Hemorrhage

Question 1

Define Haemorrhage

Answer 1

Extravasation of blood from the vessels within the circulatory system

May be external or internal (Haematoma : the escape of blood from the circulatory system into the surrounding tissue )

Haemorrhage may occur in cavaties 
*Hemothorax 
*Hemoperiteneum 
*Hemooericardium 
hemomarthrosis

Question 2

Classify hemorrhage in skin and mucous membrane

Answer 2

• Accumulation of blood within the tissues is termed hematoma
• Hematoma may be an insignificant bruising or a sufficiently large to be fatal eg retroperitoneal hematoma from ruptured aortic aneurysm

Classifications of skin hemorrhages
*Petechiae : 1-2 mm pinpoint bleeding into the skin ,mucous mm or serosal surfaces ,may be caused by locally increased intravascular pressure eg thrombocytopenia defective platelet function

Purpura : >3 mm ,above conditions as well (petechiae) ,trauma ,vascular inflammation ,vascular fragility

Esschymoses (bruises(1-2 cm )
Larger ,often trauma

Question 3

Briefly discuss causes of hemorrhage

Answer 3

1. Damahe to vessel from without
   *Trauma : surgical operation
   MVA

*Inflammation : Peptic ulcers diseases

2. Disease of the actual vessel wall
   * Congenital weakness : -berry aneurysm
   - Marfan disease

• Toxins from bacteria
• Meningococcal septicaemia
• Primary inflammation
• Polyarteritis nodosum
• Autoimmune
• Systemic lupus erythematosus
• Nutritional : Vit C
  3. Disease from within the vassel wall : hypertention

Question 4

Discuss the changes that occur after blood loss

Answer 4

In chronic external hemorhage or repeated small losses ,iron deficiency anemia eg peptic ulcer may occur

• When hemorrhage occurs within a body cavity or tissue ,iron is retained and it may be reused for hemoglobin synthesis
• Patients with extensive hemorrhage will develop jaundice as RBC are broken down to release bilirubin

Responses to blood loss

1. CNS
   * fall in blood pressure
   * Reduction in cerebral blood flow
   * loss of consciousness
2. CVS
   * decreased CO
   * Baroreceptors are simulated to trigger a response in vasomotor center in the brain
   * Vasoconstriction occurs t maintain BP
   * However coronary and cerebral vessels are not affected
3. Adrenal
   * Adrenal medulla will release NE and Epi to cause vasoconstriction and trachycardia
4. The kidneys
   * Diminished glomerular filtration rate
   * Activation of the renin-angiotensin -aldosterone - system
   - Sodium and water retention
   - vasoconstriction

• Anti-diuretic hormone is also secreted for increased H2O reabsorption and decreased water excretion

If he above mention mechanisms are not adequate ,the severe hemorrhage will result in hypovolemic shock

Question 5

Define shock

Answer 5

• A cardiovascular collapse
• Shock means hypoperfusion due to reduction in either CO or the effective virculating volume

*the end result is hypotention with impaired tissue perfusion and cellular hypoxia

Question 6

Write down types of shock

Answer 6

1. Cardiac shock
   * Result in myocardial pump failure ,CO and SV are low

Causes

• Intrinsic
• Massive myocardial infarct
• Ventricular arrhythmias
• Extrinsic
• Cardiac tamponade
• Outflow obstruction eg pulmonary embolism

2. Hypovolamic shock
   * Results from loss of blood or decrease in plasma volume

causes

• hemorrhage
• Trauma
• Severe burn

*Rapid treatment by fluids and transfusion reveres the low blood pressure and perfusion but the shock state may be irreversible if allowed to persist

3.Septic shock
Blood is pooled in the peripheral circulation

• Causes
• Overwhelming infection by gram neg bacilli release endotoxins / lipopolysaccharides ( peripheral vasodilation )
• Gram positive septicaemia
• Fungal sepsis

4. Neurogenic shock
   Occurs in the setting of anaesthetic accident or spinal accident or due to vascular toneand peripheral poolinng of blood
5. Anaphylactic shock
   * Initiated by generalized IgE mediated hypersensitivity response with systemic vasodilation and increased vascular permeability

Question 7

Describe the effects of shock on the following organs

Answer 7

Lungs
Seldom affected by pure hypovolaemic shock because they are resistant to hypoxic injury.
Red and heavy due to congestion and oedema
When shock occurs due to sepsis or trauma, diffuse alveolar damage is seen.
DAD marked pulmonary oedema
protein rich hyaline membranes-along
alveolar walls
may also result from other cause

Brain:
Ischaemic encephalopathy
Heart:
Fresh subendocardial haemorrhages usually in the left ventricle
Dark contraction band necrosis may be seen

Liver
Fatty change, central haemorrhagic necrosis.
Adrenal glands
Cortical cell lipid depletion as a stress response due to mobilisation of stored steroids .
Small areas of necrosis may be seen.
GIT
Haemorrhagic enteropathy – Mucosal haemorrhages and necrosis.

Question 8

Discuss the clinical features of shock

Answer 8

• pallor
• cold ,clammy skin(cold sweat)
• In septic shock - flushed ,warm skin
• Tachycardia : increased HR
• Tachypnoena : increased HR

*Low blood pressure

• Cyanosis
• oligueia