Acute Airway Management & RSI — Part 4: Clinical Scenarios & Post-Intubation Management

1. Trauma Airway

1.1 Unique Challenges

Trauma patients present the most complex airway scenarios, combining anatomic difficulty (blood, vomit, facial injury, cervical spine immobilization) with physiologic compromise (hemorrhagic shock, traumatic brain injury, chest injury).¹ ²

Challenge	Mechanism	Strategy
Blood and vomit in airway	Obscures visualization; aspiration risk	Aggressive suction (have 2 Yankauer catheters); head-up positioning (if not C-spine restricted); consider lateral position for passive drainage
Cervical spine immobilization	Collar and MILS limit neck extension; worsens CL grade by 1–2 grades	Remove anterior collar; apply manual in-line stabilization (MILS) by a dedicated assistant; VL first-line; bougie
Facial trauma	Midface fractures (Le Fort), mandibular fractures, dental avulsions, expanding hematomas	Airway may be distorted; nasal intubation contraindicated in midface fractures; may require surgical airway early
Hemorrhagic shock	Severe hypotension; cardiovascular collapse at induction	Fluid resuscitation and blood products BEFORE induction; ketamine or etomidate; dose-reduce; push-dose vasopressors at bedside
Traumatic brain injury	Elevated ICP; secondary brain injury from hypoxia/hypotension	Avoid hypoxia (SpO₂ > 94%) and hypotension (SBP > 100 mmHg); smooth RSI; target normocapnia (ETCO₂ 35–40 mmHg) post-intubation
Laryngotracheal injury	Blunt or penetrating neck trauma; laryngeal fracture; tracheal disruption	Surgical airway may be first choice; avoid cricothyrotomy if laryngeal fracture (do tracheostomy instead); awake technique if possible
Penetrating neck injury with expanding hematoma	Progressive airway compression; distorted anatomy	Intubate EARLY before complete obstruction; have FONA ready; two-surgeon approach if possible

1.2 Manual In-Line Stabilization (MILS) Protocol

Step	Action
1	Assistant positioned at the head of the bed, facing the patient
2	Remove the anterior portion of the cervical collar (leaving the posterior portion for support)
3	Assistant places hands on either side of the patient’s head — one on each mastoid process/temporal bone — holding the head and neck in neutral alignment
4	Assistant maintains gentle, steady, neutral positioning throughout laryngoscopy — does NOT apply traction or countertraction
5	Laryngoscopist performs intubation (VL recommended) with the head immobilized
6	After intubation confirmed, reapply the anterior collar

Key evidence: MILS reduces cervical spine motion during intubation compared to no stabilization but worsens the laryngoscopic view (CL grade increases by approximately 1 grade in 20–30% of patients). Video laryngoscopy is the recommended first-line device in the immobilized cervical spine.³

1.3 Trauma RSI Modification

Component	Modification
Induction	Ketamine 1.0–1.5 mg/kg (hemodynamic support) or Etomidate 0.3 mg/kg; dose-reduce in hemorrhagic shock
Paralytic	Succinylcholine 1.5 mg/kg (safe in acute trauma < 5 days) or Rocuronium 1.2 mg/kg
Pretreatment	Fentanyl 1–2 mcg/kg ONLY if TBI with hypertension; AVOID if hypotensive
Laryngoscopy	VL first-line; MILS maintained; bougie first-pass strategy
Post-intubation	Target SBP > 100 mmHg; SpO₂ > 94%; ETCO₂ 35–40 mmHg; CXR to confirm tube position and evaluate for pneumothorax

2. Elevated Intracranial Pressure (ICP)

2.1 Pathophysiology

Laryngoscopy triggers a sympathetic surge (hypertension and tachycardia) that can raise ICP in patients with impaired cerebral autoregulation (TBI, intracranial hemorrhage, cerebral edema). Simultaneously, hypoxia and hypotension cause secondary brain injury that worsens neurologic outcomes.⁴

