pharmacologic adjuncts to airway management and ventilation ems 352 dr aqeela bano
TRANSCRIPT
Pharmacologic Adjuncts to Airway Management and Ventilation
EMS 352 DR AQEELA BANO
Pharmacologic Adjuncts to Airway Management and Ventilation
• Decrease the discomfort of intubation• Decrease the incidence of complications • Make aggressive airway management possible
for patients who are unable to cooperate
Sedation in Emergency Intubation
• Reduces anxiety, induces amnesia, decreases gag reflex
• Undersedation:– Inadequate cooperation– Complications of gagging – Incomplete amnesia
Sedation in Emergency Intubation
• Oversedation:– Uncontrolled general anesthesia– Loss of protective airway reflexes– Respiratory depression– Complete airway collapse– Hypotension
Sedation in Emergency Intubation
• Desired level of sedation dictates dose
• Two major classes:– Analgesics:
decrease perception of pain
– Sedative-hypnotics: induce sleep, decrease anxiety
Butyrophenones
• Potent, effective sedatives – Haloperidol and droperidol relieve anxiety.
• Do not produce apnea • Little effect on cardiovascular system• Not recommended to induce anesthesia
Benzodiazepines
• Sedative-hypnotic drugs• Diazepam and midazolam– Provide muscle relaxation, mild sedation– Used as anxiolytic and antiseizure medications– Provide anterograde amnesia
Benzodiazepines
• Neuromuscular blockers preferred for muscle relaxation
• Potential side effects:– Respiratory depression– Slight hypotension
• Flumazenil: benzodiazepine antagonist
Barbituates• Sedative-hypnotic
medications• Thiopental
– Short acting– Rapid onset
• Methohexital– Ultra-short acting– Twice as potent
• Can cause – Respiratory depression– Drop in blood pressure
• Potentially irreversible in hypovolemic patients
Opioids/Narcotics
• Potent analgesics with sedative properties• Two most common: fentanyl, alfentanil• Can cause respiratory and central nervous
system depression • Naloxone: narcotic antagonist
Nonnarcotic/Nonbarbituate
• Etomidate – Hypnotic-sedative drug– Often used in induction of general anesthesia– Fast-acting, short duration– Little effect on pulse rate, blood pressure,
intracranial pressure (ICP)
Nonnarcotic/Nonbarbituate
• Etomidate (cont’d)– No histamine release and bronchoconstriction– High incidence of myoclonic muscle movement– Useful induction agent in patients with:• Coronary artery disease• Increased ICP• Borderline hypotension/hypovolemia
Neuromuscular Blockade in Emergency Intubation
• Cerebral hypoxia can make patients combative and uncooperative.– Requires aggressive oxygenation, ventilation– Neuromuscular blocking agents are safer.
Neuromuscular Blocking Agents
• Affect every skeletal muscle • Within about 1 minute, patient is paralyzed• Must be able to secure the airway• No effect on LOC.
Pharmacology of Neuromuscular Blocking Agents
• Skeletal muscles are voluntary.– Impulse to contract reaches a motor nerve– Acetylcholine (Ach) is released.• Diffuses, occupies receptor sites• Triggers changes in electrical properties of the muscle
fiber (depolarization)
Pharmacology of Neuromuscular Blocking Agents
• Paralytic medications– Relax the muscle by
impeding the action of Ach
– Two categories: depolarizing and nondepolarizing
Depolarizing Neuromuscular Blocking Agent
• Competitively binds with ACh receptor sites– Not affected as quickly by acetylcholinesterase
• Succinylcholine chloride is the only agent.– Fasciculations can be observed during its
administration.
Depolarizing Neuromuscular Blocking Agent
• Very rapid onset of total paralysis• Short duration of action • Use with caution in patients with burns, crush
injuries, and blunt trauma• Can cause bradycardia
Nondepolarizing Neuromuscular Blocking Agents
• Bind to ACh receptor sites but do not cause depolarization of the muscle fiber.
• Prevent fasciculations before a depolarizing paralytic
Nondepolarizing Neuromuscular Blocking Agents
• Most commonly used– Vecuronium bromide (Norcuron)– Pancuronium bromide (Pavulon)– Rocuronium bromide (Zemuron)
• Do not give before the airway is secured.
Rapid-Sequence Intubation (RSI)
• Safe, smooth, rapid sedation and paralysis followed immediately by intubation
• Generally used for patients who are unable to cooperate
Preparation of the Patient and Equipment
• Explain procedure, reassure the patient• Apply a cardiac monitor and pulse oximeter.• Check, prepare, assemble equipment– Have suction available
Preoxygenation
• Adequately preoxygenate all patients.– If the patient is breathing spontaneously and has
adequate tidal volume: • Apply high-flow oxygen via nonrebreathing mask.
– If patient is hypoventilating: • Assist ventilations with a bag-mask device and high-
flow oxygen.
Premedication
• Stimulation of the glottis with intubation can cause dysrhythmias and increase ICP.
• If your initial paralytic is succinylcholine, administer nondepolarizing paralytic.
• Atropine sulfate should be administered to decrease potential for bradycardia.
Sedation and Paralysis
• As soon as patient is sedated, administer paralytic agent– Onset should be complete within 2 minutes.– Signs of adequate paralysis include:• Apnea• Laxity of the mandible• Loss of the eyelash reflex
Intubation
• Intubate trachea as carefully as possible.– If you cannot intubate within 30 seconds, ventilate
for 30–60 seconds before trying again.• If ventilating with a bag-mask device, do so slowly.
Intubation
• Once tube is in the trachea:– Inflate cuff.– Remove stylet.– Verify position of the ET tube.– Secure the tube.– Continue ventilations.
Intubation
• Intubate trachea as carefully as possible.– If you cannot intubate within 30 seconds, ventilate
for 30–60 seconds before trying again.• If ventilating with a bag-mask device, do so slowly.
Intubation
• Once tube is in the trachea:– Inflate cuff.– Remove stylet.– Verify position of the ET tube.– Secure the tube.– Continue ventilations.
Maintenance of Paralysis and Sedation
• Additional paralytic administration may be necessary after intubation.– If you administered succinylcholine, administer a
nondepolarizing agent to maintain paralysis.– If you administered a long-acting paralytic,
additional dosing is usually not necessary.
Maintenance of Paralysis and Sedation
• Modification for unstable patients– If oxygen saturation
drops, ventilate slowly.
– If patient is hemodynamically unstable, judge whether sedation is appropriate.
Maintenance of Paralysis and Sedation
• Additional paralytic administration may be necessary after intubation.– If you administered succinylcholine, administer a
nondepolarizing agent to maintain paralysis.– If you administered a long-acting paralytic,
additional dosing is usually not necessary.