Test 4: Pediatric Anesthesia Pt. 2 (Andy's Cards) Flashcards
Pediatric PO and IV dose of Versed
- PO: 0.3-0.75 mg/kg up to 15 mg
- IV: 0.025-0.05 mg/kg
Pediatric IV dose of Fentanyl
- 2-10 mcg/kg
- Cardiac Cases: 50 mcg/kg
Pediatric IV and IM dose of Atropine
- IV: 0.01 mg/kg
- IM: 0.02 mg/kg
Pediatric IV dose of Lidocaine
- 1mg/kg
Pediatric IV dose of Glycopyrrolate.
- 5-10 mcg/kg
Pediatric IV dose of Propofol
Pediatric infusion dose of Propofol
- 2-3 mg/kg
- 50-200 mcg/kg/min
Pediatric IV and IM dose of Succinylcholine
- IV: 2 mg/kg
- IM: 4 mg/kg
What are the five main causes of pediatric airway management difficulties?
- Inflammatory
- Congenital
- Iatrogenic (caused by us)
- Neoplastic
- Trauma
What is Croup?
A cause of airway obstruction that occurs d/t a viral etiology with swelling and inflammation of the subglottic area of the trachea.
Croup most commonly occurs in children between what ages?
6 months to 3 years
What are the symptoms of Croup?
- URI symptoms that progress from stridor to hoarseness
- “Barky Cough”, they sound like a seal
- Low-grade fever (100 - 100.4 F)
Medical treatment for Croup
- Comfort position, sitting upright and slightly bending forward
- Humidified O2
- Racemic epinephrine nebulized aerosol
- May consider steroids
- Intubation is rare
What causes Epiglottitis?
Haemophilus Influenza type B
Epiglottis most commonly occurs in children between what age?
1-7 years old
Pediatric presentation of Epiglottitis?
- Sitting position, slumped over, drooling
Medical approach and treatment of Epiglottitis
- Establish an artificial airway, using ETT one size smaller, mask induction with Sevo.
- Fluids and Humidification
- Racemic Epinephrine
- Steroids
- Time
Besides Croup and Epiglottitis, what are other inflammatory causes of difficult pediatric airways?
- Retropharyngeal Abscess (usually from dental procedures)
- Bronchiolitis
- Asthma
- Pneumonia
- Foreign Body Aspiration
What are the congenital causes of difficult pediatric airways?
- Syndrome of craniofacial abnormalities
- Downs Syndrome
- Beckwith-Weideman Syndrome
- Goldenhar Syndrome
- Pierre Robin sequence
- Juvenile RA
- Congenital neck masses
Anesthesia considerations for Downs Syndrome patients
- Large tongue
- a small mouth
- Atlantoaxial instability
- Inhalation induction bradyarrhythmias
What are iatrogenic causes of airway management difficulties in pediatrics?
- Post-intubation croup
- Laryngospasm
What is the most frequent postop airway problem?
Laryngospasm
What is Laryngospasm?
- Reflex, involuntary closure of larynx caused by irritation
- Irritation is from the stimulation of the vocal cords during light anesthesia
- Laryngospasm can occur from the lack of full restoration of the normal glottic reflexes
What is the treatment for laryngospasm?
- 100% O2
- PEEP (APL) to 60-80 cm; this will hold cords open and help separate tissue
- Open mouth and subluxate the mandible
- IV lidocaine to control ventilation (1-2 mg/kg, onset 2 mins)
- IV Succinylcholine will affect laryngeal nerves first (5-20 secs)
- Intubate
- Emergency cricothyroidotomy (last result)
What are examples of extrathoracic upper airway obstruction?
- Foreign body
- Epiglotottitis
- Laryngospasm
What are examples of intrathoracic lower airway obstruction?
- Asthma
- Bronchiolitis
What is the first stage of laryngospasm?
Collapse of the supraglottic tissue onto itself
Therefore, during induction and emergence keep the larynx stretch. Positive pressure.
