ANESTHESIA FOR COMMON PEDIATRIC EMERGENCIES (BEYOND NEWBORN)

DANIEL E. LEE, MD PhD Associate Clinical Professor of Anesthesiology and Pediatrics University of California, San Diego

PEDIATRIC PERIOPERATIVE RISK

 Pediatric Perioperative Cardiac Arrest registry (POCA) – 1.4 cardiac arrests per 10,000 instances of anesthesia – Cardiac arrest mortality of 26% – Age < 1 year and emergency status are independent predictors of mortality  Unique Anesthetic Management Concerns – Smaller FRC, increased metabolic rate, more rapid desaturation with apnea – Often uncooperative, impacting upon ease of IV placement, preoxygenation, awake intubation, etc.

– Infants and young children in particular may have unrecognized underlying disease that can affect response to anesthesia, e.g. cardiac or airway anomalies

COMMON PEDIATRIC EMERGENCIES

 FOREIGN BODY ASPIRATION  EPIGLOTTITIS  PERITONSILLAR ABSCESS  RETROPHARYNGEAL ABSCESS  POST TONSILLECTOMY HEMORRHAGE  HYPERTROPHIC PYLORIC STENOSIS

FOREIGN BODY ASPIRATION

 Most common in toddler age group  Presentation – Coughing or choking while eating – Persistent cough or difficulty swallowing – Wheezing or stridor  Examination: locate level of obstruction – Stridor: esophageal FB at cricoid level – Severe obstruction/cyanosis: large FB trapped in glottis or trachea – Unilateral wheezing/air trapping: distal airway aspiration

Foreign Body Aspiration



Figure 1.

A chest radiograph may appear normal during inspiration (

A

) following foreign body aspiration. A hyperinflated right lung and a leftward mediastinal shift during expiration (

B

) suggest a foreign body in the right mainstem bronchus.

PEDIATRIC OTOLARYNGOLOGIC EMERGENCIES. Susan T. Verghese and Raafat S. Hannallah . Anesthesiology Clinics of North America 19 (2) : 237-256

FOREIGN BODY RETRIEVAL

FOREIGN BODY ASPIRATION - II



Preoperative Preparation

– Timing • Emergency? (e.g. cyanosis, noxious substance) • Discuss with surgical specialist re: urgency and special needs – Premedication • Atropine 20 mcg/kg IV/IM: dries secretions, facilitates topical anesthesia, maintains heart rate.



Anesthetic Induction

• Sevoflurane or Halothane inhalation induction • Maintain spontaneous ventilation initially – Avoids need for positive pressure ventilation – May decrease risk of dislodging FB

FOREIGN BODY ASPIRATION - III

 Anesthetic Maintenance – Deep Sevoflurane/Halothane, spontaneous ventilation, supplementation with propofol IV – Under deep anesthesia > direct laryngoscopy > supraglottic FB may be removed if visualized – Topical lidocaine spray (2-4%) to airway, max 3-5 mg/kg – Intermittent airway obstruction?

• Supplemental IV propofol 50-200 mcg/kg/min – Excessive coughing with airway manipulation?

• Supplemental topical tracheal lidocaine by surgeon • Short acting narcotic or paralytic. Then controlled ventilation

via

sideport of rigid bronchoscope or intermittently by mask.

– Esophagoscopy needed?

• First secure airway with endotracheal tube

EPIGLOTTITIS

 Life-threatening airway emergency  Less common since advent of Haemophilus Influenza type B vaccine  Symptomatology occasionally mistaken for croup, a more common childhood airway problem. Misdiagnosis can be disastrous.

EPIGLOTTITIS vs CROUP

    Age Organism Onset Symptoms  Physical Exam  Neck X-rays CROUP 6mo-6yr Viral Gradual Low fever Stridor Tachypnea Barking cough +/- Cyanosis Retractions Anterior view Steeple sign Subglottic edema EPIGLOTTITIS 1-7yr Bacterial Rapid High fever Stridor Tachypnea No Cough Drooling Sitting up – ‘tripod’ Retractions Lateral view Swollen epiglottis Loss of valecula

EPIGLOTTITIS - II

 Preoperative airway management: – Airway EMERGENCY – Do not agitate patient – Proceed immediately to OR if stable, parental accompaniment may help to keep child calm – ENT standby for emergency tracheostomy  Anesthetic induction & intubation: – Inhalation (Sevo/Halo) induction with patient sitting – Establish IV as soon as child is anesthetized – Atropine 20 mcg/kg and fluid bolus while anesthesia is deepened – Intubate under deep anesthesia with child spontaneously ventilating – Use styletted ETT at least 0.5mm smaller than normal – If laryngeal structures cannot be identified, external compression of thorax may allow air bubbles to be seen at the tracheal inlet

EPIGLOTTITIS - III

 Post-intubation management – IV antibiotics – 24-48 hours intubation as swelling subsides – Trial of extubation should be attempted only after airway swelling has significantly diminished (check with bronch and/or glidescope) – All preparations should be made for emergent reintubation or tracheostomy should trial of extubation fail (e.g. use tube exchanger, bronch available, LMA available, ENT surgeon/trach kit).

