Anesthesia for Dilation and Curettage

Questions and Answers

What is a primary reason for performing a dilation and curettage (D&C)?

To remove fibroid tumors from the uterus

To permanently sterilize the patient

To perform an emergency cesarean section

To collect tissue for biopsy (correct)

Which of the following is NOT a risk associated with the D&C procedure?

Hemorrhage

Infection

Uterine atony (correct)

Cervical laceration

What hormonal change is primarily responsible for preparing the endometrial lining for implantation?

Progesterone release (correct)

Estrogen dominance

Increased luteinizing hormone (LH)

Follicle-stimulating hormone (FSH) elevation

What term describes a pregnancy that has been retained for a minimum of 8 weeks without viability?

Missed abortion Signup and view all the answers

Approximately what percentage of clinically recognized pregnancies result in miscarriage within the first three months?

15% to 20% Signup and view all the answers

Which patient positioning is used during a dilation and curettage (D&C) procedure?

Lithotomy position Signup and view all the answers

What is the typical procedure for managing abnormal uterine bleeding due to fibroids?

Dilation and curettage Signup and view all the answers

What is an incorrect statement regarding ultrasound examinations and beta-hCG tests?

They are utilized mainly during the second trimester. Signup and view all the answers

Which coexisting condition is most commonly associated with abnormal bleeding in women over 40?

Endometrial cancer Signup and view all the answers

What is the effect of a decrease in hemoglobin on arterial oxygen content (CaO2)?

It decreases arterial content of oxygen. Signup and view all the answers

How does the body compensate for decreased oxygen delivery due to anemia?

By stimulating increased cardiac output. Signup and view all the answers

Which hemoglobin level is considered below normal for women?

11.0 g/dL Signup and view all the answers

What is the relationship between 2,3-diphosphoglycerate and oxygen release from hemoglobin?

It facilitates the release of oxygen from hemoglobin. Signup and view all the answers

What is a common physiological response to mild to moderate anemia in healthy women?

No additional surgical and anesthetic risk. Signup and view all the answers

How much oxygen does each gram of hemoglobin bind?

1.39 mL Signup and view all the answers

In a patient with anemia and a hemoglobin of 9.1 g/dL, what factor should the anesthetist prioritize?

Maximizing oxygenation. Signup and view all the answers

What is the relationship between obesity and miscarriage in women of reproductive age?

The incidence of miscarriage in obese women is 67% higher compared to normal-weight women. Signup and view all the answers

Which BMI classification indicates someone is considered morbidly obese?

BMI of 40 to 44.9 Signup and view all the answers

What physiological factor is NOT typically associated with obese individuals impacting anesthesia risk?

Decreased oxygen consumption Signup and view all the answers

What is a significant preoperative evaluation needed for obese patients before surgical interventions?

Electrocardiogram to identify cardiovascular risks Signup and view all the answers

Which of the following statements about hormonal changes in obese women is true?

Obese women show a higher incidence of hormonal imbalances affecting infertility. Signup and view all the answers

Which respiratory problem is often exacerbated in obese patients during anesthesia?

Decreased gastroesophageal sphincter tone Signup and view all the answers

How does the presence of polycystic ovaries in obese women affect fertility?

It contributes to abnormal ovulation and hormonal imbalances. Signup and view all the answers

What is a characteristic of 'super obesity' regarding BMI?

It is classified as a BMI greater than 45. Signup and view all the answers

What physiological effect does increased progesterone have on gastric emptying during pregnancy?

It delays gastric emptying. Signup and view all the answers

How does placental gastrin secretion affect the gastrointestinal system during pregnancy?

It increases gastric acidity and decreases lower esophageal tone. Signup and view all the answers

At what point in pregnancy should a patient be considered to have a 'full stomach' and at risk for gastric aspiration?

12 to 14 weeks gestation. Signup and view all the answers

What role does motilin play in the gastrointestinal system during pregnancy?

It facilitates gastric emptying. Signup and view all the answers

Which of the following hormonal changes is NOT associated with increased gastric aspiration risk during pregnancy?

Decreased gastric acidity. Signup and view all the answers

What is the most appropriate airway management technique for an obese patient requiring general anesthesia?

Endotracheal tube placement Signup and view all the answers

Which position is specifically recommended to enhance airway visualization in obese patients during laryngoscopy?