2.2 RSI Protocol for Elevated ICP

Step	Agent/Action	Rationale
Preoxygenation	Aggressive: NRB 15 L/min × 3 min + HFNC 60 L/min	Avoid any period of hypoxia (SpO₂ < 94%)
Pre-induction hemodynamics	Target SBP > 100 mmHg; fluid bolus if needed; vasopressor infusion ready	Hypotension (SBP < 90) increases mortality 2–3× in TBI
Pretreatment	Fentanyl 1–3 mcg/kg IV over 60 sec (3 min before induction)	Blunts sympathetic surge during laryngoscopy (↓ HR, BP → ↓ ICP spike)
Pretreatment	Lidocaine 1.5 mg/kg IV (optional, weak evidence)	May attenuate ICP rise; evidence inconsistent
Induction	Ketamine 1.5–2.0 mg/kg IV OR Propofol 1.5 mg/kg IV (if normotensive)	Ketamine: safe in TBI (ICP concern refuted); hemodynamically favorable. Propofol: reduces ICP directly but causes hypotension
Paralysis	Rocuronium 1.2 mg/kg IV (preferred) or Succinylcholine 1.5 mg/kg	Rocuronium preferred (no fasciculations that transiently raise ICP); either is acceptable
Intubation	VL first-line; single smooth attempt; bougie available	Minimize laryngoscopy time; avoid repeated attempts
Post-intubation	ETCO₂ 35–40 mmHg (normocapnia); SpO₂ > 94%; head of bed elevated 30°; adequate sedation	Hyperventilation (ETCO₂ < 30) ONLY for acute herniation (transtentorial signs: unilateral pupil dilation, posturing); routine hyperventilation is harmful

3. Status Asthmaticus

3.1 When to Intubate

Intubation in status asthmaticus carries exceptionally high risk due to dynamic hyperinflation, air trapping, and the potential for cardiovascular collapse from positive-pressure ventilation. Intubation is reserved for:⁵

Respiratory arrest or imminent respiratory arrest
Altered mental status (obtundation from hypercapnia)
Failure of aggressive medical therapy (continuous nebulized albuterol, IV magnesium, IV steroids, epinephrine)
Progressive respiratory failure with exhaustion

3.2 RSI Modifications for Status Asthmaticus

Component	Approach	Rationale
Induction	Ketamine 1.5–2.0 mg/kg IV (first choice)	Potent bronchodilator via direct smooth muscle relaxation and catecholamine release
Paralytic	Rocuronium 1.2 mg/kg or Succinylcholine 1.5 mg/kg	Succinylcholine is safe in asthma (though rare case reports of bronchospasm); either is acceptable
Avoid	Histamine-releasing agents	Succinylcholine has theoretical histamine release risk but is clinically insignificant at standard RSI doses
Post-intubation ventilator	See below	Permissive hypercapnia; long expiratory time

3.3 Post-Intubation Ventilator Settings for Status Asthmaticus

Parameter	Setting	Rationale
Mode	Volume control (AC-VC)	Guarantees tidal volume delivery
Tidal volume	6–8 mL/kg IBW	Standard lung-protective tidal volume
Respiratory rate	8–12 breaths/min (LOW)	Allows long expiratory time to prevent air trapping
I:E ratio	1:4 to 1:5 (or longer)	Prolonged expiration to allow air to escape through narrowed airways
Inspiratory flow	60–80 L/min (high)	Short inspiratory time → longer expiratory time
FiO₂	Titrate to SpO₂ 92–96%	Standard oxygenation target
PEEP	0–5 cm H₂O (low or zero)	External PEEP adds to auto-PEEP, increasing hyperinflation; some experts use low PEEP (3–5) to stent airways open
Permissive hypercapnia	Accept PaCO₂ up to 60–80 mmHg (pH > 7.15)	Prioritize allowing CO₂ clearance through prolonged expiratory time rather than increasing rate
Monitor for auto-PEEP	Check plateau pressure; check end-expiratory flow waveform	If end-expiratory flow does not reach zero before the next breath, air trapping is occurring → decrease rate or increase expiratory time
Plateau pressure target	< 30 cm H₂O	High plateau pressures indicate severe air trapping; risk of pneumothorax

3.4 Post-Intubation Bronchodilation

Agent	Dose	Route
Albuterol (continuous)	10–20 mg/hr continuous nebulization	In-line nebulizer in ventilator circuit
Ipratropium	0.5 mg q4–6h	In-line nebulizer
Ketamine infusion	0.5–2 mg/kg/hr	IV continuous infusion (bronchodilatory effect)
Magnesium sulfate	2 g IV over 20 min (if not already given)	IV
Methylprednisolone	125 mg IV q6h	IV
Epinephrine	0.3–0.5 mg IM or 1–5 mcg/min IV infusion	For refractory bronchospasm

4. Morbid Obesity

4.1 Challenges

Patients with BMI > 40 kg/m² present a combination of anatomic and physiologic difficulties that make airway management among the highest-risk scenarios in emergency medicine.⁶

