MTSA 2016, Pediatrics/PACU, Exam #3

Muscle relaxants: In peds, never stimulate at ___ or ___ sites

ulnar, posterior tibial

Due to blunted responses to exogenous catecholamines and SNS and baroreceptor reflexes are not fully mature, pediatrics are prone to bradycardia due to increased ___

vagal tone

What is the age range of neonates?

0-1 months, At highest risk for morbidity/mortality

What is the age range for infants?

1-12 months

What is the age range for toddlers?

1-3 years

Physics: In pediatrics, the airway is halved, leading to an increase in resistance up to ___ times

16

Postop hypertension is considered blood pressure >___% of the patient's baseline

20-30

What is a rough guideline for what depth of ETT to use on a peds patient?

3 x internal diameter

Post-intubation Croup is usually seen ___ hours after extubation. What is it due to?

3, due to glottic or tracheal edema

Neonates require ___ mg/kg/min of a glucose infusion to maintain euglycemia (40-125mg/dL). Preemies ___mg/kg/min

3-5, 5-6

Core temps of <___ degrees C greatly potentiates effects of CNS depressants and causes delayed anesthesia emergence

33

What is a rough guideline for what diameter of ETT to use on a peds patient?

4+age/4 = tube diameter (cm)

What is the age range for small children?

4-12 years

Hypoventilation is defined as a PaCO2 of >___mmHg

45

What is the age range for preemies?

<38 weeks gestation and <2500 gm at birth

Ped patients may have intracardiac shunts, so it is vitally important to make sure that you have removed all ___ when establishing an IV access

All air must be OUT of IVs

Emergence from inhaled anesthetics involve ___, emergency from IV agents involve ___.

Alveolar ventilation (blow off), Redistribution

When does the cytochrome P-450 pathways mature?

At the end of the neonatal period, fully functional at one month of age

What is pediatric drug dosing base on?

Based on drug per kg recommendations (weight based)

The metabolism of what kind of fat produces heat in a pediatric patient?

Brown fat (blood passing through brown fat is warmed and carries heat to the systemic circulation. This persists up to 2 years of age)

Peds: Prior to Sux, pretreat with ___ of Atropine

0.1 mg

What is a rough guideline for what length of ETT to use on a peds patient?

12+age/2 = length of ETT (cm)

What are two major risk factors for cardiac arrest in pediatric patients?

ASA 3-5, emergent procedures

Prevention of postoperative nausea and vomiting include what? List 5 interventions

Adequate hydration and use of propofol Zofran Reglan Dexamethasone Droperidol

What is the most frequently encountered PACU complication?

Airway obstruction, hypoventilation, hypoxemia

Compared to an adult, a pediatric larynx is more ___ and ___

Anterior and cephalad (at C4)

What would the benefit of using an uncuffed ETT on a child?

Avoids post-extubation stridor and subglottic stenosis

The best way to maintain an infants body heat is to do what?

Increase the OR room temperature and don't let them get cold initially

Induction: Base on weight, infants and young children require increased doses of propofol due to ___

Larger Vd

List five symptoms related to propofol infusion syndrome (drips lasting longer than 48 hours or doses >5mg/kg/hr)

Metabolic acidosis hemodynamic instability hepatomegaly rhabdomyolysis multiorgan failure

HME filters (if not pediatric sized) can cause what?

Considerably increases anatomic dead space

Post-intubation Croup is less common with cases that involved an uncuffed ETT. Why?

Cuff pressure during procedure irritates the lining of the airway. Keep pressures <25 mmHg

List four issues that cold pediatric patients can have (4 issues)

Delayed awakening from anesthesia Cardiac irritability Respiratory depression Altered drug responses

Volatile agents: Rate of emergence is fastest with ___ and ___, but, both are associated with agitation and emergence delirium.

Desflurane, Sevoflurane

A peds patient presents with epiglottitis, what do you not want to do before induction?

Do NOT perform laryngoscopy before induction of anesthesia to avoid laryngospasm

What volatile agents are least likely to irritate airways and cause breath holding/laryngospasm on induction?

Halothane and Sevoflurane

Pediatric patients have a poorly developed left ventricle that is noncompliant and fixed, therefore, cardiac output is dependent on ___

Heart rate

What defines hypoglycemia in pediatrics? What do you never want to give a child?

Hypoglycemia = blood sugar <40 Never use dextrose containing fluids for fluid boluses

What is the hallmark sign of fluid depletion in neonates?

Hypotension without tachycardia (vascular tree is less able to constrict to respond to hypovolemia)

List the steps that lead from pediatric respiratory failure to death.

Hypoxia-->Bradycardia-->cardiac arrest

The definitive treatment for Sux induced hyperkalemia is ___

IV Calcium. This restores the gap between the resting membrane potential of the cardiac cells and the threshold potential for depolarization.

What is an effective treatment for postintubation croup?

IV dexamethasone (0.25-0.5 mg/kg) and/or nebulized racemic epinephrine 0.25-0.5ml of 2.25% solution in 2.5ml of NS

In nonshivering thermogenesis, what produces the heat in a pediatric patient?

It is not the shivering that produces the heat, but, the metabolism of brown fat that increased body temp when the thermal receptors in a child detect a skin temp of 35-36 degrees C

Why do neonates need the same amount of nondepolarizing drug as the adult on a mg/kg basis?

It's a trade off. Extracellular volume of the neonate is greater but neuromuscular junction is immature (so less drug is required to block existing channels). Overall result is the same dosing as adults.

