Pediatric General Surgery Part 1 Flashcards
The _______ and ________ are very compliant in children and are prone to collapse.
- Trachea
- Bronchi
In pediatric airways, resistance is inversely related to airway radius to the ________ power.
- 5th
Where will there be the greatest resistance in infants?
- Small airways
- Bronchi
This is d/t the relatively small diameter of airway and greater compliance of the trachea and bronchi
What is airway obstruction during anesthesia usually caused by?
Loss of muscle tone in pharyngeal and laryngeal structure
Where will airway obstruction be most pronounced at?
Hypopharynx at the level of the epiglottis
Laryngospasm is a result from an _________ effort, which longitudinally separates the vocal folds from the vestibular folds.
Inspiratory
What muscles do not contract during a laryngospasm?
- Instrinsic Muscle
- Extrinsic Muscle
Two common causes of laryngospasms
- Stimulation during light anesthesia
- Secretion
Name the breathing technique that involves forcefully exhaling air while keeping your airway closed.
The Valsalva Maneuver
What is the hallmark sign of a mild laryngospasm?
High-pitch inspiratory stridor d/t cords being partially open
What are the treatments for laryngospasm?
- 100 FiO2
- Stop stimulation
- Call for help
- Sniffing position/ Jaw thrust
- IVP of Propofol
- Deepen anesthetic gas
- Positive Pressure
- Sux/Atropine (persistent laryngospasm)
Risk factors of intraoperative bronchospasm
- Loss of muscle tone during induction increases WOB
- Asthma
- Smoking
- URI
Signs and Symptoms of Intraoperative Bronchospasm
- Polyphonic and prolonged expiratory wheeze
- Increase respiratory effort
- Increase peak airway pressures
- Slow up slope of ETCO2 waveform (shark-fin)
- Increase ETCO2
- Decrease SpO2
Describe the capnograph of a bronchospasm.
Slow upslope of ETCO2 waveform (shark-fin)
Which induction drugs are excellent bronchodilators?
- Ketamine
- Propofol
Which VA can increase airway resistance in children and should be avoided?
Desflurane
List intraoperative treatment for bronchospasm.
- Removing Stimulus
- Deepen anesthesia (IV meds first)
- Inhaled β-agonist
- ↑ FiO2
- Decrease PEEP and adjust I:E ratio to minimize air trapping
- IV steroids/ epinephrine
How is I:E ratio adjusted to minimize air trapping?
The expiratory time is increased to minimize air trapping.
What is the dose of epinephrine to treat intraoperative bronchospasm?
0.05-0.5 mcg/kg every minute
What phase of breathing does laryngospasm primarily affect?
What phase of breathing does bronchospasm primarily affect?
- Laryngospasm affects the inspiratory phase
- Bronchospasm affects the expiratory phase
What sound is associated with laryngospasm?
What sound is associated with bronchospasm?
- Laryngospasm: Stridor (high-pitch)
- Bronchospasm: Wheeze, Croup
Physical presentation of laryngospasm vs bronchospasm.
- Laryngospasm: Retraction of intercostal at the suprasternal notch (tracheal tug)
- Bronchospasm: Increase use of accessory muscles of inspiration (↑ WOB)
What are the changes associated with expiration with laryngospasm compared with bronchospasm?
- Laryngospasm: No change in expiration
- Bronchospasm: Prolonged expiration
Differentiate the onset of cyanosis of laryngospasm vs bronchospasm.
- Laryngospasm: Cyanosis has fast onset
- Bronchospasm: Cyanosis has slow onset
What is Post-Extubation Croup?
- Inflammation/ Edema r/t compression of tracheal mucosa
- The reduction in the luminal diameter and increase in airway resistance
Post-extubation croup can occur in up to ___% of children.
1%
List the risk factors of post-extubation croup.
- Larger ETT than airway (no leak > 25 cm H2O)
- Change in position during surgery
- Repeated intubation attempts/ traumatic intubations
- Pediatrics b/w ages 1-4 yrs (subglottic airway narrowest in children)
- Surgery length > 1 hour
- Previous hx of croup
Treatment for Croup in pediatrics
- Nebulized Epinephrine (Racemic Epi)
- Steroids (Dexamethasone/Decadron): 0.5 mg/kg
Describe how a micro-cuff ETT is used to mitigate the risk of croup in pediatric patients.
- Micro-cuff ETT is high volume, low pressure
- Cuff with an elliptical balloon placed more distally
- No Murphy’s Eye and able to provide uniform surface contact
What is the cause of Congenital Diaphragmatic Hernias (CDH)
- Caused by failure of complete closure of pleural and peritoneal canals
- Results in herniation of abdominal organs in the thorax
How does Congenital Diaphragmatic Hernias (CDH) affect the pulmonary system?
- Inhibits lung growth (division of airways, pulmonary vasculature, decrease bronchi/alveoli)
- Decrease SA for gas exchange, leading to increased PVR and pulmonary HTN.
- The ipsilateral lung is usually affected
Most common type of Congenital Diaphragmatic Hernias (CDH)
- Postlateral Foramen of Bochdalek (90%)
- Left side
- Associated with the greatest amount of hypoplasia
Infants born with Congenital Diaphragmatic Hernias (CDH) are more likely to have what other birth defects?
- Congenital Heart Disease (20-40%)
- Chromosomal Abnormalities (5-15%)
- GU/GI malformations
Diagnosis and Findings of Congenital Diaphragmatic Hernias (CDH)
- Most diagnoses are made prenatally vis US
- Findings: Polyhydramnios, intrathoracic gastric bubble, mediastinal shift from herniation site
- Antenatal diagnosis via abdominal CXR showing intestinal loops, abdominal organs in thorax, ipsilateral lung compression
Signs and Symptoms of Congenital Diaphragmatic Hernias (CDH).
- Respiratory distress
- Tachycardia
- Tachypnea
- Cyanosis (R → L shunting contributes to severe hypoxemia)
- Concave abdomen
- Barrel Chest
- Absent breath sounds on the affected site
Congenital Diaphragmatic Hernias (CDH) Treatment
- Focus on stabilizing and optimizing patient before considering surgery
- Improve pulmonary HTN and ↓ PVR
- High-frequency oscillatory ventilation (small frequent Vt, limit Peak Pressure, and avoid CPAP).
- Vasodilator to ↑ Oxygenation (inhaled NO)
- Prostaglandin E1 to maintain PDA and reduce RV afterload
- Severe Cases of hypoplasia and pulmonary HTN: ECMO (PaO2 < 50 mmHg w/ FiO2 of 100%)
For patients with Congenital Diaphragmatic Hernias (CDH), what is the major cause of morbidity and mortality undergoing surgical repair w/o ECMO?
- Pulmonary HTN
Congenital Diaphragmatic Hernias (CDH) Anesthesia Management
- Avoid volutrauma with control ventilation
- Avoid increase PVR (hypoxemia, acidosis, hypothermia, hypercarbia)
- Decrease PVR (hyperventilation, narcotics to blunt sympathetic discharge)
- NGT should be passed before induction to decrease air entering the stomach
- Avoid N2O
- Paralysis
- Fentanyl induction (50 mcg/kg), Roc 1.2 mg/kg or Nimbex 2mg/kg, Sevo as tolerated
- Patient will go to the ICU intubated
