Module 6.1-6.3 Flashcards
1
Q
What are the 4 pressures that determines fluid movement?
A
- Capillary Hydrostatic Pressure: force of blood in capillary pushing outwards into interstitium
- Interstitial Fluid Hydrostatic Pressure: force of fluid in interstitium pushing into capillary
- Capillary Osmotic Pressure: force exerted by proteins (albumin) pulling fluid into capillary
- Interstitial Fluid Osmotic Pressure: force exerted by proteins pulling fluid into interstitial space
2
Q
What is the equation for effective filtration pressure?
A
P(effective)= [CHP+IFOP] - [COP-IFHP]
3
Q
What is the effect of all four pressures?
A
- To move fluid out of capillary at arterial end and to suck fluid into capillary at venous end
- Excess fluid and proteins are collected by lymph. system and returned to venous circulation
4
Q
What is an oedema?
A
- 1+ body compartments become inundated with fluid
- CM. local area of swelling, inc. body weight, pain on area or impaired function
- Managed by leg elevation, compression stocking, albumin infusion if there is liver failure
- Diuretics
5
Q
What is intracellular oedema?
A
- Fluid accumulation in cells due to hypertonic cells or ineffective pumping of Na/K+ out of cells
6
Q
What are the bodily mechanisms of extracellular oedema?
A
- Hydrostatic pressure: force pushing plasma into interstitial space
- Oncotic pressure: osmotic pull exerted by plasma to draw fluid back to capillaries
- Lymphatic drainage: removes excess fluid and proteins from interstitial space
7
Q
What are the causes of EC. oedema?
A
- Inc. plasma leaving capillaries due to inflam. or inc. Hydrostatic pressure
- Dec. plasma returning to capillaries due to dec. oncotic pressure
- Dec, fluid drainage due to lymphatic obstruction or inc. tissue constituents
8
Q
What is hypovolemic shock?
A
- Loss of blood/plasma in circulation
- Causes can include inc. inflammatory response or peritonitis due to fluid shift out of space (third spacing), or dehydration
9
Q
WHat are CM of Hypovolemic shock?
A
- CM are thirst, agitation initally due to SNS stimulation, Pale skin, tachycardia and oliguria
- Vasoconstriction shunts blood from surface to vital areas affecting blood flow and causing lethargy
- Inc. hypoxaemia, respiratory alkalosis and metabolic acidosis progresses
10
Q
What is third spacing?
A
- Fluid shifting out of blood into a body cavity/tissue where it is no longer available as circulating, causing hypovolemia and fluid excess in interstitial space
- Caused by peritonitis, inflam/ infect. of peritoneal membranes, ascites or burns
11
Q
What is dehydration?
A
- Fluid intake falls below fluid output, affecting the intracellular compartment where most body water is located
- What can be shunted from EC compartment to compensate but can also cause hypovolaemia
12
Q
What is the purpose of sodium ions?
A
- To determine osmolarity of ECF
- To contribute to membrane potential of excitable cells
- Normal range is 135-145 mmol/L
13
Q
What is the purpose of Potassium ions?
A
- highly concentrated in IC compartment
- involved in IC ion balance, acid/base balance and muscle function
- Hypokalaemia is serums levels less than 2 mmol/L
- Hyperkalaemia is serum levels of K+ greater than 5 mmol/L, more easily excited muscles
14
Q
What is the purpose of Calcium ion?
A
- Blood coag, neurotransmission, muscle contraction, cardiac conduction and bone/teeth forming
- Hypocalcaemia is serum level’s below 2.25 mmol/L
- Hypercalcaemia is serum levels above 2.75 mmol/L
15
Q
What is the purpose of Chloride ions?
A
- Major EC anion with serum levels of 98/106 mmol/L, follow Na due to charge (high Na = high Cl)
- Assist in acid-base balance
- H2CO3 bind with metabolic acids so Cl ions diffuse out fo RBC into serum to maintain -ve ions in blood, or if Cl dec. HCO3 will leave erythrocytes to maintain neutrality (Cl- shift)
