AIRWAY/DENTAL COMPLICATIONS

Airway Complications

Incidence

•  Unknown owing to varying significance/detection of injuries

•  Minor trauma to larynx & pharynx may be as common as 6%

•  Damage typically ↑ in relation to duration of intubation (many injuries result from placement of endotracheal tube)

•  Many injuries occur during routine, “easy” intubations

•  Delayed, chronic complications often present weeks to even months after extubation, particularly with prolonged intubations (>5 d)

Risk Factors for Intubation Trauma

•  Difficult, traumatic, multiple attempts at intubation

•  Laryngeal abnormalities (past trauma, inflammatory conditions, infection)

•  Movement of endotracheal tube (tube manipulation/surgical repositioning, coughing/bucking)

•  Impaired clearance of secretions

•  Gastroesophageal reflux

Prevention

•  Use small ETTs with lowest possible cuff pressures (leak <30 cm in pediatric pts)

•  Limit use of adjuncts (such as intubating stylets)

•  Wean ventilator to minimize duration of intubation

•  Treat airway infections aggressively & early

•  Minimize aspiration risk (when risk factors present)

•  Perform detailed assessment to prevent unanticipated airway difficulty (to ↓ chance of otherwise preventable airway injury)

•  Prepare alternative plans if intubation fails

•  Discuss risk of airway injury with pts preop (shown to ↓ litigation)

Management

•  Acute airway edema/stridor: Nebulized racemic epinephrine; dexamethasone controversial

•  Prolonged intubation (>5 d): Consider laryngeal evaluation to evaluate for injury

•  Chronic injury from repeated/prolonged intubation: Surgical correction may be required

•  Tracheobronchial rupture: Emergent surgical correction

Obtain follow-up if concerned about airway trauma

•  Inform pts if airway management was difficult/nonstandard

Dental Injuries

•  Dental trauma: Most common permanent airway injury & leading source of malpractice claims (30–40%)

•  Injuries: Fractured teeth, displaced restorations, subluxation, & avulsion (upper incisors most commonly affected secondary to use as fulcrum for laryngoscope)

Deciduous tooth loss → can result in problems with permanent teeth

•  Adverse outcomes → related to aspiration of teeth/restorations

Incidence

•  Overall incidence: Reports range from 0.02–12% (75% of injuries occur during intubation)

•  Injuries can occur during maintenance (poorly positioned airway, bite block, masseter spasm during wakeup)

Risk Factors

•  Tracheal intubation; poor dentition/periodontal disease; difficult airway characteristics; past dental restoration/endodontic treatment; elderly pts; brittle enamel; loose deciduous teeth; inexperienced laryngoscopist

Prevention

•  Detailed preop history & examination:

→ Caries/loose teeth, prostheses, past dental work

→ Assess mouth opening

→ Evaluate dentition, evidence of periodontal disease, tooth hypermobility

→ Document preexisting conditions (reduces litigation if damage occurs)

•  Consider tooth protection

→ Protectors (prefabricated rubber/custom-made by dentist)

Management

•  Loosened tooth

Return to original position promptly; splint with tape/suture

•  Displaced fragment of tooth/restoration:

Locate & recover all pieces; consider radiographs (chest, lateral head & neck) to exclude passage through glottis

•  Avulsed tooth

Immediately replace tooth to original position

Avoid wiping or drying root surface

Splint temporarily with tape/suture

If aspiration concern prevents immediate reimplantation

→ carefully place tooth in suitable medium (saline/milk)

Immediate dental referral, injury documentation & discussion with pt important

•  Most hospitals require filing an incident report

•  Reimbursement responsibility depends on hospital policy

Burns

Intraoperative burns are rare; can be devastating/fatal

Surgical Fire

•  200 surgical fires per year in the United States

•  Fire requires O₂, flammable materials, & ignition source

→ O₂ commonly administered in OR (endotracheal, nasal cannula)

→ Flammable materials = surgical drapes, alcohol prep solutions, plastic ETTs

→ Ignition sources = laser, electrosurgical units (ESUs), cautery

•  Head & neck surgeries represent most cases involving fire in OR

→ Higher risk since nasal cannulas + laser/electrocautery → combustion

→ ETT carrying enriched O₂ can also ignite, leading to a “blowtorch” effect during positive-pressure ventilation

Airway Fire

• Prevention: Decrease FiO₂ during lasering; Use heliox; Use fire resistant ETTs; Wrap ETT in metal tape; Fill ETT cuff with saline, not air

• Management: Remove ETT/stop ventilation, discontinue O₂, douse fire with saline/water, mask-ventilate pt; Perform bronchoscopy to assess airway damage

Electrocautery/Electrosurgical Unit

•  Current path: Electrosurgical pencil → through pt → out grounding pad

•  Current density dissipated over large surface area → limits risk of burn (because of low impedance return electrode)

•  ESU-associated burns:

→ Improper placement of return electrode (↓ contact surface area)

→ Fluids (blood, irrigation, skin prep) cause improper electrode contact

→ Avoid placement of return electrode over bony prominences

→ ESUs can serve as ignition source (esp if ↑ O₂ conc in use)

Magnetic Resonance Imaging

•  Complications usually involve metallic objects flying into magnetic field & burns

•  MRI radio frequency can cause heating of current conducting materials:

→ ECG cables & electrodes

Remove excess cables & avoid cable contact with skin

Do not loop cables, ensure that ECG electrodes are firmly attached

→ Medicated patches

Some contain aluminized backing (can heat in MRI)

Avoid testosterone, nitro, nicotine, scopolamine, clonidine patches

Perioperative Blindness