Ward Round Notes

Basic concepts Matter: anything which has mass and occupies space Atoms: the smallest chemical unit, indivisible by chemical means Elements: 1 type of atom which may or may not be bonded.  Compounds: Substances made from different types of atoms bonded Molecule: A covalently bonded unit.  Pure substances: A single type of compound or element Mixtures: 2 or more different types of compounds and/or elements, separable by physical means. Isotopes: Different types of atoms with the same number of protons but different number of neutrons. Isotopes may be radioactive.  1.1.1 Apply the mole concept to substances 1.1.2 Determine the number of particles and the amount of substance in moles. 

Definition: Accumulation of fluid in the pericarial space leading to restriction of the heart's pumping action and reduced cardiac output which may lead to hypoperfusion and failure of other organs. Different to cardiac effusion which is an umbrella term for a fluid collection in the pericardial space with or without haemodynamic compromise.  Pathophysiology A cardiac tamponade is caused by an increase in the pressure in the pericardial sac. The pericardial sac usually has a level of compliance (stretch) and therefore an increase in fluids in this space initially has little effect on the pressure. It is only when the sac has reached the limit of it's stretch that the pressure increases. The compliance of the pericardial sac can also be increased in a chronic effusion and as much of 2000mls of fluid can be present before it causes a tamponade. Compliance can also be reduced by some disease states.