A second technique involves a ield block of the major branches supplying the abdominal wall, to include the 10th, 11 th, and 12th intercostal nerves and the ilioinguinal and genitofemoral nerves (Nandagopal, 2001). As shown in 25-5, the former group of nerves is located at a point midway
FIGURE 25-5 Local anesthetic block for cesarean delivery. The first injection site is halfway between the costal margin and iliac crest in the midaxillary line to block the 10th, 11 th, and 12th intercostal nerves. A second injection at the external inguinal ring blocks branches of the genitofemoral and ilioinguinal nerves. These two sites are infiltrated bilaterally. The fifth and final site is along the line of proposed skin incision.
between the costal margin and iliac crest in the midaxillary line. he latter group is found at the level of the external inguinal ring. Only one skin puncture is made at each of the four sites (right and left sides). At the intercostal block site, the needle is directed medially, and injection is carried down to the fascia, avoiding injection of the subcutaneous fat. Approximately 5 to 8 mL of 0.5-percent lidocaine is injected. The procedure is repeated at a 45-degree angle cephalad and caudad to this line. he other side is then injected. At the ilioinguinal and genitofemoral sites, the injection is started at a site 2 to 3 cm lateral from the pubic tubercle at a 45-degree angle. Finally, the skin overlying the planned incision is injected.
Trained personnel and specialized equipment including alternative airways, video laryngoscopes, and fiberoptic intubation scopes are mandatory for the safe use of general anesthesia. A common cause of death cited for general anesthesia is failed intubation. This occurs in approximately 1 of every 400 general anesthetics administered to pregnant women (Kinsella, 2015). There is a growing trend to continue surgery with a supraglottic airway device, such as a laryngeal mask airway, in the event of a failed intubation (Mushambi, 2015). Because of these relatively greater morbidity and mortality rates, neuraxial analgesia is the preferred method of pain control and should be used unless contraindicated (see Table 25-6). Indeed, in two reports from the MFMU Network, 93 percent of more than 54,000 cesarean deliveries were performed using neuraxial analgesia (Bloom, 2005; Brookfield, 2013). A higher incidence of general anesthesia use for nonwhite women has been reported (Butwick,i2014).
Before anesthesia induction, several steps are taken to help minimize complication risks: 1.
Antacid administration shortly before anesthesia induction has probably lowered mortality rates from general anesthesia more than any other single practice. The American Society of Anesthesiologists Task Force on Obstetrical Anesthesia (2016) recommends timely administration of a nonparticulate antacid, an Hrreceptor antagonist, or metoclopramide. For many years, we have administered 30 mL of Bicitra-sodium citrate with citric acid-a few minutes before anesthesia induction by either general or major neuraxial block. If more than 1 hour has passed ater the first dose was given and anesthesia has not yet been induced, then a second dose is given.
2.
Lateral uterine displacement is also provided, as the uterus may compress the inferior vena cava and aorta when the mother is supine. With uterine displacement, the duration of general anesthesia has less efect on neonatal condition than if the woman remains supine.
3.