Volume I:
First Thirty Minutes
- Section 1
  Acute Care Algorithm/ Treatment Plans/ Acronyms
- Section 2
  Universal Approach
  - CALS Universal Approach To Emergency Advanced Life Support
- Section 3
  Steps 1-6
- Section 4
  Preliminary Impression/Focused Clinical Pathways
Volume II:
Resuscitation Procedures
Volume III:
Definitive Care

Airway 1: Rapid Sequence Intubation Portal

Rapid sequence intubation (RSI) is the near-simultaneous administration of a neuromuscular blocking agent and a potent sedative (also known as an anesthetic or induction agent) in order to facilitate endotracheal intubation.

RSI has its roots in the rapid induction techniques anesthesiologists use to intubate patients who may have full stomachs and are at risk for regurgitation and aspiration before unscheduled surgery. These techniques evolved to routine usage in the ED where all intubation candidates are, by definition, at risk for regurgitation and aspiration. RSI has been shown to be superior and more reliable than nasotracheal intubation, oral intubation without neuromuscular blockade, and surgical airway techniques. Numerous studies^1,2 have demonstrated the safety of RSI performed in the ED by emergency physicians, and RSI is considered by many in the United States to be the standard of care for airway management. Multiple drugs are used in this procedure, all of which have potent effects, side effects, interactions, and contraindications. Be familiar with these attributes before using the drugs.

Contraindications
If you have IV access, there are no absolute contraindications to RSI other than the use of specific drugs in specific clinical situations. There are, however, relative contraindications or cautions in the use of RSI. At times, giving a neuromuscular blocker to a spontaneously breathing patient (and thus taking away their respiratory drive) may be relatively contraindicated. Examples include: (1) a patient who is difficult to intubate and (2) an inability to ventilate a paralyzed patient with a BVM.

Situations where patients may be difficult to intubate include:

Penetrating or blunt neck trauma
Laryngeal edema; inhalation injuries
Anatomical considerations: short neck, receding mandible, prominent upper incisors
Limited mouth opening
Inability to extend at the atlanto-occipital joint

Situations where patients may be difficult to ventilate with the BVM:

Severe facial trauma
Beard

Note that the clinical situation may dictate use of RSI, even in the face of relative contraindications. Use good clinical judgement. Whether a difficult intubation is anticipated or not, the use of RSI always implies the explicit need for a backup plan for intubation failure. Backup plans may include either using other airway devices such as the laryngeal mask airway, the Combitube™, or providing a surgical airway. Depending on the urgency of the situation, an awake intubation technique (without the use of neuromuscular blockade) may be the airway technique of choice.

CALS uses a logical, sequential approach to RSI, using the letter P as a memory aid:

Prepare
Preoxygenate
Premedicate
Push the sedative
Paralyze
Position airway
Pass the tube
Patent airway assessment
Post-intubation plan

1. Prepare

Equipment: Fully stock the airway cart/headboard with airway tools not only for intubation but also for failed intubation. Have available:
1. Larygoscopes, ET tubes, endotracheal introducer, bag-valve-masks
2. Suction: 2 lines (at least one large bore); system in place for clearing clogged lines
3. Monitors: cardiac, pulse oximetry, BP, esophageal detector device, end-tidal CO₂
4. IV set-ups: preferably two
5. Easily accessible and labeled drugs.
6. Checklists and flow charts suitable for the ED.

(Some facilities may store drugs used during RSI in a kit that is kept in the refrigerator and easily accessible. [Succinylcholine needs to be refrigerated.])

Team: Assign roles and responsibilities: leader, intubation, cricoid pressure, immobilization, monitoring/equipment, and medications/timing. It is best to have at least 3 team members (some teams use 5), but this number varies according to location. As soon as it is determined that RSI is to be done, one team member needs to assemble and draw up the appropriate medications. Team communication is the KEY to success.
Patient: Sedation and/or paralysis limits assessment. Before administering pharmacologics, obtain a SAMPLE history and as much of the physical examination that is subject to change from sedating and paralyzing the patient (pupils, neuro exam including Glasgow Coma Scale, abdomen, reflexes, rectal exam). Advise and reassure the patient about the procedure to obtain maximal cooperation and response. Position bed and head appropriately.

