See also:
General anesthesia
Paralytic agents
Series of actions rapidly causing loss of consciousness and muscle tone, facilitating tracheal intubation.
Indications
Respiratory failure, which can include
Cardiac arrest
Exacerbation of
COPD
Pulmonary edema
Asthma
Pneumonia
It can result in hypoxemia from impaired oxygenation, and hypercarbia and acidemia from impaired ventilation.
Altered mental status resulting in loss of protective airway reflexes
Facilitation of diagnostic studies
Combative patients may also need sedation & intubation to conduct studies (e.g. head CT).
Intubation can protect airway in: obtunded patients with risk of loss of pharyngeal muscle tone or gastric aspiration.
Sequence
5 min Preoxygenate 100%, preferrably not bag-mask
Get IV
O2 sat
Heart monitor
Have LMA or other device on hand
Sniffing position if no risk of cervical spine injury (helps visualization of vocal cords)
3 min Pretreatment agents to blunt effects of RSI
a. Prefasciculating dose of nondepolarizing paralytic/defasciculating agent (e.g. Vecuronium) [optional]
b. Analgesic (e.g. 2 mcg/kg Fentanyl IV)
c. Lidocaine esp. if head injury (to decrease ICP) [optional]
1 mg/kg q3-5min to decrease intracranial pressure
Max 300 mg total in 1 hour
d. Atropine (0.02 mg/kg IV) esp. if <10yo or existing bradycardia. [optional]
In peds:
Atropine IV preceeds Succinylcholine to reduce oral secretions as well as its bradycardic effects
2 mg/kg succinylcholine is used
1-0 min Sedative induction agent, one of:
a. Thiopental (3-5mg/kg; onset 30-60 s; duration 10-30 min; benefits: decr ICP; A/E: decr BP)
b. Methohexital (1 mg/kg IV; onset <1min; duration 5-7 min; benefits: decr ICP; A/E: decr BP)
c. Ketamine (1-2 mg/kg IV; onset 1 min; duration 5 min; benefits: bronchodilation, dissoc amnesia; A/E: incr ICP, emergence phenomenon)
d. Etomidate (0.3 mg/kg IV; onset <1 min; duration 10-20 min; benefits: decr ICP, decr IOP, Neutral BP; A/E: myclonic excitation)
e. Propofol (0.5-1.5 mg/kg IV; onset 20-40 s; duration 8-15 min; benefits: antiemetic, anticonvulsant, decr ICP; A/E: Apnea, decr BP, no analgesia--use in combo with fentanyl)
f. Fentanyl (3-8 ug/kg IV; onset 1-2 min; duration 20-30 min; benefits: reversible analgesia, neutral BP; A/E: highly variable dose, variable ICP effects, chest wall rigidity). Use only if systolic BP > 60.
g. Midazolam
1-0 min Upon achieving analgesia and sedation, administer Depolarizing paralytic agent (e.g. 1-1.5 mg/kg Succinylcholine IV).
Paralysis occurs after 45-60 s and lasts for 5 to 9 minutes.
A/E: bradyarrhythmias, masseter spasm, incr intragastric pressure, incr intraocular pressure, possibly incr ICP, malignant hyperthermia, hyperkalemia, prolonged apnea with pseudocholinesterase deficiency, fasciculation-induced muskuloskeletal trauma, histamine release, cardiac arrest
0 min Visualize cord via direct laryngoscopy. Cricoid pressure. Tracheal tube is passed through glottic opening between vocal cords into the trachea.
Use laryngoscope #3 or 4 Macintosh or #3 Miller (straight) [most adults]
Endotracheal tube with internal diameter of
7.5-8.0 mm [adult F]
8.0 to 8.5 mm [adult M]
Tube is ideally placed 2 cm above the carina. Approx 23 cm (men) or 21 cm (women) from the corner of the mouth.
Inflate tube cuff.
0-1 min Correct placement may be confirmed by auscultating the axillae, observing condensation in the tracheal tube lumen, carbon dioxide detection, use of esophageal detector device, among others. CXR can’t confirm correct placement, but tip of tube should be ~ 2-4 cm above the carina.
1 min Continue sedation since presence of tube and positive pressure ventilation are extremely uncomfortable.
In event of acute clinical decline on ventilation: remove from vent and bag ventilate. Assess tube placement/symmetric lung inflation/lung compliance. Assess circulatory compromise due to hyperinflation of lungs or tension pneumothorax.
Great medication summary: http://med.umkc.edu/docs/em/Intubation_Chart.pdf
