Shock Flashcards
Shock is BROADLY DEFINED AS
AN IMBALANCE BETWEEN OXYGEN DELIVERY TO TISSUES AND OXYGEN CONSUMPTION BY THE TISSUES.
Shock is Most commonly classified by hemodynamic effects (circulatory) aka…? (4)
Hypovolemic
Cardiogenic
Distributive
Obstructive
Note that Multiple types can co-exist.
Several clinical stages of shock are recognized - based on the extent of physiological compensation.
Shock is sometimes also classified based on non-circulatory causes or effects aka..?
hypoxic and metabolic
Note that Multiple types can co-exist.
Several clinical stages of shock are recognized - based on the extent of physiological compensation.
Describe obstructive shock.
Obstructive shock is a type of shock that occurs when there is a physical obstruction in the circulatory system that impedes blood flow.
This obstruction can prevent the heart from effectively pumping blood, leading to inadequate perfusion of tissues and organs.
Common causes may be pericardial effusion, pulmonary embolism, cardiac tamponade or tension pneumothorax.
Describe distributive shock.
Distributive shock is a type of shock characterized by widespread vasodilation, which results in a significant drop in systemic vascular resistance and inadequate tissue perfusion despite an adequate or increased cardiac output.
In this condition, blood vessels are dilated excessively, leading to a relative hypovolemia and poor distribution of blood flow.
Common causes may be septic shock with release of inflammatory mediators, anaphylactic, neurogenic and endocrinologic shocks.
Describe cardiogenic shock.
Cardiogenic shock occurs when the heart is unable to pump sufficient blood to meet the body’s needs, despite adequate blood volume. This results in decreased cardiac output and poor tissue perfusion.
Common causes include myocardial infarction, end-stage cardiomyopathy, valve dysfunction, arrhythmias etc.
Describe hypovolemic shock.
Hypovolemic shock occurs when there is a significant loss of blood or fluids from the body, leading to a decreased blood volume.
This reduction in blood volume impairs the heart’s ability to pump effectively and reduces tissue perfusion, which can result in organ failure.
Common causes include internal or external fluid loss leading to organ failure.
List all the types of shock, both circulatory and non. (6)
hypovolemic (most common)
cardiogenic
obstructive
distributive
hypoxic
metabolic
causes of hypovolemic shock can be divided into..?
hemorrhagic and non-hemorrhagic
both of the above are further divided into internal vs external
Stages of shock can be broadly defined as
mild (compensatory)
moderate
severe (decompensatory)
Causes of external non-hemorrhagic hypovolemic shock? (6)
urine, vomitus, diarrhea, excessive salivation, burns, metabolic such as diabetes insipidus or DKA (excessive osmotic diuresis)
Decreased fluid intake could be due to..?
unable to drink
uninterested in drinking
Distributive shock is caused by..?
Give examples.
Maldistribution of blood flow
Vasodilatation
for example
- SIRS- systemic inflammatory response syndrome
- Infectious and non-infectious causes
Trauma
Pancreatitis
Burns …… - Sepsis
- Anaphylactic shock
Typical clinical signs of distributive shock. (4)
tachycardia in dogs but bradycardia in cats
mm hyperemic in dogs, mm pale in cats
CRT <1s in dogs, variable in cats
temp high in dogs, low in cats
Criteria for diagnosis of SIRS.
Systemic inflammatory response syndrome
Required: Presence of inflammatory foci + 2 or more criteria for dogs, and 3 or more in cats.
HR elevated in dogs, HR elevated OR decreased in cats
RR increased in both
Obstructive shock is caused by?
Give examples.
Physical obstruction to blood flow
To or from the heart or great blood vessels
May be accompanied by cardiogenic shock.
Common causes:
GDV (obstructive as well as hypovolemic and distributive)
Pericardial tamponade
Dirofilariasis
Pulmonary or aortic thromboembolism
Tension pneumothorax (air accumulates in the pleural space, collapses the lung, can also compress the heart and major blood vessels, leading to reduced venous return and impaired cardiac output.)
Cardiogenic shock occurs when..?
Also give examples.
cardiac output is reduced.
Causes:
Cardiac diseases
Arrhythmias
Valvular insufficiencies etc.
