Exam 1 - GDV Flashcards
what is simple gastric dilatation?
enlargement of the stomach beyond its normal limits (with air/froth) WITHOUT malpositioning
what is gastric dilatation & volvulus?
enlargement of the stomach associated with rotation of the stomach on its mesenteric axis
what is the general at risk population for GDV?
middle aged to older ‘deep chested’ large/giant breed dogs
what dog breeds are associated with having the highest risk of developing GDV?
great dane - 42% lifetime risk
gordon setter, irish setter, weimaraner, saint bernard, standard poodle, bassett hound, & GSD
what are some extrinsic risk factors associated with GDV?
eating rapidly, raised food bowls, small food particles, single food type, large volume of food per feeding, & history of kenneling/travel
what are some intrinsic risk factors associated with GDV?
increased age, first degree relative with history of GDV, males, increased thoracic depth:width, fearful/anxious animal, gastric foreign bodies, & potentially prior splenectomy
what are the steps in which a GDV occurs?
stomach dilates - either from esophageal obstruction (animal can’t eructate or vomit) or pyloric obstruction (cannot pass ingesta to small intestine)
stomach rotates in a clockwise direction (~180-270)
pylorus & duodenum move VENTRALLY & to the LEFT of midline (clockwise)
spleen is displaced to the RIGHT
what is the pathophysiology of GDV?
massive increase in intra-gastric pressure & volume - 20 mmHg will cause caval compression, with GDV, upwards of 60 mmHg
pressure on the diaphragm causes decreased tidal volume & impaired ventilation
caudal vena cava & portal system are compressed leading to obstructive shock, decreased CO, SV, MAP, & portal hypertension
distributive shock occurs with splanchnic pooling of blood
myocardial ischemia causes decreased venous return to the heart leading to circulatory shock
arrhythmias in 40-70% of cases (due to myocardial ischemia, splenic disease, & pancreatic ischemia - myocardial depression factor)
capillaries collapse causing mucosal necrosis - breakdown of gi mucosa & impaired portal system leading to bacterial translocation & endotoxemia
mixed acid base derangements
coagulopathy - multifactorial & DIC is possible
reperfusion injury from reactive oxygen species & pro-inflammatory mediators released systemically
why can a GDV dog present as anemic?
the tearing of the short gastric vessels during the volvulus leads to blood loss
why do we see mucosal necrosis in the stomach in an animal with GDV?
the mucosa is very metabolically active & receives >50% of blood flow & is >50% of the weight of the stomach - massive injury
full thickness ischemia & necrosis +/- perforation is possible
what is the most common region of the stomach to necrosis with GDV?
greater curvature/fundus
what clinical signs does a GDV patient typically present with?
gastric distension, non-productive retching, hypersalivation, restlessness, pain/praying position
progression to depression & lateral recumbency
why is a saphenous catheter for iv fluids useless in a patient with GDV?
the venous return from the abdomen is impaired
what is the first step that should be taken for treating a GDV patient?
stabilize - large bore catheters in both cephalics or jugular with shock doses of crystalloids +/- colloids
also consider - analgesia, anti-emetics, flow-by oxygen
while fluids are going for a GDV patient, what other tests/information should you pursue?
PE, TPR, BP
continuous ecg & treat as indicated
blood gas
PCV, lactate, BUN/crea, electrolytes, & coagulation panel
why should you do an ecg on a GDV patient?
many of them have arrhythmias - typically ventricular
what arrhythmia is seen here? how do you know? how do you treat it?
v-tach
sustained VPCs, rate >160 bpm, R on T waves, multiform VPCs
lidocaine
why take a right lateral of a GDV patient?
pylorus is seen cranial to the body of the stomach - double bubble or reverse C shape
what could cause a pneumoperitoneum in a GDV dog?
gastric rupture - very unlikely
what is seen on rads that is supportive of a GDV?
pylorus is seen cranial to the body of the stomach - double bubble or reverse C shape
may see decreased serosal detail - rule out blood vs. gastric rupture
T/F: if you confirm a GDV on a right lateral view, you still need a left lateral & VD view
false - stop after confirmed!!! avoid VD - can do DV if needed
where is the pylorus seen on a DV view of a GDV dog?
pylorus seen on the left
when may you do thoracic rads in a GDV patient?
