IV fluid and electrolytes management

I am gonna start with Fluid and electrolyte management….I know it’s quite a boring topic but we gotta know basic principle and am sure many of us are not aware of basics and do it blindly..so Lets start …

Case 1-50 y/o patient admitted to hospital for Pancreatitis so patient cant take anything PO to give rest to Pancreas and to decrease enzyme release from pancreas..

Case 2 -50 y/o patient admitted for diarrhea…with BP= 90/60 pr= 112 RR=14

So here we have two different pt..

1^st patient – patient is not hypovolemic but gonna be NPO so prophylactically we need to give MAINTENCE FLUID.

2^nd patient- seems hypovolemic so here we need to give something to replace lost body volume k/s REPLACEMENT THERAPY

Maintenance therapy: We need to give

1. Water—2L
2. Glucose: to prevent catabolism and anorexic ketoacidosis- 100 to 150 gm/day
3. Electrolyte mainly Na+ and K+-----------75 to 175 meq of Na+ in the form of NaCl and K+ 20 to 60 meq in the form of KCL in a day

Means as a maintenance therapy we need to give dextrose + ½ NS + KCl

Why ½ NS ?? why not NS??? ----------½ NS because water will go both ICF and ECF compartment while NaCl will go only in ECF… ½ NS = 77 meq of Na+ ---so 2 L of 1/2 NS will provide approx. 154 meq of NaCl so if we provide ½ NS ECF will get 154 Na+ and 1 L of water and ICF will get 1L of water

How to calculate rate of Maintenance IV fluid: Now usual requirement of water is 2L/day on average …so if we divide 2000ml/24 hours---roughly it is 83.33ml/hr…

( How did I calculate 2L/d fluid requirement??: Loss of fluid in a day: 800ml to 2200ml ~~ 1L urine+ 200ml stool+ 400-500 ml insensible loss – 200 ml gain of water because of endogenous metabolism--------- roughly 2L requirement)

Now 1 drop= 1/12 ml----------------------so if we give 83 ml in 1 hr-----------we have to give 83* 12 drops ~ 1000 drops/ hr-----------16 drops/min.

Replacement Therapy:

For replacement therapy we need to calculate loss of body volume:

Estimated Percentage Dehydration	Physical Examination Findings
<5	History of fluid loss but no findings on physical examination
5	Dry oral mucous membranes but no panting or pathological tachycardia
7	Mild to moderate decreased skin turgor, dry oral mucous membranes, slight tachycardia, and normal pulse pressure.
10	Moderate to marked degree of decreased skin turgor, dry oral mucous membranes, tachycardia, and decreased pulse pressure.
12	Marked loss of skin turgor, dry oral mucous membranes, and significant signs of shock.

We cant replace whole lost volume but need to replace just 80% of lost. Following is formula for deficit volme:

Deficit replacement volume (ml) = % dehydration x body weight (kg) x 1000 x 0.80

So in our pt, it would be------- 0.10 x 60 x 1000 x 0.80= 480 ml

So we need to give 480 ml bolus….

What is the rate of IV bolus-----------500ml/hr---------means 500 x 12= 6000 drops/hr-----------100drops/min

http://www.cvmbs.colostate.edu/clinsci/wing/fluids/fluids.htm