Use of autologous blood as part of the perfusate for cardiopulmonary bypass: a priming technique

Optimization of cardiopulmonary bypass prime fluid to preserve microcirculatory perfusion during on-pump coronary artery bypass graft surgery: PRIME study protocol for a double-blind randomized trial

BACKGROUND

Acute microcirculatory perfusion disturbances and organ edema are important factors leading to organ dysfunction during cardiac surgery with cardiopulmonary bypass (CPB). Priming of the CPB system with crystalloid or colloid fluids, which inevitably leads to hemodilution, could contribute to this effect. However, there is yet no optimal evidence-based strategy for this type of priming. Hence, we will investigate different priming strategies to reduce hemodilution and preserve microcirculatory perfusion.

METHODS

The PRIME study is a single-center double-blind randomized trial. Patients undergoing elective coronary artery bypass graft surgery with CPB will be randomized into three groups of prime fluid strategy: (1) gelofusine with crystalloid, (2) albumin with crystalloid, or (3) crystalloid and retrograde autologous priming. We aim to include 30 patients, 10 patients in each arm. The primary outcome is the change in microcirculatory perfusion. Secondary outcomes include colloid oncotic pressure; albumin; hematocrit; electrolytes; fluid balance and requirements; transfusion rates; and endothelial-, glycocalyx-, inflammatory- and renal injury markers. Sublingual microcirculatory perfusion will be measured using non-invasive sidestream dark field video microscopy. Microcirculatory and blood measurements will be performed at five consecutive time points during surgery up to 24 h after admission to the intensive care unit.

DISCUSSION

PRIME is the first study to assess the effect of different prime fluid strategies on microcirculatory perfusion in cardiac surgery with CPB. If the results suggest that a specific crystalloid or colloid prime fluid strategy better preserves microcirculatory perfusion during on-pump cardiac surgery, the current study may help to find the optimal pump priming in cardiac surgery.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05647057. Registered on 04/25/2023.

CLINICALTRIALS

gov PRS: Record Summary NCT05647057, all items can be found in the protocol.

Changes in colloid oncotic pressure during cardiac surgery with different prime fluid strategies

OBJECTIVE

In cardiac surgery, colloid oncotic pressure (COP) is affected by haemodilution that results from composition and volume of prime fluid of cardiopulmonary bypass (CPB). However, the extent to which different priming strategies alter COP is largely unknown. Therefore, we investigated the effect of different priming strategies on COP in on-pump cardiac surgery.

METHODS

Patients (n = 60) were divided into 3 groups (n = 20 each), based on the center in which they were operated and the specific prime fluid strategy used in that center during the inclusion period. CPB prime fluids were either gelofusine-, albumin-, or crystalloid based, the latter two with or without retrograde autologous priming.

RESULTS

In all groups, COP was lowest after weaning from CPB and one hour after CPB. Between groups, COP was lowest with gelofusine prime fluid (16.4, 16.8 mmHg, respectively) compared with crystalloids (MD: -1.9; 95% CI:-3.6, -0.2; p = .02 and MD: -2.4, 95% CI: -4.2, -0.7; p = .002) and albumin (MD: -1.8, 95% CI: -3.5, -0.50; p = .041 and MD: -2.4, 95% CI: -4.1, -0.7; p = .002). In all groups, the decrease in COP one hour after bypass compared to baseline correlated positively with fluid balance at the end of surgery (p < .001).

CONCLUSIONS

COP significantly decrease during CPB surgery with the largest decrease in COP at the end of surgery, while at the same time fluid balance increases. We suggest that prime fluid strategy should be carefully selected when maintenance of COP during cardiac surgery is desirable.

Anesthetic Considerations for Pneumonectomy With Left Atrial Resection on Cardiopulmonary Bypass in a Patient With Lung Cancer: A Case Report

Cases of pneumonectomy plus atrial resection for lung cancer have been reported in the surgical literature, but not the anesthesia literature. To achieve curative resection, cardiopulmonary bypass (CPB) may be necessary. Although CPB may complicate the management of these high-risk patients, these cases should always be undertaken in a center where it is immediately available. Here, we discuss the anesthetic management of a 70-year-old man with left lower lobe lung cancer invading the left inferior pulmonary vein and left atrium.

