Integrating Hemic and Non-Hemic Variables to Quantify Fluid and Flow

Dynamics During CPB in Neonates and Infants

Isaac Chinnappan, MS CCP LCP FPP CPBMT09-17-2016

• Integrate: Incorporate• Hemic and Non-Variables• Quantification: • How much we need to treat an abnormal variable• How Much: To calculate/To measure• More Physiological Fluid Dynamics and Flow

Dynamics• During CPB in Neonates and Infants

Description of the Topic

Thoughts……

Before even starting…

I would like to keep your mindset to remember…

Micronates

Perfusionist

• Non-Hemic Variables: Hemic Variables:– Circuitry - FFP – Colloid Osmotic Pressure– Anion Gap– Sodium– AT III– Lactate

Variables

Circuitry

• Neonates: Upto 30 days• Infant: 1 Yr.; Upto 5Kg

Non Hemic Variables - Circuitry

Age in Months Average Weight4 4-55 5-66 6.5

Age in Months Average Weight5 5

Weight (kg) Arterial (ID) Boot (ID) Venous (ID)0-3 1/8 or 3/16 3/16 3/164-7 3/16 1/4 3/16

• Old Story:– Shorter circuit: Reduction of Priming volume (increased HCT)

and foreign contact and reduction of Inflammatory mediators• The new concept or Evidence Based Clinical Practice

recommends:– Reduction of static volume– Maintenance of fluid consistency – Even very less “CIRCUITRY REDUCTION” matters positively

• How to define a small or a big baby• Patient : Circuit = Patient > < EC Volume• Circuit: Minimal Required (Size:Length:Flow)

Non Hemic Variables - Circuitry

Colloid Osmotic Pressure

Significance of altered COP• Non-Hemic Dilution (COP - Albumin) through

PRBC vs. WB vs. PRBC+FFP– Fluid Shift– Interstitial Fluid Accumulation

• L3 Mechanism: Low Weight, Longer Duration, Low Temp• Remember small vs. big baby• Compromised COP; We may not notice till off CPB• COP - Low Albumin Levels - Capillary leak –Edema• COP – Regulate at physiological range (25mmHg) during

profound & prolonged CPB

Physiological Range of COP During CPB to Prevent Pul - Edema

Clin Cardiol. 1992 May;15(5):348-52. Clinical significance of serum colloid osmotic pressure in relation to pulmonary edema and coronary instability in patients with unstable angina. Abstract: Several investigators demonstrated that severe reduction of colloid osmotic pressure (COP) predicts a fatal outcome in patients with cardiopulmonary failure. To evaluate the clinical significance of COP in relation to pulmonary edema, we studied 117 patients with unstable angina admitted in the hospital within 24 h after the chest pain. The mean COP of all 117 patients was 24.8 +/- 3.7 mmHg

Circulation: 1975; 51; 350-357

COP: 25.8 +/- 2; Absence of Pulmonary Edema

CPB – COP On Pulmonary Vasculature; “Leads to ALL complications”

Calculation• Patient Weight: 3.5kg (85ml/Kg)• Blood Volume: 298ml• HB: 15gm/dl.• HCT : 45 % ( Plasma: 55 %)• PRBC: 134ml• Initial Plasma Volume: 298 X = 298 X 0.55 = 164ml• Initial Plasma Vol : 164ml.

55100

Calculation Contd

• PD COP =

• PD COP = = = 6.7mmHg

• If I add 200ml of Colloids:

= = 14.8mmHg

25 X 164164 + 450

4100614

25 X (164 + 200)(164 + 200) + (450-200)

9100614

25 X Plasma VolumePlasma Volume + Priming Volume

• If I add 350ml of Colloids:

= = 20.9mmHg

• If I add 450ml of Colloids:

= = 25mmHg

25 X (350 + 164)(164 + 350) + (450 - 350)

12850614

25 X (450 + 164)(164 + 450) + (450 - 450)

15350614

Calculation Contd

100ml of 25% Albumin = 500ml of any Isotonic Colloids (FFP)100ml of 25% Albumin = 25gmSince I want 450ml of colloids =

= 90ml of 25% Albumin = 22.5gm = 23gm =

= 6.57 gm/kgAlso anticipate unexpected volume loss or gain due tosurgery itself

23gm3.5

Calculation Contd

450500

X 100

Anion GapPerioperative Variable

Sodium - Na

• Hyperosmolality:

• Related to hypernatremia and/or hyperglycemia.

