Pyloric Stenosis and book 4, case 6-Pyloric Stenosis

Question 1

Tell me about electrolyte abnormalities in patients with pyloric stenosis

Answer 1

They lose HCL from stomach=hypochlormeic, hypokalemic metabolic alkalosis. The kidneys try to keep sodium by getting rid of H+ and K+, making a paradoxical aciduria

Question 2

Pyloric stenosis: What to do with infants NG tube prior to induction

Answer 2

attach it to suction! make sure they have one or either an Og before inducing-turn patient right, left and side to get all of that out.

Question 3

Pyloric stenosis: What do you want in room and ready:

What is some airway stuff you are concerned about?

Answer 3

Surgeon-ready to do a trach or cricothryotomy, difficult airwya cart, several different types of lubricated tubes.
I’m concerned about undiagnosed airway abnormalitis

Question 4

Plan for induction/intubation in a pt with pyloric stenosis:

Answer 4

awake vs RSI with succ.

RSI avoids multiple attempts and then faster than struggling with conscious infant. Double dose Roc

Question 5

Wassup with post-op apnea in kids? Especially in setting of pyloric stenosis? What are you going to do about this?

Answer 5

Pts are often less than 60 weeks post conceptual age
Even though alkalemia is corrected, CSF may take longer to catch up, causing ventilatory depression.
In order to avoid these issues-avoid narcotics, rectal APAP should be fine with some local anesthesia.

Question 6

Before going to OR with these pyloric pts, what are you going to do about electrolytes? What labs matter before going to OR?

Answer 6

elecs must be NORMAL-PERIOD. THIS IS NEVER A SURGICAL EMERGENCY. the infant should have normal skin turgor, and the correction of the electrolyte imbalance should produce a sodium level that is >130 mEq/L, a potassium level that is at least 3 mEq/L, a chloride level that is >85 mEq/L and increasing, and a urine output of at least 1 to 2 mL/kg/hr. These patients need a resuscitation fluid of full-strength, balanced salt solution and, after the infant begins to urinate, the addition of potassium

Question 7

Intraop: what are things youre doing before intubation, what are you giving?

Answer 7

Suction mouth and turn patient to get it all.
Assuming normal airway, pretreat with 20 mcg/kg of atropine and perform RSI with cricoid and succinycholine. (pick induction agent based on vol status-KIM that they are likely depleted.

Question 8

As far as extubating PS patients, what you thiking:

Answer 8

extubate when you normally would. (fully awake, normal breathing patterns)
watch them post op for post op apnea
check elecs as they can get deranged again

Question 9

What fluids would you choose for hydration during medical optimization?

Answer 9

I would use normal saline to replace volume and electrolyte deficits,
and, after urine output is established, I would supplement with potassium. If the
infant’s blood sugar was low, I would consider using a glucose containing solution.
Given the likely metabolic alkalosis, lactated ringers should probably be avoided
since lactate is converted to bicarbonate.

Question 10

How do the kidneys make alkalosis worse?

Answer 10

Initially, the kidneys excrete bicarbonate to compensate for the metabolic alkalosis.
However, as dehydration and hyponatremia worsen, the kidneys must conserve
sodium. The conservation of sodium results in reabsorption of bicarbonate, further
excretion of hydrogen, and increased bicarbonate formation. Therefore, the renal
compensatory mechanisms for dehydration lead to worsening metabolic alkalosis,
making hydration an important initial step in treatment.

Question 11

How would you evaluate this neonate’s volume status?

Answer 11

I would evaluate the patient carefully for physical signs that aid in
estimating the degree of dehydration such as sunken fontanelles, skin turgor, capillary
refill, heart rate, blood pressure, and mental status. I would also ask the mother about
the frequency and volume of vomiting and wet diapers. Depending on my findings, I
would start with a fluid bolus of 10-20 ml/kg of normal saline and then titrate to urine
output and normalization of hemodynamic variables.

Question 12

Normal Hct in newborns?

Answer 12

This hematocrit may be high normal for a two-week old baby as term
neonates usually have a hematocrit around 55%, which then gradually declines to
around 30% at 3 months of age. This patient’s high normal hematocrit is most likely
due to the dehydration that accompanies pyloric stenosis.

Question 13

Pyloric stenosis pt has been medically optimized-how are you inducing?

Answer 13

Because of the risk of aspiration, I would first apply suction to the
gastric tube in the lateral, supine, and prone positions to remove as much of the
gastric contents as possible. I would then preoxygenate and perform a rapid sequence
induction with cricoid pressure to further reduce the risk of aspiration. However,
prior to induction, I would pretreat with atropine to prevent the significant
bradycardia that can occur in infants following succinylcholine administration and
laryngoscopy.

Question 14

Are you using sux in a neonate?

