Permeability studies in a hypovolemic traumatic shock model: Comparison of ringer's lactate and albumin as volume replacement fluids

In order to shed light on the controversy surrounding the choice of resuscitative fluids in shock, we used a canine model which we feel to be a superior mimic of human traumatic shock, combining hemorrhage (to a mean arterial pressure of 50 mmHg), fracture of both femora, and soft tissue crush. After 90 min, animals were resuscitated by reinfusion of shed blood, supplemented by 5% albumin (n = 8) or lactated Ringer's solution (n = 8). Plasma colloid osmotic pressure (COP), transcapillary escape rate for albumin (TER), total lung water and extravascular lung water (EVLW) were measured. COP fell in both groups, but remained above 9 mmHg in the albumin recipients, while falling below 7 in those receiving crystalloid (P < 0.05). Overall, the increase in EVLW averaged 20%; albumin recipients fared better (9.7%) than Ringer's recipients (31.1%), but wide inter-animal variation precluded statistical significance (P = 0.095). TER rose 30% per hour, without difference between groups. Quality of resuscitation (achieved blood pressure and cardiac output) was somewhat better in the albumin group. We conclude that this model allows study of the early microvascular leakage seen in shock; within the time-frame studied (maximum 4.5 h following shock), colloid and crystalloid resuscitation were approximately equivalent.