Pediatric Surgery Flashcards by Zach DeVries

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)

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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

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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%

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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%)

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Which is preferable for fluid replacement and resuscitation?

IV Ringers Lactate

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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

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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

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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

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For third space losses in surgery how much is lost in each:
Minor surgery:
Moderate surgery:
Major Surgery:

4/6/8 rule

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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

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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)

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List the differential for pediatric emesis:

Pyloric stenosis
GERD
Feeding intolerance
Infection (UTI, CNS, GI)

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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

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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.

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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.

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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

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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)

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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

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Describe the three types of hernias in terms of severity.

Hernia: protrusion of organ through abdominal opening within anatomic structure
Incarcerated hernia: protrusion of organ that cannot be reduced
Strangulated hernia: protrusion of organ that has lost its blood supply leading to ischemia, necrosis, and perforation

Describe the typical presentation of each type of hernia

Hernia:
- swelling and aching sensation that is non-tender
Incarcerated:
- painful enlargement that is non-reducible and is painful to palpation
- bowel obstruction (nausea/vomiting, abdominal distention)
Strangulated:
- painful enlargement that is non-reducible and is painful to palpation
- bowel obstruction
- fever, chills, peritonitis

Discuss the presentation and management of inguinal hernia

Demographics: 9x more males and in 40-60 year olds (<2 more likely to be incarcerated/strangulated)
Symptoms: mass in scrotum/inguinal canal that is apparent with standing or valsava but disappears with supine, groin pain
Signs: Finger in inguinal canal and get patient to perform valsava
Investigations: ultrasound
Treatment: small, asymptomatic, reducible can treat with surveillance, all others require surgery within 1 month of detection (children <2 require immediate repair)

Differentiate between an inguinal hernia and other scrotal pathology

Inguinal hernia
- cannot palpate superior to the testis
- is reducible
Hydrocele
- can palpate testis above mass
- trans-illuminates

Discuss the presentation and management of an umbilical hernia

Demographics: occur before the age of 5 as this is when the rectus abdominus fascia closes
Symptoms/Signs: asymptomatic, may interfere with feeding, reducible mass,
Treatment: rarely becomes incarcerated and will close on its by age 5, so just require observation.
Indications for surgery: strangulated/incarcerated, symptomatic, significant behavioural problems, proboscoid, fascia defect not decreasing in size

Discuss the presentation and management of biliary colic, cholecystitis, choledocholithiasis, and cholangitis

Presentation:
- Biliary Colic: RUQ pain, radiation to right shoulder, worse with food intake
- Cholecystitis: biliary colic, fever/chills
- Choledocholithiasis: biliary colic, jaundice
- Ascending cholangitis: Charcot’s triad (RUQ pain, jaundice, fever) + confusion and hypotension
Investigations:
- Leukocytosis in cholecystitis and cholangitis
- Elevated conjugated bilirubin in choledocholithiasis and cholangitis
- Elevated Alk Phosph and GGT in choledocholiathiasis and cholangitis
- Ultrasound
Treatment:
- Biliary colic: cholecystectomy
- Cholecystitis: admit, IV fluid resuscitation, urgent surgical cholecystectomy
- Choledocholithiasis: admit, IV fluid resuscitation, ERCP and cholecystectomy
- Cholangitis, admit, IV fluids resuscitation, antibiotics (ceftriaxone and metronidazole), ERCP and cholecystecomy

List that mechanism of biliary colic, cholecystitis, choledocholithiasis, cholangitis

Biliary colic: - Stone obstructs cystic duct leading to pain Cholecystitis: - obstructing stone leads to inflammation of the gallbladder Choledocholithiasis: - obstruction of the common bile duct Cholangitis: - obstruction of the common bile duct leading to stasis of bile and infection

Discuss the presentation and management of appendicitis

Demographics: Between 15-30 most common Symptoms: visceral dull, aching umbilical pain -> somatic, sharp RLQ pain, fever/chills, nausea/vomiting, anorexia, diarrhea Signs: tenderness at McBurney’s point, + Rovsing’s sign/obturator sign/psoas sign, peritoneal signs Investigations: ultrasound, CT, b-HCG to r/o pregnancy, u/a to r/o UTI Treatment: IV fluid resuscitation, antibiotics (ceftriaxone and metronidazole), appendectomy

List the complications of appendicitis

Rupture and peritonitis (require laporotomy) Bowel perforation (require laporotomy) Phlegmon (require IV antibiotics first) Abscess (require IV antibiotics first)

What is the mechanism of appendicitis?

Appendix lumen becomes obstructed from lymphoid hyperplasia, stone, or malignancy -> appendix distends from mucus and bacterial proliferation -> distention leads to venous obstruction -> edema and ischemia of appendix -> necrosis and perforation

What are the risk factors for a gall stone?