if the patient is stable enough & an older - some may have aspiration pneumonia
older patients - need to rule out neoplasia
before doing gastric compression, what should you do?
give the patient an opioid - hydromorphone/methadone/fentanyl - for pain relief & mild sedation
what are the 2 methods used for gastric decompression?
orogastric tube
trocharization/percutaneous decompression
how do you use an orogastric tube for gastric decompression?
choose a large, stiff tube with a smooth tip & measure from the tip of the nose to the last rib & mark the tube
consider elevating the front half of the body to decrease pressure at the cardia
place a roll of tape in the dog’s mouth to prevent them from biting the tube or use a tape muzzle
pass the tube through the center of the roll of tape & pass down esophagus - if you feel resistance near the cardia, DO NOT FORCE THE TUBE
once the tube is in the stomach - material should flow (have bucket ready)
can lavage after with 5-10ml/kg of warm water
how is percutaneous gastric decompression performed in a GDV patient?
determine the area of greatest tympany - often on the left side just behind the last rib - can use ultrasound to confirm the spleen is not between the body wall & stomach
clip/aseptic prep/lidocaine block of the region
use a 14 or 16 G over the needle catheter & insert into stomach - remove the stylet & consider attaching to extension set
apply gentle pressure on the abdomen to decompress
what are the benefits of using an orogastric tube for gastric decompression?
can achieve more rapid & complete decompression
can lavage the stomach
what are the benefits of using trocharization for gastric decompression?
typically no sedation required
may be better tolerated
rapid
what are the disadvantages of using an orogastric tube for gastric decompression?
some patients may not tolerate the tube without further sedation
may not be able to pass tube beyond the volvulus/cardia
may perforate the stomach if overly aggressive
what are the disadvantages of using trocharization for gastric decompression?
less complete decompression especially if large amounts of food or thick froth is present
may lacerate the spleen - usual minimal consequence
what are the goals of surgery in a GDV patient?
decompression, derotation, damage control, & permenant gastropexy
what are the anesthetic considerations for surgery for a GDV patient?
continue to stabilize the patient & close monitoring
minimize time in dorsal recumbency - clip & initial prep in lateral
minimize anesthetic time
MAC sparing anesthesia protocol
what is the first step in GDV surgery?
decompression of the stomach - make a LARGE ventral midline incision from xiphoid to pubis
must decompress the stomach before derotating (may be able to palpate cardia & guide OG tube in or can use a catheter/needle & attach to suction)
how is derotation done in GDV surgery?
standing on the dog’s RIGHT side
use your right hand to pull the pylorus TOWARDS you (ventrally/up - from left to right)
use your left hand to push the body of the stomach dorsally & to the left (away from you/down)
confirm the return to the normal anatomic position with the pylorus & duodenum on RIGHT - should be able to easily pass OG tube
after decompression & derotation is complete, what is done next in a GDV surgery?
damage control - complete abdominal explore
concurrent gi obstruction is possible (fb, neoplasia, intussusception)
confirm hemostasis
why may you see a hemoperitoneum in a GDV surgery?
short gastric arteries may tear causing a hemoperitoneum - confirm no continued hemorrhage & ligate as needed
what happens if during your abdominal explore in a GDV surgery, you see that the spleen has necrosed?
splenectomy - while rare, it can happen
look for lack of pulses & black in color
during your abdominal explore of a GDV surgery, you see that the spleen is dark purple - what do you do?
nothing - spleen will appear congested & will improve with time
what are some signs of gastric necrosis?
serosa of the stomach is gray/green/black
thin with lack of normal ‘slip’
lack of bleeding when incised
lack of peristalsis?
if in doubt about the viability of the stomach after decompression/derotation, what can you do?
complete abdominal explore & go back & re-evaluate
T/F: if necrosis or perforation is present in the stomach, resection is indicated
true - 60% of the stomach can be removed
greater curvature or fundus resected easily
what happens if there is necrosis on the cardia of the stomach?
resection isn’t always possible - may be grounds for humane euthanasia
if resection is possible - animal may have reflux esophagitis
how is resection performed on necrosed areas of the stomach in a GDV surgery?
partial gastrectomy - pack off the abdomen & place several stay sutures
cut out necrotic tissues
close in 2 layers (mucosa/submucosa SC & muscularis/serosa inverting with 2-0 PDS)
what is invagination in terms of techniques used in GDV surgery?
area of necrosis on the stomach is folded inward (invaginated) with a cushing/lembert pattern placed through the healthy tissue around it
may be faster than resection
what are some possible complications of invagination of necrotic tissues of the stomach?
ulceration - common
hemorrhage
gi obstruction from tissue
which is preferred for addressing necrotic tissue on the stomach in a GDV surgery, resection or invagination?
resection
why is a gastropexy necessary for a GDV surgery?
