Sx for Common Syndromes/Anomalies Flashcards
Resp Immaturity of Prem
Surfactant prod beings at 22wks, sharp increase at 35-36 weeks. Incr alveoli surface tension decr lung compliance, incr WOB, decr gas exchange, hypoxemia, resp failure –> freq on ventilator –> BPD, ARDS, ROP. Mgmt on HFJV, req TIVA for anesth mgmt.
CV Immaturity
SNS very underdeveloped, vagal predominance –> prone to bradycardia. CO very dependent on HR and BP very dependent on intravasc volume. Myocardium on poor portion of FS curve, easily pushed into CHF w/ excess fluid. Inability to maintain SVR with anesthetics, blood loss.
Energy Source
Limited glycogen stores and hepatic immaturity leaves prem susceptible to hypoglycemia with high glucose requirements. Stores in liver and myocardium. High risk for hypyglycemia w/ SGA, prem, DM moms, prolong fasting, on hyperalimentation. Tx 1-2cc/kg of D50 dilute to D10.
Thermoregulation
D/T incr BSA:weight, thin skin and decr subQ/adipose tissue –> all increase speed of heat loss. Rely on NSTG of BAT during hypothermic episodes –> incr temp –> neg effects of catecholamine excess and FA byproducts leading to metab acidosis.
Mechanisms of Heat Loss: Radiation>Convection>Evaporation>Conduction
Radiation & Convection Heat Loss
Radiation: 39% Majority of heat loss. Heat gradient moves warm body temp to cool environment.
Convection: 34%, 2nd most heat loss. Heat gradient moves warm body temp to cooler air mvmt surrounding. Air is warmed, rises and is replaced by cool air, cycle repeats.
Evaporation & Conduction Heat Loss
Evaporation: 24%, 3rd most heat loss. Gradient between vapor temp of body surface and environment via lungs/skin, both sensible and insensible.
Conduction: 3%, molecular transfer at skin or other body surface to other medium.
Fluid/Blood Volume
Total blood volumes are small, relatively easily in hypo/hypervolemic state. Must use blood products or colloids to replace blood loss.
EBV ml/kg: Prem = 90-100 / NB = 80-90 / 3m-3yrs 75-80 / 3-6yrs = 70-75 / 6+yrs = 65-70
Drug Calculations
Precise dosing. Emergency meds and doses readily available: atropine, epinephrine, succs. Close monitoring of IV fluids and EBL. Give IVP proximal tubing and use only NS flush.
Sick Neonates Anesthetic Choice
Paralysis and Narcotics, IV agents only, d/t cardiopulmonary immaturity.
CranioFacial Abnormalities: Pierre Robin and Treacher Collins
Micrognathia/Retrognathia - post, short/recessed chin
Glossoptosis - large tongue / Cleft palate
Restricted mouth opening
Distorted pharyngeal/laryngeal anatomy
AW obstruction, relieved by prone position, decr overtime as mandible grows.
Overall Diff intubation
CranioFacial Abnormalities: Cleft Lip/Palate
Can be only lip, bilateral lip, only palate, partial palate, bilateral with full palate involvement. Higher incidence of other congenital malformations –> chromosomal abnls, heart disease, mental retardation, subglottic stenosis.
Sx Mgmt: Cleft Lip & Palate
Lip: done < 6months, want pt rule of 10s = 10kg, 10wks, 10hgb. Mild bleeding.
Palate: done 9-18months, prior to speech development. Mod bleeding.
Throat pack placed, must be removed. Mouth gag in place, mindful of ETT mvmt/kinking.
Anesth: poss diff AW, diff mask seal and high asp risk w/ impaired swallowing mechanisms –> high susp for URI or pulmo infection. Blade stuck in defect, no nasal intubation ur oral RAE secured to mandible. Use antiemetics as blood pool in stomach, must be sxned. smooth emergence to decr bucking–>bleeding.
Post-op: lat recumbent position, #1 obstruction is by soft tissue/tongue, mouth breathing as nares are packed. No touching face, monitor for post op bleeding, signs of resp diff ie stridor, cough
Causes of PostOp AW obstructions
Bleeding, Tongue most common.
Kinking ETT, incr oral secretions, subglottic edema, flap edema, retained throat pack.
