The Journal of ExtraCorporeal Technology Issue 55-4 | Page 29

K . Kohlsaat et al .: J Extra Corpor Technol 2023 , 55 , 175 – 184 179
Table 2 . First prime laboratory values ( each circuit initially primed with the same process ).
Standard Prime ( n = 417 )
PBUF ( n = 704 )
P value
pH at prime temperature of 30C ( n = 417 , 691 )
7.37 [ 7.32 , 7.43 ]
7.37 [ 7.32 , 7.43 ]
0.84
Na + ( mmol / L ) ( n = 416 , 691 )
161 [ 159 , 163 ]
161 [ 158 , 163 ]
0.080
Glucose ( mg / dL ) ( n = 416 , 691 )
338 [ 304 , 369 ]
342 [ 307 , 368 ]
0.40
K + ( mmol / L ) ( n = 417 , 690 )
5.3 [ 4.9 , 5.8 ]
5.3 [ 4.8 , 5.8 ]
0.93
Ca ++ ( mmol / L ) ( n = 416 , 691 )
0.88 [ 0.76 , 1.02 ]
0.87 [ 0.72 , 1.07 ]
0.80
Lactate ( mmol / L ) ( n = 417 , 691 )
4.3 [ 3.5 , 5.3 ]
4.5 [ 3.6 , 5.4 ]
0.30
OSM ( mOsm / kg H 2 O ) ( n = 394 , 633 )
341 [ 336 , 346 ]
341 [ 335 , 345 ]
0.75
Values shown are number ( percent ) or median [ 25th , 75th percentiles ]. dL : deciliters ; kg : kilograms ; L : liters ; mg : milligrams ; mmol : millimoles ; mOsm : milliosmoles ; OSM : osmolality ; PBUF : pre-bypass ultrafiltration .
Table 3a . Final prime laboratory values after PBUF for that group ( no change for the SP group ).
Standard Prime ( n = 417 )
PBUF ( 704 )
P value
pH at prime temperature of 30C ( n = 417 , 703 )
7.37 [ 7.32 , 7.43 ]
7.39 [ 7.34 , 7.43 ]
0.004
Ca ++ ( mmol / L ) ( n = 416 , 703 )
0.88 [ 0.76 , 1.02 ]
1.02 [ 0.91 , 1.16 ]
< 0.001
Na + ( mmol / L ) ( n = 416 , 703 )
161 [ 159 , 163 ]
149 [ 147 , 152 ]
< 0.001
Glucose ( mg / dL ) ( n = 416 , 703 )
338 [ 304 , 369 ]
153 [ 135 , 168 ]
< 0.001
K + ( mmol / L ) ( n = 417 , 703 )
5.3 [ 4.9 , 5.8 ]
4.1 [ 3.9 , 4.4 ]
< 0.001
Lactate ( mmol / L ) ( n = 417 , 703 )
4.3 [ 3.5 , 5.3 ]
2.1 [ 1.7 , 2.6 ]
< 0.001
OSM ( mOsm / kg H 2 O ) ( n = 394 , 649 )
341 [ 336 , 346 ]
307 [ 303 , 313 ]
< 0.001
Values shown are median [ 25th , 75th percentiles ]. dL : deciliters ; kg : kilograms ; L : liters ; mg : milligrams ; mmol : millimoles ; mOsm : milliosmoles ; OSM : osmolality ; PBUF : pre-bypass ultrafiltration .
Table 3b . Final prime laboratory values within more physiologic range .
Standard Prime ( n = 417 )
PBUF ( n = 704 )
P value
Sodium in more physiologic range ( 140 – 150 mmol / L )
13 ( 3 %)
437 ( 62 %)
< 0.001
Glucose in more physiologic range (< 150 mg / dL )
8 ( 2 %)
318 ( 45 %)
< 0.001
Potassium in more physiologic range ( 3.0 – 5.0 mmol / L )
150 ( 36 %)
688 ( 98 %)
< 0.001
Lactate in more physiologic range (< 3 mmol / L )
56 ( 13 %)
612 ( 87 %)
< 0.001
OSM in more physiologic range ( 280 – 320 mOsm / kg )
23 ( 6 %)
595 ( 92 %)
< 0.001
Values shown are number ( percent ).
the similarity in final lab values may be in part explained by the fact that the patient may have been exposed to standard bank blood ( when additional blood was clinically indicated ) once on bypass since only the prime portion was treated with PBUF . Of note , the PBUF group preoperatively had a significantly greater proportion that required epinephrine and dopamine infusions . However , this was not adjusted for case complexity or preoperative risk factors . Further , intraoperative phenylephrine usage , intraoperative / postoperative inotropes , and patient outcome differences did not show statistical significance . Nonetheless , we believe the dataset provides us with confidence that making the CPB circuit prime more physiologic , and less hyperosmolar , does not increase patient risk . It could be argued that blood primes should be physiologic for patients requiring bypass unless there is compelling evidence otherwise . Our data set shows more values within the physiologic range throughout bypass and there were no adverse outcomes or events that occurred as a result of PBUF usage . We also found no evidence of a benefit with non-physiologic primes and are mindful that banked blood can have difficult to predict and dangerous levels of potassium , as reported by numerous authors [ 2 – 7 ]. We believe that since many electrolytes are known to be abnormal in prime blood , PBUF can consistently make these values more physiologic before bypass as well as throughout the cardiopulmonary bypass period .
Our dataset has led to additional practice changes . Our PBUF protocol now includes the entire unit of reconstituted blood for the procedure . Now , the entire unit of reconstituted whole blood is added to the circuit after a clear prime . PBUF is performed and then excess circuit volume , which has been PBUF treated , is returned to the original blood bag . Therefore , during CPB , the entire initial unit of blood that the patient is exposed to through the CPB circuit has been treated . See the Limitations section below . Additionally , we have modified the PBUF protocol to include more 0.45 % saline and Plasma- Lyte , which results in more physiologic values . Besides what