Dystocia - Surgical Management Flashcards
what are the causes of dystocia
- maternal abnormalities (majority)
- fetal presentation (transverse or obstructive)
- large fetus size, large litter size, or developmental anomalies
- uterine inertia or spasm
- suspicion of uterine rupture or torsion
primary uterine inertia
failure of the uterus to contract or to contract in an organized manner
secondary uterine inertia
contractions against an obstructive canal or uterine musculature exhaustion from delivery of a large litter
how often is surgical management required in dystocia
60-80% of dystocia cases
how to determine need for surgical intervention
- assess the dam
- assess progression of labor
- assess fetal heart rate
how to count fetal heart rate
ultrasound
monitor for 30-60 seconds or reassess if low heart rate occurs during contraction
fetal heart rate ranges
180-210: normal
150-170: moderate to severe stress
<150: severe distress
how does the length of dystocia affect prognosis
longer dystocia creates a greater risk to both the dam and the neonates
general surgical plan for C section
- set up O2 and space for neonatal resuscitation
- preoxygenate + patient prep PRIOR to induction
- ventral midline approach
- uterotomy
- remove the neonates
- uterine closure
- +/- oxytocin
- abdominal lavage
- abdominal closure
incision approach into the abdomen for C section
ventral midline
incise from 3 cm cranial to the umbilicus –> just cranial to the pubis
(want a LARGE incision to exteriorize entire uterus)
caution - linea is very thin and the uterus sits right below it
considerations for cutting into the uterus
want to have the entire uterus exteriorized and pack off the abdomen with laparotomy sponges - reduce leakage of uterine contents into the abdomen
single incision into the uterus
incise into the UTERINE BODY
pros: good for smaller litters but can do for any, only a single incision to close - shorter closure time
cons: may cause more bleeding (thicker muscle), may have residual scar tissue if prior C sections, may be harder to reach fetuses further up the horns
multiple incisions into the uterus
incising multiple times along the UTERINE HORNS
pros: less vascular than the body (less bleeding), reduced risk of postop adhesions, avoids scar tissue forming on uterine body, quick access to each fetus
cons: many sites to have to close (longer suture time), more sites for potential dehiscence
how to remove the neonates
- milk each fetus into the incision
- grasp and gently pull from uterus
- rupture amniotic sac
- double clamp the umbilical cord and cut in between
- sterilely pass each neonate to assistant
- repeat for all puppies
order to remove neonates
if obstructed pup in birth canal that is alive –> remove FIRST
if pups in distress –> remove FIRST
if dead fetuses –> remove LAST but don’t forget to remove them
placental removal
should EASILY detach from the uterine wall - do not force it or will cause significant hemorrhage
if doesn’t remove easily - leave behind, will pass from open cervix in few days
how to avoid premature delivery
always have the OVULATION date to estimate when to schedule a C section
uterine closure
two layer
full thickness bites for each one - simple continuous then inverting pattern on top
absorbable (PDS, monocryl)
role of administering oxytocin
given AFTER the uterus is closed to help the uterus involute/contract down
does not always need to be given but decreases bleeding and promotes passage of placentas
abdominal lavage considerations
if the abdomen got contaminated with fetal fluid –> use warm saline and remove the debris
if no contamination –> use saline to remove any clots
abdominal closure
three layer closure - linea, subcutaneous, intradermal
linea - PDS
en bloc surgery
removing the entire pregnant uterus and handing off to assistants to perform neonatal resuscitation
double clamp each horn and body –> cut between clamps –> hand off uterus
for en bloc surgery - do you ligate prior to cutting out the uterus
NO - do NOT ligate before cutting
blood supply to fetus stops immediately once clamps are placed
continue with OVH once the uterus is handed off
timing for neonatal resuscitation after en bloc surgery
neonates should ideally be delivered within 60 seconds after the first clamp is placed
indications for en bloc surgery
- infectious material in the uterus AND dam needs to be spayed
- litter is dead
- dam is in critical condition and surgery must be as rapid as possible
contraindication for en bloc surgery
fetuses are bradycardic and hypoxia is a concern