Prognosis guarded. Treatment is aimed at increasing cardiac output.
Non-circulatory types of shock.
Describe hypoxic shock:
Give examples.
Decreased oxygen content in the arterial blood.
Causes:
Anemia (e.g.IMHA)
Aspiration pneumonia
Lung contusion
Carbon monoxide poisoning
Paracetamol toxicosis
Non-circulatory types of shock.
Describe metabolic shock:
Give examples.
Reduced cellular aerobic metabolism.
Causes :
Severe hypoglycemia
Sepsis
Cyanide toxicity
Subcutaneous emphysema is
the de novo generation or infiltration of air underneath the dermal layers of skin. The development of subcutaneous air may be a benign symptom or an indication of a deeper, more concerning pathologic disease state.
triage subcut emphysema
Orange = very urgent, potentially life-threatening
triage presenting fetal parts
Red = immediate care needed, life-threatening
triage hyperglycemia with ketosis
this is Diabetic Ketoacidosis (DKA)
often arises from a combination of high blood sugar and a complete lack of insulin in the body. When the body’s cells are starved of energy from glucose, they start burning fat, resulting in acidic ketones that spill over into your blood and urine.
orange: very urgent, potentially life threatening
triage mild respiratory distress
Yellow = urgent but not life-threatening
triage recent isolated seizure
Green = non-emergent
formula for correcting dehydration?
body weight * dehydration % x 10
OR
body weight * dehydration percentage as a decimal point x 1000
Example:
8 * 8 x10 = 640 ml
8 * 0.08 x 1000 = 640 ml
Fluid Daily requirement; rule of thumb:
dogs
cats
Dogs: 2-6ml/kg/h
Cats: 2-3ml/kg/h
Normal potassium in blood is
3,5-5,5mmol/l
1 mEq/L= 1mmol/L
Do not exceed 0,5 mEq (mmol)/kg/h when supplementing.
How much should you supplement potassium in case hypokalemic at 3.2 mmol/L?
25-30 mEq KCL in 1L fluids so 15 ml KCL in 500 ml fluids
1 mEq/L= 1mmol/L
Do not exceed 0,5 mEq (mmol)/kg/h when supplementing.
Make a 5% GLU solution from a 40% GLU solution into 500 ml of fluids.
conc. of glu solution you want * volume of isotonic fluid / conc. of glu solution you have = X (volume to add)
5% * 500 ml / 40% = add 62.5 ml of 40% GLU solution to (500 ml - 62.5 ml) 437.5 ml isotonic fluid
explain B-lines
“wet lung” Ultrasound Appearance, B-lines are observed. These are vertical, laser-like, comet-tail artifacts that arise from the pleural line and extend all the way to the bottom of the ultrasound screen. B-lines move with respiration and represent the presence of fluid in the lung.
An occasional B-line is considered normal; excessive B-lines are indicative of interstitial-alveolar lung abnormality.
why might a shock patient have hypoalbuminemia?
hyperglycemia?
concurrent enteropathy
stress/shock induced hyperglycemia
what is glide sign on T-FAST?
The glide sign refers to the appearance of the pleural line (the line between the parietal and visceral pleura) moving or shimmering on ultrasound with each breath.
This movement is caused by the two layers of pleura sliding against each other as the lung inflates and deflates.
Presence of the glide sign: This suggests normal lung function and the absence of pneumothorax. The sliding movement indicates that the visceral and parietal pleura are in contact, meaning the lung is inflated.
Absence of the glide sign: If no movement is seen at the pleural line (no sliding), this is highly suggestive of a pneumothorax. In pneumothorax, air has entered the pleural space, separating the two layers of pleura, and the lung cannot slide against the chest wall.
Why should you check glucose from pyothorax exudate against peripheral blood glu value?
By comparing glucose level in the exudate to blood glucose, clinicians can better differentiate between the types of exudative effusions.
For example:
Low pleural glucose (<60 mg/dL) (or less than 50% of blood glucose) is a common finding in pleural infections (empyema) & can indicate bacterial infections (e.g., pyothorax/empyema).
Normal pleural glucose despite an exudative effusion may point toward other non-infectious causes (e.g., malignancy without significant infection).
