RSI

Presented By: Dr. Mohamad Husain AhmadSupervised By: Dr. Manal Al-Maskati

Introduction

Airway management is the most important skill for an emergency practitioner to master because failure to secure an adequate airway can quickly lead to death or disability.

Introduction

Despite the existence of the guidelines, little data exist about RSI and most of the data comes from anaesthesia literature.

RSI in comparison to regular intubation

RSI is superior in terms of higher success rate, better intubation conditions and lower incidence of complications. Proved by: Clinical experience. randomized, controlled trials describing

intubating conditions for patients intubated in the operating room have consistently reported a significantly higher frequency of excellent intubation conditions with deep sedation plus paralysis (80 to 98 percent) versus that observed with deep sedation alone (0 to 30 percent).

RSI

Stands for: Rapid Sequence Intubation.

Rapid Sequence Induction.

Definition

The process of administering a sedative and muscle relaxant to induce a state of unconsciousness and complete neuromuscular paralysis to facilitate the process of endotracheal intubation.

Aim

To take: An awake patient. With assumed full stomach. Very quickly induce a state of

unconsciousness and paralysis and securing the airway.

Without using positive pressure ventilation as much as possible.

Major Advantages

Decreases the stimulation of potentially harmful autonomic reflexes ass e intubation: E.g elevated intracranial pressure, HTN

& brady. Controls the clinical environment:

In case of anxious, frightened or uncooperative.

Minimizes the risk of pulmonary aspiration: If done along with cricoid pressure.

Major Advantages

Provides better intubation conditions: Complete jaw relaxation, open and

immobile vocal cords, and no coughing, bucking or diaphragmatic movement in response to intubation.

Minimizes the psychic trauma: Cuz the p.t will be unconscious.

Indications

Indicated for almost all the patients undergoing emergent endotracheal intubation.

Contraindications

Total upper airway obstruction (requires surgical airway)

Total loss of facial/oropharyngeal landmarks (requires surgical airway)

Used e Caution

In patients e H/O or F/H/O allergy to anesthetic agents.

In patients known to have a difficult airway: Cuz the patient will be irreversibly

paralyzed for few minutes after administering the NMB agent.

Unnecessary

Although not contraindicated, it is unnecessary and time wasting in unconscious patients.

Time needed

In the majority of situations, RSI, from the decision to intubate to successful intubation, is accomplished in 10 minutes

Steps 6 Ps

Preparation (T: -10m). Pre-oxygenation (T: -5m). Pre-medication (T: -3m). Paralysis (T: 0). Placement of tube (T: +45s). Post management (T: +2m).

Preparation

Preparation of equipment: Best remembered by the mnemonic

(SOAP-ME):▪ S: Suction.▪ O: Oxygen.▪ A: Airway equipments.▪ P: Pharmacology agents.▪ ME: Monitoring Equipment.

Preparation

• Equipments:▪ Available.▪ Proper size.▪ Functioning.

• Assess for the possibility of difficult intubation or bag-mask ventilation.

• Decide which sedative and paralytic agents you will use:▪ Dose.▪ Keep them ready and drawn in syringes.▪ IV access (preferable 2).

Rapid Review

Rapid review includes: Rapid and specific history taking. Rapid and specific physical examination.

Rapid Review

Purpose: Identify or current conditions that may

adversly affected by medications or airway manipulation (NM diseases, cardiovascular compromise, increased ICP or bronchospasm).

Clinical features that may make laryngoscopy and/or tracheal inubation difficult.

Coditions that may interfere with bag mask ventilation.

Rapid Review

History: Allergies to medications. History or F.history of malignant

hyperthermia. History of asthma. Previous intubations. Siezure disorders. Noisy breathing suggestive of upper

airway obstruction.

Rapid Review

Physical examination: Clinical features suggestive of NM

disorders. Increased ICP. Bronchospasm. Cardiovascular compromise:▪ Unexplained tachcardia, poor peripheral

perfusion, and hypotension.

Pre-Oxygenation

Benefit: To establish a reservoir of oxygen within

the lungs, as well as an oxygen surplus throughout the body. So the patient can then tolerate several minutes of apnea without oxygen desaturation, allowing intubation to be safely performed without bag-mask ventilation.

