Pediatric Surgery Flashcards
Describe the three types of fluid management strategies
Maintenance: used when the patient is not taking anything by mouth
Deficit: used when the patient has already lost fluids (dehydration, hypovolemic, shock)
Ongoing losses: used when the patient has active losses (active hemorrhage)
List the two categories of fluids and examples of each
Crystalloids: aqueous solutions of salts - Normal saline (0.9% saline) - Ringer’s Lactacte (130mEq Na, 109mEq Ca, K, Ca, lactate) - D5W (50g/L dextrose in water) - 2/3 1/3 (normal saline and D5W) Colloids: aqueous solutions of proteins - pRBCs - albumin - fresh frozen plasma
For RL and NS, ____ go into the interstitium and ____ go into the intravascular space
For D5W, ___ go into the ICF and ___ go into the ECF
For colloids, ___ go into the intravascular volume
For RL and NS, 2/3 and 1/3. Require 3:1 ratio of NS/RL:L of blood when resuscitating
For D5W, 2/3 and 1/3
For colloids, 100%
Provide an example of which fluid is best suited for each condition: Initial resuscitation - Maintenance therapy <1 day - Maintenance therapy 1-7 days - Risk of hypoglycaemia (diabetic or infant) - Vomiting/hypochloremia - Hyperchloremic metabolic acidosis - Diarrhea/obstruction/small bowel pathology - Blood loss - Inflammation - Hypovolemia - Dehydration -
Initial resuscitation - RL or NS
Maintenance therapy <1 day - RL or NS
Maintenance therapy 1-7 days - 2/3 1/3
Risk of hypoglycaemia (diabetic or infant) - D5W
Vomiting/hypochloremia - RL or NS
Hyperchloremia metabolic acidosis - RL
Diarrhea/obstruction/small bowel pathology - RL
Blood loss - pRBCs or RL or NS
Inflammation - RL or NS
Hypovolemia - RL or NS
Dehydration - hypotonic saline (0.25 or 0.45%)
Which is preferable for fluid replacement and resuscitation?
IV Ringers Lactate
List some of the advantages and disadvantages of each of the crystalloids
NS:
Advantages - highly compatible and available
Disadvantages - hyperchloremic hypernatremic non-anion gap metabolic acidosis, renal failure, volume overload
RL:
Advantages - physiological similar to ECF, decrease risk of adverse effects of NS
Disadvantages - hyperkalemia, should not be used with blood products
D5W:
Advantages - useful for those at risk of hypoglycaemia, good for dehydration/hypernatremia
Disadvantages - high risk for hyponatremia and cerebral edema
2/3 1/3:
Advantages - good for long term maintenance therapy
Disadvantages - similar to D5W
Discuss how to calculate the maintenance fluid dose in a 70kg male
4/2/1 rule where:
4mL/kg/hr for first 10kg
2mL/kg/hr for second 10kg
1mL/kg/hr for remaining 10kg
In 70kg male:
410 + 210 + (70-20)*1 = 110mL/hr = 2.64L/day
Discuss how to calculate deficit losses
Mild losses = 3% of body weight
- Signs: dry axilla or mucous membranes
Moderate losses = 6% of body weight
- Signs: oliguria, orthostatic hypotension, cool peripheries
Severe losses = 9% of body weight
- Signs: oliguria, compromised CNS function
Amount of water by gender
Male: 60%
Female: 50%
Elderly: 45%
Multiply % body water by weight and then by estimated losses to figure how much should be replaced. 1/2 should be replaced in first 8 hours and remaining 1/2 in following 16 hours
For third space losses in surgery how much is lost in each:
Minor surgery:
Moderate surgery:
Major Surgery:
4/6/8 rule
Discuss the presentation and management of pyloric stenosis
Demographics: Aged 2-8
Symptoms: acute, progressive non-bilious vomiting, abdominal pain
Signs: palpable pyloric olive, visible gastric motility waves, gastric distension, hypovolemic
Investigations: ultrasound showing thickened pyloric sphincter (>3mm, >14mm, >15mm), upper GI series
Treatment: IV fluid resuscitation, Ramsted’s pyloromyotomy
What is the mechanism of metabolic alkalosis from vomiting
Vomiting leads to loss of HCl leading to hypochloremia and metabolic acidosis -> to compensate for HCl losses bicarbonate is lost in urine -> paradoxical aciduria and hypokalemia (K is lost with HCO3)
List the differential for pediatric emesis:
Pyloric stenosis
GERD
Feeding intolerance
Infection (UTI, CNS, GI)
Discuss the presentation and management of Meckel’s Diverticulum
Demographics: 2% of population, 2% are symptomatic, 2x more likely in males, 2 blood supplies, 2 types of ectopic mucosa, 2 feet from ilealcecal junction, present under age of 4
Symptoms/Signs: bleeding (ulceration from mucosa, rectal bleeding, severe anemia), inflammation (pain, vomiting) , obstruction (nausea/vomiting, abdominal pain and distension, constipation) which can lead to intussusception or volvulus
Investigations: Technetium 99m
Treatment: surgical resection
What is the embryological mechanism of Meckel’s diverticulum?
Proximal portion of omphalomesenteric canal remains open forming a diverticulum on the mesenteric side of distal small intestine.
What is the embryological mechanism for malrotation and volvulus? Differentiate between the two.
Malrotation occurs due to the angle of Treitz and cecum lie next to each other. Volvulus occurs when small bowel twists around the super mesentaric artery leading to small bowel ischemia and necrosis.
Discuss the presentation and management of volvulus
Demographic: present within the first month of life
Symptoms: previously healthy child that develops bilious vomiting and feeding difficulties, abdominal distention with tenderness and/erythema, rectal bleeding
Investigations: Upper GI series
Treatment: IV fluid resuscitation, antibiotics, surgery (division of Ladd bands, rotation, appendectomy)
Chronic presentation: chronic vomiting, hematemesis, intermittent abdominal pain, diarrhea or constipation, failure to thrive
Discuss the diagnosis and management of intestinal atresia
Demographics: usually syndrome (Downs), present within first few days of life
Symptoms: distended abdomen, bilious vomiting, did not pass meconium
Signs: hyperbilirubinia leading to jaundice
Investigations: abdominal x-ray, upper GI series
Treatment: NG tube suction, IV fluid resuscitation, antibiotics, surgery (removal or anastamosis)
What is the embryological mechanism of intestinal atresia?
Have interruption of mesenteric blood supply -> ischemia and necrosis of fetal intestine -> resorption of distal and proximal ends