Head-elevated laryngoscopy position (HELP) Signup and view all the answers

What is a common nerve injury associated with the lithotomy position during surgery?

Common peroneal nerve injury Signup and view all the answers

In the context of obese patients, what position helps to improve diaphragmatic function before anesthesia induction?

Reverse Trendelenburg position Signup and view all the answers

Which statement regarding nerve injuries in the lithotomy position is TRUE?

The incidence of common peroneal nerve injury is 1:3608. Signup and view all the answers

Which of the following factors increases the risk of nerve injury during prolonged surgical procedures?

Thin body habitus Signup and view all the answers

What anatomical location is critical for the common peroneal nerve, which is susceptible to injury?

Lateral to the neck of the fibula below the knee Signup and view all the answers

What risk is associated with airway management in obese patients during surgery?

Difficult intubation Signup and view all the answers

What is a major complication associated with improper positioning in the lithotomy position?

Common peroneal nerve injury Signup and view all the answers

Which physiological change is least likely to occur when patients are placed in the lithotomy position?

Decreased peak inspiratory pressure Signup and view all the answers

What is the consequence of excessive external rotation when the lithotomy position is initiated?

Sciatic nerve injury Signup and view all the answers

What body's compensatory mechanism is particularly challenged in obese patients undergoing neuraxial anesthesia?

Identification of anatomical landmarks Signup and view all the answers

What treatment consideration should be prioritized for a patient receiving regional anesthesia before a D&C procedure?

Continuous sedation during the procedure Signup and view all the answers

Which factor contributes to an increased risk of hypoxemia in patients placed in the Trendelenburg position?

Increased abdominal pressure on the diaphragm Signup and view all the answers

Why might the incidence of postoperative nausea and vomiting (PONV) be lower with regional anesthesia during a D&C?

Decreased need for general anesthesia Signup and view all the answers

What is a common consequence of leg positioning in the lithotomy position regarding venous return?

Increased risk for thrombus formation Signup and view all the answers

What specific effect does obesity have on the height of the neuraxial block during anesthesia?

Increases block height due to anatomical factors Signup and view all the answers

What is a critical disadvantage of using general anesthesia during a D&C procedure?

Increases risk of aspiration Signup and view all the answers

Which inhalation agent is associated with the least degree of uterine relaxation at 1.5 MAC?

Isoflurane Signup and view all the answers

What is a significant pharmacologic action of oxytocin (Pitocin) during a D&C?

Enhances uterine contractions Signup and view all the answers

What complication is most significantly associated with general anesthesia for D&C procedures?

Postoperative nausea and vomiting (PONV) Signup and view all the answers

Which physiological response is expected when inhalation agents are administered during a D&C?

Decreased uterine smooth muscle contraction Signup and view all the answers

What local anesthetic is most commonly used for performing a paracervical block?

1% lidocaine Signup and view all the answers

Which side effect is NOT commonly associated with the administration of Pitocin?

Hypotension Signup and view all the answers

What potential effect does uterine atony have on a patient undergoing a D&C?

Increased bleeding Signup and view all the answers

Which anatomical structure is specifically targeted during a paracervical block to anesthetize visceral sensory nerve fibers?

Frankenhauser ganglion Signup and view all the answers

What primary action does oxytocin perform when administered during a D&C due to uncontrolled bleeding?

Stimulates uterine contractions Signup and view all the answers

What is a potential risk during a D&C procedure related to anesthetic depth?

Patient movement increasing risk of uterine perforation Signup and view all the answers

What technique is advised to enhance patient comfort prior to administering a paracervical block?

Administration of benzodiazepines and propofol Signup and view all the answers

Which complication is least likely to occur directly from the anesthetic technique during a D&C?

Nerve injury Signup and view all the answers

When injecting local anesthetic for a paracervical block, what is the recommended total volume at each target position?

5 mL Signup and view all the answers

Which of the following is a recognized surgical complication during a D&C procedure?

Uterine perforation Signup and view all the answers

What should be monitored carefully when large volumes of local anesthetic are administered?

Signs of local anesthetic toxicity Signup and view all the answers

What factor contributes the most to a higher incidence of postoperative nausea and vomiting (PONV) in patients undergoing a D&C?