PERITONSILLAR ABSCESS

 Most common in children & young adults  Presentation: – Fever, pain, difficulty swallowing, trismus – Uvula deviation, pharyngeal swelling at tonsillar bed  Treatment: – IV Antibiotics – Surgical incision & drainage

PERITONSILLAR ABSCESS - II

 Anesthetic management: – If minimal airway distortion and no difficulty with intubation anticipated • IV induction with short acting paralytic • Gentle laryngoscopy, avoid premature rupture of abscess • Cuffed ETT and head down position may limit soiling of the airway when abscess is lanced – If trismus is severe or any difficulty with airway anticipated • Inhalational (Sevo/Halo) induction • Maintain spontaneous ventilation • Trismus generally resolves as anesthesia deepens • Gentle laryngoscopy and intubation, advanced airway techniques if necessary, surgeon should be present for possible surgical airway  Postoperative emergence: – Airway is cleared of all inflammatory material – Child is extubated fully awake

RETROPHARYNGEAL ABSCESS

 Retropharyngeal inflammation pushes posterior pharynx forward obstructing airway  More likely to cause airway obstruction than peritonsillar abscess  Presentation: – Fever, pain, difficulty swallowing, trismus – Posterior pharyngeal mass (exam, lateral Xray, CT)

RETROPHARYNGEAL ABSCESS - II

 Anesthetic management: – If mild airway distortion and no difficulty with airway anticipated, may proceed with IV induction, gentle laryngoscopy and intubation – If any concern of difficult airway or if trismus is severe • Inhalational (Sevo/Halo) induction • Maintain spontaneous ventilation • Trismus generally resolves as anesthesia deepens • Gentle laryngoscopy and intubation, advanced airway techniques if necessary, surgeon should be present for possible surgical airway  Post-operative emergence – Airway is cleared of all inflammatory material – Child is extubated fully awake

POST TONSILLECTOMY HEMORRHAGE

 Surgical emergency  May occur early (24 hrs) or late (5-10 days)  Presentation: – Anemia – Hypovolemia – Stomach often full of blood  Pre-operative preparation: – Hematocrit, type & crossmatch – Aggressive fluid resuscitation should begin prior to induction

POST TONSILLECTOMY HEMORRHAGE - II

 Anesthetic induction – Airway may be obscured by blood – 2 x large bore suction, multiple laryngoscope blades and styletted endotracheal tubes should be prepared – Hypovolemia may persist despite aggressive pre-operative resuscitation – Rapid sequence IV induction with ketamine 2 mg/kg or etomidate 0.2 mg/kg with succinylcholine 2 mg/kg minimizes risk of hemodynamic embarrassment with induction

POST TONSILLECTOMY HEMORRHAGE - III

 Intraoperative management – Airway can be protected with a cuffed ETT or snug fitting uncuffed ETT in smaller children – If specific source of bleeding is not identified, child may have underlying bleeding disorder – Clotting studies should be sent – Clotting factors replaced as necessary if ongoing bleeding – FFP, Cryo, Platelets, DDAVP (if type of von Willebrand’s deficiency is known)  Post-operative emergence – Stomach contents are suctioned – Endotracheal extubation fully awake – Repeat hematocrit postoperatively – Monitor for airway obstruction or recurrent hemorrhage

HYPERTROPHIC PYLORIC STENOSIS

 1:500 live births  Presents ~ 6weeks of age  Pyloric muscle hypertrophy (gastric outlet obstruction) – Non-bilious, projectile emesis – Lose H+/Cl • Hypochloremic metabolic alkalosis - promotes hypoventilation • Hypokalemia - kidneys exchange K+ for H+ • Hyponatremia/hypocalcemia • Dehydration may be severe

PYLORIC STENOSIS - II

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Preoperative preparation:

– NOT true surgical emergency – should ‘tune up’ first – Rehydrate, nasogastric suction, correct electrolytes – Ready for surgery when: • HCO3 < 30 K+ > 3.2

• Cl- > 90 • Urine spec. grav. <1.02

UOP > 1-2 cc/k/hr 

Anesthetic induction:

– Premedicate with atropine 20 mcg/kg – Rapid sequence or modified rapid sequence induction/intubation if normal airway - propofol 2-3 mg/kg IV, succinylcholine 2 mg/kg IV – Awake intubation if difficult airway is anticipated?

PYLORIC STENOSIS - III

 Emergence: – Stomach contents suctioned – Child fully awake prior to extubation  Post-operative considerations: – Significant apnea risk due to residual CSF alkalosis – Intra-operative local anesthesia (bupivacaine 2.5 mg/kg max) and rectal acetaminophen (30-40 mg/kg loading dose) may minimize apnea risk by avoiding narcotics – Apnea monitoring should be maintained 12-24 hours post operatively

Most Important Part of a Pediatric Anesthetic?

AIRWAY, AIRWAY, AIRWAY

SUMMARY

Anesthesia for emergency surgery in pediatric patients carries increased risks.

These risks can be minimized with careful pre-operative evaluation and preparation.

Cooperation between the anesthesiologist and surgeon is especially important in the management ENT emergencies.

Pre-operative resuscitation and post-operative apnea monitoring in pyloric stenosis also require close coordination with surgical colleagues.