Intravenous solutions
Isotonic — NaCl 0.9 %, lactated Ringer's: expand the intravascular space. Hypovolemia, shock, blood administration. Watch for fluid overload. Hypotonic — NaCl 0.45 %, D5W once metabolized: move water into the cell. Cellular dehydration. Never in raised intracranial pressure or in burns. Hypertonic — NaCl 3 %, D10W, D5 in NaCl 0.9 %: pull water out of the cell. Severe hyponatremia, cerebral edema. Slow administration, central line often required, close monitoring. Lactated Ringer's is avoided in liver failure and in hyperkalemia because it contains potassium.