What are the early signs of laryngospasm?
- Stridulous or “crowing” noise
- Tracheal tugging (retraction)
- Increase breathing efforts
What are the latent signs of laryngospasm?
- Suprasternal, subcostal, and intercostal chest retraction
- Paradoxical movement of chest and abdomen
- Minimal or no movement of ventilation
- Minimal or no anesthesia bag movement
Complication of laryngospasm
- Hypoxemia
- Cardiac arrest
- Neg Pressure Pulmonary Edema (more often seen in adults than peds)
Patient risk factors for laryngospasm
- Age
- Smoking adults or passive smoking in pediatric patients (incidence ↑ 10x)
- Recent or ongoing URI (incidence ↑ 2-5 x)
Anesthesia risk factors for laryngospasm
- Inadequate depth of anesthesia (deep > light)
- Vocal cord irritation
- Experience level of anesthesia provider
- Choice of VA (Desflurane ↑ incidence in peds)
- Choice of airway device
Surgery-related risk factors for laryngospasm
- Risk increased in Adenotonsillectomy
- Upper airway procedures, bronchoscopy
- Foreign body aspiration
- Urgent vs. elective procedures
- Appendectomy, hypospadias repair
Prevention of Laryngospasm during induction
- Ensure adequate depth of anesthesia before airway manipulation or instrumentation
- Consider an anticholinergic as an antisialagogue
- Use of a short-term muscle relaxant for intubation
What can be done to prevent laryngospasm in a patient without a secured airway?
- Maintain an adequate depth of anesthesia
- Avoid Desflurane in pediatric patients
Prevention of Laryngospasm during emergence
- Timing of airway removal/ deep extubation
- Propofol 0.5 mg/kg
- Lidocaine 1.5-2.9 mg/kg
What is “Anti-laryngospasm Spot” (Larson’s point)?
- Group of nerves behind the earlobe but in front of the mastoid.
- When firm pressure is applied, this may resolve the spasm quickly
What can help assess the degree of airway obstruction d/t neoplastic causes?
CT/MRI
Anesthesia consideration for traumatic causes of difficult airway
- Always suspect spine precaution until confirmed clear by CT
- Even after clearance, maintain neck stability.
- Delayed extubation should be considered
- Improve your skills with a Glidescope BEFORE you need it for trauma!
At what age is foreign body aspiration common?
2-4 years old
Male to Female ratio of foreign body aspiration
2:1
Treatment of foreign body aspiration
- Usually removed with a rigid bronchoscopy
- May require post-op steroids
MAC of Sevo for 0-1 month
3.3%
MAC of Sevo for 1-5 month
3%
MAC of Sevo for 6 months-3 years
2.8%
MAC of Sevo for 3-12 years
2.5%
Advantages of Sevo (long list)
- Lower blood solubility
- Faster induction time
- Less myocardial depressant
- No significant change in BP
- Less extensively metabolized
- Less hypercarbia
- Pleasant smell
- Less airway irritation
- Significant faster recovery time
- Better patient acceptance with single breath technique
- No repeated use complications
Disdvantages of Sevo
- Excitement between 2-4min (placeboflurane)
- Fluoride ion production
- Compound A with low gas flows
- N2O only decreases MAC 24%
- Confusion and agitation during emergence
- Increased cost
Biotransformation of Sevoflurane in the human liver is ____% (range)
3-5%
Metabolism of Sevoflurane in vivo produces ___________
Inorganic fluorides
What is pyloric stenosis (Infantile Hypertrophic Pyloric Stenosis/ Gastric Outlet Obstruction)?
- Narrowing of the pylorus, the lower part of the stomach, through which food and other stomach contents pass to enter the duodenum.
- When an infant has pyloric stenosis, the muscles in the pylorus have become enlarged to the point where gastric emptying is prevented
What are the causes of Pyloric Stenosis?
- Multifactorial. Some researchers believe that maternal hormones could be a contributing cause.
