Abdominal, oral, rectal Flashcards
What are the different types of shock?
Hypovolaemic
Distributive - sepsis, anaphylaxis
Obstructive
Cardiogenic
Signs of hypovolaemic shock
Hypovolaemic
o Pale mucous membranes
o Tachycardia (or bradycardia in cats – can maintain a high vagal tone even in severe disease, possibly to increase stroke volume and cardiac output)
o Low temperature
o Weak pulses
o Increased respiratory rate
o Increased CRT
Signs of distributive shock - sepsis
Distributive (sepsis, anaphylaxis)
o Red mucous membranes
o Decreased CRT
o Tachycardia
o Pyrexia
o Bounding pulse
o Increased respiratory rat
Signs of obstructive shock
Obstructive (compression of blood vessel reducing venous return or cardiac tamponade)
o Pale mucous membranes
o Increased CRT
o Tachycardia
o Low temperature
o Weak pulses
o Increased respiratory rate
Signs of cardiogenic shock
Cardiogenic (diseased heart)
o Pale mucous membranes
o Increased CRT
o Tachycardia/bradycardia/arrythmia
o Low temperature
o Weak or asynchronous pulses which may have deficits
POCUS to determine type of shock
v Normal left ventricular ejection fraction is 25-40% (classic cardiogenic issue is reduced EF)
v Reducing preload giving less fluid to start with will increase the ejection fraction
v Bounding caudal vena cava = normal preload – used to work out whether hypovolaemia is present
v Right side of heart flapping about = not maintaining volume as can’t expand due to fluid = cardiac tamponade
v Distributive normally caused by an inflammatory process, so go and look for fluid produced by inflammation and then tap it and analyse it to find out where the problem is originating from
o Blood, urine, inflammatory exudate are the main ones in acute abdominal pain
o Also bile and transudates (seen in hepatitis, portal hypertension and especially cancer)
What can cranial abdominal pain indicate?
liver, stomach, spleen, pancreas, spine, gallbladder – inflammatory diseases, foreign body, obstruction (pancreatitis with focal peritonitis is extremely painful)
Spine causes abdominal pain everywhere – should always check the spine in cases
What can caudal abdominal pain indicate?
uterus, colon, prostate, spine, bladder – prostate is very common, particularly in uncastrated dogs
Spine causes abdominal pain everywhere – should always check the spine in cases
What can dorsal abdominal pain indicate?
kidneys, radiating pain from stomach, spleen, spin
Spine causes abdominal pain everywhere – should always check the spine in cases
What can ventral abdominal pain indicate?
spleen, intestines, spine, space occupying lesions – gravity dependent fluid so anything producing fluid can cause ventral pain
Spine causes abdominal pain everywhere – should always check the spine in cases
What can cause GDV?
Aerophagia (swallowed air)
Eating too fast
Stress/pain – care with patients in practice
Exercise after feeding (oesophagus more open)
Large deep chested dogs – thoracic width:depth ratio (Setters, GSD, Weimaraners, Great Danes, Dobermans, Dachshunds)
Results in gas distension of the stomach and the pylorus twists on the gastric axis and move up
180 degree is the most common, but 360 degrees is also seen – must be some kind of momentum
Don’t really know why
Which way does GDV normally twist?
clockwise - 90%
What type of shock can GDV cause?
Obstructive - presses on caudal vena cava
Gastric vessel occlusion – necrosis
Spleen often involved – splenic involvement and twisting
How to diagnose GDV?
Need to do a right lateral radiograph to diagnose – look for smurf hat
Can tell if the patient is bloated versus GDV if you can’t get the stomach tube down
If you do surgery and find that the stomach is just bloated, you still need to do a gastropexy as likely recurrence
How to fix the obstructive shock of GDV
Need to fix the obstructive shock – remove the obstruction
Orogastric or nasogastric tube – orogastric is larger so can decompress it faster
Some GDVs will spontaneously resolve with a nasogastric tube, but much more likely to die
16G or 18G needle or catheter through the stomach – percutaneous
Needle is quicker but can rip the stomach if it moves
Catheter won’t rip the stomach but might get bent = air won’t come out
Give plenty of oxygen therapy
Brain, heart, lungs and kidneys will struggle
Neurological exam
Fluid therapy to help the kidneys
Oxygen therapy for lungs
Heart can get hypoxic damage = arrythmias = ECG
Ventricular tachycardia is the most common finding (stimulated somehow by splenic disease)
Poor stroke volume and filling
Probably results in fibrillation and death if not treated
Treat with lidocaine (sodium channel blocker which slows down the action potential, allowing the SAN time to recapture ventricles) – bolus or CRI
Blood trapped at the back of the body = front of body isn’t getting blood so has a relative hypovolaemia cranially
Bolus fluids IVFT in the cephalic vein
Anaesthetic considerations with GDV
Surgery to untwist and decompress the stomach once stabilised
Anaesthesia
Avoid alpha 2 agonists as cause cardiovascular compression
Need to monitor cardiac output (ECG), blood pressure on front end
Can’t breathe properly due to diaphragmatic compression = ventilation-perfusion mismatch made worse by perfusion issues
Capnography
Ventilating patient
Pain relief – methadone premedication
Midazolam premedication or co-induction at the same time as propofol
Co-induction is trying to avoid dysphoria, so in a sick patient you may as well just give it as a premed
Systemic considerations of untwisting GDV
