Deep hypothermia circulatory arrest during heart surgery might cause brain injury

Bjørg Elvevoll and colleagues have investigated if different procedures during cardiopulmonary bypass affects fluid extravasation differently.


MAIN RESULTS:

  1. Acute intra-abdominal hypertension leads to microvascular fluid extravasation .
  2. Fluid extravasation was not differently affected by sevoflurane vs. isoflurance or by pulsatile vs. nonpulsatile cardiopulmonary bypass perfusion
  3. Deep hypothermia circulatory arrest is associated with brain injury.

THESIS DEFENCE:

Thesis: Microvascular fluid shifts during cardiopulmonary bypass and intraabdominal hypertension
Candidate: Bjørg Elvevoll
Time: September 28, 2018 at 11:15
Place: Haukeland University Hospital, Armauer Hansens hus: Auditorium
Link to university website (in Norwegian)


SUMMARY:

During on-pump heart surgery, fluid extravasation can cause edema and reduced post-operative organ function. Elvevoll’s experiments include randomly allocated pigs, with the aim to find interventions that could possibly reduce intraoperative fluid accumulation.

(1) In the first experiment, intra-abdominal pressure was elevated for a total of four hours, leading to increased hematocrit, fluid extravasation rate and decreased plasma volume. Moreover, femoral venous pressure, right atrial pressure, pulmonary capillary wedge pressure and mean pulmonary arterial pressure increased substantially more than in the control group. The increased intra-abdominal pressure also lead to elevated intracranial pressure and decreased tissue perfusion of the pancreas and the gastric- and intestinal mucosa.

(2) Fluid extravasation increased dramatically during initiation of cardiopulmonary bypass in pigs given isoflurane and sevoflurane anesthesia, with no between-group differences. The pigs given sevoflurane needed more fluid supplementation, probably because plasma volume was better contained with isoflurane.

(3) Pulsatile roller pump-induced cardiopulmonary bypass does not affect fluid extravasation differently than a nonpulsatile procedure. Fluid additions/losses, plasma volume and tissue perfusion also changed similarly in both groups.

(4) Deep hypothermia circulatory arrest have similar impact on fluid extravasation compared to deep hypothermic low-flow cardiopulmonary bypass. However, the pigs given deep hypothermia circulatory arrest had indication of anaerobic cerebral metabolism and ischemic brain injury.


REFERENCES:

(1) Elvevoll, B., Husby, P., Øvrebø, K., & Haugen, O. (2014). Acute elevation of intra-abdominal pressure contributes to extravascular shift of fluid and proteins in an experimental porcine modelBMC research notes7(1), 738.

(2) Svendsen, Ø. S., Elvevoll, B., Mongstad, A., Stangeland, L. B., Kvalheim, V. L., & Husby, P. (2016). Fluid filtration and vascular compliance during cardiopulmonary bypass: effects of two volatile anestheticsActa Anaesthesiologica Scandinavica60(7), 882-891.

(3) Elvevoll, B., Lundemoen, S., Svendsen, Ø. S., Mongstad, A., Grong, K., Kvalheim, V. L., & Husby, P. (2016). Does Roller Pump–Induced Pulsatile CPB Perfusion Affect Microvascular Fluid Shifts and Tissue Perfusion?The Annals of thoracic surgery102(2), 564-572.

(4) Elvevoll, B., Husby, P., Kvalheim, V. L., Stangeland, L., Mongstad, A., & Svendsen, Ø. S. (2017). Microvascular fluid exchange during CPB with deep hypothermia circulatory arrest or low flowPerfusion32(8), 661-669.