Problem A patient has the following volumes of distribution
Problem:
A patient has the following volumes of distribution:
deuterium oxide: 42 liters
inulin: 13 liters
Evans blue: 2.8 liters
Her plasma shows a freezing point depression of 0.55 degrees C. For an ideal solution, a 1 OsM solution depresses the freezing point 1.86 degrees C.
1. What is the osmolarity of her body fluids? --> 0.295
2. How much solute (osmoles) exists in each of the above compartments?
Using the data above as the initial conditions in each case, determine the effects of the following procedures on the water and solute in the ECF and ICF after equilibrium has occurred. You should be able to give the numerical values for volume and osmolarity of the ECF and ICF. Briefly explain your rationale for solving each problem. (Treat each solution below as a separate problem; do not make them additive.)
Use #2 as a starting chart for the rest of the problems. Go back to #2 as a start chart for #3-8 (each question is an independent scenario; do not make them additive).
3. Patient ingests 1 L of water, which is absorbed totally from the digestive tract.
1. Osmolarity of body fluids --> 0.295
2.
Total
ECF
ICF
Plasma
Vol L
Sol osmol
mOsM
3.
Total
ECF
ICF
Vol L
Sol osmol
mOsM
Explanation:
| Total | ECF | ICF | Plasma | |
| Vol L | ||||
| Sol osmol | ||||
| mOsM | 
Solution
dueterium oxide=total body water, inulin=ECF, evans blue is plasma volume, ICF=total volume-ECF
osmolarity=0.295, osmolarity=osmoles of solute/volume, mOsM -osmoles
2.
3. Water when absorbed from the digestive tract, is distributed proportionately across all the compartments. it enters the vascular system and interstitial cells and gets transported to each cell. There is no redistribution of any non-penetrating solutes i.e, no osmotic gradient is created as water does not have any solutes, so ECF does not change as there is no change in osmolarity.
Sol
osmol
| ECF | ICF | Plasma | ||
| Total | ||||
| Vol L | 42 | 13 | 29 | 2.8 | 
| Sol osmol | 0.295 | 0.295 | 0.295 | 0.295 | 
| mOsM | 12.39 | 3.835 | 8.555 | 0.826 | 


