Answer
Michael has been wounded by gunshot and has lost a lot of blood by external as we as by internal bleeding. The loss of blood has several consequences:
1. A decrease in blood volume, as well as decreases in the concentrations of plasma electrolytes.
2.The impairment of circulation caused by the bleeding also means that tissues are not being supplied with the normal amount of blood; consequently
they experience deficiencies in supplies of heat and oxygen.
3. One of the early symptoms of hypovolemic shock is unusual anxiety. As the blood loss approaches 25-30 % of normal volume for the patient,more
serious signs and symptoms appear. In this case Michael's blood pressure (BP) of 40 mm Hg is far below normal. Healthy blood pressure for a young male is about 120-122 mm Hg/79-82 mm Hg . His pulse/heart rate (HR) is given as 200 bpm; this means he is experiencing tachycardia, for his normal HR should be between 60 and 100 bpm.
The tachycardia is due to the frantic efforts of his heart to supply scarce blood to vital organs --it is working as fast as possible to distribute the reduced CO. But while it is beating faster, accelerated by sympathetic stimulation, it cannot generate normal pressure because of the fall in blood volume.
Michael is also described as being cool and clammy. He ss cool because the blood is the means by which heat is transferred around the body ; therefore, impaired blood supply is likely to result in cooling, especially of non-vital superficial structures. The clamminess secondary to profuse sweating (diaphoresis) is caused by response of epinephrine receptors in sweat glands . When the blood volume falls, BP also declines ; the response of the sympathetic system is to increase vasomotor tone to raise the BP. The attendant release of epinephrine into the blood stimulates epinephrine receptors of the sweat glands to increased activity.
The loss of fluid activates the renin-angiotensin system ; this leads to increased output of aldosterone by the adrenal cortex which enhances the retention of electrolytes and fluids. ADH is released from the posterior pituitary in response to a decrease of blood volume and circulating electrolytes. The combined effects of these mechanisms is that Michael is sufferin from anuria.
Work Step by Step
Hypovolemic shock is a medical emergency, and patients rapidly fall unconscious in the later stages. Michael should be rehydrated as soon as possible. Hydration is usually done by giving intravenous (IV) saline (plain or with colloids). In severe cases it is necessary to administer IV plasma ; sometime platelets must be added, dependent on how severe was the blood loss and how extensive the loss of platelets.
