small animal GI surgery Flashcards
problems with gastric and high int. vomiting and how to correct prior to surgery
- loss of HCl
- dehydration
- insufficient food intake
correct: IV isotonic crystalloids, IV K+ supplement
problems with lower int. vomiting and how to correct prior to surgery
Loss of pancreatic Na, HCO3
dehydration
insufficient food intake
correct: IV isotonic crystalloids, IV K+ supplement
How to correct before surgery if have GI bleeding
blood tansfusion, iron supplement
What do gastric surgical diseases cause?
Gastric vomiting
What do S.int complete obstruction cause?
Acute vomiting
What do S.int partial obstruction cuase?
chronic vom, diah, weight loss
What does GI bleeding cause?
haematemesis (vom blood)
melaena
Stomach surgery risks and precautions?
- Acid kills most bacteria
- antibiotics not necessary if young,healthy and under 90 min surgery
- single broad spectrum antibi. with anaerobic cover (2nd gen cephalosporin / amoxycillin-clavulante)
Small intestine surgery risk and precautions?
10^2 - 10^6 CFU/ml 50%anaerobe
- use antibiotics if compromised
- broad spectrum with anaerobic cover
Large intestine surgery risk and precautions?
10^9 - 10^11 CFU/ml 79%anaerobe
- always use antibiotics
- broad spectrum and anaerobic only (metronidazole)
Methods to decrease contamination?
- isolate site of entry
- pack abdomen with moist swabs
- change instruments and gloves for contaminated part
- lavage wound after closure
GI wound healing - 2 phases
Lag phase (1-4 d) Proliferative phase (3-14 d)
Different organ healing abilities
stomach - rapid and uncomplicated
s. int - 75-80% of tensile strength by d 14
l. int - 50% of tensile strength by d 14
Traumatic surgical techniques and electrocautery can affect healing
Suture material and why?
Monofilament so no crevices for bacteria, absorbable, retains strength >5 d
E.g PDS II
What is an exploratory laparotomy?
direct visual and tactile exam of the abdominal organs at surgery via and incision into the abdomen.
incision from xiphisternum to pubis
Gastrotomy
between greater and lesser curvature
repair in 2 layers - mucosa + submucosa and serosa + muscularis
Enterotomy
milk contents away
incise along along anti-mesenteric border
Liver biopsy
first try fine needle aspirate and trucut biopsy
take from periphery as less blood
Pancreas biopsy
Tighten suture ligature around area before cutting
Check viability of intestines
pulsations in arterial BV
peristalsis
colour
wall thickness
What is luminal disparity and how to get around it?
different opening sizes when resecting the int.
- space sutures further apart on large size
- transect small side at an angle to match diameter
- reduce big side with sutures
- spatulate small side
How to do an end - to - end anastomosis
Simple interrupted suture
1st - on mesenteric border as harder to apposition
2nd on anti-mesenteric border
Two ways of supporting a wound
omentalisation
serosal patch - tack adjacent healthy int. to wound
Signs and how to deal with a string like foreign body?
on radiograph : concertina int., stacking of int
cut string up…multiple enterotomies
What is intussusception? Signs? How to reduce?
invagination of one portion of the GI tract into the lumen of an adjoining segment
Signs: abdo pain/mass, parallel lines on ultrasounds, gas distension on radiograph
push to reduce and resect if needed
can prevent hapenning again by entroplication - suturing loops of int together
What is the main complication of GI surgery?
Septic peritonitis - bacterial inf of peritoneum
wound dehiscence
What are the results of septic peritonitis?
Hypovolaemic shock, systemic infl response, DIC, 50% die
Signs and treatment of septic peritonitis?
Signs - vomiting, anorexia, depression, abd pain, hypovolaemia, pyrexia, wound discharge, dia, haematochezia, melaena, haematemesis
3-5 d post surgery
Treat - pre-op stabilisation, exp lap to correct leak, peritoneal lavage and drainage, extensive post op care
4 approaches to colorectal surgery
- ventral midline laparotomy
- pelvic split
- dorsal perianal approach
- transanal
complication of resecting too much colon?
reduce resevoir and absorptive capacities ( increased faecal frequency and wateryness)
How much rectum can be resected out?
no more than 6 cm
Surgical diseases of the colon and rectum? (3)
megacolon
colorectal neoplasia
rectal prolapse
secondary megacolon causes
pelvic fracture intrapelvic space occupying lesion colorectal neoplasia / abcess perineal hernia inappropriate diet
How to diagnose megacolon?
chronic constipation, tenesmus, vom, anorexia, weight loss, dehydration
Signs of colorectal neoplasia
tenesmus, haematochezia, increased defecation frequency, ribbon - like faeces, rectal prolapse, weight loss
2 ways to treat colorectal neoplasia
submucosal resection
colorectal resection and anastomosis
how to repare a rectal prolaps
resect if needed, push in and put a stitch in anus to decrease diameter.
give faecal softners, anthelmintics, low residue diet
treatment of anal sac disease
- mannual expression
- sedate and catheterise them (sample and cytology)
- anal sacculectomy (open or closed removal)