Challenge	Mechanism
Rapid desaturation	Reduced FRC (up to 50% reduction at BMI > 40); increased oxygen consumption; large body mass
Difficult BVM ventilation	Redundant pharyngeal tissue; reduced chest wall compliance; difficult mask seal
Difficult laryngoscopy	Short, thick neck; limited mouth opening; large tongue; anterior larynx
Difficult positioning	Standard beds/stretchers may be inadequate; need for ramp
Difficult cricothyrotomy	Landmarks obscured by subcutaneous tissue; CTM palpation failure in up to 50%
Drug dosing complexity	Must distinguish between IBW, TBW, and LBW for different agents

4.2 Optimization Protocol for Morbid Obesity

Strategy	Implementation
Positioning	Head-elevated (25–30°) ramped position; ear-to-sternal-notch alignment; bed at maximal working height
Preoxygenation	NIV (BiPAP: IPAP 12–15, EPAP 8–10, FiO₂ 1.0) for 3–5 minutes; HFNC 60 L/min as apneic oxygenation
Identify CTM pre-induction	Palpation AND point-of-care ultrasound to mark the CTM with a skin marker before induction
Video laryngoscopy	First-line device; hyperangulated blade often needed
Bougie	First-pass adjunct
Drug dosing	See table below
Prepare for prolonged intubation attempt	Apneic oxygenation will extend safe apnea time

4.3 Drug Dosing in Obesity

Drug	Dosing Weight	Rationale
Succinylcholine	Total body weight (TBW)	Plasma cholinesterase activity and volume of distribution correlate with TBW
Rocuronium	Ideal body weight (IBW)	Rocuronium distributes to lean tissue; TBW dosing → prolonged paralysis
Sugammadex	Total body weight (TBW)	Must encapsulate all circulating rocuronium; under-dosing leads to incomplete reversal
Ketamine	Lean body weight (LBW) or IBW	Lipophilic agent; TBW dosing → higher-than-needed levels and prolonged effect
Propofol	Lean body weight (LBW)	Highly lipophilic; TBW dosing causes excessive hypotension
Etomidate	Total body weight (TBW)	Limited data; some recommend IBW; clinical judgment
Fentanyl	Lean body weight (LBW) or IBW	Fat-soluble; TBW dosing → excessive respiratory depression

Lean body weight (LBW) formulas:

Males: LBW = 1.10 × weight (kg) − 128 × (weight/height in cm)²
Females: LBW = 1.07 × weight (kg) − 148 × (weight/height in cm)²
Practical approximation: LBW ≈ IBW + 0.3 × (TBW − IBW)

5. Pregnancy

5.1 Physiologic Changes Relevant to Airway Management

Change	Effect on Airway Management
Reduced FRC (20% reduction by 3rd trimester)	Rapid desaturation during apnea; safe apnea time reduced to ~3 min even with preoxygenation
Increased oxygen consumption (20–30% increase)	Accelerated oxygen depletion
Mucosal edema (airway capillary engorgement)	Swollen nasal and oropharyngeal mucosa; use smaller ETT (6.0–6.5 mm); avoid nasal intubation if possible; bleeding risk with instrumentation
Weight gain and breast enlargement	May impair positioning and laryngoscope handle clearance; use short-handled laryngoscope
Increased aspiration risk	Reduced lower esophageal sphincter tone; increased intragastric pressure from gravid uterus; delayed gastric emptying
Difficult airway rate	Failed intubation in obstetric patients is approximately 1:300 (vs 1:5,000 in general surgical population)

5.2 RSI Modifications for Pregnancy

Component	Modification
Positioning	Left lateral tilt (15–30°) or manual left uterine displacement to prevent aortocaval compression (after 20 weeks gestation); head-up ramped position
Preoxygenation	5 minutes NRB 15 L/min (extended due to rapid desaturation); HFNC recommended
RSI preferred	Full RSI with paralysis is the standard technique for pregnancy (aspiration risk)
Induction	Ketamine 1.5 mg/kg or Propofol 1.5–2.0 mg/kg; both are safe in pregnancy
Paralytic	Succinylcholine 1.5 mg/kg (safe in all trimesters; slightly prolonged due to reduced plasma cholinesterase) or Rocuronium 1.2 mg/kg
ETT size	6.0–6.5 mm (smaller than non-pregnant due to mucosal edema)
Avoid nasal intubation	Increased risk of epistaxis from mucosal engorgement
Post-intubation	Maintain SpO₂ > 95% (fetal oxygenation depends on maternal PaO₂); target normocapnia (ETCO₂ 30–35 mmHg — normal for pregnancy is lower due to progesterone-driven hyperventilation)
Fetal monitoring	Continuous fetal monitoring during and after intubation if viable gestation (≥ 23 weeks); have obstetric team available