Pre-Oxygenation

Ways: Hypoxic, in respiratory failure, or have

insufficient respiratory reserve to achieve adequate preoxygenation with spontaneous respirations:▪ careful bag-mask ventilation with small tidal

volumes (while maintaining cricoid pressure) should be performed for several minutes to achieve adequate preoxygenation.

Breathing spontaneously:▪ nonrebreather mask for a minimum of three

minutes.

Pre-Oxygenation

Oxygen concentration used: The highest concentration available.

Pre-Treatment

Agents: Atropine. Lidocaine.

Pre-Treatment

Atropine: Indicated in p.ts receiving ketamine to

reduce the risk of excessive secretions. Indicated in p.ts at risk of developing

bradycardia:▪ Children < 1yr.▪ Children < 5 yrs receiving succinylcholine.▪ Children receiving a second dose of

succinylcholine. Timimg:▪ 1-2 min prior to inubation.

Pre-Treatment

Dose:▪ 0.02 mg/kg IV (max 1 mg & min 0.1 mg too

small doses can cause paradoxical bradycardia).

Pre-Treatment

Disadvantages:▪ In too small doses can cause paradoxical

bradycardia.▪ The effect of atropine on heart rate may

persist for several hours and prevent the bradycardic response to hypoxemia.▪ Dilates the pupils, thus interfering with

pupillary response to light as a means to evaluate a change in neurologic status once the patient is paralyzed.

Pre-Treatment

Lidocaine: Indicated in all p.ts to reduce the risk of

increase in ICP associated with laryngoscopy and intubation (vagal nerve stimulation).

Timing:▪ 2-5 min prior to intubation.

Dose:▪ 1.5 mg/kg IV (max 100 mg)

Pretreatment

Controversies: Although widely used, there are no

studies that assess the efficacy of lidocaine to improve neurologic outcome in patients undergoing RSI in acute brain traumatic injury.

Pre-treatment

In systematic review of studies of adult patients, Robinson et al, it showed conflicting results on the ability of lidocaine to blunt the increase in ICP in patients who were being intubated or undergoing endotrachial suctioning.

Premedication

Groups of patients going for RSI can be divided into: Head trauma without shock. Shock. Asthmatic. Non of the above.

Premedication

Agents: Etimodate. Thiopental. Ketamine. Propofol. Midazolam.

Premedication

Criteria to choose the sedative agent: Availability. Institutional policy. Familiarity. Clinical advantages/disadvantages with

respect to the clinical requirements of the patients.

Etimodate

Onset of action: < 1 min.

Duration: 10-20 min.

Intubation conditions: 75% success rate.

1st most common agent used in united states cuz it is hemodynamically neutral.

Etomidate

CNS: Pros: lowers ICP, protective against

generalized siezure activity. Cons: lowers the threshold for

convulsion in p.ts with focal siezure disorders.

CVS: Pros: hemodynamically neutral.

Etimodate

Adrenals: Effect:▪ Increase the risk of adrenal suppression

leading to decrease in cortisol level (one prospective randomized controlled study of 31 adults compared etimodate and midazolam specifically to assess for adrenal function. It showed that although there was significant decrease in adrenal function in the 1st 4hr in etimodate group, there was no diffrence at 12 or 24hr and measured cortisol levels remained within normal ranges).

Etimodate

Significance:▪ Not to be used in cases of sepsis or in

patients known to have adrenal insufficiency. If there is no alternative:▪ Give a single dose of corticosteroids.

Etimodate

Preferred in: As a 1st choice unless contraindicated.

Better avoid in: Focal siezure disorders. Adrenal insufficiency. Severe sepsis.

Thiopental

Onset of action: 30-40 s.

Duration: 10-30 min.

Intubation conditions: 73 - 100% success rate (better than

etimodate). The best success rate of 1st attempt in

RSI. 2nd most common agent used in

united states.

Thiopental

CNS: Pros: lowers ICP, anticonvulsant

properties. CVS:

Cons: hypotension (bradycardia and vasodilation).

Chest: Cons: laryngo and bronchospasm

(causes histamine release).