- May be that the thickening of the muscle is the stomach’s response to some type of allergic reaction in the body.
- Infants may lack receptors in the pyloric muscle that detect nitric oxide, a chemical in the body that tells the pylorus muscle to relax → leading to hypertrophy
What’s the occurrence of pyloric stenosis?
3 out of 1000 babies in the US
Pyloric stenosis is about ___ times more likely to occur in firstborn male infants.
4x
Pyloric Stenosis has also been shown to run in families - if a parent had pyloric stenosis, then an infant has up to a ____% risk of developing the condition.
20%
Pyloric stenosis occurs more commonly in _______ infants (race) than in babies of other ethnic backgrounds
Caucasian
Pyloric stenosis-affected infants are more likely to have blood type ___ or ___.
B, O
Most infants who develop pyloric stenosis are usually between ____ weeks and ____ months of age
2 weeks and 2 months
Symptoms of pyloric stenosis usually appear during or after the _____ week of life.
third
The most common cause of intestinal obstruction during infancy.
Pyloric Stenosis
The first symptom of pyloric stenosis.
- Projectile vomiting
- The breast milk or formula is ejected forcefully from the mouth in an arc, sometimes over a distance of several feet
- The vomitus will not contain bile
Inflammation in the digestive tract that may be caused by viral or bacterial infection will usually also have diarrhea with loose, watery, or sometimes bloody stools.
Gastroenteritis
Pyloric Stenosis Diagnosis and Considerations
- Usually are 3-6 weeks old
- Diagnosed with barium swallow or ultrasound
- Should always be considered a full stomach!
- Infant will need to have IV access, prior to coming to the OR
- Need to correct electrolyte depletion and dehydration
- Usually have a (hypochloremic) metabolic alkalosis
Anesthesia Management of a Pyloromyotomy
- Keep room warm-78-80 degrees
- Is the IV patent? -Give atropine watch for increased heart rate
- Monitors- ECG and SaO2
- 10-12 Fr. Salem sump, reinsert 4-5 times and change the infant’s position to decompress the stomach
- Propofol/Sux/Tube- Do not delay intubation -stylet the ET Tube
- RSI- Cricoid pressure! (gentle)
- NO NARCOTICS!
- Slow emergence is normal for this age/ They will move everything but their diaphragm
Pediatric cardiac output is derived from what factors?
- Volume
- Heart Rate
Starling’s Law is not a factor in cardiac output in pediatrics until they are 5-6 years old
Anesthesia Management of a Laparoscopic Pyloromyotomy
- Desflurane inhalation maintenance with controlled ventilation, AFTER THE AIRWAY IS SECURED!
- Utilizing higher concentrations (6-9%) of Des. allows for adequate depth of anesthesia and surgical relaxation. (Reflex tachycardia is a good thing.)
- Placement of a 12 Fr. Salem sump
- Hemostat and a Toomey syringe to inflate the stomach to check for pyloric perforation.
- NO NARCS
- Repeated doses of Succinylcholine is not recommended
- Small dose of a Non-depolarizing muscle relaxant is an option.
- Small dose of Propofol may provide enough additional relaxation
- At the end of the case, turn down/off the Desflurane and allow the ETCO2 to rise to allow for spontaneous ventilation.
- AWAKE EMERGENCE and EXTUBATION since they are still considered a full stomach
Anesthesia Considerations of Pyloric Stenosis
- This is considered an urgent case, but not an critical emergency procedure
- Assess level of electrolyte disturbance and correct dehydration and metabolic alkalosis
- Local injection by surgeon should provide adequate post op pain control
- No Narcotics!
- Always considered a full stomach! Before, during and after the case
What is the IV fluid of choice for pediatric patients?
Lactated Ringers (closest composition to extracellular fluid)
How many mls of crystalloid should be administered for every 1ml of blood loss?
The 3:1 rule is a fluid resuscitation guideline that states that for every 1 mL of blood loss, 3 mL of crystalloid fluid should be used.