6. Pediatric Airway Management

6.1 Anatomic Differences

Feature	Infant/Young Child	Adult	Clinical Implication
Head size	Proportionally large occiput	Smaller relative occiput	No pillow needed under head in infants; shoulder roll may help
Laryngeal position	High (C3–C4)	Lower (C4–C6)	More anterior; epiglottis may be more difficult to lift
Epiglottis	Omega-shaped, floppy	Flat, firm	Miller (straight) blade preferred in infants to directly lift epiglottis
Narrowest point	Cricoid ring (subglottic) in children < 8 years; glottic opening in older children/adults	Glottic opening (vocal cords)	Determines ETT size; historical basis for uncuffed tubes in young children
Airway diameter	Smaller absolute diameter	Larger	1 mm of edema causes 50% reduction in cross-sectional area in an infant (vs ~20% in an adult)
Tongue	Proportionally larger	Smaller relative	More likely to obstruct; OPA sizing important
Oxygen consumption	6–8 mL/kg/min	3–4 mL/kg/min	Faster desaturation; safe apnea time in infants ~90 seconds
FRC	Lower relative to body weight	Higher relative	Reduced oxygen reservoir

6.2 ETT Sizing by Age

Age	ETT Size (Cuffed, ID mm)	ETT Size (Uncuffed, ID mm)	Depth at Lip (cm)	Formula
Premature	2.5–3.0 uncuffed	2.5–3.0	6 + weight (kg)	—
Newborn (0–1 month)	3.0 cuffed or 3.5 uncuffed	3.0–3.5	7–8	—
1–6 months	3.0–3.5 cuffed	3.5	8–9	—
6 months–1 year	3.5 cuffed	3.5–4.0	9–10	—
1–2 years	3.5–4.0 cuffed	4.0–4.5	10–12	—
2 years	4.0 cuffed	4.5	12	Cuffed: (age/4) + 3.5
4 years	4.5 cuffed	5.0	13	Cuffed: (age/4) + 3.5
6 years	5.0 cuffed	5.5	14–15	Cuffed: (age/4) + 3.5
8 years	5.5 cuffed	6.0	16–17	Cuffed: (age/4) + 3.5
10 years	6.0 cuffed	6.5	17–18	Cuffed: (age/4) + 3.5
12 years	6.0–6.5 cuffed	7.0	18–20	Cuffed: (age/4) + 3.5
14+ years	7.0 (F) / 7.5 (M)	—	20–23	Adult sizing

Current recommendation: Cuffed endotracheal tubes are now recommended for ALL ages, including neonates and infants. Cuffed tubes reduce the need for reintubation due to air leak, reduce aspiration risk, and allow more consistent ventilation. Cuff pressure should be monitored and maintained at < 20–25 cm H₂O (< 18 cm H₂O in neonates) to prevent subglottic mucosal injury.⁷

6.3 Laryngoscope Blade Sizing by Age

Age	Blade Type	Blade Size
Premature–Newborn	Miller (straight)	0
Newborn–6 months	Miller (straight)	0–1
6 months–2 years	Miller (straight)	1
2–6 years	Miller or Macintosh	1.5–2
6–12 years	Macintosh or Miller	2–3
> 12 years / Adult	Macintosh	3–4

6.4 Pediatric RSI Medications

Drug	Pediatric Dose	Notes
Atropine (pretreatment)	0.02 mg/kg IV (min 0.1 mg, max 0.5 mg)	Recommended for all children < 1 year before succinylcholine; consider for ages 1–5
Ketamine (induction)	1.5–2.0 mg/kg IV; 4–5 mg/kg IM	Preferred induction agent in pediatrics; safe hemodynamic profile
Propofol (induction)	2.5–3.5 mg/kg IV	Higher dose required in children due to larger volume of distribution; significant hypotension risk
Etomidate (induction)	0.3 mg/kg IV	Safe in children; less studied; adrenal suppression concern similar to adults
Succinylcholine	2.0 mg/kg IV; 4 mg/kg IM	Higher dose in children; IV dose 2.0 mg/kg (vs 1.5 mg/kg in adults); contraindicated in undiagnosed myopathy/muscular dystrophy
Rocuronium	1.0–1.2 mg/kg IV	Safe in all pediatric ages; preferred if MH or myopathy concern

Succinylcholine in pediatrics — special warning: Succinylcholine has an FDA black box warning for pediatric use due to reports of cardiac arrest from hyperkalemia in children with undiagnosed muscular dystrophies (especially Duchenne). Routine use of succinylcholine in children is acceptable for RSI but should NOT be used for elective intubation when rocuronium is available. Always have IV access and resuscitation equipment ready.⁸

6.5 Pediatric FONA: Needle Cricothyrotomy

In children under 8–12 years, the cricothyroid membrane is too small and the cricoid cartilage too compliant for safe surgical cricothyrotomy. Needle cricothyrotomy is the recommended FONA technique in young children.⁹

