Anesthetic Management for Urgent Caesarean Section in Patient with Uncontrolled Hyperthyroidism and Severe Mitral Regurgitation

Background : The prevalence of hyperthyroidism in pregnancy approximately 0.05% to 3% and mostly caused by Graves’ Disease (GD). The prevalence of Hyperthyroid Heart Disease (HHD) in pregnancy is 3.87%. Uncontrolled hyperthyroidism during pregnancy can increase maternal and fetal mortality. We report a case of a pregnant woman with uncontrolled hyperthyroidism and severe mitral regurgitation that underwent cesarean section with spinal anesthesia for delivery. Case Illustration : A 33 years-old patient G4P1A2 visited the Obstetric-Gynecology outpatient clinic at our hospital at 23 weeks of gestation (WoG) due to uncontrolled hyperthyroidism caused by GD that diagnosed 3 years ago and shortness of breath. The echocardiography test obtained severe mitral regurgitation and left atrial dilatation with 58% LVEF. It was decided to maintain the pregnancy till the fetus is viable while still monitoring the patient’s condition. At 32 WoG, the patient came to the ED due to shortness of breath, chest pain, and nausea. Fetal movement and fetal heart rate (FHR) were within normal limits. The patient was given a nasal cannula at 3 liters/minute, extra furosemide 20 mg, and fetal lung maturation with dexamethasone injection. The patient was prepared for termination by cesarean section. Spinal anesthesia was performed in a sitting position using a 27 G spinal needle. Inserted at L 3-4, using a low dose of heavy bupivacaine 0.5% 7.5 mg combined with 25 g fentanyl and 0.1 mg morphine intrathecally. C-section was successfully performed and hemodynamics during surgery was stable, resulting the delivery of a preterm baby who weighed 1.9 kg at birth and the baby was transferred to the NICU for further treatment.


INTRODUCTION
Spinal anesthesia is still the first choice for caesarean section due to its deep sensory block as well as fewer side effect to the mother and the fetus. (10)inal anesthesia with hyperbaric bupivacaine is the most commonly used anesthetic technique for elective caesarean section and urgent or emergency scenarios due to its simplicity and ease of performance, low cost and quick installation of anesthesia, providing adequate analgesia and muscle relaxation for surgery.However, when used alone, higher dose are required to obtain satisfactory result, and consequently, major adverse events will be raise, such as arterial hypotension and fetal distress 11,14 .A sudden decrease in

CONFLICT OF INTEREST
The Authors declare that they have no conflict of interest.

REFERENCE
/ml), free thyroxine (FT4) level 7.77 ng/dl (normal range : 0.78-2,0 ng/dl), and TSH receptor antibody (TRAb) level 69.1 IU/L (normal range : 0-14 IU/L).Previously, the patient was treated with propylthiouracil (PTU) 50 mg t.i.d, however, in the past 1 severe mitral regurgitation, left atrial dilatation with 58% Left Reyfal Khaidar, Andri Subiantoro, Wahyu Sugiharto, Tomy Oky P Anesthetic Management for Urgent Caesarean Section in Patient with Uncontrolled Hyperthyroidism and Severe Mitral Regurgitation Ventricular Ejection Fraction (LVEF), without regional wall abnormality.It was decided to maintained the pregnancy till the fetus is viable while still controlling thyroid hormone level and monitoring patient's heart condition.The patient received thiamazole 10 mg daily, aspirin 80 mg s.i.d and pregnancy supplementation and advised to routinely control to obstetrics and gynecology clinic.After visiting our clinic, the patient underwent a series laboratory tests while taking thiamazole 10 mg daily (table 1), which was increased to 20 mg daily and added with propranolol 10 mg t.i.d after 25 WoG.However, despite the increase dosage, TFTs remained abnormal and the patient complained was deteriorated.Resulting in a second dose increase to 30 mg daily at 26 WoG.Afterwards, she maintained a FT4 level < 4.0 ng/dl (normal range 0.93 -1.7), systolic blood pressure < 160 mmHg, heart rate (HR) < 100 bpm, at follow up examination.

Fetal
movements and heart rate were within in normal limits.The patient was given 3 liters/minutes oxygenation with nasal cannulae, furosemide 20 mg extra, and fetal lung maturation with dexamethasone injection.And then the patient is prepared for termination by caesarean section.

Figure 4 .
Figure 4. Perioperative systolic arterial blood pressure (sABP) and heart rate (HR).The patient's sABP and HR before and after intrathecal injection are shown.Note that the sABP remained stable, and even decreased following the intrathecal injection.HR remained relatively stable throughout the operation preload and afterload due to spinal technique can aggravates the patient condition, so in some literature this technique is contraindicated in patient with heart disease.There are several ways to reduce incidence of post-spinal Reyfal Khaidar, Andri Subiantoro, Wahyu Sugiharto, Tomy Oky P Anesthetic Management for Urgent Caesarean Section in Patient with Uncontrolled Hyperthyroidism and chord which will affect the motor and sensory impulses of afferent and efferent fibers.This level of blocks depend on the technique, agent and the dosage used.Intrathecal opioids selectively produce an analgesic effect through interaction with opioid receptors and thus can minimize the dosage and supraspinal effects of local anesthetics.The main location of the opioid receptors is in the dorsal horn of the spinal cord, that is in the substantia grisea of the substantia gelatinosa.This is the basis of the anatomy of selective analgesia by intrathecal opioids 7,12 .Hydrophilic opioids such as morphine provide excellent selective spinal analgesia because of small volume of distrubution and slow clerance from the spinal cord.However, slow spinal cord penetration and prolonged duration in cerebrospinal fluid (CSF) caused by hydrophilicity also results in slow onset, prolonged duration of action, and risk of delayed respiratory depression from rostral spread in CSF.Lipophilic opioids have a more favorable clinical profile of fast onset, modest duration, and little risk of delayed respiratory depression.Fentanyl is the most commonly used spinal lipophilic opioids 13 .The combination, therefore, is expected to have the advantage of a prompt onset of analgesia and a long action.Low-dose bupivacaine (< 8 mg) is expected to have minimal effects on hemodynamics of the mother and fetus.The addition of opioids could reduce the dose requirements of local anesthetics and prevent hemodynamic fluctuations and increase the effects of intraoperative and postoperative analgesia.The association of low dose bupivacaine with fentanyl, a lipophilic opioid has beed proposed to improve quality of blockade, prolong duration of analgesia and reduce intraoperative nausea and vomiting.Several dose of fentanyl (from 2.5 -50 mcg) have been described in the literature, and the 25 mcg dose was frequently used in the studies 7,11,14 .Low dose hyperbaric bupivacaine combined with fentanyl and morphine provide the adequate block with minimal systemic side effects and preventing hypotension during spinal anesthesia.Study from Isngadi, et al stated that low Reyfal Khaidar, Andri Subiantoro, Wahyu Sugiharto, Tomy Oky P Anesthetic Management for Urgent Caesarean Section in Patient with Uncontrolled Hyperthyroidism and .This technique is preferable due to its sympathetic block, non-tocolytic effect, and good postoperative analgesia which beneficial to avoid stimulates of thyroid storm.