Why do neonates (less than 3 or 4 months) need fluids with dextrose?
Neonates have low glycogen stores and cannot break down triglycerides and convert them to usable energy. Therefore, fluids with dextrose (D5, D10) are needed for these patients.
How will you make D2.5 from D50?
Mix 2.5 mL of D50 with 47.5 mL of LR.
How will you make D10 from D50?
Mix 10 mL of D50 with 40 mL of LR.
How will you make D7.5 from D50?
Mix 7.5 mL of D50 with 42.5 mL of LR
How do you calculate fluid deficit?
- 4-2-1 rule
- 4 mL/kg for the first 10 kg
- 2 mL/kg for the second 10 kg
- 1 mL/kg for the rest of the weight
Generally, for short pediatric cases, what is the rate of fluid replacement?
10-20 mL/kg
Total blood volume for a preemie
100 mL/kg
Total blood volume for a neonate
90 mL/kg
Total blood volume for an infant
80 mL/kg
Total blood volume for a child
70 mL/kg
The formula for calculating the max allowable blood loss
[EBV x (pt Hct - 25)] / pt Hct
What is the max allowable blood loss for an 8 kg infant if Hct is 36?
EBV = 8 kg x 80 mL/kg = 640
Blood Loss = [EBV x (pt Hct - 25)] / pt Hct
[640 x (36-25)]/36 = 195
Max allowable blood loss is 195 mL
24 kg child, NPO for 6 hours.
What will be the fluid deficit?
Use 4-2-1 rule.
4 mL/kg x 10 kg = 40 mL
2 mL/kg x 10 kg = 20 mL
1 mL/ kg x 4 kg = 4 mL
64 mL/hour x 6 hours = 384 mL
How do you make 5% albumin if you only have a 25% albumin bottle?
- Get 100 mL NS bag
- Take 20 mL NS out of the bag
- Replace with 20 mL of 25% albumin.
Estimate of Minimum SBP for 0-1 month
60 mmHg
Estimate of Minimum SBP for 1 month to 1 year
70 mmHg
Estimate of Minimum SBP for 1-10 years of age
70 mmHg + (2 x age in years)
Estimate of Minimum SBP >10 years in age
90 mmHg
Estimate of HR in Infant.
85-220 bpm
What HR should SVT be suspected in an infant?
> 220 bpm
Estimate HR of a child
60-180 bpm
What HR should SVT be suspected in a child?
> 180 bpm
Estimate of RR in Children
20-60 breaths per minute
(Note WOB, effort, mechanics, assess sounds, skin tone, pulse ox)
What is the number one cause of bradycardia in a child?
Hypoxemia
What is a BMT?
- Bilateral Myringotomy and Tubes, used to treat otitis media.
- A surgeon inserts the tubes to ventilate (let air into) the area behind the eardrum and to keep the pressure equalized to atmospheric pressure in the middle ear.
Anesthesia techniques for BMT
- Inhalation induction with Sevo or Halo
- Spontaneous ventilation, mask maintenance
- Keep nitrous on to help separate drum from middle ear
- Turn head to the side and keep head still
- Hard to chart and provide airway at the same time
Anesthesia techniques for Tonsils and Adenoids
- Inhalation induction, deep intubation
- Use a drying agent (robinul)
- IM narcotics
- Zofran and Decadron
- FiO2 < 30 w/ air
- Deep extubation
What are the 3 criteria for deep extubation
- Hemostasis
- Good PACU staff
- Airway expert available to go PACU if needed
In regards to pediatrics w/ URI when should surgery be postpone?
- Active infection w/ high fever, purulent nasal drainage, purulent cough
- Cancel the procedure, post-pone for 2 weeks
What are major considerations for eye muscle surgeries?
- Malignant Hyperthermia caution
- N/V
- Oculocardiac reflex
- Intubate/Extubate deep with Oral Rae
- Bradycardia and Apnea periods are not uncommon with eye surgery
Which drug class can’t be given for a pylormyotomy?
Narcotics