Hyperoxia test algorithm: How will you carry out and interpret this test?

Hyperoxia test algorithm: How will you carry out and interpret this test?

Persistent pulmonary hypertension in the newborn can be sometimes very difficult to distinguish from true cyanotic congenital heart disease. Response to oxygen may also be sluggish, simulating cyanotic CHD. There can be a transient right to left shunt across PFO and PDA. Shunt across PDA in

this baby produced a differential saturation (>5% difference between radial and femoral samples).

ECG will often show RVH with strain and qR in V1 or V3 R, indicating suprasystemic PA pressure.

The clinical picture may simulate obstructed TAPVC, but chest X-ray (CXR) in TAPVC will be most often characteristic—“white wash lung”. If echo is not available, a modified hyperoxia test may pick up PPHN (see the flow chart).

Management is essentially supportive, by using oxygen, IV diuretics, sildenafil (IV or oral) and inotropes. Both dobutamine and milrinone are useful. Mechanical ventilation, nitric oxide (NO) inhalation and extracorporeal membrane oxygenation (ECMO) may be the other advanced options, if available.

Cardiovascular System Examination Approach

Cardiovascular System Examination

Approach

General Observation

§  Look at the surroundings

§  Things connected to the patients

§  Observe any sounds “Prosthetic valve?”

§  Well or unwell (conscious, toxic, pain, …)

§  Respiratory distress: Count the RR “10Sec.X 6”

§  Growth & nutritional status

§  Dysmorphic features & Face

§  Colors (Cyanosis, Pallor, Jaundice)

 Hand

§  Clubbing (Test if in doubt) Examine the clubbing if present (angel, curvature, fluctuation & degree).

§  Cyanosis (Cold hand)

§  Pallor (Compare pt.’s hand with yours)

§  Perfusion (Capillary refill)

§  Pulse (Equality, rate, volume, character. Femoral “leave to the end)

§  BP (at the end)

§  Others (Hand anomaly, stigmata of Endocarditis & Xanthoma ..)

Head

§  Pallor & Cyanosis (Stick your tongue out)

§  Comment on Teeth

§  Sings of respiratory distress (Grunting & working Ala nasai)

Neck

§  Neck veins (Turn neck to your side & look to the other side)

§  Thrill (Suprasternal “Inform the child” & supraclavicular “Neck”)

Inspection chest

§  Scars (Raise arms up)

§  Precordial bulge

§  Visible pulsations

§  Dilated veins

Palpation chest

§  Apex (Both hands on the chest then, count the rib spaces & point the apex)

§  Thrill (in 4 areas & timing)

§  Parasternal heave (lift)

§  Palpable heart sound

Percussion chest

§  Upper border of the liver (if there is hepatomegaly)

Auscultation

§  Front basic 4 & total 6 areas (apex, Lt. LSB, Lt. Middle SB, Lt.USB, Rt. USB & Axillae) (Use the Bell for apex only & diaphragm for other areas)

§  Back "Below & in between scapula"

§  Change patient’s position

§  Lung bases for crackles

§  Comment (Heart sounds, splitting S2, added sounds & murmur)

§  Murmur (comment on 6 items)………… Timing (hand on pulse), character, site, radiation, grade & changeable

At the end

§  Growth charts

§  Femoral pulses “No or ↓ : Infant or Radiofemoral delay: elder child”

§  BP (4 limbs if suspect coarctation)

§  Other systems (Abdomen mainly for liver & leg edema … signs of heart failure, Rheumatic or endocarditis)

§  O2 Saturation

§  Offer to look at ECG & CXR