Case report:
A one -year- old, 5.5 Kg,with a BSA of 0.33 m2,male child presented
withhurried breathing since birth, and recurrentupper respiratorytract
infection and easy fatiguability with decreased activity since three
months of age.There was no history of cyanotic spells. On auscultation,
a pansystolic murmur was present at the left fourth intercostal space.
Chest X- ray showed pulmonary artery enlargement, cardiomegaly and
increased pulmonary vascularity. Echocardiography revealed a large
doubly committed VSD of 8.8 mm with moderate PAH,dilated RA,RV, and
pulmonary artery(2.6 cm), and normal biventricular functions with LVEF
of 60%, and TAPSE of 21mm.He was puton oraldigitalis, enalapril,
sildenafil and furosemide,and after obtaining informed consent from the
parents, he was taken up forVSD patchclosure under cardiopulmonary
bypass (CPB).He was premedicated with oral midazolam(3mg) two hours
before surgery. In OR, standard ASAmonitoring was started. His baseline
heart rate was 140 bpm and arterial saturation was 99%. General
anaesthesia was induced with fentanyl (50mc), thiopentone sodium (5mg),
midazolam( 0.5mg), and vecuronium bromide(1mg) was used to facilitate
the endotracheal intubation with 4.5 mm cuff tube.After
inductionofanaesthesia, 20GLeadercath was inserted in the left femoral
artery for continuous BP monitoring and intermittent ABG analysis. A 4.5
Fr triple lumen catheter was inserted via right internal jugular vein
for CVP monitoring and administration of anaesthetic drugs and
inodilators.His baseline BP and CVP were 85/ 50mmHgand 6
mmHgrespectively, and ABG revealed a pH 7.40, PO2-176 mmHg,PCO2 -35mmhg,
Hb-11gm%, HCO3- 25mmol/l, SaO2- 99.8%. Anaesthesia was maintained with
intermittent fentanyl, midazolam, vecuronium bromide, and
sevoflurane(1-2%) and oxygen in air with fraction of inspired oxygen
(FiO2) of 0.5–1.Anticoagulation with heparin(300U/kg)was used to
achieve an ACT of >480 Sec. Aortic cannulation was done
using 12 Fr straight Styletted cannula (Medtronic), Venous drainage was
done using single stage 14 Fr angled DLP cannula for SVC and 16 Fr
angled DLP cannula for IVC. VSD was closed with Gore- Texpatch under
standard moderate hypothermic CPB, and potassium enriched
(Den-Lido)cardiopegic myocardial protection.Weaning from CPB was easy
with the use of infusion of milrinone (0.5mc/kg/min), dobutamine(5
mc/kg/min) and NTG (1mc/kg/min). On direct needle insertion, PA
pressures were 22/7(10) mmHg,at cardioplegia line was 70/ 40 mmHgand
atside port of the aortic cannula were 35/18mmHg, as compared to femoral
artery pressure of 30/17 mmHg. However, on visual assessment, the LV
contractility deteriorated and progressed to distension and cardiac
arrest andnecessitatedtoreinstitute CPB. Patient had similar repeated
three episodes of cardiac arrest on each successful weaning from CPB,
and LV contractility and hemodynamicscould not be maintained even with
the use of very high doses of inotropes.But we noted an unusual BP
difference at proximal to aortic cannulationmeasured by direct needle
insertion (90/ 40 mmHg)and femoral artery(30/17mmHg). Therefore, it was
decided to insert the TEE probe to rule out coarctation of aorta and
other cardiac anomalies, and to assess the VSD patch closure and
hemodynamics.TEE confirmedadequate VSD closure, and absence of
Coartation of aorta and any other cardiac anomalies, andgood LV
contractilitywhile patient was on CPB support.Therefore, one more
attempt for weaning off CPB was made under the TEE guidance.However,
still there was a big difference between FA pressure and aortic pressure
proximal to cannulation. Once again, the LVgot distendedand became
almost akinetic. Consequently,the patientalso developed severe mitral
regurgitation with 2-3 MR jets and hemodynamic deterioration. [Fig.1,
Video 1]Finally in a desperate scenario, it was decided to remove the
aortic cannula even in severehemodynamic instability (BP 31/17 mmHg),
realizing that the aortic cannula might be the culpritfor
thedeterioration of the LV function by obstructing the aortic blood
flow.Following aortic decannulation, the LV contractility and
hemodynamicsimproved gradually and maintainedevenwith minimum infusion
of dobutamine, milrinone. [Fig. 2, Video.2] [Fig.3, video. 3a,
3b]Utmost important to mention here that the similar sudden fall in
blood pressure was also noted following aortic cannulation, however,
that was managed as usual byvolume administration through aortic cannula
andpromptlyinstitution of CPB.Heparin was neutralized with
protamine(1:1.3 ratio). Total CPBtimes were188min, 15min,22min, 40 min,
and ischemia time was 140 min. Chest was closed after achieving proper
haemostasis.His Blood pressureand CVP before shifting to ICU were 90/45
mmHg and 7 mmHgrespectively, and ABG showed a Ph-7.47, HB- 8.8 gm%,
PCO2- 27, PaO2-244 mmHg, and SaO2- 99%.Tracheal extubation was done on
2nd postoperative dayandinodilatorstapered slowly.
Post -extubation, child was fully alert without any neurocognitive
dysfunctions. Rest of the course was uneventful, and patient was
discharged on 10th postoperative day.