Complex Cyanotic Congenital Heart Disease and Cervical Spine Surgery: Ticking All the Right Boxes

ABSTRACT

Although complex congenital heart disease (CHD) patients usually present in childhood, it is not rare to see adults well past middle age. These patients undergo continuous pathophysiological changes in their heart and blood vessels, making anesthetic management more challenging if surgery is required. Herein, we report a case in which understanding the anatomy and pathophysiology helped optimally manage a patient with a double outlet right ventricle (DORV) who underwent plating and fixation for a hangman’s fracture in the prone position.

INTRODUCTION

It is common for anesthesiologists to encounter patients with complex congenital heart disease (CHD) scheduled for emergency or elective high-risk surgery. Although cyanotic CHD patients are usually present in childhood, it is not rare to see adults well past middle age undergoing surgery. Patients with complex CHD undergo continuous pathophysiological changes in their heart and blood vessels, which makes the situation more challenging for physicians caring for them during the perioperative period. We report a case in which understanding anatomy and pathophysiology helped optimally manage a patient with a double outlet right ventricle (DORV) who underwent plating and fixation for a hangman’s fracture.

CASE DESCRIPTION

A 42-year-old female presented to the emergency department after sustaining injuries due to a fall from approximately seven to eight feet. A preliminary survey revealed a fracture of the C2 vertebra without neurological injury. She also had an associated closed fracture of the left proximal humerus and blunt trauma to the chest. There was no history of loss of consciousness. Further inquiry into her medical history revealed she was on tablet propranolol 40 mg bd. Her previous medical records showed a ventricular septal defect (VSD), and she was admitted with dyspnea on mild to moderate exertion. On auscultation, a pansystolic murmur and peripheral cyanosis were present. Cardiology consultation was sought, and two-dimensional echocardiography revealed a large inlet VSD of 34 mm, severely malposed great vessels, aorta anterior to the pulmonary artery, and valvular pulmonary stenosis (PS) with a gradient of 72 mmHg and a visual ejection fraction of 50%. The final impression of DORV with a large VSD, severe valvular PS, and severely malposed great vessels with normal left ventricle systolic function was made. The patient was scheduled for emergency cervical plating and fixation.

In the preoperative period, the patient was counseled for likely major adverse perioperative cardiac events and the possibility of postoperative mechanical ventilation. Preoperative vital signs were noted [oxygen saturation (SpO2 85%)]. Standard monitors were attached inside the operating theatre. In addition, an arterial catheter was threaded into the right radial artery before induction, and a bispectral index (BIS) and neuromuscular monitor were attached. The patient was induced with fentanyl 200 mcg, etomidate 12 mg, and vecuronium 6 mg. After securing the airway with a 7.5 mm endotracheal tube, the right subclavian vein was cannulated using a triple-lumen central venous catheter. The patient was placed in a prone position for the surgery. Intraoperative anesthesia was maintained with O2/air/Sevoflurane/fentanyl infusion and intermittent boluses of vecuronium with a target BIS of 40–50 and a train of four (TOF) count of 0–1.

While operating close to the spinal cord, the patient developed ventricular ectopic beats that were abolished after the surgeon stopped working in that field. Intraoperatively, noradrenaline infusion was initiated at a minimal rate. The fluid replacement was guided by pulse pressure and systolic pressure variation (PPV, SPV). 350 ml red blood cells were transfused based on blood loss (1000 ml) and arterial blood analysis. Intraoperatively, arterial saturation varied between 82 and 87%. Acidosis and hemoglobin levels were assessed by arterial blood gas analysis and managed accordingly. At the end of the surgery, the patient was turned supine. Once BIS values reached 80 and train of four counts were 4, neostigmine (5 mg) and glycopyrrolate (2.5 mg) were administered. The trachea was extubated after ensuring the patient was fully awake, followed commands, and had adequate muscle power. She maintained a SpO2 of 94–95% in the postoperative area with oxygen supplementation. Subsequently, the patient was transferred to the intensive care unit.