Female | Obesity

What are the risk factors for a perianal abscess?

``` Male Obesity Smoking Type 2 diabetes Previous abscess Chron’s TB Radiotherapy ```

What is the mechanism for a perianal abscess?

Have obstruction of the anal crypts at pectinate line -> glandular secretions become static -> stasis and infection

Discuss the presentation and management of perianal abscess

``` Symptoms: dull perianal discomfort that is worse with sitting and defecating, discharge, fever/chills Signs: tender erythematous mass Investigations: CT or ultrasound Treatment: Incision and drainage Antibiotic indications: - type 2 diabetes - valvular heart disease - immunocompromised ```

List the differential for a inguinascrotal swelling

``` Inguinal Hernia Hydrocele Hydrocele of the cord Testicular torsion Epididymitis/Orchitis Varicocele Spermatocele ```

Discuss the presentation and management of testicular torsion

Symptoms: acute onset of severe testicular pain, nausea/vomiting, Signs: swelling and erythema of testicle, Bell-Clapper deformity, absent Phren’s sign and cremasteric reflex Investigations: ultrasound to show decreased blood flow, if suspect torsion take to OR as testicle will die in <6hrs Treatment: bilateral orchipexy

Discuss the presentation and management of orchitis and epididymitis

Demographics: <35 it is e.coli or gonorrheae/chlamydia, >35 it is e.coli Symptoms: acute onset of painful, swollen, erythematous testicle, urethral discharge, STI symptoms Signs: Positive phren’s sign and cremasteric reflex, can palpate painful epididymis Treatment: bed rest with testicular elevation, antiobiotics (gonorrheae: ceftriaxone, chlamydia: ezithromycin, e.coli: ciprofloxacin or fluoroquinolone)

Discuss the presentation and management of intussusception

Demographics: occur between 3-9 months of age Symptoms: abdominal pain, non-bilious vomiting Signs: rectal bleeding (red currant jelly), abdominal distention Investigations: ultrasound to show pseudo-kidney or doughnut sign Treatment: colon or air enema, surgery

List the risks of intussusception

In those <3months or >3 years must consider - Meckel’s diverticulum - Lymphoma - Duplication cyst of the terminal ileum

Discuss the presentation and management of Hirschsprung’s disease

Demographics: Present mainly in neonatal period, with male more common and majority being sporadic Symptoms: delayed passage of meconium (>48hrs), bilious vomiting, abdominal distention, explosive diarrhea on rectal exam Delayed presentation: chronic abdominal pain, constipation, malnutrition, failure to thrive Investigations: Contrast enema, manometry showing internal sphincter tone elevation and absence of relaxation of with rectal distention, biopsy showing absence of ganglion cells Treatment: IV fluid resuscitation, antibiotics, rectal washout, surgical resection of aganglionic colon with anastomosis 1cm above dentate line

What is the embryological mechanism of Hirschsprung’s disease?

Interrupted development of myenteric nervous system -> absence of intestinal ganglion cells -> functional bowel obstruction due to failure to propagate propulsion and relaxation and increase in sphincter tone with rectal distention

Discuss the most important features when examining a child with possible dehydration

History: intake vs losses (be clear), fever, respiratory distress LOC Peripheral pulses: capillary refill, mottling Pulses: babies can not increase SV, so high HR could mean low fluid. Blood pressure does not drop until late in babies due to high systemic vascular resistance. Urinary output

What are the deficit loss replacements for a child <1 year old?

Mild: 5% - increases losses and reduced intake, decreased urinary output, decreased tearing Moderate: 10% - dry mucous membranes, sunken fontanelles/eyes, severely reducing urinary output, Severe: 15% - decreased BP and LOC Over 1 it is the same as adult

What is the minimum systolic BP rule for pediatrics?

70mmHg + (2 x age) | Unless <1-2 months then it is 60

How do you calculate deficit losses in pediatrics?

Estimated fluid losses = kg x estimated loss x 1000mL/kg

Calculate a bolus dose of fluids for a 50kg patient

Bolus of NS = 20mL/kg x 50kg | = 1000 mL

What is the K add-in with maintenance NS?

~20mEq/L in maintenance dose

Calculate the fluid requirements for a 24kg 8 year old with moderate dehydration

Bolus: 480mL in 20 minutes Maintenance: 64mL/hr with 20mEq/L of K Deficit: 1440mL Order: 480mL bolus of NS over 20 minutes with 124mL/hr of D5NS for first 8 hours and then 94mL/hour of D5NS for 16 hours. After 24 hours begin at 64mL/hour of D5NS with 20mEq/L of K

What are the best oral rehydration options in pediatrics?

Pedialyte: 45mEq/L of Na Lytren: 50mEq/L of Na Gatorade: 25mEq/L of Na