Book 4, Case 3-CDH and prematurity Flashcards
Newborn at 38 weeks gestation has resp distress with nasal flaring, sternal retraction and cyanosis shortly after birth. also has a scaphoid abdomen and absent breath soundson left:
What does this result in?
CDH-herniation of abdominal contents into the thoracic cavity. This results inimpaired maturation of lung
tissue (leading to a decreased number of alveoli, decreased surfactant production, and
abnormal pulmonary vasculature) with subsequent impaired gas exchange,
intrapulmonary shunting, and pulmonary hypertension (the muscle mass in the
arterioles increases and they become more reactive). Pulmonary hypertension
impairs the transition from fetal circulation. The resultant extrapulmonary shunting
through the patent foramen ovale and patent ductus arteriosus leads to worsening
hypoxia, hypercarbia, and acidosis, which, in tum, further exacerbate pulmonary
hypertension, setting up a vicious cycle.
Pt with CDH has a PAO2-PaO2 difference of 420?
Intrapulmonary and extrapulmonary shunting (extrapulmonary-through pFO and ductus arteriosus) intrapulmonary
Normal A-a gradient in young adult non smoker:
Less than 10
Greater than 500=poor prognosis
Initial treatment of CDH:
surgical intervention should be delayed until the
neonate is medically stable (the goal is to reduce the pulmonary hypertension that is
causing right-to-left shunting through the patent foramen ovale and the patent ductus
arteriosus), So…until then…
avoid positive pressure mask ventilation (can further
compromise respiratory function by distending intrathoracic viscera) and excessive
endotracheal suctioning (may result in transient hypoxemia or a decrease in Fi02); (2)
establish intravenous access; (3) provide supplemental oxygen; ( 4) intubate the neonate (awake and RSI both acceptable)
-insert naso or orogastric tube for stomach decompression. Establish ventilator settings-avoid high airway pressures.
Place appropriate monitors, sedate with opioids, give muscle relaxant
correcdt hypothermia
If the intervention of intubating patient and correcting hypercarbia don’t work, what can you do to reduce PVR?
Prostaglandin E1 or nitric oxide-be careful-these can cause hypotension
Ligation of PDA to reduce shunting (could cause Right heart failure)
ECMO
What is the goal of medical mgmt in these CDH patients, and how long does it take
24-48 hours if mild
7-15 days if severe
goal: preductal O2 sat with peak inspiratory pressures <25
Mechanical ventilation guides in CDH:
pressures should NOT exceed 30 cm H20 due to the risk of PTX which is more likely on CONTRALATERAL side. moderate hypercapnia is sometimes allowed to avoid ventilator induced lung injury. High frequency oscillatory ventilation cdan be used
What is high frequency oscillatory ventilation?
Constant distending airway prssure over small tidal volumes at high respiratory frequency
Consider what pressor in CDH pts wiht right sided heart failure?
Consider milrinone
Contraindications to ECMO in kids:
Intracranial hemorrhage
Congenital heart disease
Gestation <34 weeks
Why would you avoid neck veins in kids with CDH? So then, where woudl you get access?
because it might be needed for ECMO, not to mention yuo already only have one good lung-do NOT cause a pTx . Umbilical or femoral–recognizing that lower extremity access may be less reliable if return of neonates viscera results in increased abdominal pressures.
How to cannulate the umbilical vein?
(1) sterilize and drape the
area, (2) place caudal traction on the umbilical stump (caudal traction facilitates
insertion during umbilical vein catheterization; cephalad traction facilitates insertion
during umbilical artery catheterization), (3) carefully insert a soft catheter filled with
heparinized solution a distance that approximates the length between the insertion site
and the right atrium (the desired position for the catheter tip), (4) obtain a radiograph
to confirm proper placement at the junction of the inferior vena cava and the right
atrium, and (5) secure the catheter at the insertion site with suture, antibiotic
ointment, and a protective covering.
If you can’t get umbilical catheter in, then can you still use it?
temporarily as long as its not more than 2 cm beyond abdominal surface and blood is still freely aspirated, however this will NOT allow us to monitor CVP
Complications associated with umbilical vein catheterization?
infection and sepsis portal cirrhosis endocarditis cardiac tamponade Due to these complications, the catheter should be removed as soon as alternative IV Access is established
Can you use an umbilical ARTERY catheter to give drugs?
It’s acceptable for emergency admin, but due to complications-exasnguination (accidental disconnection of stopcokc), vasospasm-I’d only use for BP monitoring