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Abstract
Introduction
Case Report
Discussion
References
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Regional anesthesia (RA) has a number of advantages over general anesthesia (GA) in obstetrics, including reduced aspiration risk, better postoperative pain control, improved maternal birth experience, and decreased fetal exposure to the depressant effects of GA (
5,6). GA drugs also lead to decreased uterine tone and decreased platelet function (
7). RA has been associated with decreased blood loss and decreased need for transfusion in major obstetric hemorrhage (
8,9). Furthermore, in elective CS randomized to RA or GA, blood loss is lower with RA (
10).
In addition to the above-mentioned advantages of RA for CS, an epidural technique facilitates placement of IIAOBC that can take 45 minutes. Starting these cases with GA exposes babies to large doses of anesthesia, which is of concern in certain high-risk situations, such as the premature twins in our series. We chose an epidural as opposed to a single-shot spinal to reduce the initial sympathectomy and to allow re-dosing if the operation was prolonged. Many clinicians continue to use GA for CS when postpartum hemorrhage is anticipated, citing concerns of sympathectomy with blood loss. This case series demonstrates that CS with high risk for postpartum hemorrhage can be safely conducted under RA with preoperative IIAOBC placement.
Two patients had extensive placental abnormalities requiring long surgeries with persistent blood loss despite IIAOBC. These were converted to GA because of concerns regarding development of airway edema because of continuing resuscitation (
11), patient restlessness, and surgeons concerns regarding the extensive dissection and potential continued blood loss. This decision was not influenced by any concern for the sympathectomy induced by epidural anesthesia and could have been managed under epidural anesthesia from a hemodynamic standpoint. It is our practice to intubate the airway in a timely fashion to minimize potential for a difficult airway after extensive fluid resuscitation.
In our case of uterine AVM, the utility of intraarterial balloons is undisputable, as the blood loss was terminated by IIAOBC. However, in other cases blood loss, although decreased, continued with the IIAOBC inflated.
It is possible for abnormal placentas to have collateral blood flow, causing blood loss despite occlusion of the internal iliac arteries (12) and contingency plans should be made. In cases of placenta accreta, potential for blood loss is massive.
In a report of 56 cases of placenta accreta, estimated blood loss exceeded 2000 mL in 41 cases, 5000 mL in 9, 10,000 mL in 4, and 20,000 mL in 2, with 3 patients requiring 70 U of blood (13). The efficacy of arterial balloon catheters and pelvic embolization in active obstetric hemorrhage is well established (
4,14,15), but the role of prophylactic arterial balloon catheter placement is still to be determined (
4,16,17). However, given the incidence of significant morbidity in patients with placenta percreta adherent to the bladder (
13), we believe that blood loss would have been larger without IIAOBC (
18,19).
In one case, despite suspected placenta percreta on prenatal imaging, no placental abnormality was found at CS. Starting this case under GA would have exposed mother and fetus to the risks of GA unnecessarily. Sensitivity and specificity of ultrasound diagnosis of placenta accreta are reported to be as frequent as 82% and 97% (
3), respectively. Magnetic resonance imaging (MRI) is helpful for imaging patients with a history of myomectomy or posterior placenta (
2). However, a retrospective study shows that the sensitivity of these techniques may be as low as 38% for MRI and 33% for ultrasound (
20). Diagnostic accuracy probably depends on institutional expertise and will likely improve as technology evolves.
At Stanford University, all patients with prenatal imaging suggestive of a major placental abnormality are considered candidates for IIAOBC placement. The cases in
Table 1 represent 18 months of experience at our institution. In our series, the two patients who still had major blood loss despite the IIAOBC had placenta percreta with adherence to the bladder and represent a subset of patients at risk for major morbidity and death (
13,18,19).
The prophylactic use of IIAOBC placement is controversial and large randomized controlled trials will be necessary to prove that the technique decreases blood loss. These will be difficult to conduct because of the large numbers required and variability associated with abnormal placentation. Anecdotally, we believe that IIAOBC improve surgical conditions and reduce blood loss when compared with cases in which similar patients are without the catheters. When making the decision to use prophylactic IIAOBC, it is important to balance the risks of catheter placement such as arterial injury, radiation exposure, and bleeding with potential benefits of hemorrhage control and preservation of fertility (
21). To minimize morbidity in these cases, there should be a multidisciplinary team approach, including involvement of anesthesiologists, obstetricians, and, possibly, other specialists such as interventional radiologists and gynecological oncologists. In our experience, CS in patients at risk for hemorrhage who receive prophylactic IIAOBC can be successfully performed under epidural anesthesia. However, IIAOBC does not control all cases of hemorrhage and provisions for the possibility of significant hemorrhage and conversion to GA must be anticipated.