Untwisting the stomach results in sudden reperfusion, which can spread a load of toxins from the lysis of necrotic stomach cells back into the bloodstream
Heaps of potassium released = hyperkalaemia – use blood gas machine to measure or look at ECG or give fluids
Length of surgery increases risk of infection – could give prophylactic antibiotics at least during the procedure
Gastropexy
Gastropexy
Decompress stomach fully before derotating, even if decompressed before surgery
Prevents ripping off gastric arteries and subsequent haemoabdomen
Many different approaches
Don’t do tube gastropexies as these increase risk of infection
Belt loops use serosa and create a kind of triple layer, but is more difficult with no clear benefit
Incisional gastropexy is the best option
Incision into the serosa of pylorus of stomach (don’t penetrate stomach lumen) and deep into the abdominal wall
Stitch them together
Some bleeding and inflammation creates an adhesion, creating scar tissue which keeps the stomach in a normal position
If the spleen is black then remove it, if purple it’ll probably be fine, but if in doubt it’s always safer to take it out, especially if twisted (don’t untwist before you remove it so no toxins are released)
Post op GDV care
Post-operative care
o Monitor electrolytes, lactate and keep the ECG on for at least 24-48 hours as can go into ventricular tachycardia or atrial fibrillation at any time after
o Methadone
o Lidocaine for the next 24 hours – excellent pain relief as well as helping ventricular tachycardia
o Best not to send them home straight away as still a risk of sudden death
Septic causes of peritonitis
GI perforation
- Foreign body ingestion – scavenger, vomiting, pain
Haematogenous
- Distributive shock
Extenal penetrating injury
- Obvious
Iatrogenic
- Recent surgery – e.g. swabs left in
- Pain, distributive shock, vomiting
Ascending urinary tract infection
- Reduced urine volume, stranguria, increased frequency of urination
- Pain
- Haematuria
- More likely in male dogs with prostatitis
Aseptic causes of peritonitis
Pain Vomiting PUPD
Splenic abscess (uncommon)
Hepatitis
Nephritis
Cholangitis
Pancreatitis – enzyme release
Bile
- Super painful
- History of chronic disease (weight loss, inappetance, etc.)
- Jaundice if ruptured due to an obstruction
Haemoabdomen
Urine
Stomach contents – gastric perforation
- Foreign body or gastric ulcer
- Super painful at first when the foreign body/ulcer is eroding, then lack of pain when it ruptures and then super painful again as peritonitis develops
- Vomiting, anorexia
Aseptic causes are fluid which contains no bacteria but will still illicit an inflammatory response (e.g. not chyle because this doesn’t stimulate the immune system)
POCUS for peritonitis
Look for triangles/shapes with angles to demonstrate free fluid
Circular things on ultrasound = organs/blood vessels
What to do with tap of free fluid in peritonitis
Gross colour
· Low glucose and high lactate
o If bacteria present then they are respiring anaerobically = use up glucose and produce lots of lactate
o Glucose 1mmol/L or lower supports sepsis
o Lactate 2mmol/L or higher supports sepsis
· Smear cytology – back-up as takes time away from patient; look for intracellular bacteria
· If you can’t reach fluid due to lack of volume then stick some more fluid inside = diagnostic peritoneal lavage
o 22ml/kg of warm saline into abdomen, then shake the animal and take a sample
o Expect glucose and lactate to be lower than normal in that sample = not diagnostic tests in this case
Treatment of peritonitis
Treatment – source control
· Depends on the source
· Can remove the fluid and/or fix/remove the source of the fluid
· Enzyme leakage = place a drain to constantly remove them if the source can’t be resolved +/- lavage
o Until patient is fixed and a lot better
· Don’t give antibiotics if an aseptic cause
· In sepsis they need antibiotics immediately – risk of death increases 7-10x for every hour you wait to give antibiotics
o Though if you can do source control well you may not need antibiotics, but you have to be brave
o Could avoid giving antibiotics at first and only give once culture and sensitivity has come back with evil stuff/patient is getting worse
o Could give lots of antibiotics and then see what culture and sensitivity comes back as
o Septic process:
§ Amoxicillin clavulanate
§ Optional metronidazole
§ Fluoroquinolone
What to do if haemoabdomen
POCUS!!
Tap fluid and analyse
· Red fluid could be a serosanguinous fluid and not always pure blood
· Don’t diagnose on whether or not it clots as haemoabdomen will be using up all the clotting factors and platelets to stop the bleeding
· Use PCV to differentiate (PCV of 2-3% will still look like blood)
o Compare to animal’s blood PCV
o Serosanguinous fluid will always be significantly lower than blood PCV
o Fluid PCV higher than blood PCV = semi-acute issue as the animal has an acute bleed a few hours ago and has probably stopped bleeding
o Fluid PCV lower than blood PCV = chronic issue (e.g. cancer) as has bled a while ago and now haemosiderophages (differentiated macrophages) start to eat up the blood + inflammation and fluid leakage into the area = dropped PCV
o Fluid PCV same as blood PCV = acute haemoabdomen
Causes of haemoabdomen
Neoplastic bleed
Trauma - blunt, pointy
Coagulopathy
Aneurysms
Splenic rupture secondary to neoplasia more than splenic trauma
Neoplastic haemoabdomen
Blood pressure and lactate to measure perfusion
o Poor perfusion = fluids and transfusion?
