Shock, stabilisation & venous access Flashcards
Define collapse
A sudden loss of postural tone sometimes accompanied with L.O.C
What is the basic definition of syncope?
Transient loss of consciousness due to global cerebral hypoperfusion caused by an acute drop in systemic BP.
What are the three classifications of syncope? What are some examples of what causes each?
- Cardiac: bradyarrhythmia (SSS, 2/3 AVB, A Standstill), tachyarrhythmia (AFib, vtach, atach), Structural (Thrombosis, stenosis, AV valve disease, DCM)
- Reflex-mediated: neurocardiogenic (stress, fear, pain), situational (excitement, increased activity, coughing, vomiting, defecating), carotid sinus hypersensitivity (baroreceptor dysfunction [fainting collie, genetic mutation], cervical neoplasia)
- Orthostatic: drug-induced hypotension, volume depletion
How does to BJ Reflex said to cause syncope?
A drop in BP (‘perceived’ hypovolaemia) is sensed by baroreceptors in the carotid sinus, which augments activity of the efferent sympathetic fibers causing increased heart rate, increased contractility and vasoconstriction. This leads to an underfilled ventricle which causes stimulation of the mechanoreceptors in the ventricular wall to send impulses via afferent C-fibers to the medulla oblongata (brain). There is then sudden withdrawal of sympathetic tone and increased vagal tone resulting in paradoxical bradycardia, hypotension, reduced contractility causing syncope.
What is the typical length of a syncopal event and how may it differ from a seizure?
Seconds to minutes. Usually patients completely recover whereas seizure patients may be mentally inappropriate and take some time to return to normal.
What monitoring/diagnostics are involved in the work up of the collapsed patient?
- BP
- ECG
- Holter study
- Echocardiogram
- Neurological exam
- Biochemistry
- T4
- Cardiac enzymes
- CBC
When does shock occur?
When tissue oxygenation consumption (VO2) exceeds tissue oxygen delivery (DO2). Thus there is inadequate oxygenation and anaerobic metabolism.
Activation of the renin-angiotensin-aldosterone system occurs in response to:
a. volume overload
b. decreased baroreceptor firing
c. respiratory distress
d. kidney failure
b.
In a giant-breed dog suffering from hypotension and hypovolemic shock, which of the following fluids will provide the fastest physiological response in the patient to increase intravascular volume?
a. Hypertonic saline
b. Lactated Ringer’s solution
c. Synthetic colloid
d. Packed red blood cells
a.
This test is used to determine platelet function.
a. Platelet estimate
b. PT
c. aPTT
d. BMBT
d.
How is hypoxia defined?
a. When metabolic demand is less than oxygen delivery
b. When metabolic demand exceeds oxygen delivery
c. When partial pressure of oxygen and oxygen saturation are equal
d. When partial pressure of oxygen and oxygen saturation are unequal
b.
Which answer best describes cardiogenic shock?
a. A physical obstruction in the circulatory system
b. Decreased intravascular volume
c. Inability of the heart to maintain a normal cardiac output
d. Frequently associated with decreased systemic vascular resistance
c.
Which of the following is not a cause of type B hyperlactatemia?
a. Systemic disease
b. Toxicity
c. Inherited disease
d. Poor perfusion
d.
Which of the following is not associated with volume overload?
a. Pulmonary edema
b. Chemosis
c. Decreased skin turgor
d. Increase in respiratory rate or effort
c.
A patient has a heart rate of 150^bpm and a systolic blood pressure of 90^mmHg. Calculate the patient’s shock index.
a. 60
b. 13^500
c. 0.6
d. 1.6
d.
Nasal oxygen flow rates via a cannula should be:
a. 50–150^mL/kg/min
b. 50–150^ml/kg/h
c. always 1–2^L/min
d. 200–500^mL/kg/min
a.
Which of the following does not contribute to delivery of oxygen to tissue?
a. Blood pressure
b. Cardiac output
c. Hemoglobin
d. PaO2
a.
Solutions of greater than how many milliosmoles should only be given through a central venous catheter?
a. 300^mOSm
b. 450^mOSm
c. 600^mOSm
d. 750^mOSm
c.
Which catheter type and length should have the most maximal flow?
a. 18 G × 2”
b. 18 G × 1¼”
c. 20 G × 2”
d. 20 G × 1¼”
b.
In which patient would a central venous catheter potentially be contraindicated?
a. A cat with DKA
b. A dog with Evans syndrome
c. A hypoglycemic puppy on 7.5% dextrose
d. A cat receiving IV chemotherapy
b.
When Virchow’s triad is applied to IV catheters, which of the following can be a cause of thrombosis?
a. Endothelium damage
b. Hypercoagulation
c. Turbulent flow
d. All of the above
d.
Winged or butterfly catheters are contraindicated for which use?
a. Long-term use
b. Blood draws
c. Cortrosyn administration
d. Subcutaneous fluid administration
a.
In anticipation of a patient’s needs, when is an IO catheter indicated?
a. Hemodynamically stable seizure patient
b. 1^kg kitten with hypovolemia
c. 45^kg GDV
d. Six-month-old Shepherd for OVH
b.
Over-the-needle intravenous catheters should be left in place:
a. no longer than 48 hours
b. no longer than 72 hours
c. as long as there are no complications with the insertion site
d. only if the patient is receiving intravenous fluids
c.