Monday, April 7, 2014

Rapid Sequence Intubation

Definition
Administration of potent induction agent after pre-oxygenation followed immediately by rapidly acting neuromuscular blocking agent to induce unconscious and motor paralysis  for tracheal intubation without interposed positive airway ventilation

Indications for intubation
Inability to maintain patent airway/tone
Upper airway sweling, facial/neck trauma, Poor GCS
Ventilatory compromise

Hypoventilation, large pneumothorax, flail chest, Severe COPD, status asthmaticus
Failure to adequately oxygenate
Severe hypoxemia, APO, PE, ARDS
Anticipation of deteriorating course

Severe haemorrhagic shock, ICB with poor GCS, Septic shock


Contraindications
  • Total upper airway onstruction
  • Total loss of oropharyngeal/ facial landmarks


7 P's
1. Preparation
2. Pre-oxygenation
3. Pre-treatment
4. Paralysis with induction
5. Positioning
6. Placement with proof
7. Post-intubation management

1. Preparation
Patient must be managed in resuscitation area
Prepare yourself, have a skilled assistants
Prepare the equipment- Remember this mnemonic MALES+4S

Mask and Monitoring

•Non-rebreather mask/Bag valve mask
•Cardiac monitor, pulse ox, BP cuff opposite arm with IV line

Airway

•Airway adjuncts (e.g. OPA, NPA, LMA) and Ask for difficult airway trolley

Laryngoscope

•Blade – Mac 3 or 4 for adults – curved blade
•Miller 3 or 4 for adults – straight blade
•Handle – attach blade and make sure light source works

ETT

•7.5 ET tube with stylet fits most adults, 7.0 for smaller females, 8.0 for larger males

Suction

•Immediate suction with a large bore Yankauer suction

Stylet

placed inside ET tube for rigidity, bend it 30 degrees starting at proximal end of cuff (i.e. straight to cuff, then 30 degree bend)
Stethoscope

Use this to listen to air entry and in ryles tube insertion later
Syringe and securing tape

Use syringe to inflate the cuff after successful intubation and tape to anchor the tube

Other suggested mnemonic: MARBLESx2 or SOAP-ME

Assess airway upon patient arrival. Use mnemonic LEMONS
  • Look externally- for maxilofacial/neck trauma, beard, obesity, cachexia, edentulous mouth
  • Evaluate 3:2:2 rule (3 fingers for mouth opening, 3 fingers between hyoid bone and mentum, 2 fingers between thyroid cartilage and hyoid bone
  • Mallampati score- direct peroral pharyngeal visualization and that seen with laryngoscopy.
  • Obstruction. Evaluation for stridor, foreign bodies, and other forms of sub- and supraglottic obstruction should be performed in every patient prior to laryngoscopy.
  • Neck mobility

2. Preoxygenation
Principle
•establishment of oxygen reservoir within the lung, blood and body tissue to permit several minutes of apnoea without arterial oxygen desaturation
•no bagging principle
•Replacement of predominantly nitrogenous mixture of room air with oxygen allowing several minutes apnea time before Hb saturation <90%

Principle reservoir - functional residual capacity (FRC) ~ 30ml/kg

Method
•Administration of 100% oxygen for 3 minutes,
•or by having the patient take 8 vital capacity breath while on 100% oxygen


3. Pretreatment
Administration of drugs to mitigate adverse effects associated with the intubation or patient's underlying comorbidities.
Adverse effects include
  •  Bronchospastic reactive airway
  •  Increased ICP
  •  Reflex sympathetic response to laryngoscopy (RSRL)

Given 3 minutes before the induction agents and succinylcholine

Pre-treatment Drugs
  •  Fentanyl    1mcg/kg over 30-60 sec
  •  Lignocaine       1.0-1.5ml/kg

Apply ABC principle
A
Asthma, reactive airway disease
Use lignocaine
B
Brain, increased ICP
Use lignocaine or fentanyl
C
Cardiovascular, IHD, hypertension, ICB
Use fentanyl

Based on current evidence, the following previous practices are no longer recommended:
  • use of defasciculating, non-depolarizing muscle relaxant in high ICP and penetrating eye injury
  • use of atropine to prevent succinylcholine-induced bradycardia in small children.