80% recurrence rate without a pexy - need to do a right sided gastropexy to prevent the same problem from happening
incisional gastropexy preferred
T/F: after a GDV surgery, the patient can be considered out of the woods
false
what is included in post-operative management of GDV surgery patients?
continuous ECG for at least 24 hours, blood pressure, PCV/TS, lactate, +/- periodic brief abdominal ultrasound
+/- cbc/chem every few days
if the arrow is pointing out the caudal most extent of the diaphragm, what does the line next to it represent?
location of where you should do the gastropexy
what are some common post-operative complications of GDV?
arrhythmias, hypotension, ileus (vomiting/regurgitation), anorexia, & aspiration pneumonia
less common - DIC & sepsis/peritonitis (gastric necrosis not identified & treated intra-op or dehiscence)
what is the ball structure seen in the center? what is to the right of it?
omentum
spleen
when should you use antibiotics post-op in a GDV patient?
indicated if there was perforation/septic peritonitis or evidence of septicemia
T/F: you should avoid NSAIDs in post-op GDV patient
true
opioids instead - methadone has less gi effects
what kind of gi support should be offered to post-op GDV patients?
antiemetics, prokinetics as needed, & antacid meds
may need an ng tube to periodically empty the stomach if there is severe ileus
how is nutrition handled post op in a GDV patient?
begin feeding within 12-24 hours
if anorexic for >24 hours - consider NG tube
what are some poor prognostic indicators in GDV patients?
lactate that doesn’t improve, pre-op arrhythmias, >6hr of clinical signs, hypotension at any time, need for splenectomy/partial gastrectomy, peritonitis/sepsis, & DIC
T/F: there is 10-28% mortality reported in GDV patients
true
T/F: lactate increases in GDV patients due to hypoxia secondary to anaerobic metabolism
true
T/F: there is a general shift towards response to resuscitation rather than a cut off value in predicting prognosis when it comes to watching lactate values
true - there are many papers evaluating the prognostic value of lactate & they all have conflicting results
T/F: you should recommend a prophylactic gastropexy to at risk breeds & any dog that develops dilatation as it will prevent volvulus, bloat, & dilatation
false - while you should recommend the surgery, it only prevents volvulus not bloat/dilation
what are some ways owners can prevent the risk of their pet developing GDV?
avoid raised bowls
minimize stress/anxiety especially during feedings
feed multiple smaller meals rather than one large meal a day
______ ________ is a possible sequela to GDV & can require resection of the stomach
gastric necrosis
T/F: stabilization in a GDV patient before surgery is extremely important
true - fluids & gastric decompression
how is an incisional gastropexy performed?
4-6cm incision is made through the peritoneum & transversus abdominis on the right body wall 1cm behind the last rib & parallel to the linea
make a similar 4-6cm incision through the seromuscular layer of the pyloric antrum
use 0 or 2-0 PDS in a simple continuous pattern, suture the dorsal aspect of each incision together followed by the ventral aspect
how is a belt loop gastropexy performed?
seromuscular flap created around a vessel along the greater curvature of the pyloric antrum
make 2 5 cm incisions along the right body wall through the peritoneum/transversus abdominis m. for flap to be passed through
how is a circumcostal gastropexy performed?
make a double or single-hinged flap of the seromuscular layer over the pyloric antrum passed cranial to caudal around the 11th or 12th rib
rare complications include - pneumothorax (particularly if using the mid to proximal portion of rib) & rib fractures
what are some common post-operative complications of GDV?
arrhythmias, hypotension, ileus (vomiting/regurgitation), anorexia, & aspiration pneumonia
less common - DIC & sepsis/peritonitis (gastric necrosis not identified & treated intra-op or dehiscence)
