UBP 6.4 (Short Form): Obstetrics – Laparoscopic Appendectomy

Question 1

What are your concerns regarding nonobstetric surgery for a pregnant patient?

(A 16-year-old, 5’4”, 68 kg, pregnant female presents for laparoscopic appendectomy at 22 weeks gestation. She reports nausea and vomiting for the past 24 hours. Her medical history is significant for depression and poorly controlled insulin dependent diabetes mellitus. She denies any other medical history. Her medications include 20 U of NPH and 10 U of Lispro insulin each morning and Zoloft (which she has not been taking during pregnancy). Her vital signs are: BP = 128/86 mmHg, P = 93, R = 18, T = 37.8 C.)

Answer 1

In addition to the risks associated with the underlying disease process and the planned surgical procedure,

the obstetric patient is exposed to increased morbidity and mortality when undergoing surgery and/or anesthesia due to the many physiologic changes associated with pregnancy.

• The mother is exposed to increased risk of failed intubation, pulmonary aspiration, hemorrhage, infection, and thromboembolism.
• The baby is also exposed to increased risk, including – preterm labor/delivery (especially with abdominal surgery), teratogenesis (although the highest risk is during organogenesis, which occurs around the 15th - 50th day post-conception), fetal asphyxia, intrauterine growth restriction, miscarriage, and neurotoxicity (exposure of the developing brain to general anesthesia may lead to neurodegeneration, with subsequent long-term neurocognitive deficits).

Undergoing laparoscopic surgery carries specific risks for the obstetric patient, such as –

• damage to the gravid uterus (this risk is reduced by employing alternative sites for the Varess needle and trocars),
• increased risk of miscarriage or preterm labor (because abdominal surgery), and
• hypercapnia-induced fetal acidosis (risk reduced by adjusting mechanical ventilation to maintain normocapnia or by employing gasless laparoscopy.)

Question 2

When is the best time to perform semi-elective surgery on a pregnant patient?

(A 16-year-old, 5’4”, 68 kg, pregnant female presents for laparoscopic appendectomy at 22 weeks gestation. She reports nausea and vomiting for the past 24 hours. Her medical history is significant for depression and poorly controlled insulin dependent diabetes mellitus. She denies any other medical history. Her medications include 20 U of NPH and 10 U of Lispro insulin each morning and Zoloft (which she has not been taking during pregnancy). Her vital signs are: BP = 128/86 mmHg, P = 93, R = 18, T = 37.8 C.)

Answer 2

Given the increased risk of miscarriage and teratogenesis in the first trimester, and the increased risk of preterm labor/delivery in the third trimester, the optimal time for semi-elective surgery during pregnancy is the = second trimester.

Furthermore, it is preferable to operate before the 23rd week of pregnancy in order to further minimize the risk of preterm labor and allow for adequate surgical access within the abdomen.

However, in deciding when to perform semi-elective surgery, I would always weigh the risks of surgical delay against the risks to the baby.

Question 3

Which anesthetic agents are teratogenic?

(A 16-year-old, 5’4”, 68 kg, pregnant female presents for laparoscopic appendectomy at 22 weeks gestation. She reports nausea and vomiting for the past 24 hours. Her medical history is significant for depression and poorly controlled insulin dependent diabetes mellitus. She denies any other medical history. Her medications include 20 U of NPH and 10 U of Lispro insulin each morning and Zoloft (which she has not been taking during pregnancy). Her vital signs are: BP = 128/86 mmHg, P = 93, R = 18, T = 37.8 C.)

Answer 3

While almost any agent can prove teratogenic if the dose is large enough and given at the right time,

human studies have NOT conclusively shown that any anesthetic agent results in increased congenital abnormalities.

The conclusions of past studies that suggested possible teratogenic effects associated with nitrous oxide and benzodiazepines have been questioned, and are NOT supported by more recent studies and epidemiologic data.

Question 4

Would you administer prophylactic glucocorticoids prior to surgery?

(A 16-year-old, 5’4”, 68 kg, pregnant female presents for laparoscopic appendectomy at 22 weeks gestation. She reports nausea and vomiting for the past 24 hours. Her medical history is significant for depression and poorly controlled insulin dependent diabetes mellitus. She denies any other medical history. Her medications include 20 U of NPH and 10 U of Lispro insulin each morning and Zoloft (which she has not been taking during pregnancy). Her vital signs are: BP = 128/86 mmHg, P = 93, R = 18, T = 37.8 C.)