2. Preoxygenate

Spontaneously breathing patient: Deliver 100% oxygen for 3 to 5 minutes via a snug mask. This creates an adequate oxygen reservoir for the patient and eliminates the need for ventilating the patient from the time the relaxant is given until the airway is secure, thus decreasing the risk of aspiration.
Assisted ventilation patient: Position patient for optimal bag-valve-mask ventilation. Consider use of Sellick’s maneuver (see description under Position Airway). Bag the patient with 100% oxygen for 3 to 5 minutes.^a
Immediate intubation cases: Some oxygen is better than none; preoxygenate as much as possible.

3. Premedicate

To be effective, pretreatment drugs should be given at least 2 to 3 minutes before giving the sedative and paralytic agents.
PEDS: In children < 8 years old: atropine 0.02 mg/kg IV (min 0.1 mg) to prevent bradycardia/asystole.^8,9
In head injury or asthma patients,^b consider lidocaine 1.5 mg/kg IV, at least 2 minutes before intubation.^1,17,18
In patients with unstable, ischemic heart disease, give Fentanyl 1 to 2 µg/kg IV to avoid rises in heart rate or blood pressure.¹⁹
Succinylcholine causes fasiculations, which may cause increased pressure in various areas of the body. Drugs that attenuate this effect may be used in this premedication period, if time permits. (See succinylcholine for drugs and their defasiculation doses.)

4. Push the Sedative (Anesthetize)

5. Paralyze

Succinylcholine 2.0 mg/kg IV for both adult and (PEDS) pediatric patients.
Note the pretreatment drugs that may be used with succinylcholine to prevent its fasiculation effects, if time permits. (See succinylcholine.)
If succinylcholine is contraindicated, choose another paralytic agent. (See RSI Drugs.)

6. Position Airway

Position the patient for optimal laryngoscopic view. In adults, if C spine trauma is not a consideration, elevate occiput 2 to 3 inches with a stack of towels, and extend head (sniffing position). If an unstable C spine is a concern, ask an assistant to immobilize head and neck in the neutral position.
Sellick’s maneuver is optional. (See footnote a.) Immediately after pushing the paralytic agent, ask an assistant to apply steady posterior pressure (the equivalent pressure to buckle the tip of one’s nose) on the cricoid cartilage (the tracheal ring just below the larynx), causing posterior displacement of the proximal airway. If this interferes with the laryngoscopic view, modify position or pressure or discontinue. Otherwise, do not release until placement of the ET tube has been confirmed.
Regardless of whether or not Sellick’s maneuver is performed, consider external manipulation of the larynx, or (PEDS) in children the BURP (back, upward, rightward pressure) maneuver for a better view. This can be carried out by an assistant or the intubator using the free hand.
If regurgitation does occur, perform immediate laryngoscopy, suction, and intubation to prevent aspiration.

7. Pass the Tube

Use in-line immobilization if the potential for cervical injury is a concern. The team member must communicate movements of the head/neck to the intubator.
Wait until the patient is fully relaxed. Have someone count the elapsed 5 to 10 second intervals. Succinylcholine takes 45 or more seconds. Resist the overwhelming urge to ventilate this non-breathing patient if you were able to preoxygenate the patient successfully. There are several minutes of oxygen reserve. Be assured by watching the pulse oximeter.
Intubate. Time is usually available for several intubation attempts, if necessary. Watch for desaturation on the oximeter: if necessary, ventilate until re-saturated and continue attempt(s). Monitor other vital signs.
Failed intubation: Ventilate the patient while securing the airway with another device such as Combitube, laryngeal mask airway, or surgical airway.