TrachEsophFistula
Most common type is Eso –> blind pouch (atresia) with fistula at lower esophagus attached to distal trachea (IIIB). breathing = gastric insufflation. Feeding = choking, coughing, cyanosis (3 Cs). 25% assoc w/ congenital heart disease. Pneumonia often present. Required Immed ligation of fistula, GT placement.
TEF signs/symptoms
Born small, diff gain weight, excess salivation, drooling, coughing and cyanosis –> freq aspiration.
VACTERL syndrome association:
V = vertebral defects A = anal defects
C = cardiac anamolies T = trachesophagealfistula
E = Esophageal atresia R = renal problems
L = limb anamolies, radial bone aplastic
Anesthesia for TEF (emergency sx)
Protect from aspiration, NPO, upright position, Eso suctioning, Abx for lung infection
Awake, upright induction/intubation, maintain spont vent. Avoid PPV, promotes gastric insufflation.
Poss Inh induction w/ gentle PPV. Prefer narcs and NDMR, less inh better for immature cardiopulm systems.
ETT must be placed distal to fistula location –> verify with GT bubbles present or absent. ETT obstructed by blood clots, secretions, sx compression. Precordial Left Axilla for mainstem compression, ALine for GVessel compression
Diaphragmatic Hernia (CHD)
Abdominal contents hernia through defect, esophageal, morgagni (ant), or PostLat Bochdalek (most common) which is Left side most common (85-90%). Classic triad: cyanosis from lung hypoplasia, dyspnea, dextrocardia d/t medistinal shifting. Hypoxia, schaphoid abdomen, abnl cxr. Creates hypoplastic Left lung, high risk Right PTX –> pulmoHTN –> retain fetal circulation –> LV dysfxn.
Anesthesia for CHD (emergency sx)
Reduce gastric distention w/ NGT decompression, reduce asp risk. Avoid high PPV as very decr pulmo compliance, risk of PTX and avoid gastric insufflation. Awake intubation p/ pre-oxy. No N2O as expands bowels. PAP < 25-30. Abdo contents replaced reduced LE venous return, want UE IVs. Sudden change in ventilation = PTX –> HD instability with exacerbated R->L shunt. Poss ECMO use, Poss NO use. Post op with ETT, avoid myocardial depressants in NB.
Oomphalocele
Central abdominal wall defect at umbilical ring –> herniation of intestinal/abdominal contents in (yolk) sack at base of umbilicus. 50-75% have other defects: GI, cardiac, GU, craniofacial, Diaphragm hernias, down syndrome.
Gastroschisis
Abdominal wall defect around/lateral to umbilical cord (right) w/o sack, usually with sm/lg bowel exiting, rarely liver. Often isolated anomaly. Large risk for heat loss/dehydration, increased infection risk. Local visceral changes.
Anesthesia for Oomphalocele, Gastroschisis
Repair defect –> replaced contents –> impaired venous return and diff ventilation. Maintain adequate ventilation, intravasc volume. Often require Abx for sepsis prevention, avoid trauma to exposed organs, decompress GI contents with NG/OG. Large fluid shifts/requirements –> monitor ABG, lytes, UOP. NDMR and Narcs, limit Inh Rx. Maintain normothermia
Pyloric Stenosis
Most common GI abnormality in first 6 mo. Gross thickening of pyloric smooth muscle –> obstructs gastric outlet. Diff with food exiting stomach. Assoc w/ cleft palate, GERD, Eso atresia, oomphalocele. Hallmark symptoms: feeding intolerance w/ projectile non-bilious vomiting, hypovolemia, GERD, visible peristalsis. Hallmark Electrolytes: hypochlormia, hypokalemic, metabolic alkalosis (left oxyC. Fluid replacement w/ NS + KCL.
Anesthesia for Pyloric Stenosis
Optimize fluid and electrolyte status, Aspiration precautions, NGT for decompression in various positions. RSI or awake intubation. Avoid N2O, NDMR ok for sx. At risk for hypoventilation post op d/t baseline alkalosis. Monitor for hypoglycemia post op, may include dextrose IVPB.
Spina Bifida
Most common form of neural tube defect characterized by a cleft in the spinal column. The defect results from abnormal fusion of one or more vertebral posterior arches.
