hypovolemic shock and haemothorax

Hypovolemic shock

-acute circulatory failure with inadequate or inappropriately distributed tissue perfusion resulting in generalized cellular hypoxia due to loss of circulatory volume.

Complications
Inadequate tissue perfusion:
a) skin- cold, pale, blue, slow capillary refill, clammy (peripheral cyanosis)
b) kidneys- oliguria, anuria (Oliguria is defined as a urine output that is less than 1 mL/kg/h in infants, less than 0.5 mL/kg/h in children, and less than 400 mL/day in adults. Anuria is defined as absent production of urine)
c) brain- drowsiness, confusion and irritability
d) multi organ failure due to lack of perfusion to organs

Increased sympathetic tone:
a) tachycardia, narrowed pulse pressure, “weak” or “thready” pulse
b) cold and clammy
c) blood pressure- maybe maintained initially but later hypotension will occur

Metabolic acidosis- anaerobic glycolysis occur within tissues to lack of oxygen


Haemothorax

A haemothorax is a condition that results from blood accumulating in the pleural cavity. Its cause is usually traumatic, from a blunt or penetrating injury to the thorax, resulting in a rupture of either of the serous membrane lining the thorax and covering the lungs. This rupture allows blood to spill into the pleural space, equalizing the pressures between it and the lungs. Blood loss may be massive in people with these conditions, as each side of the thorax can hold 30%-40% of a person's blood volume. If left untreated, the condition can progress to a point where the blood accumulation begins to put pressure on the mediastinum and the trachea, effectively limiting the amount of diastolic filling of the ventricles and deviating the trachea to the unaffected side.

Same pressure between pleural cavity and atmosphere means that there is no pressure gradient. Thus air does not enter or leave the lungs. There is no ventilation of the alveoli hence blood flowing through the capillaries do not get adequately oxygenated. This will result in hypoxia and infarct of tissues.
abnormal fast breathing
Dyspnoea.
Cyanosis.
Decreased or absent breath sounds on affected side.
Tracheal deviation.
Dull resonance on percussion.
Unequal chest rise.
Tachycardia.
Hypotension.
Pale, cool, clammy skin.
Possibly subcutaneous air
Narrowing pulse pressure