**2.9 Perimortem cesarean section**

The incidence of cardiac arrest in pregnancy in the United States from 1998 to 2011 was estimated to be 1 in 12,000 pregnant women [26], and although this number is quite low, it is higher than the most recent estimated incidence in the United Kingdom of 1:20,000 [27]. This increase is potentially attributable to a number of causes, including an increase in pregnant women with acquired or congenital heart disease, who survive to a reproductive age, and events such as acute bleeding, amniotic fluid embolism, and sepsis. An international consensus on cardiopulmonary resuscitation and cardiovascular emergency care, in 2010, established therapeutic recommendations trying to determine if any specific interventions would improve

the outcome of pregnant women in cardiac arrest [28]. During full-term pregnancy, occlusion of the inferior vena cava by the uterus and fetus is significant, resulting in a 30% decrease in blood volume for the pregnant woman compared to that of a non-pregnant woman [28]. Placing pregnant women on a left lateral inclined plane, to prevent aorto-caval compression by the pregnant uterus, has numerous maternal and fetal benefits in non-arrest situations:


The sum of these benefits suggests that positioning on a left lateral inclined plane should be desirable in the case of cardiac arrest to improve maternal and fetal status during resuscitation; however, the method chosen to position the woman in a left lateral tilt during chest compressions may be important for maternal survival. There are few clinical studies on resuscitation techniques for pregnant women. In a systematic review [27], only two studies were identified that used manikins to test the effectiveness of chest compression. These studies suggest that although chest compressions can be performed in the left lateral inclination position, they are not as effective as those performed in the supine position: with the increase in the inclination angle, the effectiveness of chest compressions decreases. Considering the importance of effective and uninterrupted chest compressions in maintaining the perfusion of critical organs, the authors recommend manual displacement of the uterus as a valid alternative to the left lateral tilt position, stressing that the former is equally effective in relieving caval compression during cesarean delivery in patients not in arrest [27]. For the mother, the extraction of the fetus and the afterbirth of the placenta can lead to a rapid improvement in the hemodynamic state, including the return of the pulse and the improvement of blood pressure. Maternal resuscitation is in fact improved from delivery, allowing more blood to return to the heart through the inferior vena cava once the fetus has been extracted [28]. Immediate extraction is even more important when you have a viable fetus, as quick action can make a difference in its survival. Based on data collected between 1900 and 1985, delivery of a viable fetus within 5 minutes of the mother's cardiac arrest is associated with survival with intact neurological status [29], while newborns delivered more than 5 minutes after the onset of arrest are more likely to undergo neurological sequelae, the severity of which appears less with increasing gestational age. A perimortem cesarean section should be performed normally but with an emergency character [29]: time should not be wasted in determining fetal heart tones, since the extraction of the fetus from the uterus guarantees greater chances of fetal and maternal survival. The patient may or may not be moved to the operating room, depending on the logistics and time required for transit; since the procedure will be essentially bloodless, due to the absence of maternal cardiac output, the surgery can be performed in almost all places with relative ease. Only after the extraction of the fetus, with the return of cardiac output, and the consequent appearance of blood loss, the closure of the various abdominal layers must comply, as efficiently as possible, with the standard procedure. In general, a vertical skin incision is recommended because of the speed with which the fetus can be extracted, but ultimately, any type of incision that can be done quickly should be done. Where defibrillation is required, the absence of

#### *Complex Cesarean Section DOI: http://dx.doi.org/10.5772/intechopen.109165*

difference in transthoracic impedance during pregnancy suggests that the standard adult energy settings appear appropriate [26], although the study making such observations was performed on an undersized patient sample [27].
