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:
- reduced risk of Mendelson syndrome;
- better post-surgery pain control;
- no risk of awareness;
- no risk for the fetus being exposed to the effect of general
anesthetics;
- participation of the mother in the birth of her baby;
- continuous monitoring of the patient’s level of consciousness, which
indicates the level of brain perfusion and, thus, of hemodynamic
status;
- abolition of the side effects of general anesthetics, such as the
reduction of the uterine tone and platelet functionality.
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:
- the patient does not feel possible visceral pain due to traction and
adherence to previous surgeries;
- it strengthens the status of controlled hypotension, further reducing
intraoperative bleeding; and
- it allows for an easier shift to general anesthesia, if necessary.
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.