Altered interstitial fluid space dynamics and postresuscitation hypertension
C. W. Dawson, C. E. Lucas and A. M. Ledgerwood
Hypertensin occurred 24 to 48 hours after resuscitation in 35 of 86 injured
patients, who had combined systolic and diastolic hypertensin (150/100
mmHg) for six or more consecutive hours. Plasma volume (PV), RBC volume,
extracellular fluid (ECF) volume by the inulin dilution technique, renal
plasma flow, glomerular filtration rate, and peripheral renin levels were
measured in hypertensive and nonhypertensive patients an average of 40
hours after injury. The hypertensive patients had an average mean arterial
pressure (MAP) of 114 mmHg, compared with 95 mmHg in the nonhypertensive
patients. The RBC volume and ECF were comparable for both groups, whereas
PV was increased in the hypertensive patients (3.6 L vs 3.3 L). Calculated
interstitial fluid space (IFS) volume was greater in the nonhypertensive
patients, as was the ratio PV/IFS. The MAP in both groups correlated
directly with PV/IFS and serum albumin concentrations, and inversely with
peripheral renin concentrations. This suggests that postresuscitative
hypertension is not due to fluid overload but rather to the fluid
maldistribution related to altered IFS compliance as reflected by the
increased PV/IFS.
