Fluids and Anaphylaxis Flashcards
Why are children more at risk of hypothermia than adults?
Larger % body water. Water has a high specific heat capacity therefore it takes longer for a hypothermic child to readjust to their optimum body temperature because more water has to heat up.
Describe the fluid compartments of the human body
60% of our body is water
Intercellular fluid - 40%
Extra cellular fluid- 20% (interstitial fluid>plasma)
What is osmosis ?
Net diffusion of water across a semipermeable membrane from an area of high water contraction to low water concentration (low solute concentration to high solute concentration)
What is osmolarity ? What is the difference in units in osmolarity and osmolality ?
Osmolarity is the total solute concentration of a solution . Osmolarity is measured in kg whereas osmolality is measured in mols
What is hydrostatic pressure?
The pressure exertion by a fluid
What is oncotic pressure?
Oncotic pressure is a type of osmotic pressure that is generated by plasma proteins preventing the net diffusion of water from an area of high water concentration to low water concentration.
What is an isotonic solution?
Solution that contains the same number of non penetrating solute molecules as those in extra cellular fluid
What is a hypertonic solution?
Solution that contains more non penetrating solute particles than normal extracellular fluid
What is a hypotonic solution?
Solution that contains fewer non penetrating solute particles than normal extracellular fluid
List 5 things that can alter fluid distribution in the human body?
ADH, aldosterone , ANP, oestrogen, progesterone, glucocorticoids
+ baroreceptors
What is starlings equation (in relation to fluid)?
The net direction of fluid across vasculature as a result of the hydrostatic and oncotic pressure acting against ex
What is the metabolic consequence of rapid saline 0.9% infusions?
Hypercholaemic metabolic acidosis.
Strong ion theory. A strong ion is one that dissociates straight away when in water. NA+ and Cl- are both strong ions in this sense.
Strong ion difference (SID) affects pH with a decrease in SID reducing the pH. The difference between NA+ and Cl- dissociation dictates pH. Increase in Cl- relative to NA+ increases the dissociation of water, increasing the number of H+ ions resulting in a metabolic acidosis as the SID decreases.
What type of shock is anaphylaxis? What is the definition of this shock?
Distributive shock . Low systemic vascular resistance secondary to the release of vasodilators
What is the definition of shock ?
Acute circulatory failure resulting in inadequate/inappropriate tissue perfusion which leads to decreased delivery of oxygen to tissues
Explain the pathophysiology of anaphylaxis
Genetically predisposed individual exposed to allergen ‘sensitisation’
APC T helper stimulate memory B cells which result in B cell production of IgE.
IgE circulate the body and bind to mast cells. When the person is exposed to the allergen for the second time, the allergen binds to the IgE antibody on the mast cell causing the release of histamine and other inflammatory markers.
This exact process also occurs in basophils