What is shock?
- A syndrome
- Characterised by tissue ischemia from decreased perfusion and impaired cellular metabolism
- Causes imbalance between supply and demand for 02 and nutrients to tissues
What is cardiogenic shock (systolic)?
caused by ventricular ischaemia, structural problems or arrhythmias -> systoiloc dysfunction, lowering stroke volume, and decreasing cardiac output.
This decreases oxygen supply, lowering tissue perfusion and impaired cellular metabolism.
What is cardiogenic shock?
Damage to the heart that decreases the blood flow to the body. Can be caused by damage to heart muscles, irregular heart rhythm, or very slow heart rhythm
What is cardiogenic shock (diastolic)?
Ineffective filling causing lowered stroke volume, and decreasing cardiac output - > pulmonary oedema and decreased oxygenation.
- These changes decrease cellular oxygen supply, lowering tissue perfusion and causing impaired cellular metabolism
S/S of cardiogenic shock?
- Tachycardia, decreased BP, decreased capillary refill, chest pain
- Tachypnoea, crackles, cyanosis,
- Increased Na and h20 retention, decreased renal blood flow, decreased urine output
- Pallor, cool clammy
- Decreased cerebral perfusion – anxiety, confusion, agitation
- Decreased bowel sounds, nausea, vomiting
- Increased cardiac markers, increased BGL,
What is hypovolaemic shock?
Occurs when there inst enough blood in the blood vessels to carry oxygen to the organs. This can be caused by severe blood loss
-> causes decreased circulating volume and stroke volume.
This decreased cardiac output, decreasing cellular oxygen supply and then decreasing tissue perfusion, ultimately causing impaired cellular metabolism.
S/S of hypovolemic shock?
- Decreased preload, decreased stroke volume, decreased capillary refill
- Tachypnoea causing bradypnoea (late)
- Decreased urine output
- Pallor, cool clammy
- Decreased cerebral perfusion – anxiety, confusion, agitation
- Absent bowel sounds
- Decreased haematocrit, decreased haemoglobin,
What is neurogenic shock?
Caused by damage to the CNS,-> lowering the heart rate and cardiac output.
- also causes vasodilation (warm skin), causing decreased venous return, decreasing stroke volume and also lowering cardiac output.
This decreased cellular oxygen supply, lowering tissue perfusion and causing impaired cellular metabolism
S/S of neurogenic shock?
- Bradycardia, hypotension
- Dysfunction related to level of injury
- Bladder dysfunction
- Initially warm due to massive dilation, later cool dependent on room temperature
- Decreased cerebral perfusion – anxiety, confusion, agitation
- Absent bowel sounds
What is anaphylactic shock?
Sereve allergic reaction that triggers a dangerous immune response with histamine causing vasodilation. - cause maldistribution of blood, lowering venous return, decreasing cardiac output, then decreasing tissue perfusion, then decreasing BP, and causes LOC.
- Vasodialation causes increased capillary permeability which causes cell fluid to shift causing oedema, then inflammation, causing decreased oxygen and a LOC.
S/S of anaphylactic shock?
- Chest pain, third spacing of fluid
- Shortness of breath, oedema, wheezing, stridor, rhinitis
- Incontinence
- Flushing, pruritus, urticaria,
- Anxiety, feeling of impending doom, confusion, decreased LOC, metallic taste
- Cramping, abdominal pain, nausea, vomiting, diarrhoea
What is septic shock?
Infections that lead to bacteria entering the blood stream-> damage to endothelial lining, causes release of tumour necrosis factors, and cytokines. This causes myocardial depression and cells to increase capillary membrane. This causes maldistribution of circulating blood volume, decreasing cellular oxygen supply, decreasing tissue perfusion and impairing cellular metabolism
What is obstructive shock?
Caused when there is an interruption to blood flow. Causes include a build up of air or fluid in the chest cavity, pneumothorax, haemothorax, and cardiac temponade
-causes decreased venous return, lowering stroke volume, then lowering cardiac output,. This lowers cellular oxygen supply, lowering tissue perfusion and impaired cellular metabolism
What is MDT care for shock?
high flow oxygen, have intravenous (IV) access secured, and have basic monitoring instituted (non-invasive blood pressure, pulse oximetry, and continuous ECG).
Treat underlying cause
If anaphylactic shock is suspected (rash, wheeze, allergen exposure), then fluid therapy is appropriate along with intramuscular adrenaline (epinephrine). Similarly, if septic shock is suspected (petechial rash, high fever, presence of infective source, rigid abdomen), then fluids should be given.
What are the stages of shock?
- Initial stage
- Compensatory stage
- Progressive stage
- Refractory or Irreversible Stage
What are changes in the respiratory system due to shock?
- Respirations in acute setting should be counted for 1
minute when patient has rested (Note increased work of breathing, use of accessory
muscles, lung expansion, colour of patient)
Problems highlight: - Need to ↑O2, ↓Co2, important role in regulation of acid-base balance,
- Acidosis or alkalosis
- CNS
What are changes in heart rate due to shock?
- If deteriorated central pulse may be required (Pulse estimations must NEVER be taken from pulse oximeter)
- Tachycardia usually occurs in response to compensatory mechanism (Tachycardia is a later sign than changes in respiration and changes may be subtle first)
What are changes in LOC due to shock?
AVPU- if unconscious consider ABC (AIRWAY)
Diagnostic vitals that indicate shock
Heart rate > 100
Respiratory rate > 22
Hypotension (systolic blood pressure < 90 mm Hg) or a 30-mm Hg fall in baseline blood pressure
Urine output < 0.5 mL/kg/hour
What is pneumothorax?
collapsed lung
What is hemothorax?
blood collects in the space between the chest wall and lung
What is cardiac temponade?
blood or fluids fill the space between the sac that surrounds the heart and the heart muscle
Interventions for obstructed airway when patient is unconscious
Head tilt, jaw thrust
- commonly caused by the patient’s tongue blocking the airways
Oropharyngeal airways
inserted into the mouth so long duration of jaw thrust doesnt need to happen. Keeps the tongue from obstructing the airway
