Dr. Ghiamat MD Anesthesiologist

 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

 “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

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

 Patient experiences relief from pain without sedation.

Level of Consciousness Awake Analgesia Anxiolysis Hypnosis “Conscious Sedation” Deep Sedation General Anesthesia The Spectrum of Sedation Patients may travel quickly in either direction along this spectrum! Protective Reflexes Potential Loss Potential Loss PresentTotal LossPresent ED/Transport Mgmt

Continuous Pulse Oximetry Emergency meds, O2 suction and airway equipment available Personnel #2 (Monitors Patient) Personnel #1 (Performs Procedure) Vital SignsBaselineQ 5 min.Q 15 min. *Consent *H & P *Records meds. & Dosages *Discharge Instructions Before Procedure During Procedure After Procedure Sedation Protocol * = Present * * ** **

 There must be a documented evaluation of the patient’s anesthetic risk prior to administration of conscious sedation using the ASA rating.

 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

 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)

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

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.

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?

 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)

 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, minutes.  Duration minutes.

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

 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

 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.

 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

◦ Impaired mental status. ◦ Pregnancy ◦ Pneumothorax ◦ Bowel obstruction. ◦ Children < 5 years. ◦ Full stomach.

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

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

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

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

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

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

 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 % (Low)

 Respiratory & Cardiovascular effect are minimal  No need of closed supervision.

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

 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)

 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.

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

“Few things a doctor does are more important than relieving pain. Pain is soul destroying…the 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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