Prospective study on cardiopulmonary bypass prime reduction and its effect on intraoperative blood product and hemoconcentrator use

Purpose: Evaluate the feasibility and clinical significance of crystalloid prime reduction during the initiation of cardiopulmonary bypass (CPB) using a modified bridge on the cardioplegia delivery system.

Methods: Prospective trial of crystalloid prime reduction using a standard Duraflow®-coated CPB circuit and Vanguard® 2:1 cardio plegia delivery system. Standard prime volume was 1500 cc of Plasmalyte. Prime was reduced via the bridge in the cardioplegia system during initiation of CPB. Packed red blood cells (PRBC) were transfused for hematocrit (Hct) less than 24% while rewarming. A hemoconcentrator was used if the patient’s circulating blood volume exceeded 150% of calculated. All data were prospectively collected.

Results: Two hundred and twenty-two consecutive patients undergoing cardiac surgery utilizing CPB were evaluated. There were 107 patients with normal prime volume (NPV) and 115 patients with reduced prime volume (RPV). There was no significant difference in sex, mean age, weight, body surface area (BSA), pre-op Hct, procedure time or procedure between the two groups. There was no difference in total crystalloids infused by the anesthetists (average NPV 1205 cc versus RPV 1148 cc). The average RPV was 622 cc (range 400 - 1100 cc) or a 59% reduction. Post-op Hct revealed no difference (NPV 28% versus RPV 29%). There was a 24% reduction in patients requiring PRBC (NPV n=23 versus RPV n=18). The use of hemoconcentrators was reduced by 49% (NPV n=18 versus RPV n=11). The average urine output for both groups exceeded 100 cc/hour while on CPB.

Conclusion: Using a modified cardioplegia delivery system is a safe and effective method of CPB prime reduction. A RPV resulted in fewer patients requiring PRBC transfusions and fewer hemoconcentrators used. Based on our experience, we would recommend attempting to reduce prime volume in all patients undergoing CPB.

Albumin versus crystalloid for pump priming in cardiac surgery: Meta-analysis of controlled trials

OBJECTIVES

To determine the effects of pump priming fluid choice on platelets, fluid balance, and clinical outcomes.

DESIGN

Meta-analysis of controlled clinical trials. Primary endpoints were platelet counts, colloid oncotic pressure, on-bypass fluid balance, postoperative weight gain, and colloid usage.

SETTING

Cardiac surgery with cardiopulmonary bypass.

PATIENTS

Adult and pediatric patients undergoing cardiac surgery, including coronary artery bypass grafting, valve procedures, and correction of congenital cardiac anomalies.

INTERVENTIONS

Extracorporeal circuit priming with either albumin or crystalloid.

MEASUREMENTS AND RESULTS

The meta-analysis included 21 controlled trials with 1,346 total patients. Albumin prime significantly reduced the on-bypass drop in platelet counts. The pooled weighted mean difference in platelet count drop with albumin versus crystalloid prime was -23.8 x 10(9)/L (confidence interval [CI], -42.8 to -4.7 x 10(9)/L). The colloid oncotic pressure decline was also smaller when albumin rather than crystalloid was used for priming, with a pooled weighted mean difference of -3.6 mm Hg (CI, -4.8 to -2.3 mmHg) during bypass and -2.0 mmHg (CI, -2.9 to -1.1 mmHg) after surgery. Albumin prime correspondingly reduced on-bypass positive fluid balance (-584 mL; CI, -819 to -348 mL) and postoperative weight gain (-1.0 kg; CI, -0.6 to -1.3 kg) compared with crystalloid. Postoperative colloid usage was lower with albumin than crystalloid prime (-612 mL; CI, -983 to -241 mL).

CONCLUSIONS

Albumin prime better preserves platelet counts than crystalloid. Albumin also favorably influences colloid oncotic pressure, on-bypass positive fluid balance, postoperative weight gain, and colloid usage. The clinical significance of these observations merits further investigation.