SIRS, Sepsis, MODs, DIC and Fluid therapy

Question 1

What is SIRS and what can it result in?

Answer 1

Self-amplifying dysregulated systemic inflammatory response
Triggered by bacterial toxins, lipopolysaccharide from cell walls of Gram -ve bacteria, Staphylococcus aureus, burns, neoplasia and pancreatitis (non-equine)
Causes cell death and apoptosis due to inflammation
Can result in coagulopathies

Question 2

What is the difference between Sepsis and SIRS?

Answer 2

Sepsis is SIRS with a culture proven infection

Question 3

True or False?
Severe Sepsis is Sepsis (SIRS and culture proven infection) plus systemic hypoperfusion

Answer 3

False
Severe Sepsis is Sepsis (SIRS and culture proven infection) plus organ hypoperfusion or dysfunction

Question 4

Describe the term ‘Septic Shock’

Answer 4

Severe Sepsis plus systemic hypotension
Common in foals and rare in adults; also occurs in small animals

Severe Sepsis:
- SIRS
- Culture proven infection
- Organ hypoperfusion or dysfunction

Question 5

What are the 2 categories of Multi-Organ Dysfunction Syndrome?

Answer 5

Primary:
- Well-defined insult
- Organ dysfunction occurs early as a direct consequence of the insult
- E.g. burns and neoplasia

Secondary:
- Organ failure not in direct result to the insult
- Consequence of host response (SIRS)

Question 5

What are the 2 categories of Multi-Organ Dysfunction Syndrome?

Answer 5

Primary:
- Well-defined insult
- Organ dysfunction occurs early as a direct consequence of the insult
- E.g. burns and neoplasia

Secondary:
- Organ failure not in direct result to the insult
- Consequence of host response (SIRS)

Question 6

Define the term ‘Multi-Organ Dysfunction Syndrome’ (MODS)

Answer 6

Altered organ function in an acutely ill animal
Haemostasis can’t be maintained without intervention

Question 7

What is the name of the condition which causes a consumptive coagulopathy involving microvascular clotting, haemorrhagic diathesis and consumption of procoagulants?

Answer 7

Disseminated Intravascular Coagulation

Question 8

What is haemorrhagic diathesis?

Answer 8

Abnormal tendency to have spontaneous, often severe bleeding

Question 9

What conditions is DIC associated with?

Answer 9

SIRS
Sepsis
Septic Shock
Multiple Organ Dysfunction (MODS) - systemic neoplasia, enteritis and colitis

Question 10

What are the clinical signs seen in large animals with DIC?

Answer 10

Thrombosis more common than spontaneous haemorrhage in large animals
Petechial haemorrhage
Bleeding following trauma (venipuncture, surgery, NG intubation)

Question 11

How is Disseminated Intravascular Coagulation diagnosed?

Answer 11

3 out of the following must be present:
- Thrombocytopaenia (lack of platelets)
- Prolonged Prothrombin Time
- Prolonged Activated Partial Thromboplastin Time
- Increased antithrombin 3

Also low fibrinogen - not used very often as reference range <4g/L

Question 12

Give 4 conditions which are common complications of GI disease in horses

Answer 12

SIRS or sepsis
Hypovolaemia (acute pre-renal disease)
Dysregulation of perfusion
Hypoproteinaemia
Ileus
Nutritional challenges
Gut flora changes
Thrombophlebitis
Coagulation abnormalities
Pain

Question 13

Which of the following isn’t an unusual complication of GI disease in horses?
1. Electrolyte abnormalities
2. Anaemia
3. Coagulation abnormalities
4. Laminitis

Answer 13

Coagulation abnormalities - common GI disease complication

Unusual GI disease complications also include ventricular dysrhythmias, e.g. due to large colon volvulus or GDV

Question 14

What is the most important prognostic indicator when treating the critically ill patient?