§ Autotransfusion will seed the neoplasia everywhere, but evidence in humans suggests that metastatic rates are low, so could still do them
§ Donor whole blood
§ Packed red blood cells fixes short term – could combine with fresh frozen plasma to get everything you need
o Surgery to remove the mass or chemo/radiotherapy or euthanasia if unremovable
Trauma haemoabdomen
Blunt
Bleeding from many places so avoid surgery if at all possible
RTAs most common cause
Acute issue = can quickly die
Blood pressure and lactate to measure perfusion
Poor perfusion = fluids and transfusion
Whole blood
Packed red blood cells combined with plasma
Tranexamic acid
Antifibrinolytic that prevents or reduces bleeding by impairing fibrin dissolution
Pointy
Measure blood pressure and lactate to look for poor perfusion
Poor perfusion = fluids and transfusion
Whole blood
Packed red blood cells and plasma
Tranexamic acid
Surgery
Coagulopathy haemoabdomen
Iatrogenic causes most common
Warfarin ingestion
IMHA
Von Willebrand’s – Dobermans
Measure blood pressure and lactate to look at perfusion
If perfusion is poor then give fluids and transfusion
§ Autotransfusion is the best idea alongside plasma – contains micro-aggregates
Then fresh frozen plasma as contains clotting factors
Then packed red blood cells
The whole blood (last option)
Avoid surgery as much as possible
What to do with uroabdomen
Diagnosis:
POCUS!!
Put bubbles into fluid into bladder and radiograph – if bubbles are outside the bladder on ultrasound then there is a bladder leak/rupture
Or above with other contrast media on radiograph
Tap fluid and analyse
Urea is a freely moving solute, so won’t see any difference in uroabdomen compared to normal
Creatinine >2x blood = uroabdomen
Potassium >1.4x blood = uroabdomen
Electrolytes – blood gas analysis
Hyperkalaemia assessed via ECG – bradycardia or atrial standstill if really bad
Glucose upregulates sodium/potassium pumps = want to upregulate this to get potassium back into the cells
Want to get glucose into cells = give insulin (care with hypoglycaemia so add in glucose) or feed the patient or give a glucose bolus (if pancreas works)
Or give biocarbonates
Or give a beta-2 agonist like salbutamol
Give Hartmann’s fluid – ultimate option as is acidic
Source control
· Urinary catheter into a ruptured bladder can help the patient remove fluid and reduce inflammation for a couple of days before surgery (or even resolvement)
Ascites - clinical signs and prognosis
Clinical signs
Dependent on underlying cause
The obvious – abdominal distension
Some discomfort
Dyspnoea – either from pressure on diaphragm, or if also have pleural effusion
Lethargy
O’s may report weight gain, difficulty getting up/lying down
Other signs depending on underlying cause (e.g. V/D – liver disease, coughing/syncope – CHF etc.)
ddx for ascites
Organomegaly - splenomegaly, hepatomegaly
Abdominal mass
Pregnancy
Bladder distension
Obesity
Gastric distension
All these cause abdominal distension without effusion
Identifying ascites
History - past and recent
Clinical exam - whole animal!
Ballottement
Ultrasound
Sample it
- Abdominocentesis
- blind or US guided
Gross appearance and smell - septic - opaque and foul smelling
Cellularity - number and type - good quality smears
Protein content - total protein on refractometer
Or send to lab
Exudate vs transudate
Total Nucleated Cell Count
Exudates are fluids, CELLS, or other cellular substances that are slowly discharged from BLOOD VESSELS usually from inflamed tissues
Transudates are fluids that pass through a membrane or squeeze through tissue or into the EXTRACELLULAR SPACE of TISSUE
Causes of transudate - protein poor - ascites fluid
Altered fluid dynamics
Hypoalbuminaemia will cause this
Decrease in plasam colloid oncotic pressure
ddx
- PLE
- PLN
- Hepatic failure - hypoalbuminaemia or pre-hepatic portal hypertension
Biochem, urinalysis and US
Causes of protein rich transudate - ascites fluids
Caused by
increased hydraulic pressure within blood and or lymphatic circulation - usually lungs or liver
Protein leaks from permeable capillaries, ascites develops when resorbative capacity of regional lymphatics is overwhelmed
TP is more important - transudates will irritate mesothelium - inflammation and increased TNCC - total nucleated cell count
ddx
- cardiovascular disease
- chronic liver disease - post hepatic portal hypertension
- neoplasia
- thrombosis - rare
investigations
- US
- Radiography - thoracic - neoplasia and heart disease
- Biochem - after imaging
