Rapid Sequence Intubation (RSI)

RSI INTUBATION

Julia E. Martin M.D.

Associate Professor

Department of Emergency Medicine

General information:

Airway control is always the most important objective in the initial resuscitation and stabilization.  It takes the highest priority in primary assessment. The trauma team must be prepared for any airway emergency.

RSI involves the use of neuromuscular blocking agents and sedatives to facilitate endotracheal intubation.  Rapid Sequence induction technique is used to prevent regurgitation and aspiration of gastric contents.  Requires preoxygenation and denitrogenation by using 100% oxygen via non-rebreather face mask and a nasal cannula at 15 lpm.  The nasal cannula should be left in place during the intubation, to prevent apnea related hypoxia during the procedure. During induction, a skilled assistant provides manual in-line axial stabilization of the head and the front of the c-collar is removed. Main disadvantage is once anesthesia has been induced there is no turning back. The only contraindication to RSI intubation is a practitioner who is not skilled in airway management.  A skilled provider should have excellent working knowledge of oral tracheal intubation, supraglottic airways, difficult airway skills and surgical airway skills.  Indication for surgical airway is the inability to obtain or maintain an airway to provide adequate ventilation. In neck trauma, intubation may be difficult or impossible and surgical airway may be required.

Short acting agents are used to allow patient to resume spontaneous respirations and to allow close monitoring of neurological status.  Oral endotracheal intubation is usually the preferred method.  If the head and neck are stabilized by an assistant there is almost no risk of spinal cord injury by oral tracheal intubation.

Always anticipate vomiting.  Even patients, who otherwise seem relatively unresponsive, may vomit during attempted intubation without RSI.  This may result in loss of airway control and aspiration of gastric contents.  Struggling patients increase muscle activity making hypoxemia worse and increase ICP. As a general rule, presume all trauma patient’s have just eaten. Risk for aspiration is greatest during anesthesia induction and instrumentation of the upper airway. 

Patients with severe closed head injury are of major concern because intracranial pressure can rise precipitously during intubation.  Rapid sequence induction of anesthesia and oral intubation is recommended for patients with head injuries to minimize the rise in ICP.

Remember, rendering a patient apneic, when endotracheal intubation is beyond the skill of the operator, may be rapidly fatal.

Indication for RSI Endotracheal Intubation of the Acute Trauma Patient:

Trauma patients with GCS < 8

Significant facial trauma with poor airway control

Airway obstruction

Closed head injury or hemorrhagic CVA

Burn patients with airway involvement and inevitable airway loss

Class 3-4 hemorrhagic shock

Failure to maintain adequate oxygenation (SaO2 < 90% despite 100% FiO2)

Paralysis due to high spinal cord injury

Need for positive pressure ventilation

Blunt chest trauma with compromised ventilatory effort

Mandibular fractures with loss of airway muscular support

Evaluation:

“Talking patient” usually indicates airway is patent for the moment.

Respiratory distress associated with trauma to the upper airway is frequently made worse by blood or gastric contents in the airway and requires prompt action. These patients are often combative because of hypoxia.

When evaluating an awake patient with severe facial trauma ask them if they are getting enough air.  If they cannot answer, stick out their tongues fairly easily or are hyperventilating, they should probably be intubated.  In unconscious patients, it is probably best to intubate.

Tachypnea may be subtle but an early sign of airway or ventilatory compromise.  Tachypnea is often also associated with pain and/or anxiety.

Agitated and combative patients that are not hypoxic, hypoglycemic or have a significant head injury are better managed with Haldol 5-10 mg IV/ IM or Zyprexa 10mg IM.

Signs of Airway Obstruction:

Agitation = hypoxia

Obtudation = suggests hypercarbia

Cyanosis = hypoxia

Retractions and use of accessory muscles

Snoring, gurgling, stridor = partial obstruction at pharynx

Hoarseness = laryngeal obstruction/ injury

DRUGS:

Sedatives:

Versed:

Benzodiazepine

Rapid onset (1-2 min) and short duration (20 min)

Amnesic

Anticonvulsant

Muscle relaxant

Decrease in blood pressure and increase in pulse rate

No increase in ICP

Dose: 0.1 mg/kg

Etomidate:

Nonbarbiturate, nonnarcotic sedative-hypnotic induction agent

Good agent in multisystem trauma as it evokes minimal change in HR and CO

Decreases ICP and IOP during procedure

Rapid onset (<1 min) and short acting (5 min)

Vomiting, especially with combined with a narcotic

Dose: 0.3 mg/kg

Propofol:

            General Anesthetic (hypnotic sedative)