Answer 14

Time until treatment - abnormalities treated within 24 hours are more likely to survive

Question 15

True or False?
Hypoproteinaemia, electrolyte disturbances and appropriate antimicrobial use are all prognostic indicators when treating the critically ill horse

Answer 15

True
Also correction of sepsis/SIRS and correction of decreased cardiac output/hypotension

Question 16

How can you assess volume status in horses during your clinical exam?

Answer 16

Heart rate
Capillary refill time
Jugular filling time
Temperature of extremities
Demeanour

Question 17

What clinical pathology tests can be used to assess volume status in horses?

Answer 17

Lactate
PCV/TP
Creatinine

Question 18

You have diagnosed a critically ill 8 year old cob gelding with hypovolaemia. How will you treat him? Include all steps.

Answer 18

Calculate percentage fluid deficit (hypovolaemia isn’t dehydration)
Calculate maintenance fluid rates (2-3ml/kg/hr)
Replace 50% of fluid deficit as a bolus in the first 2-4 hours
Replace remaining 50% and maintenance requirements over the next 6-8 hours
Include estimate of fluid loss in vomit/reflux, diarrhoea, etc.

Question 19

A horse presents with a skin tent lasting 3 seconds, tacky mucous membranes, CRT 2 seconds, heart rate of 44bpm, and a decreased arterial pulse quality. Blood lactate is 5mmol/L. What is the fluid deficit of this horse?

Answer 19

About 8%
Skin tent 3-5 seconds
Tacky mucous membranes
CRT 2-3 seconds
HR normal to 60bpm
Lactate 3-6mmol/L
Decreased arterial pulse quality

Question 20

What clinical signs would you see in a horse with a 5% fluid deficit?

Answer 20

Skin tent lasting 1-3 seconds
Moist to slightly tacky mucous membranes
CRT <2
HR 28-44bpm
Lactate <3mmol/L
Decreased urine output

Question 21

A horse presents with a skin tent lasting 7 seconds, dry mucous membranes, HR 65bpm, decreased jugular fill, poor pulse quality and sunken eyes. Blood lactate is 7mmol/L. What level of fluid deficit does this horse have?

Answer 21

10-12%

Question 22

True or False?
Dehydration is rare in horses

Answer 22

True - start with hypovolaemia and true dehydration is quite rare

Question 23

You have a horse with ileus. Will you give him oral or IV fluids?

Answer 23

IV fluids, though more expensive
Oral fluids are cheaper, but generally won’t be absorbed and will cause discomfort and pain
Oral fluids often ok if fluid deficit is <5%

Question 24

Which type of IV fluids should you give to a horse with hypovolaemia?

Answer 24

Hartmann's or Lactated Ringers Except in horses in intrinsic renal failure, as the kidneys may not be able to deal with the electrolytes Kidney will be able to sort out the acid-based and electrolyte issues as long as it is adequately perfused

Question 25

Which 2 minerals are likely to be lacking in horses which have had food withheld whilst being given resuscitation fluids?

Answer 25

Potassium and magnesium Both obtained from the diet, so giving food again normally fixes it

Question 26

Are animals more likely to have a slightly high Na and Cl in hypovolaemia or diarrhoea?

Answer 26

Hypovolaemia - due to haemoconcentration Diarrhoea animals often have a low Na and Cl as they are lost through the GIT

Question 27

How can you correct hypokalaemia and hypomagnesemia in a horse which is being given IV Hartmann's and is Nil Per Os?

Answer 27

Supplement IV fluids with tablets Initial and serial measurements of electrolytes to ensure you're not causing any harm (especially important with potassium and calcium)

Question 28

What are the issues with monitoring hypoproteinaemia in horses?

Answer 28

Can be affected by volume status Markedly hypovolaemic horses look like they don't have protein level issues until fluid levels are restored

Question 29

What is the safest treatment for hypoproteinaemia?