8. Patent Airway Assessment

Once the tube is passed:

Immediately use the esophageal detection device and/or end-tidal CO₂ detection.
Ventilate the patient, using 100% oxygen.
Check breath sounds. Auscultate abdomen first then check for bilateral breath sounds.
Be prepared to extubate the patient and ventilate with bag-valve-mask if esophageal intubation is suspected.
Secure the tube at estimated proper depth. (Check the depth with chest x-ray as soon as it is feasible.) Record the depth of the tube.
Suction as needed (may need immediate attention).
Check vital signs, monitors.

9. Post-Intubation Plan

Refocus yourself—shift gears. Anticipate the needs and concerns of ongoing airway evaluation/management/therapy in the context of overall patient management. These include surgery/invasive procedures, ventilator management, gastric lavage, CT scan(s), intracranial pressure (ICP) issues, seizure control, restraints, pain management, and transfer plans.
Match the appropriate agents with the needs for analgesia, continued sedation, prolonged paralysis. Remember the times given and duration of action of medications. Paralyzed patients are still able to sense pain or discomfort; treat pain accordingly. Do not keep a patient paralyzed without sedation.
Check patient’s temperature in 15 minutes if succinylcholine has been used.

Drugs Used In RSI: Pharmacology and Rationale for Use

Premedication Drugs

The physiologic response to the procedure of laryngoscopy and endotracheal intubation is as follows:

Cardiovascular: Increase in heart rate and blood pressure. PEDS: In children, vagal stimulation occurs, causing bradycardia.
CNS: Increased ICP
Respiratory: Bronchospasm

The physiologic response to succinylcholine may include:

muscle fasciculations, which are associated with increased ICP and intraocular pressure (IOP)
bradycardia or asystole in infants and small children
prolonged paralysis
hyperkalemia in selected patients

Depending on the clinical situation, these physiologic effects have the potential to cause untoward effects in a patient. For example, in a head-injured patient who may have a loss of cerebral autoregulation, even a transient increase in ICP during intubation may have ill effects. Likewise, in a critically ill asthmatic patient, stimulation of the airway causing bronchospasm may be harmful. Severe bradycardia or even asystole may occur in a sick child who receives succinylcholine and vagal stimulation from the airway procedure.

Patients may be premedicated in order to attenuate some of these physiological responses. If a patient needs an airway immediately, there may not be time to administer premedication drugs. If time does permit, use the following:

Lidocaine (1.5 mg/kg) IV administered 2 to 3 minutes before intubation may block the transient rise in ICP that may be of significance in a head-injured patient. In addition, lidocaine may block a bronchospastic response to intubation.^11-13
PEDS: Give atropine (0.02 mg/kg, minimum 0.1 mg) to children < 8 years of age to prevent the vagal response (and the bradycardic/asystolic effect of succinylcholine).
Fentanyl 1 to 2 µg/kg IV may be given to avoid rises in heart rate or blood pressure (eg, a patient with unstable, ischemic heart disease).
Vecuronium defasciculating dose—0.01 mg/kg (which is about one-tenth of its usual paralyzing dose). Give to partially block the fasciculations that will be caused by the subsequent use of succinylcholine.

Sedative Agents (Anesthetic)

In anesthesiology terms, sedatives are induction agents. Each of several choices has its set of benefits as well as adverse effects. The clinical situation determines the choice of the appropriate drug. Etomidate is a clinically versatile drug that may be used in numerous situations.

Etomidate (Amidate)
An ultra short-acting nonbarbiturate hypnotic.
Advantages: Short acting, lowers ICP, no adverse cardiovascular effects, rarely causes apnea. No histamine release.
Disadvantages: May cause nausea, myoclonus (may resemble a seizure)
Suppresses cortisol. Even a single dose of etomidate can suppress cortisol production,^20,21 which may be detrimental to patients in septic shock.²² Exercise caution when using etomidate in patients with septic shock.²³ Consider using a different sedative or giving supplemental steroids.
Uses: Best sedative to use in head injury, cardiovascular disease, shock. Etomidate may also be used in asthma. PEDS: Etomidate is not FDA-approved for children; however, several studies support its safety in the pediatric population.

