Our internal protocol

The present article intends to share the internal protocol developed in our center, Villa Sofia-Cervello Hospital, Palermo, Italy (Figure 1).
Our hospital meets the criteria outlined by the American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine to provide the most appropriate level of maternal care required for the management of PAS disorders4. This article focuses on the anesthesiologic management of the procedure, while the surgical management is not detailed herein.

From diagnosis to surgery

Table 1 describes the steps we follow from diagnosis to surgery. In particular, early diagnosis allows for a multidisciplinary team, careful tailoring of the management plan, and adequate preparation of the elective cesarean section and subsequent hysterectomy.

Anesthesiology management

To date, there is no consensus on the best type of anesthesia in cases of complete placenta previa with suspected accretism. However, historically, the most frequently used technique is general anesthesia8, which is generally preferred because it reduces the mother’s anxiety, allows the anesthetist to concentrate on the hemorrhage and cardiovascular stability, and avoids the risk of hemodynamic instability due to an urgent shift (due to hemorrhage) from locoregional to general anesthesia.
Our internal protocol, which indicates general anesthesia in emergency regimens, provides the use of peridural anesthesia not only during birth but also during the hysterectomy, considering the shift to general anesthesia in case of emergency (bleeding or hemodynamic instability). From our point of view, several beneficial effects may be achieved with peridural analgesia, such as:
Comparing the current state of the art with that of the past, the pivotal role of the interventional radiologist is apparent in reducing the vascular inflow to the operating field and, in case of hemorrhage during the hysterectomy, to stop the bleeding6. Therefore, it is now possible to use locoregional anesthesia in obstetrics to have good outcomes, such as reduced bleeding, reduced use of blood products in the major obstetric hemorrhages, and better management in post-surgery pain therapy. Finally, we chose peridural anesthesia over combined spino-epidural technique because the peridural catheter is placed in the obstetrics operatory room 60 minutes (radiological time) before the skin incision in the interventional radiology room. Therefore, the maximum effect of spinal anesthesia would begin to decrease. In our experience, the peridural anesthesia has a reduced hemodynamic effect compared with the spino-epidural technique.
During the entire procedure, two anesthetists from the dedicated group of obstetrics are present.

Obstetric operatory room

The patient was prepared in the obstetrics operatory room after fasting for at least 8 hours. During this phase, the anesthesiologists explained the procedure step by step to the patient. Two large peripheral veins are cannulated with 16 G or 18 G cannulas. Antibiotic prophylaxis and 7 ml/kg saline (to replace fluids lost through fasting) are administered. While maintaining the absolute sterility of the operating field, the skin is disinfected. Cutaneous wheal is formed using 4-6 mL of 2% lidocaine. The peridural space is identified, generally at the L2-L3 level, using the loss-of-resistance technique. The peridural catheter (16 or 18 G) is placed on the patient in a sitting or lateral position on the operating bed, while electrocardiogram (ECG), oxygen saturation, and noninvasive blood pressure (NIBP) are monitored. Once the peridural space is identified, the catheter is introduced in the cranial direction approximately 3 cm beyond the bevel of the Tuohy needle. The aspiration test (to rule out the presence of blood or liquor) and dose test are performed with 2 ml of 2% lidocaine. Afterwards, the catheter is attached to the skin. The operating room cart is prepared (Supporting Information 2) by nurses supervised by the anesthetist. Finally, the patient and the cart are moved to the interventional radiology room.

Interventional radiology room

Time 1
The patient is placed on an X-ray transparent operating bed and warmed up with a thermal mattress. The equipment and devices to be used in the radiological procedure are already in this room (digital angiograph, C arch), as well as the respirator and the dedicated space for the neonate. Colloids (10 mL/kg) are infused intravenously and vital parameters are monitored. Subsequently, two boluses of 14-18 mL of 0.75% ropivacaine (105-135 mg) and fentanyl 50 γ are administered 7-8 minutes apart to avoid hypotensive episodes.Radial artery cannulation is performed to monitor the arterial pressure during the whole surgical intervention and for serial arterial blood gas analysis before and after the surgery (to monitor hemoglobin levels and metabolic status). A central venous catheter is also placed in case of difficult access of other peripheral veins. A wedgeis placed under the right hip of the patient to avoid compression of the uterus on the vena cava. While waiting for the maximum effect of anesthetics, invasive blood pressure, oxygen saturation, electrocardiogram, and body temperature are monitored, and a pre-surgery arterial blood gas analysis is performed. After approximately 15 minutes, the Pin Prick test is done to evaluate the anesthetic plan of the central block in terms of depth, width, and symmetry. Hollmen and Bromage scales are useful in the assessment of the dermatomal level achieved. When the anesthetic plan reaches the T4-T5 dermatomal level and the Hollmen scale is 3, urinary catheterization may be performed, and the radiological-vascular time starts with the placement ofendovascular catheters in the hypogastric arteries .
Time 2
Once the radiological examination is completed, cesarean section is performed, generally using a supra-umbilical-pubic incision. The patient is then awake, has no pain, and participates in the birth of her child. After extraction, the premature fetus is handed to the neonatology team. The mother is given uterotonic agents intravenously to trigger uterine contraction, facilitate the possible placental stage, and reduce further blood loss.
Time 3
If the placenta is not delivered, morbid placenta adhesion is confirmed. Therefore, the obstetric team performs the riskiest phase of the surgery: hysterectomy . In this phase, in order to reduce the mother’s anxiety, a mild sedation may be administered with i.v. benzodiazepine (midazolam) and, in the absence of apparent hemorrhage signs, after several minutes, a 1.5 mg/kg bolus of i.v. propofol may be slowly administered (over approximately 90 seconds) so that the patient can breathe spontaneously with a Ventimask (40%, O2flow 8 L/min). Subsequently, a continuous infusion of propofol may be given (1.5-3 mg/kg/h). Sedation has some advantages:
Time 4
The last part of the procedure is proper evaluation of the possible hemorrhages . For the management of hemorrhagic emergency, in accordance with the current guidelines of the Italian Ministry of Health10, an operative protocol was drawn up and is followed (see Supporting Information 3). Finally, the possible referral to ICU is considered, taking into account the amount of bleeding, the type of anesthesia, the length of surgery, the hemodynamic stability, and the level of consciousness. Otherwise, after suturing the abdominal belt, sedation is suspended, with awakening of the patient in a very short time.

Post-surgery monitoring

After surgery, patients remain under observation in the recovery room in the obstetrics and gynecology unit, where they are monitored and warmed up, assisted by an anesthetist, a midwife, and a nurse. All parameters are registered in the medical record. After 4 hours, if the vital parameters are within the normal range, the Aldrete score is 9-10, and the numerical rating scale (NRS) is 2, the patient is moved to the ward, where the monitoring can be continued. The blood count is controlled every 4 hours in the first 12 hours, and subsequently every 8-12 hours, according to hemoglobin and hematocrit levels. For the first 6 hours after surgery, continuous pressure monitoring is performed, in addition to pulse oximetry, urine output measurement with fluid balance, thromboelastography, serum electrolytes test, and kidney function tests.

Post-surgery pain control

For the 24/48-hour peridural pain management, we follow the protocol reported in Supporting Information 4. Briefly, pain management is administered via the pump for programmed intermittent epidural bolus (PIEB), through which boluses of 8-12 ml of 0.1% ropivacaine (hourly) and acetaminophen (at established times) are administered. The peridural catheter is removed on the third day, 12 hours after the last low-molecular-weight heparin administration, and upon assessment of possible alterations in coagulation status.