What are arguments against using an uncuffed ETT?

Leak of anesthetic agent into environment Requires more fresh gas flow Higher risk for aspiration

Why do neonates need more succinylcholine on a mg/kg bases (give two reasons)?

Neonates have a greater Vd and an immature neuromuscular junction

What is the etiology of laryngotracheobronchitis (croup)?

Parainfluenza virus (presents on Xray as "steeple sign" or a narrowing in the airway)

What is a nursing tool you must have on you at a peds rotation at all times?

Precordial stethoscope

What is the first monitor you want to place on a peds patient?

Pulse Ox is first monitor placed, followed by precordial stethoscope

When do you use Sux in kids?

RSI, full stomach, laryngospasm

How would you set your vent settings for a peds patient?

Rapid rate with low tidal volumes are desired

List five reasons why it is so difficult to keep newborns warm

Readily lose heat d/t greater surface area per body weight ratio Cannot compensate by shivering Limited subQ fat for insulation Limited stores of brown fat Unstable thermoregulatory systems

What is the preop fasting guideline for a child <6 months old?

Restrict solids x 4 hours Restrict clear liquids x 2 hours Formula ok up to 4 hours prior to induction

What is the preop fasting guideline for children 6-36 months old?

Restrict solids x 6 hours Restrict clear liquids x 3 hours Formula or solids up to 6 hours prior to induction

What is the preop fasting guideline for children > 36 months old?

Restrict solids x 8 hours Restrict clear liquids x 3 hours

What volatile agent causes the least respiratory depression, no reports of renal toxicity, and is generally the preferred induction agent.

Sevoflurane

When using ped oral airways, it is important to have the appropriate size. What happens if the oral airway is too long? Too short?

Too long - trigger laryngospasm if touches epiglottis Too short - pushes tongue back = obstruction

T of F, Volatile agents work faster on pediatrics patients because they have lower functional residual capacity, higher alveolar ventilation, and higher blood flow to vessel-rich organs.

True

T or F, avoid PACU shivering

True

If a child has a recent ___ then a surgical procedure may be deferred until a later date.

Upper Respiratory Tract Infection (within 2-4 weeks)

Neonates and infants have less efficient ventilation due to what? (11 reasons)

Weak intercostal/diaphragmatic musculature Horizontal and pliable ribs Chest wall very compliant Protruberant abdomen Hypercapnic ventilatory drives not well developed High rate of O2 comsumption (2x that of adults) Elevated respiratory rate Small airways resulting in high airway resistance Immature alveoli Limited alveoli Work of breathing is increased and easy muscle fatigue

Essentially, a viral infection within 2-4 weeks places a child at increased risk for periop pulmonary complications such as... (4 answers)

Wheezing Laryngospasms Hypoxemia Atelectasis

Can a pediatric laryngospasm occur prior to IV induction?

Yes, can occur during inhalation induction before IV administration

Greatest decreases in force residual capacity occur after upper ___ and ___ procedures

abdominal, thoracic

Unlike adults, pediatric patients that develop atelectasis and hypoxemia results in ___

actually depresses respiration (desire to breath not well established. Hypercapnic drives not well developed)

List 8 complications from emergence from general anesthesia in the PACU

airway obstruction shivering agitation delirium issues with pain control nausea and vomiting hypothermia autonomic lability

Succinylcholine is dangerous in peds. Profound ___ and sinus node ___ can occur after the first dose of Sux without atropine pretreatment

bradycardia, arrest

The ___ is the narrowest point of the airway in children younger than 5 years of age

cricoid cartilage (1mm of edema will have a proportionately greater effect because of smaller tracheal diameter, uncuffed ETT often used in kids <6 years)

Left to right shunts usually ___ affect inhaled induction

do not

Many toddlers react to the stress of surgery with a ___ in serum glucose

drop

Wheezes and postop pulmonary ___ are most often seen in the first postop hour.

edema

Pediatrics and Muscle relaxants: Do not stimulate at ___, orbicularis oculi is more resistant to blockade, therefore, if you successfully block this muscle, this may be an irreversible block.

facial nerve area

The most common cause of hypoxemia after general anesthesia is increased intrapulmonary shunting from decreased ___ relative to closing capacity.

force residual capacity

Fentanyl and midazolam can cause profound ___

hypotension

Larger surface area per kg, thin skin, lower fat content makes ___ a serious and dangerous problem.

hypothermia

The most common cause of hypotension in PACU is ___

hypovolemia, in PACU fluid test with small boluses (250-500ml crystalloid) to confirm hypovolemia

The infants' extracellular body fluid compartment is ___

large (compared to adults)

Water soluble drugs will have ___ volumes of distribution in the infant

larger

82% of cardiac arrests occur during induction. Give three complications that attribute to this statistic.

medication related (decreased HR, BP, O2 saturation) Laryngospasm Equipment issues

Muscle relaxants: Lifting both legs means that the ped patient can generate adequate ___

negative inspiratory force

The most prevalent form of ischemia in the PACU is ___ ischemia, and it is more prevalent than ischemia occurring before or during a procedure.

postoperative myocardial

Long standing left to right shunts can eventually cause ___

pulmonary hypertension

Right to left shunts result from increased resistance to blood flow through the ___. Patients have marked ___ and ___.

pulmonary vasculature hypoxemia and cyanosis

Right to left shunts usually ___ inhalation induction

slow

Lipid soluble drugs will have ___ Vd in the infant

smaller

Infants cannot alter their ___ so the only way to alter their CO is to change their ___

stroke volume heart rate