Fluid and Electrolytes Water and Na Flashcards
Intacellular fluid comprises how much of the total BW
67%
Interstital fluid comprises how much of the total BW
20%
Intravascular fluid comprises how much of the total BW
8.3%
***Total BW for OLDER CHILDREN AND MEN LESS THAN 70
0.6 X body weight
***Total BW for WOMEN LESS THAN 80 AND MEN OVER 70
0.5 X body weight
***Total BW for WOMEN OVER 70
0.45 X body weight
Sodium maintenance needs
Closer to 2 mEq/kg
Potassium maintenance needs
Closer to 1 mEq/kg
5% loss Volume Depletion
Decreased skin turgor Dry membranes Pale skin Diminished urine output Normal BP Normal to increased HR Flat fontanelle Consolable CNS Capillary refill >2 seconds
10% Volume Depleted
Tenting skin turgor Very dry membranes Grey skin color Severly decreased urine output Normal to decreased BP Increased HR Soft fontanelle Irritable CNS
15% Volume Depleted
Tenting skin turgor Parched mucous membranes Mottled skin color Azotemic urine output Decreased BP Significantly increased HR Sunken fontanelle Lethargic/coma CNS Tilt test increase by 30 beats/min Capillary refill >3 seconds
Tilt Test Procedures
BP and HR are recorded after pt has been supine for 2-3 minutes
BP/HR are recorded after pt has be standing for 1 minu
Positive Tilt Test
Increased HR by 30 beats per minute or more (15% volume loss)
Presence of sx of cerebral hypoperfusion
Capillary refill
Time for the nail bed to return to the normal color is counted in seconds
Less than 2 seconds is normal
Urine output is an indicator of:
Organ perfusion if pt has normal renal function
Normal urine output is:
More than 1.0 mL/kg/hr
Reduce urine output is:
0.5-1.0 mL/kg/hour
Severely reduced urine output is:
Less than 0.5 mL/kg/hr
Lab values in volume depleted:
Albumin will increase unless hypoalbuminemic
Hemoglobin will increase unless anemic
BUN:SCr will increase >20:1 in pre-renal azotemia
Serum lactate > 3 mmol?L = severe shock
Replacement Fluids 1st thing you do:
Initiate a 20 mL/kg bolus over 30 of NS and repeat until improved hemodynamics
Example of how to calculate percent of fluid loss
5% loss in a 70 kg 35 yo man
MF: 1500+ (20 50) = 2500
TBW: 0.670*0.05 = 2L
Replacement fluid rules
3/4 in the first 24 hours
Rest in the next 24-48 hours
Bolus is ALWAYS NS
RF can be 1/2 NS
Isotonic Crystalloids
Lactated Ringers
NS
100% extracellular
Hypotonic Crystalloids
Depending on osmolality fluid will move to intracellular space
D5W has no sodium or chloride
1/2 NS has some sodium and chloride
1/4 NS has even less sodium and chloride
Hypertonic Crystalloids
3% Saline
High sodium and chlroide
Isotonic Crystalloids
0.9% saline or NS
Has sodium and chloride
AE of Lactated Ringers
Hyponatremia
Hyperkalemia
Lactate –> bicarbonate (lactate will accumulate in liver disease)
D5W Uses
Uncomplicated dehydration or water deprivation
Dextrose is rapidly taken up by cells leaving free water
D5W AE
Hyponatremia