Exam IV: Anesthesia for Neonates and Infants Flashcards
preterm definition
< 37 weeks gestation
low birth weight def:
<2500 gram (5.5 lb)
very low birth weight def:
<1500 gram (3.3 lb)
extremely low birth weight def:
<1000 gram (2.2 lb)
Premie Respiratory Physiology
Small airways predispose to _______
obstruction
Premie Respiratory Physiology
Surfactant production incomplete until ____ ____ gestation
36 weeks
Premie Respiratory Physiology
Low surfactant leads to increased _____ _____ _____
alveolar surface tension
Premie Respiratory Physiology
O2 toxicity and barotrauma causes ________ ______ (____)
bronchopulmonary dysplasia (BPD)
Apnea
Common in premies, decreases with advancing ____-_____ ____
post-conceptual age
Apnea
Central: Failure to breathe (usually _____)
neuro
Apnea
Obstructive: Inability to maintain a _____ _____
patent airway - some have a mix of both central and obstructive
Apnea
_____ increases the incidence of apnea
Anesthesia
Apnea
Incidence of apnea significantly decreases at ____ ____ _______ age
55 weeks postconceptual
Apnea
Incidence depends on (3 things)
postconceptual age, HCT & surgical procedure
Apnea
Most significant risk factor:
Postconceptual age
Apnea
Usually begins within the 1st post-op hour and risk continues for ____ ____
48 hrs
Apnea
Studies show apnea can occur after _____ alone
regional
Premie CV Physiology
Cardiac output dependent on heart rate (_______ can be LETHAL)
bradycardia
Premie CV Physiology
Small absolute blood volume so _____ & ______ occur quickly
hypovolemia & hypotension
Premie CV Physiology
poorly developed ______
autoregulation
Premie CV Physiology
Many have a ____ _____ _____ (___) causing pulmonary hypertension and CHF
patent ductus arteriosus (PDA)
Premie Neuro Physiology
- Pain receptors begin developing at ____ _____ gestation
- Controversy: When does pain perception and memory begin?
- Current practice: Anesthesia and analgesia with post-op pain management - regardless of _____ ____
19 weeks
gestational age
neuro phys:
- ______ _____ (___) huge problem in premies
- Grade I – IV
- Grade IV causes severe long-term neuro consequences (CP, development delays, neurologic devastation)
- Many risk factors (fetal distress, low APGARs, acidosis, hypercapnia, +pressure ventilation, vasopressors, rapid changes in cerebral blood flow)
Intraventricular hemorrhage (IVH)
Temp Regulation
Premie method of heat production:
Non-shivering thermogenesis
Temp Regulation
Dependent on brown fat stores (____ in premies)
low
Temp Regulation
Lots of warming techniques:
Lights, fluid warmers, plastic, low flows, warm OR
Temp Regulation
Most effective means of warming:
Forced Hot Air Warming
Metabolic Physiology
- Decrease renal fx due to less nephrons and smaller glomerular size
- Hypo______ common
- Immature hepatic fx can affect drug metabolism
- At risk for _____ _____ _____
- Thrombocytopenia common (sepsis, DIC, NEC)
natremia
spontaneous liver hemorrhage
Glucose Requirements
At risk for hypoglycemia due to ↓ _____ & ____ ____
At risk for hyperglycemia due to combo of ↓ insulin production and glucose infusions
Glucose infusions via pumps with monitoring of blood glucose levels should _____ _____
glycogen and body fat
continue intraoperatively
General and regional techniques used
Generals done with inhaled and IV agents
Current trend: Low volatile with opioids or regional when possible
Common in neonates:
High dose opioid with relaxant and post-op ventilation (promotes hemodynamic stability)
venous access is
a MAJOR PROBLEM r/t small vessels, dehydration, 3rd space losses, over-used thrombotic veins
where to go?
UACs, UVC, scalp, peripheral, CVLs, and PICCs
may need
surgically placed lines
Routine monitoring:
EKG, precordial or esophageal stethoscope, non-invasive BP, temp, SaO2 & EtCO2
May need _____ line (UAC, radial, posterior tibial, dorsalis pedis) and _____
arterial
foley
Preductal SaO2: ____ hand
Right
_____ductal SaO2: Any other extremity (Historically useful to trend shunting)
Post
Prevention:
- Heat the room, the OR table, fluids, circuit
- If staff is not sweating (especially the surgeon), the OR is probably too cold
- LABS, LABS, LABS
- Blood availability
- NICU vent settings
- Access (may need CVL consult)
- Fluids & pumps
- Informed consent
Neonatal Airway Procedures (5)
- Choanal Atresia & Stenosis
- Laryngeal Webs
- Subglottic Stenosis
- Tracheoesophageal Fistula (TEF)
- Congenital Diaphragmatic Hernia (CDH)