The time of hemorrhage due to AVM in pregnant women is most common at the 15th-20th weeks in younger patients but bleeding may ocur at any stage including during labour or in the puerperium . In our case, the patient was symptomatic at the 16th week of gestation. The uterine contractions of labour and the Valsalva effect of vaginal delivery are accompanied by dramatic, transient increases in venous pressure, cardiac output, and cerebrospinal fluid pressure. For this reason, Caesarean section is recommended for patients with inoperable AVMs .
Successful treatment requires thorough diagnostics and close monitoring in a flexible teamwork to address both the varying maternal and fetal needs. The fundamental aims of anesthesia are to maintain oxygenation and stable systemic, cerebral and placental hemodynamics and to avoid increased intracranial pressure .
The most important problem in anesthetic management for the pregnant that has an emergency Caesarean section and AVM is the acute subarachnoid hemorrhage due to the intra-operative rupture caused by hypertension. So far various volatile anesthetics, regional anesthetic techniques and antihypertensive agents have been used. However, it is impossible to select one of these methods as precisely superior to the others since most of the studies were merely case presentations. Anesthetic goals for these patients included fetal and maternal well being.
The regional anesthetic technique could be preferred because it avoids the haemodynamic stress associated with laryngoscopy, intubation and extubation during general anesthesia [4, 8] but in this case, because of the emergency of the case, we preferred general anesthesia and haemodynamic stress was prevented by using nitroglycerin, remifentanil, lidocaine and propofol during induction. During the maintenance of anesthesia, an invasive monitorization of arterial blood pressure was used to prevent hypertension. We maintained both the intra-cranial pressure and the uteroplacental perfusion at appropriate levels by keeping the mean arterial pressure within certain limits.
It is known that preoperative maternal hypothermia appears to be well tolerated by the fetus but the use of hypotensive techniques is more controversial. It is suggested that the fetus is kept protected from hypotension induced by the careful use of volatile anesthetics, beta-adrenoreceptor blockers or sodium nitroprusside. It is also important to avoid hypotension during epidural block, and the increase in intracranial pressure caused by vomiting can be dangerous . The securing of the aneurysm, such as balancing the treatment of undesired hyper/hypotension with the risk of possible re-bleeding/cerebral hypoperfusion, allows greater flexibility in managing the remainder of the pregnancy. Furthermore, Caesarean section can be undertaken without any concern for the fluctuating cerebral perfusion pressure that accompanies Caesarean section . For these reasons, we preferred general anesthesia to keep the mean arterial pressure within certain limits. Additionally, we also have to take into consideration the possible side effects of the chosen anesthetic agent on the fetus.
In recent times; remifentanil is a synthetic opiate with evident advantages for various anesthetic techniques, enhancing the quality of anesthesia. Remifentanil may be used in obstetric analgesia-anesthesia thanks to the advantages demonstrated in patients with heart disease and in those requiring neuron-anesthesia. Remifentanil is known to cross the placenta rapidly and to be rapidly metabolized and redistributed to both the mother and the fetus. Based on this, and on pharmacokinetic and pharmacodynamic studies on children , we judged remifentanil to be indicated for use for our patient who underwent an emergency Cesarean section and for whom hemodynamic stability and immediate postoperative assessment were basic requirements.
We concluded that general anesthesia can be used satisfactorily for the Caesarean section of a pregnant woman with cerebral AVM in case of emergency. Ensuring optimal maternal and fetal well-being, we are of the opinion that it is also possible to control the arterial blood pressure of patients with general anesthesia.