General anesthesia Signup and view all the answers

Which medication is now considered the drug of choice for PONV prophylaxis in patients undergoing D&C?

Dexamethasone Signup and view all the answers

What characteristic pain is typically experienced by patients after a D&C procedure?

Uterine cramps Signup and view all the answers

Which combination therapy has been noted to be beneficial for preventing PONV?

Dexamethasone and a serotonin antagonist Signup and view all the answers

What is considered an essential measure to reduce the possibility of PONV after a D&C procedure?

Adequate intravenous volume replacement Signup and view all the answers

What is the primary mechanism suggested for the antiemetic properties of dexamethasone?

Decreasing prostaglandin synthesis Signup and view all the answers

In addition to female gender, which other factor increases the risk of PONV for patients scheduled for a D&C?

Obesity Signup and view all the answers

What is the typical duration of pain experienced following a D&C procedure?

24 hours Signup and view all the answers

Study Notes

Anesthesia for Dilation and Curettage

Dilation and curettage (D&C) is a gynecologic procedure for diagnostic or therapeutic purposes involving cervix dilation and uterine lining curettage.
Most patients undergoing a D&C are discharged on the same day as the procedure.
Risks of D&C include uterine perforation, cervical laceration, infections, and hemorrhage.

Pathophysiology

Abnormal uterine bleeding can be caused by benign fibroid tumors, polyps, hormonal imbalances, retained placenta, or early pregnancy loss.
The uterus, a muscular organ, has a lining (endometrium) that thickens due to estrogen; progesterone prepares it for potential embryo implantation after ovulation.
IVF involves multiple steps: hormonal medications, egg harvesting post-ovulation, fertilization in vitro, embryonic incubation, and embryo transfer to the uterus after 2 to 5 days.
Approximately one-third of women experience mild to moderate cramping or light bleeding in early pregnancy, but severe cramping followed by bleeding indicates possible miscarriage.
Miscarriages occur primarily in the first trimester and account for 15% to 20% of recognized pregnancies.
Diagnostic methods like ultrasound and beta-hCG tests are used when vaginal bleeding suggests possible early pregnancy termination.
A missed abortion refers to a nonviable pregnancy retained for at least 8 weeks, while an incomplete abortion involves the retention of some fetal or placental tissue in the uterus.

Surgical Procedure

The patient is placed in the lithotomy position with legs in stirrups for the procedure.
A tenaculum is placed into the vagina to stabilize and expose the cervix.
A uterine sound is inserted to measure the safe insertion depth for cervical dilators and curettes.
In cases of incomplete abortion, the cervix may already be open; if closed, it requires dilation.
Metal dilators are used to achieve approximately 1.5 cm of cervical dilation.
After dilation, a sharp curette can be utilized to scrape the uterine lining, or vacuum aspiration may be performed.
Suction aspiration can be executed via electric vacuum or manual aspiration using a 60-mL syringe and cannula.

Coexisting Diseases in Women for D&C

Women presenting for D&C may have various medical conditions affecting perioperative management.
Younger women (under 40) often experience unexplained bleeding related to hormonal imbalances; common is coexisting endocrine pathology.
Menstrual issues linked to obesity are prevalent in young women.
Women over 40 often have abnormal bleeding, which can be a sign of endometrial cancer.
Cardiac disease is more common in postmenopausal women and may accompany uterine procedures.
Anemia frequently occurs after hemorrhage; a patient with two weeks of vaginal bleeding can develop anemia, which may not significantly increase surgical and anesthetic risks.

Anemia and Tissue Oxygenation

Hemoglobin binds 1.39 mL of oxygen per gram; normal hemoglobin levels range from 12.1 to 15.1 g/dL for women.
Excessive vaginal bleeding can lower hemoglobin, subsequently decreasing arterial oxygen content (CaO2), impacting tissue oxygen delivery.
The body compensates for low CaO2 through increased production of 2,3-diphosphoglycerate, shifting the oxygen-hemoglobin dissociation curve to the right, enhancing oxygen release.
Increased sympathetic nervous system activity elevates cardiac output to deliver more oxygen.
In an anemic patient with a hemoglobin of 9.1 g/dL and hematocrit of 27.3%, ensuring optimal oxygenation and possibly increasing fraction inspired oxygen is crucial.

