Surgical procedures part 2- Additional info Flashcards
Describe malrotation and midgut volvulus.
results from abnormal migration or incomplete rotation of the intestines from the yolk sac back into the abdomen
intestines twisted around the superior mesenteric artery may produce kinking or compression of the vascular supply
may result in atretic segments, comprised perfusion, and intestinal ischemia
Describe the meaning of volvulus
bowel strangulation and shock
Describe the presentation of malrotation and midgut volvulus.
1/3rd of cases present within the first week of life with bilious vomiting, distended abdomen, & hemodynamic instability- may present with hypotension, hypovolemia, and electrolyte abnormalities
blood stools are an ominous sign
rapidly compromised blood supply
a true surgical emergency due to risk necrosis
Describe surgery for the intestinal malrotation with midgut volvulus.
reduces volvulus and relieves obstruction by dividing the fixation bands between the cecum and the duodenum or jejunum and widening the base of the mesentery
children with less than 30 to 40 cm of small bowel generally develop short-gut syndrome and ultimately require TPN
Describe Ladd’s procedure
performed to alleviate intestinal malrotation
involves counterclockwise detorsion of the bowel, surgical division of Ladd’s bands, widening of the small intestine’s mesentery, performing an appendectomy, and reorientation of the small bowel on the right and the cecum and colon on the left
Describe anesthetic concerns for the patient with midgut volvulus.
risk for aspiration–> RSI
avoid N2O
septic shock- IV access/a-line, often an opioid based anesthetic and paralysis with ketamine as the induction agent of choice
Hypovolemic- fluid, blood and electrolyte replacement, blood products should be available, Hct may be falsely increased secondary to marked intravascular volume depletion
Describe omphalocele and gastroschisis.
external herniation of abdominal contents through an anterior abdominal wall defect
Describe the presentation of omphalocele and gastroschisis
may present with impaired blood supply to herniated organs, intestinal obstruction, and major intravascular fluid deficits
How is omphalocele and gastroschisis diagnosed
US confirms presence of lesions at nuchal scan at 10 to 13 weeks gestation
large defects are an indication for C-section
Describe omphalocele.
hernia or rupture at the umbilicus
failure of the gut to migrate from the yolk sac into the abdomen
Omphalocele has associated ______ abnormalities.
genetic, cardiac, urologic, and metabolic abnormalities. **
In omphalocele, the viscera emerge
from the umbilicus and are covered with a membranous sac*****
Describe gastroschisis.
exstrophy of “belly” “viscera” through an abdominal wall gap
results in occlusion in the omphalomesenteric artery during gestation
Gastroschisis is ________ with other congenital anomalies.
usually associated
In gastroschisis, the herniated viscera are exposed to
air after delivery resulting in worsening inflammation, edema, dilation with abnormal bowel function
Although gastroschisis and omphalocele are different in presentation,
they have almost identical anesthetic and medical managements
Maintenance of perfusion and reduction of FLUID LOS from exposed visceral surfaces is important
closure of the abdomen is the goal however is often delayed to avoid exposing the viscera to excessive pressure
With gastroschisis and omphalocele, high intra-abdominal pressure may result in
cardiorespiratory failure, renal failure, decreased hepatic function, ischemic bowel, and death
pressures >20 mmHg are poorly tolerated
A silo is
temporary housing for the bowel
sutured to the defect and over the next several days, the silo is reduced to allow accommodation of gastric contents into abdominal wall via gravity & stretching
Anesthetic considerations for gastroschisis and omphalocele include
assess for associated anomalies
increased IAP- gastric tube inserted to decompress stomach
severe electrolyte disturbances- monitor blood glucose
rehydrate (gastroschisis lose more fluid than omphaloceles)- availability of blood products, plan for IV access
-prevent hypothermia
aspiration risk necessitating RSI, avoid nitrous oxide
-risk for infection
Describe the postoperative considerations for the patient with gastroschisis and omphalocele
assess ability to extubate
-continue gastric suction until bowel function recovers
continue IV fluids and glucose
may require IV alimentation (weeks to months)
often remain intubated with IV sedation, paralytics, and opioids until clinical status stabilizes
Criteria for aborting primary closure in gastroschisis and omphalocele includes:
intragastric pressure >20 mmHg
intravesical pressure >20 mmHg
end-tidal CO2 50 mmHg or higher*
max ventilatory pressure of 35 cmH2O or greater
Esophageal atresia and tracheoesophageal fistula are often associated with
VATER or VACTERL V-vertebral abnormalities A- imperforated anus C- congenital heart disease T-tracheo E- esophageal fistula R-renal abnormalities L-limb abnormalities
Tracheoesophageal fistula occurs because of
incomplete separation of the trachea and esophagus that begins during the 4th-5th week of gestation
Survival of infants with TEF and no other congenital abnormalities is
> 95%
Risks associated with TEF include:
pneumonia, poor nutrition, gastric distension which impairs ventilation
Esophageal atresia with or without TEF is normally diagnosed immediately after
birth when the newborn has excessive secretions, coughing, and choking after first feeding
-additional indicators: recurrent pneumonias, OG cannot be passed into the stomach
Treatment for TEF includes
surgical repair with ligation of fistula and anastomosis of esophagus
Describe surgery for TEF.
