Introduction: Rapid Sequence Intubation

Background of RSI

Brief History

• Mendelson first described the deleterious effects of aspiration in 1946.
• Succinylcholine was introduced in 1951.
• Cricoid pressure first described by Sellick in 1961.

• These were collated by Stept and Safar in 1970 to describe a technique they called Rapid Sequence Induction and Intubation.
  • It consisted of preoxygenation, induction with a predetermined dose of thiopental followed by succinylcholine, application of cricoid pressure at loss of consciousness, avoidance of positive pressure ventilation, and finally tracheal intubation with a cuffed tube before removal of the cricoid pressure.
• Airway management is the cornerstone of resuscitation and is a defining skill for the specialty of emergency medicine

Definition

• Rapid sequence intubation (RSI) is the virtually simultaneous administration of a sedative and a neuromuscular blocking (paralytic) agent to render a patient rapidly unconscious and flaccid in order to facilitate emergent endotracheal intubation and to minimize the risk of aspiration

Indications for Intubation

Failure to oxygenate or ventilate

• Ventilatory failure is a primary indication for intubation if it can not be reversed by clinical means and persistent hypoxemia persists despite maximal oxygen supplementation.
  • This assessment checks the patient’s respiratory status, blood oxygen levels and includes a physical examination of their breathing.
  • Healthcare professionals can use capnography for continuous monitoring on exhaled CO2 levels which are related with ventilation pattern & ABGs measure pH values along with pCO2 (partial pressure carbon dioxide) level that can be done by accessing arterial line insertion site through an incision made near elbow or wrist-armpit area.
  • Patients who need assisted ventilation due to poor lung function may need intubation.

Failure to Maintain or Protect the Airway

• If a patient is unable to maintain an open airway, the clinician should use various maneuvers that will aid in establishing one.
• When a patient requires airway protection, intubation is usually necessary unless they are experiencing temporary or reversible conditions. For example, if someone needs to be put on an oxygen tank while recovering from opioid overdose then other methods of protecting their airways should suffice until the condition passes.

Anticipated Clinical Course

• The presence of certain conditions are indicators that an intubation is necessary for a patient even if there isn’t immediate threat to airway patency or adequate ventilation.
  • These signs indicate with moderate likelihood that the condition will require intubation in order to evaluate and treat them.
  • Examples include drug overdoses, multiple trauma patient with hypotension, and pentrating neck trauma.

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7 P’s of Intubation

1. Preparation
2. Preoxygenation
3. Pretreatment
4. Paralysis with Induction
5. Protection and Positioning
6. Placement
7. Post-intubation management

Preparation (~Zero minus 10 min)

• Before an intubation, the patient is assessed for difficulty and a plan of action is made to prepare all necessary drugs and supplies.
• At least one good intravenous line should be established before continuing with RSI in order to avoid any mishaps during this process.
• Items and situations to consider during preparation:
  • ETT, stylet, blades, suction, BVM
  • Cardiac monitor, pulse oximeter, ETCO2
  • One ( preferably two ) iv lines
  • Drugs
  • Difficult airway kit including cricothyrodotomy kit
  • Patient positioning

Preoxygenation ( ~ Zero minus 5 min)

• Preoxygenation is a technique that involves administering 100% oxygen for 3 minutes of normal tidal volume breathing in order to establish an adequate oxygen reservoir.
• Manual ventilation prior to intubation should be reserved for patients who are hypoxic (saturation <91 percent).
  • Slow rate 8 bag/mask ventilations to avoid over inflation of lungs and stomach which increase the risk of aspiration.
• This allows the patient to have 3-8 minutes of safe apnea before they began desaturating into dangerous levels without needing bagging assistance during RSI (rapid sequence intubations).

Pretreatment ( ~ Zero minus 3 min)

• Laryongoscopy can activate coughing and gagging.
• Patients that have increased risk of the unwarranted hemodynamic changes with RSI:
  • Infants: Bradycardia
  • Adults: High BP, Bronchospasm, Increase ICP and Heart Rate

In highly emergent cases it is not worth it to wait for pretreatment and pretreatment can be judiciously omitted.

• Over time we have seen how insignificant it has been to make sure that a pre-treatment approach helps optimize our patients’ physiology prior to any attempts of laryngoscopies/trachael intubations.

Paralysis with Induction ( Zero)

• When inducing anesthesia, a potent sedative agent is administered by rapid intravenous push in a dose capable of producing unconsciousness rapidly. This will be immediately followed by an intubating dose of NMBA. It’s usual to wait 45 seconds from when the succinylcholine was given and 60 seconds after rocuronium has been given for sufficient paralysis to occur so that surgery can begin safely with minimal issues.

Protection and Positioning ( Zero plus 30 s)

• Patients should be positioned for intubation as they lose consciousness. Usually, that means flexing the neck and head downwards with cervical spine extension. However, a full sniff position is best if DLs are used to keep their necks extended.

Placement ( Zero plus 45 s)

• After you administer the NMBA, a patient should become relaxed enough to be able to insert an ETT. Test for this by moving their mandible and testing if they retain muscle tone. Then, place the ETT during glottic visualization with laryngoscopy before confirming placement of the tube.

Post-intubation Management ( Zero plus 2 mins)

• Once tube placement has been confirmed using ETCO2, place the patient on continuous capnography. Avoid long-acting neuromuscular blockers (e.g., pancuronium) and focus instead on optimal management with opioid analgesics and sedatives to facilitate mechanical ventilation if available.

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