Answer 4

I would NOT administer prophylactic glucocorticoids for the purpose of fetal lung maturation, since this baby has not yet reached the age of viability (23-24 weeks).

Current recommendations are to administer a single course of corticosteroids when there is a significant risk of preterm delivery between 24 and 34 weeks gestation.

• Prophylactic administration at this gestational age has been demonstrated to significantly reduce the incidence of respiratory distress syndrome, intraventricular hemorrhage, and neonatal death in infants delivered prior to 30 weeks gestation.

I would, however, consider administering dexamethasone to help with the mother’s nausea, keeping in mind that the administration of a glucocorticoid to a diabetic patient may further complicate glucose control.

Question 5

Would you administer a prophylactic tocolytic?

(A 16-year-old, 5’4”, 68 kg, pregnant female presents for laparoscopic appendectomy at 22 weeks gestation. She reports nausea and vomiting for the past 24 hours. Her medical history is significant for depression and poorly controlled insulin dependent diabetes mellitus. She denies any other medical history. Her medications include 20 U of NPH and 10 U of Lispro insulin each morning and Zoloft (which she has not been taking during pregnancy). Her vital signs are: BP = 128/86 mmHg, P = 93, R = 18, T = 37.8 C.)

Answer 5

I would NOT administer prophylactic tocolytics because,

although surgery places the pregnant patient at increased risk of preterm delivery (the risk is even higher with abdominal surgery, as in this case),

there is NO evidence to support the routine use of prophylactic tocolytic agents.

However, I would utilize tocodynamometry during the perioperative period to identify any onset of uterine contractions and allow for expeditious tocolytic treatment, if appropriate

(there is no consensus concerning the lower gestational age limit for tocolytic therapy – some sources suggest viability and others 20 weeks).

Unfortunatley, monitoring of uterine contractions and early tocolytic therapy has NOT been proven to reduce the incidence of preterm delivery.

Question 6

Is aspiration prophylaxis necessary at this gestational age?

(A 16-year-old, 5’4”, 68 kg, pregnant female presents for laparoscopic appendectomy at 22 weeks gestation. She reports nausea and vomiting for the past 24 hours. Her medical history is significant for depression and poorly controlled insulin dependent diabetes mellitus. She denies any other medical history. Her medications include 20 U of NPH and 10 U of Lispro insulin each morning and Zoloft (which she has not been taking during pregnancy). Her vital signs are: BP = 128/86 mmHg, P = 93, R = 18, T = 37.8 C.)

Answer 6

While it is unclear at what point in gestation the effects of pregnancy significantly increase the risk of pulmonary aspiration

(i.e. mechanical compromise of the gastroesophageal junction, progesterone-induced relaxation of the lower esophageal sphincter, increased intragastric pressure),

most practitioners recommend aspiration prophylaxis after 18-20 weeks gestation.

This patient not only falls within this range, but is at increased risk due to –

• the emergent nature of the procedure,
• an increased risk of difficult intubation (due to the physiologic changes of pregnancy and/or diabetic stiff joint syndrome),
• potential gastroparesis (acute abdomen and/or diabetic autonomic neuropathy),
• concurrent nausea and vomiting, and
• the fact that she is undergoing laparoscopic surgery.

Therefore, I would take steps to minimize the risk of pulmonary aspiration, such as –

• administering metoclopramide, an H2-receptor antagonist, and/or an nonparticulate antacid;
• performing a rapid sequence induction with cricoid pressure and the patient in reverse trendelenburg (improves respiratory mechanics, facilitates rapid intubation, and inhibits passive regurgitation) ;
• emptying the stomach with a nasogastric or orogastric tube; and
• delaying extubation until the patient is fully awake.

Question 7

What is diabetic stiff joint syndrome?

