myocardial protection for correction of av canal defect ron angona, ms, ccp university of rochester...
TRANSCRIPT
Myocardial Protection for correction of AV Canal Defect
Ron Angona, MS, CCP
University of Rochester Medical CenterRochester, NY
• None
Disclosures
• 2 y.o. w/ AV canal defect, Trisomy 21– Admitted from home
• Balanced canal, moderate atrial component with small ventricular component completely occluded by tricuspid valve
• Mild MR, cleft MV, nl LV fxn
– 85cm, 10 kg BSA 0.49 m2
– Bicaval cannulation– antegrade cardioplegia
Background
• Initial dose typically 40-60 mL/kg• 4:1 Blood:Crystalloid
– Crystalloid solution is Plasmalyte-A w/ 52.8 meq K+ added– Made in house by pharmacy– No additives– Single dose in 95% of cases
• Essentially all but ASO
– Up to 100 minute x-clamp times
• Arrest typically occurs at 5mL/kg
Myocardial Protection
• Cardioplegia initiated• Delayed arrest (mostly) occurred around 10 mL/kg
• Rapid investigation– Is the crystalloid bag opened?– Is the plegia cold?– Good root pressure– Ratio set correctly at 4:1– Correct tubing sizes
– Potassium?
Continued…
• Sample of crystalloid cardioplegia solution taken, run on ABG analyzer
• Concurrently, (at about ~20 mL/kg) surgeon asks:
“Did you put potassium in the cardioplegia?”
Run a Sample
• K+ in plegia bag should be out of range– Actual value of sample was 4.6 mmol/L
• Call another perfusionist– Double check observations
• Plegia dose finishes at 55 mL/kg– Surgeon icing heart, concerned
• Sample off plegia heat exchanger (post-mix), completed after dose finished, showed HCT 14%, K+ 3.8.– Pt. K+ at this time was 3.8, K+ in Normosol is 4.6…
Results
• Sample run from another bag of plegia showed a k+ of 15, as would be expected
• Stuck needle in line when we took back the plegia, K+ again was 3.8– We questioned the composition of the blood of the top of
the heat exchanger– Early Resumption of Activity
• Pharmacist called• Plegia bag sequestered, samples sent to pharmacy
More Samples…
• Pharmacy verified the mistake that evening– Several bags effected no others had been used
• Pump time 1:36, x-clamp 1 hour (55 min ischemic time)
• Normal resumption of activity• Pt. weaned from CPB on expected regiment of Epi
(0.03), Dopa (3), Milrinone (0.5)• To PICU intubated
Findings, Results
• Extubated following morning 9am to NC 2L– Lactate nl, Epi + Dopa off by that point– Peak troponin 0.36, lactate 1.8,
• POD 2 – milrinone off, ambulates, PO diet– CK Peak 2090, CKMB 44.9
• Sedated ECHO POD 9 – nothing significant• Delayed discharge (POD 10) d/t continued drainage
from MT tube– Uneventful otherwise
• 1 month f/u – no limitations, no cardiac meds
Post Op
• Could have added more K+– Time constraint
• Second dose of cardioplegia• Plegia now made in OR by perfusion
– Mix is tested prior to clamping, administration • Temporary?• Liability?
Process Improvement / Fall out
• Sentinel events can make you question even your most basic assumptions
• Very fortunate patient was unharmed
• How important is cardioplegia composition in PEDIATRIC cardiac surgery?
– Cardioplegia in Pediatric Cardiac Surgery: Do We Believe in Magic? Doenst T
Ann Thorac Surg 2003;75:1668-77
Conclusion