Midazolam (Versed)
Benzodiazepine drug. Note that the dose for induction (0.1 to 0.3 mg/kg) is much higher than the dose for sedation, which is a common use for this drug.
Advantages: Amnesia
Disadvantage: May have too long an onset (1 to 3 minutes) for some inductions. May cause myocardial depression and reduce mean arterial pressure (MAP) and thereby lower cerebral perfusion pressure, which could add to cerebral ischemia in head-injured patients. Therefore, also use with caution in patients with shock or cardiovascular compromise.
Uses: Most often used post intubation for continued sedation.

Sublimaze (Fentanyl)
A narcotic analgesic with rapid onset and short duration.
Advantages: No histamine release, no hypotension.
Disadvantage: At induction doses (3 µg/kg), Fentanyl may cause chest wall rigidity. (It this occurs, treat with succinylcholine.)
Uses: Not commonly used as the induction agent as it is not a sedative; generally, Fentanyl is used in combination with a sedative/hypnotic. Fentanyl may be given as a premedication to attenuate the reflex sympathetic activity during intubation. This would be beneficial in a patient with ischemic heart disease where you might want to avoid tachycardia and a rise in blood pressure.

Ketamine (Ketolar)
A PCP derivative. Ketamine does not sedate but produces a dissociative state.
Advantages: Rapid action. Sympathomimetic effects, including bronchial smooth muscle relaxation. Ketamine may be given IM as well as IV so may be useful in a patient who does not have IV access.
Disadvantages: Ketamine may cause a rise in ICP: do not use in head-injured patients. Emergence reactions from the dissociative state can be treated with a benzodiazepam.
Uses: Useful in hypotensive patients. May be best drug in asthma.

Propofol (Diprovan)
Ultra short-acting sedative hypnotic
Advantages: Extremely quick in action and brief in duration.
Disadvantages: May cause hypotension via peripheral vasodilatation: loss of preload and positive pressure ventilation (PPV) can be a deadly combination in patients with cardiovascular and/or hypovolemic problems.
Uses: induction in cardiovascularly stable patients.

Agent/Class	Dose: mg/kg	Onset	Duration	Key Notes
etomidate/ imidazole derivative	0.3 mg/kg over 30 to 60 seconds	< 1 minute	5 to 14 minutes	best all-around profile
midazolam/ benzodiazepine	0.1 to 0.3 mg/kg	2 to 3 minutes	30 to 60 minutes	amnesia, reversible
Fentanyl/ opiate	0.002 to 0.01 mg/kg (1 to 2 µg/kg)	< 1 minute	30 to 60 minutes	analgesia, reversible
ketamine/ dissociative	1 to 2 mg/kg	1 minute	10 to 30 minutes	bronchodilation, amnesia, analgesia; avoid in the head (ICP)
propofol	1.0 to 2.0 mg/kg	30 to 60 seconds	3 to 5 minutes	May cause hypotension

Paralytic Agents
Succinylcholine (Anectine)
An ultra short-acting depolarizing neuromuscular blocker. Onset of action: 45 to 60 seconds. Duration: 6 to 12 minutes. Fasciculations occur in about 45 seconds. Associations with fasciculations are increased ICP and IOP. This may be prevented by administering a defasciculating dose of a competitive, non-depolarizing neuromuscular blocker such as vecuronium at one-tenth the usual paralyzing dose (ie, 0.01 mg/kg) in the premedication step.

Contraindications: Use a different neuromuscular blocking agent: Personal or family history of malignant hyperthermia; hyperkalemia and potential hyperkalemia—(burns > 3 days prior, massive crush injury or other conditions in which rhabdomyolysis may be a concern, chronic renal disease with hyperkalemia, denervating neuromuscular diseases; stroke or spinal cord injury from 1 week to 6 months prior); eye injuries where you would want to avoid elevations of IOP. Precautions: consider using a different neuromuscular blocking agent: increased ICP; increased intragastric pressure; cocaine intoxication. PEDS: CAUTION: This drug may induce bradycardia/asystole in infants and/or small children. Prevent this by pretreatment with atropine. Concern also exists regarding undiagnosed neuromuscular disease in younger children.

