shock and fluid replacement Flashcards
what is homeostasis
an attempt to return things to normal
What is haemodynamic stability
a state where there is adequate tissue perfusion.
what is shock
when the body does not get enough blood flow so there is reduced tissue perfusion, making someone not be able to function properly.
how many people die from shock
1 in 5
what are the 4 stages of shock
- initial stage where the cells begin to be deprived of oxygen.
- compensation stage- where the body triggers different mechanisms to try and maintain tissue perfusion.
- progressive stage-where compensatory mechanisms start to fail with signs of inadequate tissue perfusion.
- decompensated stage- irreversible damage occuring where death is inevitable and imminent.
what are the causes of hypovolemic shock
haemorrhage, then burns, peritonitis and excessive diuresis (production of urine)
what is hypovolemic shock
when you lose more then 20% of your bodys blood or fluid supply.
when is cardiogenic shock associated with MI
when 40% or more of the myocardium is necrotic. carries a poor prognosis with hospital mortality of 70-90%
following an MI, what gives rise to cardiogenic shock?
partial papillary muscle rupture and ventricular septal defects (hole in heart).
what are the effects of gastro intestinal shock ?
mucosal ischemia, ileus (an obstruction in ileum) and gangrene (death of body tissue) of bowel can lead to perforation (rupturing) of the bowel with faecal contamination leading to peritonitis (inflammation of peritoneum).
what can stagnation of blood within capilliaries lead to
disseminated intravascular co-agulation (a condition in which blood clots form throughout the bodys small blood vessels)
what detects alterations in blood pressure
baro receptors stimulate the sympathetic nervous system in an attempt to restore the BP.
what will renal hypotension trigger
renin release which will stimulate the renin angiotensin aldosterone mechanism.
what does pulmonary hypoperfusion increase
pathological dead space and VQ mismatch (where perfusion and ventilation do not match).
is respiratory shock, why does the respiratory rate increase?
in attempt to compensate for anaerobic metabolism and resulting metabolic acidocis
what drug therapy will help manage respiratory shock
inotropic shock, diuretics, and sodium bicarbonate
when and why were IV fluids first used
in 1830s for treatment of fluid loss due to chlorea
whats the average requirement of IV fluid
1500mls per square metre of body area every 24hrs.
what are the 5 r’s
resucitation, routine maintenance, replacement, redistribution, reasessment
what do you give if a patient needs fluid resucitation
crystalloids that contain sodium in the range 130-154 mmol/l with a bolus of 500 ml over less then 15 minutes
what would you restrict the prescription to for a patient who needs routine maintenance
25-30ml/kg a day of water and
approximately 1mmol/kg a day of potassium, sodium and chloride
and approximately 50-100g a day of glucose to limit starvation ketosis (when the body uses fat as a reserve for energy instead of carbs).
how big are fluid compartments
as small as a cell or as large as a heart or blood vessel
what separates fluid compartments
a selectively permeable membrane
what is tonicity
used to describe the number of particles dissolved within a solution.
Isotonic means the number is the same as those within the cells.
Hypertonic means there are a greater number of particles then within the cells .
Hypotonic means that there are less particles then in the cells.
