Author + information
- Geng Qian, MD∗ (, )
- Feng Cao, MD,
- Hongliang Su, MD and
- Yundai Chen, MD ()
- ↵∗Chinese PLA General Hospital, Division of Cardiology, 28 Fuxing Street, Beijing, 100853, China
We appreciate the comments of Vallabhajosyula et al. on our clinical trial. Although there are some confounding factors when evaluating volume by central venous pressure (CVP), low CVP always indicates hypovolemia, which is affected by few confounding factors. In our study, 73.9% of patients (195 of 264) had initial CVP less than 12 cm H2O, and 19.7% of patients (52 of 264) had initial CVP less than 6 cm H2O. We tried to improve insufficient blood volume status using aggressive hydration. Because hypovolemia is an essential risk factor for contrast-induced nephropathy (CIN), patients with the lowest CVP (<6 cm H2O) received the greatest benefit of CIN prevention from CVP-guided vigorous volume expansion (1). Rapid infusion guided by CVP could help avoid dehydration and maintain stable blood volume.
Patients with heart failure usually do not receive adequate hydration in routine clinical practice, because of concern for pulmonary edema. We aimed to explore a “safe” hydration method to avoid fluid overload. Fluid infusion rate was dynamically adjusted by CVP in our clinical trial. Although there are some disputes regarding CVP-guided fluid therapy, recent researches have indicated that lower and higher CVP values had positive and negative predictive value, respectively, for fluid responsiveness (2). In our study, 52 patients in the CVP-guided hydration group had obvious increases in CVP and thus reductions in infusion rate. Aggressive volume expansion did not increase the incidence of pulmonary edema in our trial. To prevent acute heart failure, the fluid infusion rate should be determined by comprehensive indicators (such as dyspnea, pulmonary rales, change in brain natriuretic peptide, etc.), rather than a single hemodynamic index.
Invasive central venous catheterization is extensively applied in clinical practice for rapid fluid resuscitation and hemodynamic monitoring. Left ventricular end-diastolic pressure–guided hydration seems to be effective in preventing CIN, but it could not dynamically monitor the change in left ventricular end-diastolic pressure during hydration (3). Noninvasive dynamic measure technologies have not been carried out widely in clinical application. Hydration guided by noninvasive dynamic measures may be a good approach to the prevention of CIN, which requires further investigation in a prospective randomized controlled trial.
Please note: The authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- American College of Cardiology Foundation