Parameter	Pediatric Needle Cricothyrotomy
Needle size	18 gauge (neonates–infants); 14–16 gauge (children > 2 years)
Technique	Same as adult (see Part 3, Section 6.4); caudal 45° angle; aspirate for air
Ventilation	Transtracheal jet ventilation at 1 psi/kg body weight (maximum 50 psi); OR attach catheter to 3.0 mm ETT connector → BVM for low-pressure ventilation
Duration	Bridge only; convert to definitive airway as soon as possible
Children > 10–12 years	Surgical cricothyrotomy is acceptable (CTM is large enough)

6.6 Broselow Tape Reference

The Broselow-Luten tape is a length-based resuscitation tool that estimates weight and provides equipment sizing and medication dosing for pediatric patients based on body length.¹⁰

Broselow Color Zone	Weight Range (kg)	ETT Size (Cuffed)	ETT Depth at Lip (cm)	Laryngoscope Blade	LMA Size	Suction Catheter (Fr)
Gray	3–5	3.0	9	Miller 0–1	1	6–8
Pink	6–7	3.5	10.5	Miller 1	1.5	8
Red	8–9	3.5	10.5	Miller 1	1.5	8
Purple	10–11	4.0	12	Miller 1–2	2	8–10
Yellow	12–14	4.0	13	Miller/Mac 2	2	10
White	15–18	4.5	14	Miller/Mac 2	2.5	10
Blue	19–23	5.0	15	Mac 2	2.5	10
Orange	24–29	5.5	16.5	Mac 2–3	3	10–12
Green	30–36	5.5–6.0	18	Mac 3	3	12

7. Angioedema and Anaphylaxis Airway

7.1 Angioedema

Angioedema causing tongue, lip, oropharyngeal, or laryngeal swelling is a rapidly progressive airway emergency. The key principle is early intervention before complete obstruction.¹¹

Feature	Management
Recognition	Progressive lip/tongue swelling; drooling; muffled voice; stridor; difficulty handling secretions
Etiology	ACE inhibitor–induced (bradykinin-mediated); hereditary angioedema (complement-mediated); allergic (histamine-mediated); idiopathic
Nebulized epinephrine	Racemic epinephrine 0.5 mL of 2.25% solution in 3 mL NS nebulized; reduces mucosal edema
Early intubation	Intubate early while the airway is still patent but deteriorating; delay risks complete obstruction
Technique	Awake fiberoptic intubation is ideal (preserves spontaneous breathing); if RSI required, have FONA immediately ready; use a smaller ETT (6.0–6.5 mm) — swelling narrows the lumen
FONA readiness	Prepare surgical cricothyrotomy kit before ANY attempt; supraglottic swelling may make SGA ineffective
Medical treatment	ACE-inhibitor angioedema: fresh frozen plasma (provides kininase II), icatibant (bradykinin B2 antagonist), C1 inhibitor concentrate; Hereditary: C1 inhibitor concentrate, icatibant, ecallantide; Allergic: epinephrine IM, diphenhydramine, steroids

7.2 Anaphylaxis Airway

Priority	Action
Epinephrine first	Epinephrine 0.3–0.5 mg IM (anterior lateral thigh) immediately; repeat q5–15 min
Airway assessment	Assess for stridor, tongue swelling, laryngeal edema
Intubate early	Do not wait for complete obstruction; edema progresses rapidly
Technique	RSI with ketamine preferred (bronchodilation, hemodynamic support); have FONA ready
Bronchospasm	Albuterol nebulized continuously; epinephrine IM/IV; ketamine induction
Post-intubation	Epinephrine infusion 0.1–0.5 mcg/kg/min; steroids; H1/H2 blockers

8. Burns and Inhalation Injury

8.1 Indications for Early Intubation

Indicator	Significance
Facial burns (2nd/3rd degree)	High risk of progressive airway edema
Singed nasal hair, eyebrows, or facial hair	Suggests exposure to extreme heat
Carbonaceous sputum	Indicates inhalation of combustion products
Stridor or hoarseness	Suggests existing laryngeal edema — intubate immediately
Extensive burns (> 40% TBSA)	Massive fluid resuscitation will worsen edema
Burns in enclosed space	CO and cyanide exposure; smoke inhalation
Progressive respiratory distress	Do not wait for desaturation

Key principle: Intubate early, before edema peaks. Airway edema from inhalation injury and fluid resuscitation progresses over 12–24 hours. An airway that is manageable at initial assessment may be impossible to intubate 6 hours later.¹²