(A 16-year-old, 5’4”, 68 kg, pregnant female presents for laparoscopic appendectomy at 22 weeks gestation. She reports nausea and vomiting for the past 24 hours. Her medical history is significant for depression and poorly controlled insulin dependent diabetes mellitus. She denies any other medical history. Her medications include 20 U of NPH and 10 U of Lispro insulin each morning and Zoloft (which she has not been taking during pregnancy). Her vital signs are: BP = 128/86 mmHg, P = 93, R = 18, T = 37.8 C.)

Answer 7

Diabetic stiff joint syndrome (a.k.a. diabetic scleroderma), which is due to –

glycosylation of proteins and abnormal collagen cross-linking, –

may develop in patients with long-standing type I diabetes mellitus.

The syndrome can result in limited movement of the atlanto-occipital, temporomandibular, and cervical spine joints, potentially increasing the difficulty of direct laryngoscopy and intubation.

I would use the “prayer sign” to screen for this syndrome.

If the patient is unable to completely approximate the palmar surfaces of the phalangeal joints of the hands (prayer sign), this is suggestive of stiff joint syndrome, which raises concerns of difficult airway management.

Question 8

Her blood sugar comes back at 356 mg/dl. What would you do?

(A 16-year-old, 5’4”, 68 kg, pregnant female presents for laparoscopic appendectomy at 22 weeks gestation. She reports nausea and vomiting for the past 24 hours. Her medical history is significant for depression and poorly controlled insulin dependent diabetes mellitus. She denies any other medical history. Her medications include 20 U of NPH and 10 U of Lispro insulin each morning and Zoloft (which she has not been taking during pregnancy). Her vital signs are: BP = 128/86 mmHg, P = 93, R = 18, T = 37.8 C.)

Answer 8

Given this patient’s clinical picture, including potential infection, high blood sugar, abdominal pain, and nausea and vomiting,

I would be very concerned that this type I diabetic has developed diabetic ketoacidosis (DKA) secondary to, or independent of, appendicitis (abdominal pain, nausea, and vomiting are all symptoms of DKA as well as appendicitis).

Therefore, I would –

• notify the surgeon;
• administer an IV bolus of 10 U of insulin;
• begin fluid replacement with normal saline;
• check for serum and urinary ketones;
• obtain an arterial blood gas, blood urea nitrogen, creatinine, and electrolytes; and
• determine the anion gap (DKA results in an increased anion gap acidosis).

If it were determined that the patient was in DKA, I would –

• continue fluid replacement;
• start an insulin infusion with the goal of reducing plasma glucose by 75-100 mg/dL per hour (more rapid reductions risk cerebral edema);
• add 5% dextrose to the insulin infusion when the serum glucose reaches 250 mg/dL (to prevent hypoglycemia and to provide a continuous energy source);
• replace potassium, phosphate, and magnesium as necessary; and
• continue to monitor serum potassium, blood glucose, serum ketones, and the anion gap.

Clinical Note:

• The normal anion gap is 12 +/- 4. Some labs with more modern measurement techniques (providing more accurate measurements of chloride levels) will list the normal anion gap as 7+/- 4.
• Also note that these “normal” anion gap ranges are based on the omission of K+ from the equation. Therefore, you should always consult your specific laboratory’s normal reference range when making clinical decisions.

Anion Gap = Na+ - (Cl- + HCO3-)

or

Anion Gap = [Na+] + [K+] - [Cl-] - [HCO3-]

Question 9

You determine that she is in DKA. Would you delay this emergent case?

(A 16-year-old, 5’4”, 68 kg, pregnant female presents for laparoscopic appendectomy at 22 weeks gestation. She reports nausea and vomiting for the past 24 hours. Her medical history is significant for depression and poorly controlled insulin dependent diabetes mellitus. She denies any other medical history. Her medications include 20 U of NPH and 10 U of Lispro insulin each morning and Zoloft (which she has not been taking during pregnancy). Her vital signs are: BP = 128/86 mmHg, P = 93, R = 18, T = 37.8 C.)

Answer 9

The decision to delay this case for treatment is a risk/benefit decision that must be made in consultation with the surgeon.

In that discussion, I would point out that even a short delay to partially resolve metabolic acidosis, hypovolemia, and hypokalemia may reduce the risk of intraoperative cardiac arrhythmias and hypotension.

However, the decision would have to be made recognizing that delaying the case risks worsening appendicitis, peritonitis (if not already present), and further metabolic deterioration.