            Caution with known egg or soy allergy

            Blood pressure drop in hypovolemic patients

            Dose:  Kids (3-16):  2-3 mg/kg, titrating at rate of 20mg every 10 sec

Healthy adults:  2 mg/kg at rate of 40mg every 10 sec

                        Elderly: 1-1.5 mg/kg at rate of 20mg every 10 sec

                       

Ketamine:

General Anesthetic (produces dissociative state with analgesia and sedative properties)

Can cause hallucinations, emergence delirium and excitations à manage with benzodiazepines 

Onset 30 sec

Duration 5-10 minutes

Dose:  1-2 mg/kg IV

Fentanyl:

Narcotic

Little or no histamine release

Rarely causes hypotension

Consider in head-injured patients as a premedication to prevent increase in ICP (blunts pressor response)

Rapid injection may cause chest wall rigidity

Dose: 3-5 mcg/kg

Onset in 2 min with 30-40 min duration

Paralytic Agents:

Succinylcholine:

Depolarizing agent, which causes muscle fasciculations which can be prevented by pretreatment with a non-depolarizing neuromuscular agent

Rapid onset (30-60sec) with short duration of action (5-7 min).

Dose:             Adult 1.5 mg/kg

Pediatric (<10 y.o): 2.0 mg/kg

Contraindications:

Burns > 7 days old

Extensive crush injuries > 7 days old.

Paraplegia > 7 days old.

Narrow-angle glaucoma

Neuromuscular Diseases:

Guillain-Barre, myasthenia gravis, Multiple sclerosis, muscular dystrophy, Parkinson’s disease.

Others susceptible to increased potassium:
Renal failure (no real evidence that RSI increases K+)

Rhabdomyolysis

Vecuronium:

Nondepolarizing agent

Onset 2-3 minutes

No histamine release

Defasciculating dose: 0.01 mg/kg

Paralytic dose: 0.1 mg/kg

Rocuronium:

Non-depolarizing agent

Onset < 1 min.

Duration 20-30 min.

Paralytic Dose: 1 mg/kg

Defasciculating dose: 0.1 mg/kg

Adjunctive:

Atropine:

Succinylcholine will cause bradycardia in infants and children therefore they should be premedicated with atropine.  Also pretreat any adult who is already bradycardic

Children < 8 y.o.

Dose: 0.01 - 0.02mg/kg up to 1 mg (minimum dose of 0.1 mg)

Lidocaine:

Dose: 1.5 mg/kg

Some studies recommend intravenous Lidocaine to blunt the pressor response of increased pulse, increased blood pressure, increased intracranial pressure, and increased intraocular pressure associated with intubation, its usefulness is controversial.  However, because a single dose of lidocaine is unlikely to cause harm, it seems reasonable to use in the patient who has a known or suspected head injury

Should be administered 2-3 min prior to intubation

Procedure:

The 5 P’s of rapid sequence intubation:

Preparation

Preoxygenation

Pretreatment

Paralysis (with anesthesia)

Placement (of the endotracheal tube)

1.     Preoxygenation with 100% oxygen for 3-5 minutes via NRB mask (or 3 vital capacity breaths, avoid BVM if possible)

2.     Secure IV’s, ECG, pulse oximeter

3.     Prepare intubation equipment:  ETT with stylet, suction, BVM, laryngoscope

4.     Premedication:

            Lidocaine (head injury) 1.5 mg/Kg

            Vecuronium (defasciculating dose) 0.01 mg/Kg

            Versed 0.1 mg/Kg

            Atropine (peds) 0.02 mg/Kg

            Etomidate 0.3 mg/Kg

5.     Succinylcholine 1.5 mg/Kg (Peds: 2.0 mg/Kg)

6.     Wait 30-60 sec, place ETT

7.     Confirm ETT placement by: listening for bilateral breath sounds, chest rise and fall, tube fogging, & positive colorimetric ETCO2.  Final confirmation by CXR

8.     Secure ETT

9.     Attach continuous waveform ETCO2 monitoring

References:

1.      Mace SE.  Challenges and Advances in Intubation:  Rapid Sequence Intubation.  Emerg Med Clin N Am: 2008: 26:1043-1068.

2.      Practice Guidelines for Management of the Difficult Airway:  An Updated Report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway.  Anesthesiology 2013;118

3.      Singh A, Frenkel O.  Evidence-Based Emergency Management of the Pediatric Airway.  Pediatric Emergency Medicine Practice: 2013;10(1):1-28.

4.      Richard Levitan’s Anatomic Insights and Practice Changing Concepts.