedation using the ASA rating.

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Importance of pain management

• The early treatment of pain is important
• Pain that is not relieved can have profound
  effects on the patient
• The effective management of pain helps to
  promote
• Feelings of well-being
• An environment where patients feel able to comply
  with uncomfortable procedures

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Pain management alternatives

• Current analgesic alternatives may be less than
  ideal due to
• Limited efficacy
• Inconvenient administration starve or premed?
• Length of onset or duration of action
• Adverse reactions (e.g., respiratory depression)
• Narrow Therapeutic Window
• Increasing tolerance requiring larger doses
  (e.g. opioids)

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Pain management alternatives 1

• Oral medications / sedatives administration
  needs to be planned, long onset, may be
  sedating.
• Local anaesthetics - can producevery effective
  localised analgesia,but long acting numbness
  follows
• Topical creams
• Injections

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Pain management alternatives 2

• Inhaled analgesics
• Nitrous Oxide heavy equipment,
  cleaning/sterilising, analgesia ceases on
  cessation of inhaling the gas. Occupational
  Health and Safety concerns for administrators in
  closed environments?
• Methoxyflurane (trade name Penthrox) - vide
  infra.

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Pain management alternatives 3

• IM / IV analgesia - usually narcotics.
  Unpredictable delayed onset of analgesia. Side
  effects (nausea, vomiting, respiratory and
  cardiovascular depression especially in the
  shocked and/or injured). May require i/v access.
• IV sedation requires i/v access and monitoring.
• General anaesthesia?

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There are a number of existing options for
pre hospital and emergency pain relief

• Used in Pre hospital, emergency and hospital
  settings with a very rapid onset of action
• 1. Inhaled Agents
• Nitrous Oxide Oxygen
• Penthrox (Inhaled methoxyflurane)
• 2. Injected agents Opioids (i.e. morphine)

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Nitrous Oxide

• Nitrous oxide, commonly known as "laughing gas",
• Colorless, odorless gas.
• Used 50/50 mixture with O2.
• Safe and effective.
• Wash-out with 100 O2 for 5 minutes.
• Patient controlled titration. (Demand Valve)
• Onset of action, 3 - 5 minutes.
• Duration 3 - 5 minutes.

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Nitrous Oxide

• Action
• Mild analgesia.
• Sedation, amnesia.
• Anxiolytic
• Detached attitude towards pain.
• Side Effects
• N. V.
• Agitation
• Diffusional Hypoxia

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Nitrous Oxide

• It diffuse into gas filled cavities ( e.g., the
  intestines, thorax, middles ears) which increases
  the volume and pressure in the spaces.
• Therefore, contraindicated in patients at risk
  of pnumothrox, bowel obstruction, head injury
  with impaired consciousness and decompression
  sickness

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Nitrous Oxide

• It causes the depression of myocardial
  contractility and increase myocardial work load.
• It is associated with increase rate of mortality
  with in patients with CAD.
• Unintentional loss of consciousness.

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Nitrous Oxide

• Low solubility in Blood and tissues and rapidly
  eliminated from the body
• Pollution exceeds recommended levels in enclosed
  environment
• In fact it has more than several hundred times
  pollution effect than Methoxyflourane

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Contraindication

• Impaired mental status.
• Pregnancy
• Pneumothorax
• Bowel obstruction.
• Children lt 5 years.
• Full stomach.

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Nitrous Oxide

• Toxicity
• Blood disorders (megalobalstic Bone
  marrow changes, agranulocytosis)
• Interference with DNA

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Parenteral Opioids

• Morphine , Pethidine Fentanyl
• Powerful analgesia but addictive and subject to
  abuse
• It needs skilled supervision for administration
  and needle stick injury

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Parenteral Opioids

• Morphine , Pethidine Fentanyl
• Powerful analgesia but addictive and subject to
  abuse
• It needs skilled supervision for administration
  and needle stick injury

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• Action
• Moderate to severe analgesia.
• Rapid onset of action
• Sedation, Euphoria,
• Side Effects
• Nausea , Vomiting Constipation
• Tolerance and dependency
• Respiratory Depression
• Hypotension, tachycardia, palpitation,

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Contraindication

• Acute respiratory depression
• Head Injury ( Increased Intracranial Pressure)
• Phaechromocytoma ( risk of presser response to
  histamine release)

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Fentanyl

• Difficulty of Intranasal administration
• Necessary to have titrated dose
• Patient Positions (trauma patients)
• IV administration satisfactory analgesia but
  needs a 5- 10 minutes of each doses interval.
• Continuous supervision is must

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Inhaled Analgesia

• Methoxy Flourane (MEOF) (Penthrox)
• Only volatile anesthesia with significant
  analgesic properties
• Analgesia effect dose do not cause drowsiness or
  unconsciousness.
• Onset of action after 6-8 breaths
• Inhaled Concentration is 0.1-0.4 (Low)

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Inhaled Analegesia

• Respiratory Cardiovascular effect are minimal
• No need of closed supervision.

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Advantages of Penthrox 1

• Powerful, effective, simple, safe analgesia
• No preliminary fasting or premedication
• Rapid onset analgesia begins in six breaths
• 1-1.5 minutes to establish
• self administered intermittently
• Stable cardio-respiratory systems
• No vomiting, over-sedation
• Simple equipment easy to train and administer

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Advantages of Penthrox 2

• Almost all patients find Penthrox acceptable
• Side effects rare and non-threatening
• Occasionally drowsy if little stimulation
  instantly rousable
• Very effective for children they like its taste
  
• Clinical observation only no other monitoring
• Quickly back to normal (driving/machinery not
  recommended)

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Summary

• Methoxyflurane has been clinically demonstrated
  over many years to be a simple, safe and
  effective agent for the relief of pain and
  suffering.
• In Australia two million administration of MEOF
  for the management of pre-hospital pain relief in
  Ambulance Services in 30 years.

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Benefits to clinicians who offer early pain
management

• Reduction or elimination of pain and associated
  anxiety
• Reduction of movement and reaction to treatment
• Improved health outcomes
• WIN WIN situation for both the patient and
  clinician

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• Few things a doctor does are more important
  than relieving pain. Pain is soul destroyingthe
  quality of mercy is essential to the practice of
  medicine here of all places it should not be
  strained.
• Angell M. Nejm, 1982

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Thank You