Anesthetic Management Using Echocardiography for Surgery of Lower Extremity in a Patient with Ebstein’s Malformation

To the Editor:

Ebstein’s malformation is rare congenital heart disease with the downward displacement of the tricuspid valve into the right ventricle. The hazards occurs tachydysrhythmias and hypoxemia owing to the right-to-left intracardiac shunt. We report epidural anesthesia with evaluation of echocardiography during anesthesia in a patient with Ebstein’s malformation. A 58-yr-old woman underwent emergent repair for left foot joint fracture. The Ebstein’s malformation had been found at 42 yr of age, but no right-left shunt was found at that time. Echocardiography revealed downward displacement of the tricuspid valve but no right-to-left shunts. We estimated cardiac function using echocardiography from the start of anesthesia. After spinal anesthesia was induced with 0.5% bupivacaine (10 mg), the epidural catheter was introduced to the epidural space via the L4-5 space. A total dose of 11 mL of mepivacaine 1% produced analgesia from S5 to T11.

Arterial blood pressure and heart rate did not change with anesthesia and Spo₂ also remained at 100%. The right ventricle diastolic diameter before and after anesthesia was 2.9 cm and 3.0 cm, respectively (Figures 1 and 2). During surgery, we continued observing the right ventricle diastolic diameter to avoid excessive administration of IV fluids. Total fluid was 700 mL. During and after anesthesia, her vital signs did not change to any clinical significant degree.

Figure 1.: View of echocardiography before anesthesia.

Figure 2.: View of echocardiography after anesthesia. The right ventricle diastolic diameter did not change from before anesthesia.

Hazards during anesthesia include development of cardiac tachydysrhythmias and hypoxemia as the result of increases in the magnitude of the right-to-left intracardiac shunts. Several anesthetic managements in patients with Ebstein’s malformation have been described (^1–4). General anesthesia has the advantage that hypotension tends to be avoided, but arrhythmia and tachycardia may occur after intubation and extubation of the trachea. In contrast, Linter and Clarke (²) showed the successful use of a two-catheter technique for elective Cesarean delivery with extradural analgesia. Epidural or spinal anesthesia may be appropriate in non-severe patients, but excessive administration of fluid should be avoided because it may increase right arterial pressure sufficiently to cause an increased right-to-left shunt and hypoxemia.

In this anesthesia, we evaluated cardiac preload and function using echocardiography. Although central venous pressure monitoring or the insertion of a pulmonary artery catheter may be useful to evaluate cardiac preload, these measures may be technically difficult in Ebstein’s anomaly and lead to complications such as tachyarrhythmias or paradoxical emboli. Transesophageal echocardiography may be also useful, but it would be difficult to monitor in our case for an extended period because the patient was awake during surgery. Echocardiography is and noninvasive and can be used frequently. It provides much information about changes of the cardiovascular system, especially for this patient with Ebstein’s malformation even during anesthesia. In conclusion, epidural or spinal anesthesia may be appropriate in non-severe patients and echocardiography should be useful monitoring during anesthesia for patients with Ebstein’s malformation.

Takafumi Horishita, MD, PhD

Kouichiro Minami, MD, PhD

Kazunori Koga, MD, PhD

Junichi Ogata, MD, PhD

Takeyoshi Sata, MD, PhD

Department of Anesthesiology

School of Medicine

University of Occupational and Environmental Health

Yahatanishiku, Kitakyushu, Japan

[email protected]