RT Book, Section A1 Li, Yunping A2 Hess, Philip E. A2 Li, Yunping A2 Kowalczyk, John J. A2 Stiles, Justin K. SR Print(0) ID 1199673226 T1 Common Medications T2 Obstetric Anesthesia: Quick References & Practical Guides YR 2023 FD 2023 PB McGraw Hill PP New York, NY SN 9781264671465 LK obgyn.mhmedical.com/content.aspx?aid=1199673226 RD 2024/10/10 AB Table Graphic Jump Location|Download (.pdf)|PrintAzithromycin500 mg, diluted in 20 mL of normal saline (NS)/lactated Ringers, infusion slowly over 1 hour.4 mg of Ondansetron intravenously (IV) before infusion due to significant nausea and vomiting.Indications: intrapartum cesarean section, spontaneous rupture of membrane.Reference: N Engl J Med. 2016;375:1231-1241.BicitraGeneric name: sodium citrate/citric acid; 30 mL per container.Per os (PO), before epidural placement and before cesarean delivery.Chloroprocaine3% chloroprocaine, preservative free (PF).Alkalization: In a 30-mL syringe, add 2 mL of 8.4% bicarbonate to 20 mL of chloroprocaine.Use for emergent cesarean delivery or for forceps delivery.STAT Cesarean Kit: Prepackage in obstetric anesthesia office: (1) 3% chloroprocaine; (1) 8.4% bicarbonate; (1) 30-mL syringe; (1) blunt needle. Replace it after use.DexmedetomidineDilute 200 µg in 20 mL of NS, final concentration 10 µg/mL.Indications:Severe shivering after delivery: 10 µg IV, may repeat up to 30 µg.Severe pruritus associated with epidural fentanyl, see Chapter 6.Reference: Int J Obstet Anesth. 2021;45:49-55.EphedrinePremixed by pharmacy, 5 mg/mL.Historically, ephedrine was used as the “Gold standard” for spinal hypotension.Higher placental transfer than phenylephrine; it can cause clinically insignificant fetal acidosis.Since late 1990s, used as a second-line medicine for maternal hypotension.References: Am J Obstet Gynecol. 1968;102:911.Anesthesiology. 2009;111:506-512.EpinephrineAdd 250 µg to 150 mL premixed bupivacaine/fentanyl epidural solution; final concentration will be 1.67 µg/mL.Add 5 µg/mL of epinephrine into 2% lidocaine for cesarean delivery.Mechanisms: alpha-2 synergic effect, alpha-1 vasoconstriction to prolong the duration of anesthesia and decrease systemic absorption.Reference: J Anesth Perioper Med. 2019;6:1-7.Lidocaine2% lidocaine, PF.Alkalization of lidocaine: in a 30-mL syringe, add 2 mL of 8.4% bicarbonate to 20 mL of lidocaine.For cesarean delivery, add 5 µg/mL of epinephrine.Magnesium2 g/h infusion as maintenance dose.For preeclampsia, continue magnesium for entire cesarean delivery.For fetal neuroprotection, discontinue magnesium after delivery.Reference: The Magpie Trial. Lancet. 2002;359:1877-1890.Morphine0.5 mL/mL, PF, pre-made by pharmacy, stored at 4°C.Indications:Cesarean delivery—spinal 250 µg, epidural 3 mg.Labor CSE for dysfunctional labor—spinal 100 µg.After third degree vaginal laceration repair—epidural 2 mg.Refer to Chapters 2, 41, and 42 for details.Nitroglycerin400 µg/mL, light sensitive. Kept in Omnicell in the operating room. Dilute to 100 µg/mL.Dose: 100 µg IV, may repeat, titrate to effect.Indications: cervico-uterine relaxation, inverted uterus, difficult extraction at cesarean delivery.Reference: Am J Obstet Gynecol. 1998;179:813.PhenylephrinePre-made by pharmacy, 100 µg/mL.Indications: first-line medication for maternal hypotension.Phenylephrine use is associated with a decrease in maternal cardiac output, but the clinical significance is not clear.Infusion at 0.5 to 0.7 µg/kg/min or bolus 100 µg, titrate to effect.Reference: Anesth Analg. 2012;114:377.Terbutaline1 mg/mL, use 0.25 mg, subcutaneously, administrated by the nurse.Indications:Tachysystole contraction with associated fetal heart rate changes.Before external cephalic version at obstetrician’s discretion.ACOG Practice Bulletin No. 106.Tranexamic AcidTranexamic acid (TXA) 1 g, diluted in 20 mL of NS, infuse over 10 min.Treatment of postpartum hemorrhage (PPH) after vaginal or cesarean delivery.Prophylaxis in high risk of PPH (e.g., women with hypertensive disorder and asthma).Discourage use of TXA for prophylaxis in low-risk women (no proven benefit).Exclusion: History of deep vein thrombosis/pulmonary embolism/myocardial infarction/cerebrovascular accident, acquired color blindness.Decreased dose (5 mg/kg) for renal failure.Refer to Chapter 3 for details.References: N Engl J Med. 2018;379:731-742.Lancet. 2017;389:2105-2116.UterotonicsIncluding oxytocin, methylergonovine (methergine), carboprost (hemabate), misoprostol ...