Answer 14

Given the risk of aspiration in this case, I would use succinylcholine
to aid in rapidly securing the airway. However, I would first treat with atropine to
avoid the profound bradycardia and even sinus arrest that may occur with
administration to children. Also, I would recognize that there is increased risk of
hyperkalemia, cardiac arrhythmias, rhabdomyolysis, masseter muscle spasm, and
malignant hyperthermia, when succinylcholine is administered to children.

Question 15

What is the dose of succinylcholine in neonates? Why is it higher?

Answer 15

The dose of 2-3 mg/kg is higher in infants secondary to a relatively
larger volume of distribution.

Question 16

Is an inhalational induction faster or slower in a neonate when compared to an
adult?

Answer 16

An inhalational induction is faster in a neonate, secondary to a higher
minute ventilation-to-PRC ratio and increased blood flow to vessel-rich organs.
Additionally, the blood/gas coefficient is lower in neonates as compared to adults.

Question 17

You place the ETT and are unable to ventilate. What will you do?

Answer 17

I would quickly switch to 100% oxygen, check the circuit, ensure a
patent ETT, and attempt to verify proper ETT placement by auscultation and directlaryngoscopy. Ifl thought the ETT was in the correct place, I would consider
bronchospasm the most likely diagnosis, apply positive airway pressure, take steps to
deepen the anesthetic with an inhalational agent and/or other anesthetic drugs, and
administer a Beta-agonist. If the bronchospasm persisted, I would administer a small
dose of epinephrine. Following initial treatment, I would look for evidence of
stomach contents in the oropharynx, since the patient is at high risk for aspiration and
regurgitant material could have been the cause of the bronchospasm.

Question 18

You break the bronchospasm and bilateral breath sounds have improved on
auscultation, but the airway pressures are still high. What will you do?

Answer 18

I would again confirm proper ETT placement, continue to apply
gentle positive pressure ventilation, administer a -Beta agonist, and ensure a sufficiently
deep plane of anesthesia. This could be residual bronchospasm, atelectasis from
hypoventilation, or the result of aspiration of gastric contents. While I would make
the surgeon aware that possible aspiration has occurred, bronchoscopy, pulmonary
lavage, and antibiotics are probably not indicated even if regurgitant material was
noted in the oropharynx.

Question 19

Are you concerned about hypothermia?

Answer 19

It is important to avoid hypothermia given its association with
delayed wakening, respiratory depression, cardiac irritability, and increased
pulmonary vascular resistance. This is of particular concern in this case because
neonates are more susceptible to hypothermia with their low fat content, thin skin,
and relatively higher ratio of surface area to weight.

Question 20

Describe temperature regulation in the neonate.

Answer 20

Neonates produce heat primarily through nonshivering
thermo genesis, which involves the metabolism of brown fat. This relatively
inefficient process may be further limited by the use of volatile anesthetics and in
premature and sick neonates who often have reduced fat stores.

Question 21

How are you extubating pyloric stenosis kids?

Answer 21

Given this patient’s continuing risk of aspiration, and assuming she
was demonstrating adequate spontaneous ventilation, maintaining normocapnia, and
had undergone full reversal of nondepolarizing muscle relaxants, I would extubate her
in the OR, when fully awake, and in the later position. However, since she
experienced intra-operative bronchospasm, I would administer adequate narcotics and
a ~z-agonist prior to lightening of anesthesia, followed by intravenous lidocaine just
prior to extubation.

Question 22

Post op concerns in pyloric stenosis?

Answer 22

With this patient’s medical condition, I continue to be concerned
about the risk of aspiration and subsequent pulmonary dysfunction. I am also
concerned about the anesthetic complications generally associated with premature
neonates such as hypothermia, hypoglycemia, retinopathy of prematurity, and
postoperative apnea.

Question 23

Is this neonate at increased risk for postoperative apnea?

Answer 23

Yes, she is at increased risk because she is less than 50 weeks
postconceptional age and because of the effects of preoperative alkalosis on the pH of
the cerebral spinal fluid.

Question 24

What are the risk factors for post-op apnea in premature infants?

Answer 24

The risk factors include low gestational age at birth, a history of
chronic lung disease, a history of apnea and bradycardia, multiple congenital
anomalies, sepsis, anemia, and neurological abnormalities. Additionally, anything
that would exacerbate respiratory depression, such as narcotics for pain control,
would possibly increase the risk. Caffeine or aminophylline may be given to reduce
the risk.

Question 25

How long will you monitor this patient postoperatively?

Answer 25

Since this patient is less than 50 weeks postconceptional age, I would
monitor her closely for at least 12 hours and maybe 24 hours postoperatively. If this
patient were between 50-60 weeks postconceptional age, I would consider a shorter
period of monitoring.