Answer 29

Plasma - gives clotting factors as well

Question 30

Which of the following isn't seen in SIRS and Sepsis? 1. Deactivation of the inflammatory cascade 2. Vasodilation 3. Dysregulation of tissue perfusion 4. Leaky capillaries (extravasation and oedema)

Answer 30

Deactivation of the inflammatory cascade - this is activated instead

Question 31

What does intensive care of horses with sepsis involve?

Answer 31

Antimicrobials Fluid resuscitation and pressure support Treatment for inflammation, endotoxaemia and coagulopathy

Question 32

True or False? Flunixin has anti-endotoxic effects

Answer 32

False Misquoted paper

Question 33

Which opioid shouldn't you give to horses with SIRS or sepsis?

Answer 33

Butorphanol - very little analgesic effect Give other opioids, NSAIDs or paracetamol for analgesia

Question 34

Why might you give ketamine to a horse with SIRS or sepsis?

Answer 34

NMDA receptor antagonist which reduces the opening of ion channels in neurons = decreased calcium permeability into neurons = decreased pain signals = analgesia Much lower dose than for anaesthesia Good for chronic pain

Question 35

Give one positive and one negative for using lidocaine to treat horses with SIRS or sepsis

Answer 35

Positive - anecdotally good for visceral analgesia; can offset some negative consequences of NSAIDs (prokinetic) Negative - controversial

Question 36

Do SIRS and sepsis result in vasodilation or vasoconstriction?

Answer 36

Vasodilation

Question 37

Which drug classes would you use to treat vasodilation in a horse with sepsis/SIRS?

Answer 37

Positive inotropes - e.g. dopamine, which increases cardiac output and contractability Vasopressors - e.g. norepinephrine, which increases vessel tone and perfusion pressure Aim is to restore vascular volume as lots of horses with SIRS/sepsis still have hypotension despite fluids

Question 38

Why is ileus often a post-op condition after abdominal surgery?

Answer 38

As a result of gut handling and chronic stretch Also a general consequence of GIT disease

Question 39

What is the most important cause of ileus?

Answer 39

Pain Abdominal surgery, drugs (anaesthetics), GI abdominal disease and inflammation are also causes

Question 40

What are the 4 ways we can treat ileus in horses?

Answer 40

Prokinetics Analgesia Treatment of primary disease Restoration of perfusion

Question 41

What makes ileus such an important condition to treat in horses?

Answer 41

Horses can't vomit (lower oesophageal cardiac sphincter), so ileus can lead to gastric distension and rupture NG intubation and reflux is very important when treating ileus

Question 42

How long can you starve a donkey for after surgery? Does this differ to horses and ponies?

Answer 42

Fat ponies and donkeys can be starved for a maximum of 12-24 hours after surgery Adult horses can be starved for 48-72 hours after surgery

Question 43

Should you feed horses enterally or parenterally after surgery?

Answer 43

Ideally feed enterally, but this is impossible if the horse is refluxing and has ileus If you can't feed enterally, carefully monitor triglyceride concentrations and consider parenteral nutrition (glucose, lipids and amino acids)

Question 44

Why isn't 5% dextrose a good source of parenteral nutrition?

Answer 44

Very quickly metabolised Low in calories Free water = cell rupture

Question 45

What should partial parenteral nutrition for horses consist of?

Answer 45

40-50% dextrose +/- amino acids Only use IV glucose on it's own for a maximum of 24 hours (quite cheap)

Question 46

What is the difference in the composition of partial parenteral nutrition and total parenteral nutrition?

Answer 46

Total parenteral nutrition contains lipids as well as 40-50% dextrose and amino acids Partial parenteral nutrition doesn't contain lipids Don't try to provide all caloric requirements - 10-40Kcal/kg/day

Question 47

When doing partial or total parenteral nutrition, what else should you give the horse?

Answer 47

Insulin - start at 5Kcal/kg/day

Question 48

How can you monitor nutrition status in ill horses?

Answer 48

Weight Physical exam Hydration status Metabolic lab work Blood glucose TS (Transferrin Saturation) Triglycerides BUN - body using own reserves Electrolytes

Question 49

What GI changes are seen when food is withheld from horses?

