MEDI7212 Lecture Notes - Lecture 24: Vasodilation, Water–Electrolyte Imbalance, Hypocalcaemia
Document Summary
Local site complications: extravasation, phlebitis/ thrombophlebitis, haematoma. Crystalloid (iv fluid: most common, types - isotonic, hypotonic, hypertonic. Iv fluids containing small salts & lmw substances that pass cell membranes: hypertonic - draw fluid from cell/ interstitium -> intravascular compartment, hypotonic - draw fluid from intravascular compartment -> cell/ interstitium. Isotonic - remain in intravascular space & expand intravascular compartment: note: difference between tonicity vs osmolarity, osmolarity takes into account penetrating + non-penetrating substances, tonicity only takes into account non-penetrating substances, note: Isosmotic - same oncotic pressure as blood in humans. Isotonic - same na concentration as normal cells in body and blood: moa, transfer from bloodstream (intravascular) -> cells & body tissues (interstitial space) Larger volumes of crystalloid > colloids required for fluid resuscitation. Isotonic: 150mmol/l na + 150mmol/l cl (0. 9% weight, ph ~6, cheap, widely available, use, hypovolemia (+250ml iv volume/ 1000ml added)