8.2 RSI Modifications for Burns

Component	Approach
Induction	Ketamine 1.5–2.0 mg/kg (hemodynamic support; bronchodilation; analgesic)
Paralytic	Acute burn (< 5 days): Succinylcholine safe; Burn > 5 days: Succinylcholine CONTRAINDICATED (hyperkalemia risk) — use Rocuronium 1.2 mg/kg
ETT size	Use a larger ETT than expected (7.5–8.0 in adults, or 0.5 mm larger than age-predicted in children) — swelling will progressively narrow around the ETT
Secure the tube well	Tape may not adhere to burned skin; use circumferential ties or commercial holders secured to non-burned skin; wire the tube to teeth if necessary
Post-intubation	Monitor for progressive edema; if tube becomes too small (large cuff leak despite inflation), reintubation with larger tube may be needed

9. Post-Intubation Ventilator Settings by Clinical Condition

9.1 Initial Ventilator Settings Reference Table

Clinical Condition	Mode	Tidal Volume	RR	FiO₂	PEEP	I:E	Special Notes
Standard / Default	AC-VC or AC-PC	6–8 mL/kg IBW	14–18	Start 1.0 → titrate to SpO₂ 92–96%	5 cm H₂O	1:2	Standard starting point; adjust based on ABG
ARDS	AC-VC	6 mL/kg IBW (strictly)	20–30 (to maintain minute ventilation)	Start 1.0 → titrate per low-tidal-volume protocol table	10–20 cm H₂O (titrate per PEEP/FiO₂ table below)	1:1 to 1:2	Plateau pressure < 30; driving pressure < 15; consider prone positioning if P/F < 150¹³
Status asthmaticus	AC-VC	6–8 mL/kg IBW	8–12 (LOW)	Titrate to SpO₂ 92–96%	0–5 (LOW)	1:4 to 1:5	Permissive hypercapnia; monitor auto-PEEP; priority is adequate expiratory time
Elevated ICP / TBI	AC-VC	6–8 mL/kg IBW	Adjust to ETCO₂ 35–40 mmHg	Titrate to SpO₂ > 94%	5–8	1:2	Normocapnia; avoid hyperventilation except for acute herniation
Pulmonary embolism	AC-VC	6–8 mL/kg IBW	16–20	Start 1.0	5 (low)	1:2	Minimize PEEP (avoid RV preload compromise); hemodynamic support with vasopressors
Metabolic acidosis (DKA, sepsis)	AC-VC	6–8 mL/kg IBW	Match pre-intubation RR (may be 25–35)	Titrate to SpO₂ 92–96%	5	1:2	CRITICAL: match minute ventilation to pre-intubation compensatory hyperventilation; failure causes acute pH drop → cardiac arrest
Morbid obesity	AC-VC or AC-PC	6–8 mL/kg IBW (NOT TBW)	14–20	Titrate to SpO₂ 92–96%	8–15 (higher; to recruit atelectasis)	1:2	Use IBW for tidal volume; higher PEEP for atelectasis; recruitment maneuver if needed
Pregnancy	AC-VC	6–8 mL/kg IBW	Adjust to ETCO₂ 30–35 mmHg	Titrate to SpO₂ > 95%	5	1:2	Normal pregnancy PaCO₂ is 28–32 mmHg; maintain maternal hyperventilation

9.2 Low-Tidal-Volume Protocol PEEP/FiO₂ Tables

Lower PEEP table (most commonly used):

FiO₂	0.3	0.4	0.4	0.5	0.5	0.6	0.7	0.7	0.7	0.8	0.9	0.9	0.9	1.0	1.0
PEEP	5	5	8	8	10	10	10	12	14	14	14	16	18	18	20–24

Higher PEEP table:

FiO₂	0.3	0.3	0.3	0.3	0.4	0.4	0.5	0.5	0.5–0.8	0.8	0.9	1.0	1.0
PEEP	5	8	10	12	14	16	16	18	20	22	22	22	24

10. Post-Intubation Sedation and Analgesia Regimens

10.1 Standardized Approach

Priority	Agent	Dose	Target
1. Analgesia	Fentanyl infusion: 25–200 mcg/hr OR Hydromorphone: 0.2–1.0 mg/hr	Titrate to pain scale (BPS or CPOT)	BPS < 5; CPOT < 3
2. Sedation	Propofol: 5–50 mcg/kg/min OR Dexmedetomidine: 0.2–1.5 mcg/kg/hr	Titrate to RASS target	RASS 0 to -2 (light sedation) unless deeper sedation required
3. Adjunct	Ketamine: 0.1–0.5 mg/kg/hr	Opioid-sparing; bronchodilatory	Reduces opioid and propofol requirements
4. PRN agitation	Midazolam 1–2 mg IV q15min PRN	For acute agitation/ventilator dyssynchrony	Use sparingly; benzodiazepines associated with increased delirium¹⁴