4. Paralysis with induction
Administration of rapidly acting induction agent in a dose adequate to produce prompt unconsciousness immediately followed by neuromuscular blocking agent

Induction Agent
Dosing
Advantages
Disadvantages
Midazolam
0.1-0.5mg/kg
Amnetic, sedative
Hypotension, respiratory suppression
Ketamine
2mg/kg
Good bronchodilator, used in Asthma, severe hypotension/shock
Increased BP/HR/ muscle tone/ salivation/ IOP, readily cross placenta
Etomidate
0.3mg/kg
Very cardiostable, used in cardiac patient and haemodinamically unstable patient
Suppression of synthesis of cortisol
Propofol
2.0-2.5mg/kg
Conscious sedation
Depression of cardiovascular/ respiratory


Neuromuscular blocking agent:
1.Scolene (suxamethonium / succinylcholine) - depolarising muscle relaxant
  •    Adult           1mg/kg
  •    Children   2mg/kg
  •    Neonate       3mg/kg
   Onset :  within 60sec
Duration : 3-5minutes
Adverse effects
- hyperkalaemia (increased by 0.5mmol/l)
- Bradycardia
- malignant hyperthermia
- increased ICP/IOP
 observe for fasciculation
2. Esmeron (recuronium) - non-depolarising muscle relaxant
  • Dose            0.6-1.2mg/kg
  • SE: hypokalaemia

Test for patient's jaw for flaccidity
  • 45sec after administration of scolene
  • 60sec after administration of rocuronium

5. Positioning
The head should be extended on the neck (Sniffing position). If cervical spine trauma is suspected, have an assistant provide in-line immobilisation.
Sellick maneuvre (application of firm pressure on cricoid cartillage to prevent passive regurgitation) is considered optional because it can worsen laryngoscopic view and impair tube insertion.

6. Placement with proof
During this stage, laryngoscopy is performed to visualize the glottis. The endotracheal tube is then passed in between the vocal cords, and a cuff is inflated around the tube to hold it in place and prevent aspiration of stomach contents.

Proof:
  • Direct visualisation
  • Calorimetric end tidal CO2 detector
  • Vapour in ETT
  • SPO2 monitoring
  • 6 points auscultation
  • Chest rise

7. Post-Intubation Management
  1. Secure ET tube, note depth of initial tube placement on documentation
  2. Initiate mechanical ventilation
  3. RT insertion - confirmed by rapid introduction of air in 10cc syringe with auscultation at epigastic
  4. CXR
  5. Assess pulmonary status (remember CXR does not confirm placement, but assesses the tube height
  6. above the carina). Ensure that mainstem intubation has not ocurred
  7. Administer sedative/analgesia for patient comfort, decreased oxygen demand and to decrease ICP, 
  8. Obtain arterial blood gases, if facility is capable
  9. Document all components of the procedure accurately/ completely including time, tube size, depth of insertion and number of attempts
  10. Maintain rigorous patient monitoring and oversight for continued ventilatory effectiveness
  11. sedation and paralysis, hemodynamic stability and patient comfort
Example: IV midazolam infusion (20mg in 20cc NS run 2cc/H) and IV Fentanyl (200mcg in 20cc NS run 2cc/H)
  1. May give IV Ranitidine 50mg to reduce the risk of gastric aspiration
  2. Insert CBD



Complications
Esophageal intubation
Right mainstem intubation
Failure to intubate
Hypotension
Aspiration
Iatrogenic induction of obstructive airway
Pneumothorax
Dental/oral trauma
Post intubation pneumonia
Vocal cord avulsion

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