Acute pulmonary Hypertensive Crises.
Welcome to PICU Doc On Call, A Podcast Dedicated to Current and Aspiring Intensivists.
I'm Pradip Kamat and I'm Rahul Damania. We are coming to you from Children's Healthcare of Atlanta - Emory University School of Medicine.
Welcome to our Episode a 7 month old boy ex-26 week premature infant with acute hypoxemia, bradycardia episodes, poor perfusion
Here's the case:
A 7 month old ex-26 week male was transferred from the outside hospital to our PICU for tracheostomy evaluation. Patient was intubated on second day of life. He had a prolonged course, on inhaled Nitric Oxide for first 2-3 months of life in the setting of severe pulmonary hypertension, requiring HFOV for a prolonged period of time. Failed extubation attempts multiple times. Received steroid burst x2. BPD settings trialed (lower rate, longer iTime, high PEEP, larger TV) without improvement. At time of transfer he was in PRVC mode on the ventilator — TV ~10ml/kg, 50%, PEEP 8, rate 28 (Peak pressures 27-32). Patient received albuterol Q4 for bronchospasm/wheezing and pulmicort BID. Patient was deeply sedated with morphine and midazolam. Interstitial lung disease panel was negative. ECHO showed: systolic septal flattening, moderate RV hypertrophy with normal systolic functioning. Patient was not on any PH medications at transfer. Patient is also on furosemide, hydrochlorothiazide and spironolactone.
Patient has completed a course of antibiotics for klebsiella tracheitis from a ETT CX a week prior to admission to our picu. Patient tolerated feeds via an NJ tube.
The team continues to evaluate his case as the Patient continues to have episodes of acute desaturation, tachycardia, cool extremities and poor perfusion.
To summarize key elements from this case, we have a 7month old who is ex-26 week premie
Patient has BPD and is on high vent settings and failing extubation
Abnormal echocardiogram with flat septum and hypertrophied Right ventricle
Episodes of cold shock-tachycardia, poor perfusion, and cool extremities
Hypoxia

All of which bring up a concern for acute pulmonary hypertensive crisis
Rahul Let's transition into some history and physical exam components of this case?
What are key history features in this infants who presents with an acute pulmonary hypertensive crisis
Prematurity
BPD

Remember BPD is defined by a requirement of oxygen supplementation either at 28 days postnatal age or 36 weeks postmenstrual age.
Are there some red-flag symptoms or physical exam components which you could highlight?
Presence of cold shock: tachycardia, cool extremities and poor perfusion
Hypoxia
Cardiac exam will reveal a bounding right ventricle, prominent loud single S2
Although not obvious in this patient: some patients can have a palpable liver, cardiac gallop, peripheral edema and jugular venous distention

S2 heart sound represents the closure of the PV very close to AV — In pulmonary hypertension this PE sign is seen with equal right and left ventricular pressures.
To continue with our case, the patient's labs were consistent with:
Respiratory acidosis (PCO2 > 100)
CMP, CBC are normal
BNP < 100, serum lactate normal

Echocardiography findings in these patients can show tricuspid regurgitation. We can estimate right ventricular systolic pressure on echo and, by extension, systolic PAP (sPAP), by using tricuspid regurgitant (TR) jet velocity in combination with other echocardiographic findings. Using the modified bernoulli principle 4 x TR jet velocity squared, we can estimate the sPAP. If sPAP >2/3 systemic sBP with severe flattening or posterior bowing of the interventricular septum the patient can be diagnosed with severe pHTN.
Pradip, what if the patient had a PDA on echo — what would you see?
Rahul, when you see Predominantly right-to-left shunting across the PDA suggests suprasystemic sPAP. And as a result these patients can be hypoxemic
Ok, to summarize, we have:
A 7-month ex-26 week