Fluid Rate Is Important As Much As Fluid Tonicity: An Experimental Study

Area of Science:

• Physiology
• Pharmacology
• Nephrology

Background:

• Fluid therapy is crucial in medical settings.
• Understanding the impact of fluid tonicity and infusion rate on plasma osmolality is vital for patient safety.
• Previous studies have not simultaneously evaluated both factors.

Purpose of the Study:

• To determine the effect of different fluid tonicities and infusion rates on plasma osmolality.
• To identify the safest and most appropriate intravenous fluids for various clinical scenarios.
• To provide evidence-based recommendations for fluid management.

Main Methods:

• An experimental study was conducted on rats, divided into seven groups.
• Groups received different concentrations of dextrose (D5) with either 0.45% or 0.9% NaCl at high (150 ml/kg/24h) or maintenance (100 ml/kg/24h) rates.
• Plasma osmolality and sodium levels were measured after 24 hours.

Main Results:

• The groups receiving 0.9% NaCl at a high rate ([D5(1)150]) and 0.45% NaCl at a maintenance rate ([D5(½)100]) showed plasma sodium and effective osmolality closest to the control group.
• Statistical analysis indicated no significant difference in these parameters compared to the control.

Conclusions:

• 0.9% NaCl solution is recommended for high-rate fluid therapy to maintain normal plasma osmolality.
• 0.45% NaCl solution is suggested as the safest option for maintenance fluid therapy.
• These findings aid in selecting appropriate fluids for optimal patient outcomes during fluid resuscitation or maintenance.