Obesity and Infertility

Obesity prevalence has surged, particularly among women of reproductive age in the U.S.
Obese women in reproductive years have a 67% higher miscarriage rate compared to those of normal weight, which increases with infertility treatments.
Conditions associated with obesity include polycystic ovary syndrome, abnormal ovulation, and hormonal imbalances, negatively impacting pregnancy success.

BMI and Anesthetic Risk

Body Mass Index (BMI) measures body fat using height and weight; calculated by weight (lbs) / (height (inches)²) × 703 or weight (kg) / (height (m)²).
Normal BMI ranges from 18.5 to 24.9; overweight (25-29.9), obesity (30-34.9), severe obesity (35-39.9), morbid obesity (40-44.9), super obesity (>45).
Obesity raises anesthetic morbidity and mortality risks through effects on metabolic demands, oxygen consumption, sleep apnea, and the pharmacokinetics of anesthetic agents.
Obese patients show decreased functional residual capacity and gastroesophageal sphincter tone, increasing aspiration risk; rapid sequence induction is often necessary.
Preoperative assessments include ECGs for ischemia and arrhythmias, chest X-rays for heart size and pulmonary hypertension, and potential cardiology consultations for patients with cardiac symptoms.

Physiologic Changes in Pregnancy

Increased levels of progesterone during pregnancy lead to significant physiological changes.
Progesterone antagonizes motilin, a peptide that stimulates uterine contractions and aids in gastric emptying.
The delay in gastric emptying caused by elevated progesterone can lead to an increased volume of gastric contents.

Hormonal Influences

Placental secretion of gastrin during pregnancy elevates gastric acidity.
Decreased lower esophageal tone (the valve that prevents stomach contents from refluxing) contributes to a higher risk of aspiration.
Increased intragastric pressure due to hormonal changes can exacerbate the risk of gastroesophageal reflux.

Anesthesia Considerations

Pregnant patients, particularly those at 12 to 14 weeks gestation, are classified as having a "full stomach."
This classification signifies an elevated risk of gastric aspiration during anesthesia, necessitating careful pre-anesthetic assessment and management.

Airway Management for Obese Patients

General anesthesia is often preferred for obese patients due to increased risks.
Mask techniques or laryngeal mask airway (LMA) insertion are unsuitable because of a higher risk for aspiration and difficult intubation.
Endotracheal tube placement is essential to secure the airway effectively.
Head-elevated laryngoscopy position (HELP) enhances visibility of laryngeal structures by aligning airway axes.
Reverse Trendelenburg position improves diaphragmatic excursion and functional residual capacity, aiding in preoxygenation before anesthesia induction.

Anesthetic Considerations in Lithotomy Position

Improper positioning during lithotomy can lead to nerve injuries, particularly to the femoral, sciatic, obturator, lateral femoral cutaneous, and common peroneal nerves.
Incidence of nerve injury in lithotomy is approximately 1 in 3608 patients, with common peroneal nerve injuries being most frequent.
Common peroneal nerve, a branch of the sciatic nerve, may sustain injury from compression against stirrups causing foot drop and paresthesia.
Adequate padding of stirrups and careful leg positioning is vital to prevent nerve damage.
Care during lithotomy phase includes simultaneous leg movements and avoiding excessive hip flexion or external rotation to reduce injury risks.

Physiological Changes in Lithotomy Position

In ventilated patients, peak inspiratory pressure and end tidal carbon dioxide (ETCO2) levels tend to rise while lung capacities decrease.
Abdominal content displacement during hip flexion can impede lung expansion, worsening ventilation in obese patients.
The lithotomy position poses a higher risk of gastric aspiration during general anesthesia.
Blood volume in the legs ranges from 250 to 500 ml; lithotomy shifts blood towards the central circulation, altering central venous pressure and increasing pulmonary capillary wedge pressure.
Venous stasis from this position heightens risk of deep vein thrombosis and impacts cardiac output, particularly when combined with Trendelenburg position.