• Bank Blood necessitated the need for more NaHCO3 in prime to neutralize acidity in the prime (Extracellular – CPD) and (Intracellular – Due to storing)

• Higher Na causing fluid retention in the post operative period; complications to brain, lungs and renal function, infection-open chest

REF: Encephalopathies caused by electrolyte disorders: EPUB: Seminar Neurol. 2011; 31(2):135-8

The Changing Pattern of Hypernatremia in Hospitalized Children; PEDIATRICS Vol. 104 No. 3 September 1999, pp. 435439

Increased Need of NaHCO3For Pump Prime

Just Look at HCO3 and BE

PH Stat – Profound Hypothermic

PH Stat – Profound Hypothermic

PH Stat – Profound Hypothermic

PH Stat – Profound Hypothermic

• Profound Hypothermic: Higher HCO3levels and Base Deficit during profound Hypothermic PH stat acid-base management

• If higher HCO3 – Is Hypernatremic?

HCO3 and BE

• NaHCO3 – Not functioning as buffer at profound Hypothermic temp

• Renal excretion stopped and/or compensatory mechanism is compromised –why?

• Norwood – Clamping Descending Aorta• “Head and Heart” or KIT• FFP: Why – When - Evidence Based?

Higher HCO3 with Base Deficit

Possible causes for Hypernatremia During Profound

Hypothermic CPB/pH stat in micronates-Neonates-Infants?

• Hypernatremic perfusate may be due to two reasons

FFPRequirement of adding more NaHCO3 during

PROFOUND HYPOTHERMIC PERFUSION and PH STAT to buffer the HYPERCARBIC (acidic) perfusate

Ref:Encephalopathies caused by electrolyte disordersEPUB: Seminar Neurol. 2011; 31(2):135-8

The Changing Pattern of Hypernatremia in Hospitalized Children. PEDIATRICS Vol. 104 No. 3 September 1999, pp. 435-439

pH stat - Normothermic

ACID BASE STAT

pCO2 NORMO

pCO2 Hypothermic

ALPHA 35-45 35-45pH 70-75 30-40

How to Treat Base Deficit • In the prime• During CPB• During profound hypothermic CPB• pH Stat; base deficit correction sodium levels• pH Stat; range of pCO2 to prevent hypercarbic

influenced acidosis• THAM

AT III• Do you know AT III levels of your patient?• It’s clinical feature in pediatrics?• AT III: HDR and Slope?• AT III and Blood Conservation• Quick Fix: Heparin and FFP for inadequate

ACT?• Just by knowing AT III ……..

Lactate

Lactate

Internal:Intracellular vs. Extracellular

External:Transfusion

• Modified CUF or ZBUF• Power wash….• Plasmalyte as Dialysate • When you are adding

plasmalyte……• Na, K, Ca, Lac, Heparin;

etc.• Additives: 6mL NaHCO3

+ Required HEPARIN• Flow and Duration

Dialysis

pH………………………………………………………………….7.40Hematocrit: One Time of ……………………………… 40%PCO2..One time of 40@ Temp …………………….40mmHgPO2….Two times of 40 ………………………………80mmHgCOP: Around 40/1.5 .……………25mmHg (Osmolarity: 7-8)AT III: Two to three times of 40 ………. 80 to 120 %Glucose: Two to three times of 40 ……….80 to 120mg/dlLactate: Less than 40/15 ………. 2.6mmol/litHCO3: 40/1.5………..26mmol/litSaturation: 2 – 2.5 times of 40 ……80%

Rule of 40

“In Pediatric Cardiac Surgery you cannot too gentle and you cannot too accurate”.

- Dwight McGoon, MD

- 1982- Reed and Charles-“Complex procedures but no issues; Simple procedures – extensive issues AND the The perfusionist challenge lies between the two”

Fluid dynamics determines the dynamics of Flow and…….

In Summary

Questions?

Thanks!!!