Thiopental

Preferred in: Cases of ICP without hypotension. Cases in which etimodate is

contraindicated or not available and patient is hemodynamically stable.

Better avoid in: Hemodynamically unstable patients. Bronchial asthma patients.

Ketamine

Onset of action: 1 min.

Duration: 30-60 min.

Ketamine

CNS: Controversial: increases ICP (very weak data) Pros: has anticonvulsant properties, increase

cerebral perfusion. CVS:

Cons: hypertension (tachcardia and vasoconstriction).

Chest: Pros: bronchodilator. Cons: laryngospasm.

Ketamine

Eyes: IOP.

Salivation: Cons: hypersalivation (better to pre-treat

with atropine).

Ketamine

Prefered in: Bronchial asthma, anaphylactic shock.

Avoid in: Aortic dissection, abdominal aneurism or

acute myocardial infarction. Penetrating eye trauma. HTN.

Controversial: ICP.

Midazolam

Onset of action: 1-2 min.

Duration: 20-30 min.

Midazolam

CNS: Pros: anticonvulsant properties.

CVS: Cons: hypotension.

Chest: Cons: causes respiratory depression, so

p.ts may develop apnea before receiving the paralytic agent which interferes with the effectiveness of pre-oxygenation.

Propofol

Onset of action: 10 s.

Duration: 10-15 m.

Propofol

CNS: Pros: anticoncvulsant properties, lowers

ICP. CVS:

Cons: hypotension (vasodilatation and bradycardia).

Other: It contains egg lecithen, egg yolk

phospholipids and soybean oil.

Premedication

No ideal sedative exists for every RSI situation.

Etomidate or thiopental for the uncomplicated patient undergoing RSI.

Premedication

Hypotension: Etimodate or ketamine (especially in

septic shock). Increased ICP:

Any agent but thiopental and midazolam are not preferred cuz they decrease the mean arterial pressure leading to decrease in cerebral perfusion pressure.

Premedication

Hypotension with head injury: Etimodate or ketamine.

Status asthmaticus: Ketamine or etimodate.

Status epilepticus: Thiopental, midazolam or etimodate

(especially if hemodynamically unstable).

Paralysis

Agents: Depolaryzing:▪ Succinylcholine.

Non-depolaryzing:▪ Vecuronium.▪ Rocuronium.▪ Pancuronium.

Succinylcholine

Onset of action: 30-60s

Duration: 3-8 min.

1st most commonly used paralytic agent cuz of its rapid onset of action and short duration of paralysis.

Succinylcholine

Action: Mimics the effect of acetylcholine at the

nicotinic cholinergic receptor, causing continuous depolarization of the muscle membrane. This inhibits repolarization, resulting in paralysis.

Succinylcholine S.E

Bradycardia: Patients at risk:▪ Children < 5 yrs receiving succinylcholine.▪ Children receiving a second dose of

succinylcholine. Recommendation:▪ Pre-treating with atropine.

Succinylcholine S.E

Malignant hyperthermia can be triggered by succinylcholine.

Elevated ICP and IOP: Recommendation:▪ Pre-treat with lidocane.

Succinylcholine S.E

Hyperkalemia: Patients at risk:▪ Myopathies (such as Duchenne or Becker’s

dystrophy). Succinylcholine interacts with the unstable muscle membrane causing rhabdomyolysis and rapid increase in serum potassium.

Succinylcholine S.E

Conditions resulting in up-regulation of skeletal muscle acetylcholine receptors (such as motor neuron lesions, muscle injury, muscle disuse, or muscle atrophy) → exaggerated efflux of potassium from the muscle occurs after depolarization. The increase in number of receptors usually occurs within 2-3 days following an injury.

Succinylcholine S.E

Recommendation:▪ To minimize the hyperkalemia it is recommended to

give a defasciculating dose of a non-depolarizing agent 2 min before the administration of succinylcholine.

▪ In a small randomized controlled study, 45 children, 3–15 years old, were pretreated with either saline or a nondepolarizing paralytic agent, and then treated with succinylcholine. While there was no difference in the amount of fasciculations, the rise in serum potassium levels was significantly less when pretreated with a nondepolarizing agent (0.45 mmol/L for saline group vs. 0.0 for nondepolarizing agent group).