Regional Anesthesia for D&C Procedures

Spinal or epidural anesthesia offers significant advantages, including reducing the need for airway management and ventilation.
Benefits also entail less anesthetic use, decreased cardiopulmonary depression, and a lower incidence of postoperative nausea and vomiting (PONV).
Disadvantages include potential difficulties in technique due to anatomical challenges in obese patients, like locating iliac crests or spinous processes.
The relationship between an increase in weight and the height of the block necessitates caution, as abdominal mass can alter dosages and lead to unexpected high blocks.
Regular sedation and premedication with benzodiazepines or opioids may be essential to manage patient anxiety during regional anesthesia in awake procedures.

General Anesthesia for D&C

Provides complete unconsciousness, preventing awareness of suction sounds post-miscarriage.
Pelvic relaxation enhances gynecological examination and procedure efficacy.
Increased risk of aspiration and nerve injuries with general anesthesia.
Potential challenges in airway management may arise.
Higher incidence of postoperative nausea and vomiting (PONV) associated.
Inhalation agents can cause dose-dependent uterine atony, increasing bleeding risks.

Effects of Inhalation Agents on Uterine Smooth Muscle

All inhalation agents induce uterine smooth muscle relaxation by reducing intracellular free calcium.
Degree of uterine relaxation varies with the administered dose.
Uterine atony correlates with increased blood loss complications.
Desflurane and sevoflurane result in greater uterine relaxation than isoflurane at 1.5 MAC.

Pharmacologic Properties of Oxytocin (Pitocin)

Oxytocin synthesized in the hypothalamus; secreted by the posterior pituitary gland.
Stimulates uterine contractions and is administered to enhance contraction strength and frequency.
Used during spontaneous abortion with uncontrolled bleeding; 10 units administered to improve uterine contractions.
Side effects include headache, bradycardia, tachycardia, nausea, and vomiting.

Technique for Paracervical Block Administration

Performed as a nerve block by the gynecologist using local anesthetics like 1% lidocaine or 3% chloropropane.
Sedation with benzodiazepines and small doses of propofol recommended for patient comfort.
Under sterile conditions, locate cervicovaginal joint; inject local anesthetic at various depths (0.5 cm, 1 cm, 1.5 cm) in specified clock positions.
Total injection volume per location: 5 mL, targeting the sacrouterine ligaments and anesthetizing the Frankenhauser ganglion.
Monitor injected anesthetic volumes, be cautious of potential local anesthetic toxicity.

Complications Associated with D&C Procedure

Anesthetic risks linked to patient’s pre-existing health conditions and comorbidities.
Anesthesia-related complications may include airway management difficulties and nerve injuries.
Low incidence of surgical complications associated with D&C, including uterine perforation, cervical tears, infections, and bleeding.
Anesthetist should ensure depth of anesthesia is adequate during peak surgical stimulation to minimize patient movement and risk of complications.
Reduce inhalation agent concentration if possible to decrease uterine relaxation and associated bleeding risks.

PONV Management After D&C Procedure

PONV (Postoperative Nausea and Vomiting) is related to general anesthesia and is more prevalent in gynecological surgeries.
Risk factors for PONV include:
- Female gender
- Outpatient status
- Young adult age
- Obesity
Adequate intravenous fluid replacement can help mitigate PONV risks.
Low-dose droperidol was previously used but is no longer recommended due to FDA warnings regarding cardiac risks.
Dexamethasone is effective for PONV prevention, similar to droperidol, although the exact mechanism is unclear.
The possible antiemetic action of dexamethasone may involve reduced prostaglandin synthesis or inhibition of neurokinin-1 receptors.
Ondansetron, a serotonin antagonist, is also effective for PONV prevention and treatment.
Combination therapy (dexamethasone + serotonin antagonist) enhances PONV prophylaxis by targeting multiple neurologic pathways and receptors affected by anesthetic agents.

Postoperative Pain Management After D&C Procedure

Common postoperative pain after D&C is characterized by uterine cramps, lasting about 24 hours.
Oral acetaminophen with codeine is typically prescribed for pain relief.
Continuous use of aspirin and ketorolac is discouraged to minimize the risk of uterine bleeding.
Persistent or severe pain post-procedure necessitates evaluation for possible uterine perforation.

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Description

This quiz covers the key aspects of anesthesia used during Dilation and Curettage (D&C) procedures, including associated risks and the pathophysiology of conditions that may lead to such interventions. Understanding these elements is crucial for both practitioners and patients to ensure safety and effective treatment outcomes.