Agenesis of inferior vena cava in pregnancy: A case report and narrative review.

Agenesis of inferior vena cava (AIVC) is an extremely rare congenital abnormality. In AIVC, venous flow from the lower extremities enter superior vena cava mainly through the azygous and hemiazygous system, forming anastomotic collateral vessels. A global increase in intra-abdominal pressure by the gravid uterus may further stress the collateral system, increase venous stasis and decrease venous return. We present the management of a 37-year old pregnant woman with AIVC who underwent caesarean section with norepinephrine infusion and general anaesthesia. She presented with shortness of breath when seated, episodes of dizziness while walking or sitting upright with subsequent tachycardia. Cardiac status was monitored using an arterial pulse contour CO monitor. We did not observe large fluctuations in CO, SV, MAP during induction and intubation as well as during delivery. We believe that administration of an infusion of norepinephrine from induction to anaesthesia through caesarean section contributed to this result. Sympathetic activation caused venoconstriction, which significantly increased venous return and maintained haemodynamic stability.

Anesthetic management of mosaic Turner's syndrome posted for elective cesarean delivery after spontaneous pregnancy.

Turner's syndrome, one of the most common sex chromosome abnormalities in females, is caused by loss of part or all of an X chromosome. We report a case of mosaic Turner's syndrome, posted for elective cesarean delivery under low-dose sequential combined spinal-epidural anesthesia. The unique features of this case were the combination of an anticipated difficult airway and both short stature and scoliosis in the lumbar region. A titrated combined spinal-epidural technique was performed in order to avoid hemodynamic instability, which could have been exacerbated in the presence of cardiovascular deformities that accompany this syndrome in many cases. The patient was managed successfully under regional anesthesia, which is generally a preferred technique to general anesthesia, to avoid sympathetic stimulation during intubation and emergence. Further, this technique may avoid potential complications associated with difficult airway management.

Pencil-point needle bevel direction influences ED50 of isobaric ropivacaine with fentanyl in spinal anesthesia for cesarean delivery: a prospective, double-blind sequential allocation study.

BACKGROUND: There is little evidence on the influence of bevel direction of a pencil-point needle on the median effective dose (ED50) of isobaric ropivacaine and fentanyl in spinal anesthesia for cesarean delivery. METHODS: In this prospective, double-blind, sequential allocation study, 82 parturients scheduled for elective cesarean delivery under combined spinal-epidural anesthesia were included. We sought to determine the median effective dose of intrathecal 0.75% isobaric ropivacaine plus fentanyl 15µg with two different bevel directions of a 26-gauge Whitacre needle using up-down sequential allocation. Parturients were randomly allocated to either Group Ce (needle aperture oriented in a cephalad direction) or Group Ca (aperture directed caudally). The initial dose was 0.75% ropivacaine 11.25mg plus fentanyl 15µg in both groups. Each dose was classified as effective if, after 15min and during the next 60min, there was inability to appreciate pin-prick as sharp at T4, a visual analogue pain score <2 and no requirement for an epidural rescue bolus. RESULTS: Eighty patients were included in the analysis. The ED50 in group Ca was significantly higher (13.09mg, 95% CI 12.19-14.00) than in group Ce (10.10mg, 95% CI 9.54-10.65, P <0.001). CONCLUSION: The orientation of the distal aperture of a 26-gauge Whitacre needle during induction of spinal anesthesia for cesarean delivery influences the ED50 of 0.75% ropivacaine.

Management of pregnancy and delivery of a patient with malfunctioning ventriculoperitoneal shunt.

The use of ventriculoperitoneal shunts increased the life expectancy of many women with hydrocephalus who are able to reach childbearing age. It is believed that pregnancy may be associated with shunt malfunction and the management of pregnant women with a malfunctioning ventriculoperitoneal shunt is a challenging medical condition for the anaesthetist, the obstetrician and the neurosurgeon. We report on a case of a 35-year-old primiparous woman who underwent a scheduled caesarean delivery at 30 weeks' gestation due to deteriorating neurological condition during pregnancy. The patient had a history of astrocytoma resection in the past and placement of a ventriculoperitoneal shunt due to obstructive hydrocephalus. She had a normal life without neurological deficits until the 18th week of gestation, when the first neurological symptoms appeared. An MRI was done that showed significant dilatation of the fourth ventricle and it was believed that the shunt was not functioning properly so the patient's symptoms were present because of raised intracranial pressure. In the 30th week of gestation, she had a caesarean delivery under epidural anaesthesia and she gave birth to a live female infant. Her neurological condition started improving 48 h after delivery and the symptoms gradually regressed. At 20 days after surgery she was discharged from hospital. The presence of a ventriculoperitoneal shunt is not a contraindication for pregnancy. Maternal shunt dependency carries a relatively high incidence of complications for some patients, e.g. shunt malfunction due to raised intraabdominal pressure caused by the gravid uterus. The results of pregnancies and deliveries in women with pre-existing ventriculoperitoneal shunts are favourable if there is proper management.

The distance from the skin to the epidural and subarachnoid spaces in parturients scheduled for caesarean section.

BACKGROUND: The purpose of this study was to measure the skin to epidural space distance (SED), the skin to subarachnoid space distance (SSD) and the epidural to subarachnoid space distance (ESD) at the L3-4 interspace in parturients scheduled for caesarean section (CS) and to investigate whether any correlations exist between these distances and various physical and anthropometric parameters. METHODS: This study consisted of 332 parturients scheduled for CS. The epidural space was identified by noting the loss of resistance to air at the L3-4 intervertebral space with a Tuohy needle, thus permitting measurement of the SED. The spinal needle was introduced through the Tuohy needle and, after identification of the subarachnoid space, was locked in the epidural needle. The distance between the tip of the Tuohy needle and tip of spinal needle (ESD) was recorded. This number was added to the SED to obtain the SSD value. RESULTS: Mean values ± standard deviations for SED, SSD and ESD were 5.6 ± 1.6 cm, 6.5 ± 1.2 cm and 0.9 ± 0.5 cm, respectively. Statistically significant correlations were observed between SED, SSD and ESD with body mass index and body weight of the parturients, as well as between the SED and the parturient's height. Furthermore, a significant negative correlation was observed between the ESD and gestational age. Finally, a significant correlation existed between the SSD and ESD. CONCLUSION: Measurements of SED, SSD and ESD in parturients and the correlations between these distances to various physical and anthropometric parameters may be of potential value for combined spinal-epidural anesthesia (CSEA) in parturients scheduled for CS.