DISCUSSION

Advancements in medical, surgical, and interventional procedures for managing CHD have resulted in the survival of more patients into adulthood. Approximately, 25% of adults with CHD have a mild disease that has permitted them to survive into adulthood without surgery or any intervention, the most common being atrial and VSDs.[1] Despite having a complex defect, the index case survived in her 40s without surgery, making anesthetic management more challenging.

Cervical spine surgery in the prone position is challenging because patients experience hypotension due to reduced total peripheral resistance despite preserved cardiac output.[2] Moreover, surgery in the cervical spine region can lead to arrhythmias and bradycardia.[3] These cardiac changes may become more pronounced in patients with cardiac disease, including those with shunt lesions.[4] Distinguishing and identifying the cause of arrhythmia is both challenging and paramount. Under general anesthesia, hypoxia, hypercarbia, acidosis, hypothermia, and hypovolemia should be considered to avoid an increase in pulmonary vascular resistance (PVR).

DORV is a rare complex entity that affects 1% of individuals with CHD.[4] The reported incidence is 0.06 cases per 1000 live births. It occurs as a consequence of both the aorta and pulmonary trunk arising from the right ventricle, with the aorta overriding more than 50% into the right ventricle. It is frequently associated with a VSD. The Society of Thoracic Surgeons database has classified DORV into five types as mentioned:[5]

1. VSD type with sub-aortic or doubly committed VSD without PS

2. Tetralogy of Fallot (TOF) type with PS

3. Transposition of great arteries (TGA) with or without PS

4. Remote VSD type with or without PS

5. DORV with atrioventricular septal defect (AVSD).

Patients in low socioeconomic countries cannot afford proper care. When they present for emergency surgery, they are often unoptimized and require resuscitation before commencing surgery. The anesthetic management must be tailored to the cardiac lesion and the patient’s cardiac status [Table 1]. The following strategies should be followed to optimize cardiac output and systemic oxygen delivery:

Table 1.

Tailored anesthetic management based on the classification of DORV

Type of DORV	Anesthetic management
Ventricular septal defect (VSD) type	Similar to VSD
	a) Ventilatory measures to reduce pulmonary flow and increase PVR
	b) Inotropic support in case of inadequate systemic perfusion
Tetralogy of Fallot (TOF) type	Similar to TOF
	a) Good volume status
	b) Adequate anesthetic depth
	c) Measures to increase systemic vascular resistance in case of cyanotic spells
	d) Avoid tachycardia
Transposition of great arteries (TGA) type	Similar to TGA
	a) Maintain systemic oxygen delivery
	b) Prevent increase in pulmonary blood flow

1. Maintain preload and cardiac contractility and avoid hypovolemia.

2. Optimize ventilation to maintain PVR and avoid hypoxia and hypercarbia.

3. Inotropic support to maintain high systemic vascular pressure (SVR) to prevent venous blood recirculation.

4. Blood transfusion to maintain oxygen-carrying capacity.

Single ventricle physiology is considered a parallel circulation in DORV, as seen in the indexed patient. The patient was managed using vasopressors (norepinephrine) to augment SVR. SPV and PPV-guided fluid administration was done, and higher doses of opioids were used to blunt the sympathetic response to intubation and surgical manipulation.

An important consideration in patients with cyanotic CHD is bleeding and thrombotic risk attributed to platelet dysfunction and coagulation cascade anomalies. A preoperative assessment of coagulation must be done, and transfusion of factors must be catered for.

Considering the rarity of a DORV presenting in adulthood, only a handful of case reports describing anesthetic management in these patients are available in the literature. Most case reports are on anesthetic management for cesarean sections under neuraxial anesthesia.[6] Chowdhury et al.[7] reported the management of a case of DORV post-Glenn shunt under general anesthesia. Hartono et al.[8] successfully managed a pregnant patient under spinal and epidural anesthesia for a cesarean section. To our knowledge, there is no report in the literature on the anesthetic management of an adult with uncorrected DORV for cervical spine surgery in the prone position.

To conclude, uncorrected DORV in adulthood is rare. Understanding the physiology of lesions is essential for their successful management. As our patient had TOF physiology, we administered high doses of opioids to blunt the hemodynamic responses, used norepinephrine to augment SVR, and transfused blood to maintain oxygenation.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.