Objective: To determine coronary and renal blood flows during two methods of CPR in pigs. Methods: 10 adult swine were used for the study. Catheters were placed into the left ventricular cavity, for microsphere injection, and both femoral arteries, for reference blood withdrawal. After a thirty minute stabilisation period, the first color fluorescent microspheres (FM) were injected. Ventricular fibrillation was induced and animals received either closed-chest cardiac massage (CCCM) or minimally-invasive direct cardiac massage (MIDCM) [R.F. Buckman et al, Resuscitation 1995; 29: 237]. After 5 min and 10 min of cardiac massage, the second and third colors of FM were injected. Organs were digested in 4M KOH and FM extracted by vacuum filtration. Dye was extracted using Carbitol® acetate and organ blood flows determined. Results: Microsphere recovery rates were 80% for the heart and 83% for the kidneys overall. Organ blood flows (mls/g/min) (mean±SEM).
| Baseline | 5 mins | 10 mins | ||
|---|---|---|---|---|
| Coronary | CCCM | 1.63±0.19 | 0.36±0.19* | 0.27±0.19* |
| MIDCM | 0.94±0.21 | 0.32±0.21* | 0.22±0.21* | |
| Renal | CCCM | 7.45±0.39 | 0.58±0.39* | 0.17±0.39* |
| MIDCM | 7.97±0.42 | 0.81±0.42* | 0.32±0.42* |
Conclusions: Coronary and renal blood flows were significantly reduced from baseline with both techniques of CPR. No differences were found between techniques. Organ blood flows during CPR using FM are similar to those previously reported using radioactive microspheres.