Succinylcholine

Absolute contraindications: Chronic myopathies. Denervating NM disease. 48-72hrs post burns, crush injuries, or

acute denervating event. H/O malignant hyperthermia. Pre-existing hyperkalemia. Renal failure.

Succinylcholine

Relative contraindications: Increased IOP or ICP. Patients with pseudocholinestrase

deficiency (risk of prolonged duration).

Non-Depolarizing agents

Mode of action: Induces muscle paralysis by competitive

antagonism at the nicotinic cholinergic receptor.

Rocuronium

Onset of action: 1-3 min.

Duration: 30-45 min.

The best alternative to succinylcholine cuz of its rapid onset of action and shorter duration of action when compared with the other non-depolarizing agents.

Rocuronium

Rocuronium v.s succinylcholine: Some clinicians prefer the disadvantage

of rocuronium longer duration of action to the small but fatal risk of using succinylcholine.

Succinylcholine provides better intubating conditions than rocuronium. This can be compensated by giving higher doses of rocuronium but unfortunately, it is associated with longer duration of paralysis.

Placement of Tube

When: Once the child is apneic and the jaw can

be easily opened (proper muscle relaxation).

Placement of Tube

Confirmation of proper position: Visualizing the ETT passing through the

vocal cords. Yellow color change in CO2 detector (the

color might change even with esophageal intubation cuz of hyperinflation of the stomach when BMV is needed. The color might not change in case of prolonged cardiac arrest).

Placement of Tube

Good wave form on the carbonograph (ETCO2 monitor).

Auscultation over the lungs and stomach.

Improvement in patient vital signs.

Post Intubation Management

Secure the ETT in position. Initiate mechanical ventilation. Chest radiograph. Administer appropriate analgesia

and sedation for patient comfort.

Complications

Adverse physiologic reactions (hypotension, bradycardia or increase ICP) secondary to vagal stimulation induced by direct laryngoscopy.

Failure of intubation in a patient who cannot be ventilated (the so called cannot intubate/cannot ventilate situation). A rescue airway techniques must be done.

Complications

Side effects from the pharmacological agents.

Esophageal intubation. Barotrauma (due to administration of

excessive tidal volume) causing pneumothorax.

Mechanical trauma to the oral cavity and larynx during insertion or manipulation of the ETT or laryngoscope.

Complications

Aspiration pneumonitis: Usually patient comes with full stomach. Sometimes cricoid pressure must be

relieved and BMV must be initiated giving more chance for air to enter stomach and causes reflux.

Cricoid Pressure

Benefit: Occlude the esophageal lumen, which

reduces the risk of passive regurgitation, which reduces the risk of aspiration.

When to apply: Once the sedative and paralytic agents

are administered until the endotracheal intubation is confirmed.

Cricoid Pressure

Risks (remove once you have one of the following): Difficulty viewing the larynx during

intubation. Airway obstruction when ventilation is

required. Movement of the cervical spine in

patients with unstable fractures. Esophageal injury in patients who are

actively vomiting.

Difficult Airway

Can be assessed by the following methods (LEMON): L: Look externally. E: Evaluate the 3-3-2 rule. M: Mallampati classification. O: Obstruction. N: Neck mobility.

Difficult Airway

Look externally for difficulty in the following: Positioning:▪ Prominent or misshapen occiput, short neck

or poor neck mobility. Bag mask ventilation:▪ Facial anomalies, facial trauma (including

burns).

Difficult Airway

Laryngoscopy:▪ Small mouth, small mandible, abnormal

palate, large tongue. Intubation:▪ Signs of upper airway obstruction

(hoarseness, stridor, drooling).

Difficult Airway

Evaluate 3-3-2 rule: 3: patient is able to insert 3 of his or her

own fingers between his teeth. 3: can accommodate 3 of his her own

fingers breadth between his or her hyoid bone and the mentum.

2: can accommodate 2 of his her own fingers between his or her hyoid bone and the thyroid cartilage.

Mallampati classification

Difficult Airway

Obstruction look for 3 signs: Drooling (inability to swallow secretions). Stridor. Hoarsness.

Neck mobility: Inability to move the neck makes it a

difficult airway.