10.2 Sedation Targets

Clinical Situation	RASS Target	Rationale
Standard ICU ventilation	0 to -2	Light sedation improves outcomes (shorter ventilation, less delirium)
Neuromuscular blockade	-4 to -5	Must be deeply sedated during paralysis (patient is aware but unable to move/communicate)
Elevated ICP/TBI	-3 to -5	Deep sedation reduces cerebral metabolic rate; may use propofol or barbiturate coma
Severe ARDS with proning	-3 to -4	Moderate-deep sedation for patient comfort and safety during prone positioning
Active seizures	-4 to -5	Deep sedation required for seizure control

11. Extubation in the Emergency Department

11.1 General Principles

Extubation in the ED is uncommon but may be appropriate for patients intubated for brief, self-limited conditions (e.g., procedural sedation complication, opioid overdose responsive to naloxone, brief seizure).¹⁵

11.2 Extubation Criteria

Criterion	Requirement
Underlying condition resolved	The reason for intubation has been definitively treated
Adequate oxygenation	SpO₂ > 92% on FiO₂ ≤ 0.4 and PEEP ≤ 5 cm H₂O
Adequate ventilation	Spontaneous tidal volume > 5 mL/kg; RR < 30; no accessory muscle use
Hemodynamic stability	No vasopressor requirement; stable heart rate and blood pressure
Neurologic function	Awake, follows commands; GCS ≥ 8T; intact gag and cough reflexes; can lift head off bed for ≥ 5 seconds
Cuff leak present	Deflate ETT cuff; air leak heard around the tube during positive-pressure breath (suggests no significant laryngeal edema) — absence of cuff leak does NOT necessarily preclude extubation but raises concern for post-extubation stridor
Low risk for reintubation	No anticipated clinical deterioration; no need for ongoing airway protection
Rapid shallow breathing index (RSBI)	RR / VT (liters) < 105 predicts extubation success

11.3 Extubation Risks

Post-extubation stridor/edema — treat with nebulized racemic epinephrine; may need reintubation; dexamethasone 0.5 mg/kg IV (max 10 mg) if given 4–6 hours pre-extubation reduces post-extubation stridor
Aspiration — suction oropharynx before cuff deflation
Reintubation — have full intubation equipment at bedside during extubation; keep patient fasting

12. Complete Equipment Reference Tables

12.1 Endotracheal Tube (ETT) Size by Age and Sex

Patient	ETT Internal Diameter (mm)	Depth at Lip (cm)	Depth at Nares (cm)
Premature infant (< 1 kg)	2.5 uncuffed	6.5–7	7–8
Premature infant (1–2 kg)	3.0 uncuffed	7–8	8–9
Term newborn (3–4 kg)	3.0 cuffed / 3.5 uncuffed	8–9	9–10
3 months (5–6 kg)	3.0–3.5 cuffed	9–10	10–11
6 months (7–8 kg)	3.5 cuffed	10	11–12
1 year (10 kg)	3.5–4.0 cuffed	11	13
2 years (12 kg)	4.0 cuffed	12	14
4 years (16 kg)	4.5 cuffed	13	16
6 years (20 kg)	5.0 cuffed	14–15	17
8 years (25 kg)	5.5 cuffed	16–17	19
10 years (30 kg)	6.0 cuffed	17–18	21
12 years (40 kg)	6.0–6.5 cuffed	18–20	22
Adult female	7.0–7.5 cuffed	19–21	22–24
Adult male	7.5–8.0 cuffed	21–23	24–26

12.2 Laryngoscope Blade Size by Age

Age	Miller (Straight)	Macintosh (Curved)	Preferred Type
Premature–Newborn	0	—	Miller
1–6 months	0–1	—	Miller
6 months–2 years	1	—	Miller
2–5 years	1.5	2	Miller or Macintosh
5–10 years	2	2	Either
10–14 years	2	2–3	Macintosh
Adult female	—	3	Macintosh
Adult male	—	3–4	Macintosh

12.3 Supraglottic Airway (SGA) Size by Patient Weight

Patient Weight (kg)	i-gel Size	LMA Classic/ProSeal Size	King LT Size
< 5	1	1	0
5–12	1.5	1.5	1
10–25	2	2	2
25–35	2.5	2.5	2
30–50	3	3	3
50–70	4	4	4
70–100	4	5	4
> 100	5	5–6	5