Rocuronium (Zemuron)
A competitive, non-depolarizing neuromuscular blocker. Shorter acting and duration than vecuronium. Advantage: Premixed. Onset: 70 seconds. Duration: 30 to 60 minutes.

Vecuronium (Norcuron)
A competitive, non-depolarizing neuromuscular blocker. Onset of action: 1 to 2 minutes. Duration: 45 minutes. Used mostly for postintubation paralysis. If time permits, use one-tenth dose as a defasciculating dose prior to use of succinylcholine.

Agent/Class	Dose: mg/kg	Intubation	Duration	Key Notes
succinylcholine/ depolarizing	2 mg/kg	45 to 60 seconds	6 to 12 minutes	See prior caveats. PEDS: Do not repeat dose in small children
rocuronium/ nondepolarizing	1.0 mg/kg	45 to 75 seconds	25 to 60 minutes	can also use as an infusion; tachycardia possible
vecuronium/ nondepolarizing	0.1 mg/kg	90 to 240 seconds	25 to 120 minutes	reversible: few cardiovascular side effects

The CALS pocket card for rapid sequence intubation (RSI) reads as follows:

1. Prepare:	Equipment, meds, team, patient (basic airway management, positioning)
2. Preoxygenate:	100% O₂, 3 to 5 minutes
3. Premedicate:	Atropine (0.02 mg/kg IV; PEDS minimum 0.1 mg in children < 8 years) Lidocaine 1.5 mg/kg IV (head injury, asthma)
4. Push the sedative:	Use one: Etomidate 0.3 mg/kg IV: Use with caution in septic shock. Consider alternative sedation or supplemental corticosteroids Midazolam 0.1 mg/kg IV (adults) PEDS: 0.3 mg/kg IV: Suggested maximum single dose 10 mg; reduce dose or consider alternative in hypotension or elderly Ketamine 1 to 2 mg/kg IV (bronchodilator) Raises intracranial pressure; avoid in head injury.
5. Paralyze:	Use one: Succinylcholine 2 mg/kg IV Avoid in hyperkalemia, neuromuscular disease, or ocular trauma Vecuronium 0.1 mg/kg IV OR Rocuronium 1 mg/kg IV Wait for relaxation (45-60 sec). Do not bag unless hypoxic.
6. Position airway:	Head/neck position; laryngeal manipulation, BURP, cricoid pressure as needed
7. Pass the tube:	Maintain in-line cervical immobilization in head/neck trauma
8. Patent airway assessment:	Use esophageal intubation detector, check breath sounds, CO₂detector
9. Post-intubation plan:	Drugs and dosages depend on medications used during intubation Sedation: Midazolam 0.05 to 0.3 mg/kg IV. Suggested maximum single dose 10 mg; reduce dose or consider alternative in hypotension or elderly Paralysis: Vecuronium 0.1 mg/kg IV (if not used for intubation) Analgesia: Fentanyl 1 to 2 MICROgrams/kg IV Morphine 0.05 to 0.15 mg/kg IV Consider need for seizure prevention.

Repeat as needed to maintain sedation, paralysis, and analgesia.

References

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Miller RD, editor. Miller’s Anesthesia, 6th ed. Philadelphia, Pa: Churchill Livingstone, 2005.
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Weiss LD, Generalovich T, Heller MB, et al. Methemoglobin levels following intravenous lidocaine administration. Ann Emerg Med. 1987;16:323-325.
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Salhi B, Stettner E. In defense of the use of lidocaine in rapid sequence intubation. Ann Emerg Med. 2007;49:84-87.
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Zed PJ, Mabasa VH, Slavik RS, Abu-Laban RB. Etomidate for rapid sequence intubation in the emergency department: is adrenal suppression a concern? CJEM. 2006;8:347-350.
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Jackson WL Jr. Should we use etomidate as an induction agent for endotracheal intubation in patients with septic shock? A critical appraisal. Chest. 2005;127:1031-1038.

Airway 1: Rapid Sequence Intubation Portal

References

Edition 13-October 2011