surgery is urgent, but not emergent
+/- gastrostomy placement
ligation of the fistula
anastomoses of esophagus atretic segments
left lateral decubitus position and right thoracotomy
Describe the discussion involving clinical presentation of TEF in the preop period.
inability to feed, chest x-ray, prenatal US with polyhydramnios
Describe associated anatomic anomalies of the patient with TEF.
prematurity, cardiac defects/echo, vacterl, cleft
Describe assessment of the pulmonary system for patients with TEF.
aspiration, PNA, diaphragmatic expansion
Describe medical management of the patient with TEF.
NPO, NG tube, gastric tube, IV fluids, TPN, corrected acidosis, ABG, CBC, electrolytes, T&C, glucose
Describe the positioning and monitoring for TEF patients.
left lateral position- right thoracotomy
standard monitors
a-line q1 hour ABGs (lung retraction may compromise accurate ETCO2)
left-sided precordial to assess tube migration
minimal blood loss- however proximity of surgical site to major vessels and organs (T&C), Hct goal> 30%
glucose infusion and monitoring
Describe airway management for TEF.
RSI
challenging airway- consider fiberoptic and awake intubation- minimizes gastric distension & allows precise placement of ETT cuff
-inhalation induction-avoiding positive pressure ventilation- maintain spontaneous ventilation
-confirm ETT placement**
-crucial to place ETT between fistula and carina*** (distal to fistula, right main-stem and slowly withdrawal until BBSE)
The presence of bowel gas suggests
TEF, on occasion abdominal distension is severe enough to cause atelectasis and impede ventilation
Describe maintenance of anesthesia for TEF.
combination inhalation and opiates
avoid nitrous oxide (decreases fraction of inspired O2 and contributes to bowel distension)
muscle relaxation
large surgical surface area- at risk for hypothermia
surgical traction may compromise lung, great vessels, trachea, heart & vagus nerve
A common pitfall during TEF is
adequate tissue oxygenation
If a patient experiences arterial hypoxia during TEF
the surgeon may need to release traction and alveolar recruitment maneuvers performed
Precipitous O2 desaturation can occur during TEF for a variety of reasons:
atelectasis and secretions preoperative= shunting of pulmonary blood flow
retraction on lung tissue, bleeding, tracheal, and bronchial compression
ETT malposition
Adequate tissue oxygenation for TEF patients invovles
monitoring ABGs & frequent suctioning and ventilator setting changes
Early complications of TEF includes
anastomosis leaks and strictures
GERD
feeding aversions
esophageal dysmotility
Long-term complications of TEF icludes
strictures
pulmonary disease
tracheomalacia
Early extubation for TEF is desirable because
it prevents prolonged pressure of the ETT on the suture line
- may extubate if adequate spontaneous respirations
- respiratory depression in the neonate can be due to hypothermia, hypoglycemia, or anemia
The following may complicate recovery for TEF postop patients.
recurrent laryngeal injury, overlook additional fistulas, and recurrent fistulas
Patients with TEF may remain intubated
although it can cause excessive pressure on new anastomosis, reintubation can also be traumatic
- position ETT 1 cm away from fistula repair
- suction catheter marked with distance for insertion to stay above suture line
Conditions requiring emergency surgery in neonates may be accompanied by
concurrent medical problems*****
_______ of an average neonate is 5-8 mL/kg/min.
Oxygen consumption*****
rapid decreases in arterial O2 content after brief periods of ventilatory compromise must be balanced coupled with risk of ROP and lung tissue toxicity from hyperoxia
_______ is a large concern for any neonatal case
postoperative apnea monitoring*****
Temperature regulation requires
warming the room temperature***** and active warming
_______ has an increased affinity for oxygen and can reduce oxygen release of Hgb to the tissues
Fetal Hgb
______ results in increased Co2 production and the respiratory rate must be increased to facilitate CO2 elimination
high metabolic rate***
-expired O2 may be diluted with exhaled gas and dead space