12.4 Oral Airway (OPA) and Nasal Airway (NPA) Sizing

OPA (Guedel airway):

Age/Size	OPA Size (color code varies by manufacturer)	Measurement Method
Premature/Neonate	000 (30 mm)	Corner of mouth to angle of mandible
Infant (3–12 months)	00 (40 mm)	Corner of mouth to angle of mandible
Small child (1–3 years)	0 (50 mm)	Corner of mouth to angle of mandible
Child (3–8 years)	1 (60 mm)	Corner of mouth to angle of mandible
Small adult	2 (70 mm)	Corner of mouth to angle of mandible
Medium adult	3 (80 mm)	Corner of mouth to angle of mandible
Large adult	4 (90 mm)	Corner of mouth to angle of mandible
Very large adult	5 (100 mm)	Corner of mouth to angle of mandible

NPA (nasal trumpet):

Age/Size	NPA Size (French)	Approximate ID (mm)
Child	12–20 Fr	4.0–6.7 mm
Small adult	24–26 Fr	6.0–6.5 mm
Average adult female	26–28 Fr	6.5–7.0 mm
Average adult male	28–32 Fr	7.0–8.0 mm
Large adult	32–36 Fr	8.0–9.0 mm

12.5 Suction Catheter Sizing

ETT Size (mm ID)	Suction Catheter Size (Fr)	Rule
2.5	5–6	Catheter Fr = ETT ID × 2
3.0	6
3.5	6–8
4.0	8
4.5	8–10
5.0	10
5.5	10
6.0	10–12
6.5	12
7.0	12–14
7.5	14
8.0	14–16

12.6 Quick Reference: RSI Drug Dosing by Weight

Weight (kg)	Ketamine 1.5 mg/kg (mg)	Ketamine 2.0 mg/kg (mg)	Propofol 1.5 mg/kg (mg)	Etomidate 0.3 mg/kg (mg)	Succinylcholine 1.5 mg/kg (mg)	Rocuronium 1.2 mg/kg (mg)
5	7.5	10	7.5	1.5	10*	6
10	15	20	15	3	20*	12
15	22.5	30	22.5	4.5	30*	18
20	30	40	30	6	40*	24
30	45	60	45	9	45	36
40	60	80	60	12	60	48
50	75	100	75	15	75	60
60	90	120	90	18	90	72
70	105	140	105	21	105	84
80	120	160	120	24	120	96
90	135	180	135	27	135	108
100	150	200	150	30	150	120
120	180	240	180	36	180	144**

*Pediatric succinylcholine dose: 2.0 mg/kg for children < 10 years

**Rocuronium in obesity: use ideal body weight (not total body weight); this row assumes IBW for dosing

13. Sugammadex Quick Dosing Reference

Weight (kg)	Sugammadex 16 mg/kg — Immediate Reversal (mg)	Sugammadex 4 mg/kg — Deep Block (mg)	Sugammadex 2 mg/kg — Moderate Block (mg)
40	640	160	80
50	800	200	100
60	960	240	120
70	1,120	280	140
80	1,280	320	160
90	1,440	360	180
100	1,600	400	200
120	1,920	480	240

Note: Sugammadex is dosed on total body weight (including in obese patients). Vials typically contain 200 mg/2 mL or 500 mg/5 mL.

14. Push-Dose Vasopressor Reference

Peri-intubation hypotension is common and dangerous. Push-dose vasopressors should be prepared BEFORE induction for any patient at risk.¹⁶

14.1 Push-Dose Phenylephrine

Step	Action
1	Take a 10 mL syringe; draw up 1 mL of phenylephrine 10 mg/mL (standard vial)
2	Add 9 mL of normal saline → concentration = 1 mg/10 mL = 100 mcg/mL
3	Administer 0.5–2 mL (50–200 mcg) IV push q2–5 min as needed
Effect	Pure alpha-1 agonist: increases SVR and BP without chronotropy; reflex bradycardia possible

14.2 Push-Dose Epinephrine

Step	Action
1	Take a 10 mL syringe; draw up 1 mL of epinephrine 1:10,000 (0.1 mg/mL, cardiac concentration)
2	Add 9 mL of normal saline → concentration = 10 mcg/mL
3	Administer 0.5–2 mL (5–20 mcg) IV push q2–5 min as needed
Effect	Alpha-1 + Beta-1 agonist: increases SVR and cardiac output; preferred in shock/bradycardia

Critical safety: NEVER use epinephrine 1:1,000 (1 mg/mL) for push-dose preparation — this concentration is 10× more concentrated and a dose calculation error could be lethal. Always start with the 1:10,000 (0.1 mg/mL) cardiac concentration.

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