Answer 49

Villi stunting Decreased absorptive capacity Also predisposed to mild gastric ulceration - gastric acid has a purpose so suppressing may be bad

Question 50

What are your 3 options when managing changes in GI flora?

Answer 50

Do nothing - common Pre- and pro-biotics - often no evidence based medicine to support them, may have inappropriate/pathogenic organisms and unlikely to survive gastric acid Transfaunation - need to find the right donor

Question 51

What is thrombophlebitis and how is it treated?

Answer 51

Blood clot in the vasculature (normally veins) Treated with: - Broad spectrum antibiotics - Aspirin (prevents further clots) - NSAIDs (inactivates platelets) - Topical Dimethyl Sulfoxide (DMSO - analgesia) - Heparin (prevents further clots) - Vasodilators (glyceryltrinitrate - improves blood flow around thrombus) - Raise head

Question 52

What alternative venous access routes do you have in horses with thrombophlebitis?

Answer 52

Lateral thoracic vein (just behind the forelimb) Cephalic vein

Question 53

What might you need to do in horses with bilateral thrombosis?

Answer 53

Tracheostomy Oedema of the head and airways = upper airway obstruction Surgery to strip and/or graft the vein have been described but are rarely done

Question 54

What is the most frequent cause of excessive bleeding in horses as a result of SIRS/sepsis?

Answer 54

Hypocoagulation - decreased amount or function of components of primary or secondary haemostasis Also caused by hyperfibrinolysis or increased anticoagulant activity

Question 55

What cause of excessive bleeding in horses can occur iatrogenically?

Answer 55

Increased anticoagulant activity

Question 56

Name 3 causes of excessive thrombosis in horses

Answer 56

Hypercoagulation Hypofibrinolysis Decreased anticoagulant activity

Question 57

Excessive thrombosis common in horses. Is it normally a primary or secondary condition?

Answer 57

Excessive thrombosis is normally secondary - rarely seen as a primary condition in horses

Question 58

Clopidogrel can be given to horses with excessive thrombosis. What is its mechanism of action?

Answer 58

Platelet ADP receptor inhibitor which prevents platelets sticking together and forming a clot

Question 59

Heparin is used to treat horses with excessive thrombosis. What is its mechanism of action?

Answer 59

Binds to anti-thrombin and potentiates inhibition of activated clotting factors

Question 60

What is the mechanism of action of aspirin?

Answer 60

Inhibits cyclooxygenase, which prevents thromboxane A2 production in platelets

Question 61

How can we try to prevent laminitis occurring in horses after SIRS or sepsis?

Answer 61

Early identification and treatment of SIRS/primary disease Icing feet constantly (cryotherapy) Laminitis is a significant contributing factor to mortality in colitis and large colon volvulus cases

Question 62

You are presented with a horse with SIRS and a heart rate of 60bpm. This is a much higher heart rate than you would expect in this horse. What should you check for next?

Answer 62

Ventricular dysrhythmias - due to electrolyte abnormalities or myocarditis secondary to SIRS Occasionally occurs in horses and dogs with GDV

Question 63

Why is is so important for ventricular dysrhythmias to be corrected in horses with SIRS/sepsis?

Answer 63

Often compromise cardiac output, and so perfusion will improve if they can be resolved

Question 64

You have a horse with SIRS and a ventricular dysrhythmia. What are your next steps to help treat the ventricular dysrhythmia?

Answer 64

Check electrolytes Check volume status IV magnesium sulphate (membrane stabiliser) IV lidocaine (one-off dose, can try an infusion if working) IV procainamide (anti-arrhythmic; not readily available)

Question 65

Why is anaemia a concern in horses with GIT issues?

Answer 65

Can lose a dramatic amount of blood through the GIT Concurrent hypovolaemia will mask some anaemia Splenic contraction can mask blood loss for up to 24 hours in horses