pharmacologic adjuncts to airway management and ventilation ems 352 dr aqeela bano
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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.
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