Shock Flashcards
(40 cards)
What are the cellular effects of shock?
- cell membrane ion pump dysfunction
- intracellular edema
- leakage of intracellular contents into the extracellular space
- inadequate regulation of intracellular pH
Systemic effects of shock?
- alterations in the serum pH and endothelial dysfunction
- stimulation and release of pro- and anti-inflammatory mediators
What are the general signs/clinical presentation of shock?
LOW BP
DECREASED URINE OUTPUT
ALTERED MENTAL STATUS
(these signs may not always be present)
What are the 4 main types of shock?
- Hypovolemic shock
- Cardiogenic shock
- Distributive shock
- Obstructive shock
What are the stages of shock?
Shock begins with an inciting event, such as a focus of infection (i.e. abscess) or an injury (i.e. gunshot wound)
This may progress through:
pre-shock
shock
end-organ dysfunction that can culminate in irreversible end-organ damage and death
What is pre-shock?
Pre-shock, also referred to as warm shock or compensated shock, is characterized by rapid compensation of diminished tissue perfusion by various homeostatic mechanisms.
Compensatory mechanisms during pre-shock allow an otherwise healthy adult to be asymptomatic despite up to a 10 percent reduction in total effective arterial blood volume.
What are the early signs and symptoms of shock?
As a patient passes through the pre-shock stage, the compensatory mechanisms become overwhelmed and signs and symptoms of organ dysfunction will begin appear.
Such signs and symptoms include but not limited to: hypotension, tachycardia, dyspnea, mental confusion, restlessness, diaphoresis and cool, clammy skin.
What are the later signs and symptoms of shock?
Even with appropriate, aggressive treatment intervention, the patient may progress to later stages of shock, signs and symptoms of which include:
Dropping or unobtainable blood pressure, a rapid, thready pulse, dusky discoloration of skin, skin is cool or cold to the touch, irregular, gasping respirations and decreased level of consciousness with eventual unresponsiveness.
What is Hypovolemic shock?
Loss of blood: examples include trauma with either external or internal bleeding - may be referred to as hemorrhagic shock.
External loss of fluids: examples include vomiting, diarrhea, burns and severe exfoliative dermatitis (i.e. SJS and TSS).
Internal loss of fluids (“third spacing”): examples include ascites and pancreatitis.
Hypovolemic shock symptoms?
Loss of effective circulating blood volume leads to the patient having:
A rapid, weak, thready pulse due to decreased blood flow combined with tachycardia.
Rapid and shallow breathing due to sympathetic nervous system stimulation and acidosis.
What are some causes of Hemostasis?
Bleeding may be spontaneous, excessive, or delayed in onset following tissue injury.
When bleeding appears excessive it may be due to multiple risk factors such as:
Disorders involving vascular integrity
Disorders of platelet number and/or function
Disorders of coagulation factors
Medications
Common cause of hemostasis?
One of the more common causes of increased bleeding is due to the patient’s use of non-steroidal anti-inflammatory drugs.
NSAIDs inhibit the aggregation of platelets, thereby increasing the risk of bleeding.
The effect of aspirin is irreversible; therefore, the inhibitory effect of aspirin is present until the affected platelets have been replaced.
What drugs inhibit platelet aggregation and increase hemostasis?
Ibuprofen (Motrin, Advil) and related drugs, are reversible inhibitors of the COX 1 and 2 enzymes.***
Platelets exposed to the drug are able to resume their pre-medication level of aggregation with 48 to 72 hours of discontinuing the drug.
What medication can cause increased bleeding by inhibiting vitamin k?
In addition to bleeding that is exacerbated by NSAID use, another cause of medication-related bleeding is due to Warfarin (Coumadin).
Coumadin needs to be closely monitored as the bleeding risk can be markedly increased by interactions with other medications.
Warfarin acts by inhibiting the production of Vitamin K in the gut.
What clotting factors require vitamin k?
Vitamin K is required for the production of the clotting factors, II, VII, IX, and X.
One of the more common causes of Warfarin-related bleeding is the concurrent use of antibiotics as the number of vitamin K producing gut bacteria can be significantly reduced.
What is shock index?***
The shock index is the patient’s heart rate divided by the pt’s systolic blood pressure.
SI has been shown to be a stronger predictor of the impact of blood loss than either the heart rate and blood pressure alone.
The shock index has been used to better risk stratify patients for increasing transfusion requirements and for mortality.
What are the shock index values?
Normal SI = 0.5 - 0.7
SI > 0.9 then approach the patient as though they are actively bleeding.
SI > 0.9 predicts twice the risk of massive transfusion.
SI > 1.1predictsfour times the risk of massive transfusion.
SI > 1.3predictsnine times the risk of massive transfusion.
Don’t rule out a bleed if SI is WNL.
What does the “scale of hemorrhagic shock” measure?
A grading scale has been created to approximate the effective loss of blood volume in patients with hemorrhagic shock.
The severity of hemorrhagic shock is graded on a scale of 1 to 4.
The grading scale is based upon physical exam findings.
What percent of patient blood volume indicates Class I hemorrhage?
Class I hemorrhage involves 1 to 15% of the patient’s blood volume.
There is typically no change in the patient’s vital signs.
Fluid resuscitation is not usually necessary.
What percent of patient blood volume indicates Class II hemorrhage?
Class II hemorrhage involves approximately 15 to 30% of the patient’s total blood volume.
A patient is often tachycardic with a narrowing of the difference between the systolic and diastolic blood pressures.
In class II hemorrhage, the body attempts to compensate for decreasing circulatory blood volume with peripheral vasoconstriction.
With class II hemorrhage, the skin may look pale and be cool to the touch.
Volume resuscitation with crystalloids such as hypertonic saline solution or lactated Ringer’s solution is generally required.
If the source of blood loss has been adequately treated than a blood transfusion is generally not required.
What is Lived reticularis?
Livedo reticularis is a common skin finding consisting of a mottled reticulated vascular pattern that appears as a lace-like purplish discoloration of the skin. The discoloration is caused by swelling of the venules owing to obstruction of capillaries by small blood clots. This condition may be normal or related to more severe underlying pathology. Its differential diagnosis is broadly divided into possible blood diseases, autoimmune diseases, cardiovascular diseases, cancers and endocrine disorders. It may be aggravated by exposure to cold, and occurs most often in the lower extremities. The condition’s name derives from the Latin livere meaning bluish and reticular which refers to the net-like appearance
What percent of patient blood volume indicates Class III hemorrhage?
Class III hemorrhage involves the loss of approximately 30 to 40% of the patient’s circulating blood volume.
Blood pressure drops, heart rate increases, peripheral hypoperfusion increases and mental status worsens with altering level of consciousness.
Fluid resuscitation with crystalloid fluids and blood transfusion is usually necessary.
What percent of patient blood volume indicates Class IV hemorrhage?
Class IV hemorrhage involves the loss of >40% of the patient’s circulating blood volume.
The limit of the body’s compensation is reached and aggressive resuscitation is required in order to prevent death.
What do you do when someone is going into Hemorrhagic shock due to trauma?
Establish a patent and protected airway while protecting the cervical spine
Maximize oxygenation
Gain intravenous access and initiate fluid resuscitation
Control hemorrhage
Monitor level of consciousness and reassess V/S at least every 3 - 5 minutes.
Controlling hemorrhage as much as possible.
Must maintain pressure to bleeding site(s), especially if dealing with an arterial bleed.
Elevate lower extremities and maintain a head‑low position unless contraindicated, as in severe facial or scalp injuries and bleed.
Immobilize fractures as this lessens damage to soft tissues from splintered bone ends.
No food or drink.
