Mechanism of blood-flow promotion during thoraco-abdominal compression-decompression CPR and standard CPR in man - preliminary results

Background

CPR with thoraco-abdominal compression-decompression (TACD) enhances coronary perfusion and resuscitability in animal studies.

Aim of the study

To observe aortic pressure (AoP), right aterial pressure (RAP) and mitral valve ((MV) position during CPR with a new, manually operated device to administer TACD in order to detect the operative mechanism of blood flow promotion and compare it to standard CPR (sCPR) with a mechanical device (Thumper^®).

Methods

Included were 11 adult patients with witnessed cardiac arrest brought to the emergency department under chest compressions. Arterial and venous catheters were placed to monitor AoP and RAP continuously, the MV was visualized by transesophageal echocardiography (TEE). RAP < AoP in the compression phase indicates that blood-flow promotion is most likely due to cardiac pump, if RAP = AoP in the compression phase chest pump is most likely operative [1].

Results

In all patients TEE was performed during TACD-CPR and in four patients during both sCPR and TACD-CPR. In 10 patients catheters could be placed. For MV position and the relation between AoP and RAP in the compression phase see the table.

Conclusions

It appears that in both sCPR and TACD-CPR, the prevailing mechanism of blood-flow promotion is by means of thoracic pump. The MV-position during the compression phase of CPR cannot be used to differentiate between thoracic or cardiac pump mechanism.

Table