Atrial Septal defect in a child - Nursing Case Study

Pathophysiology

• Primary mechanism: An Atrial Septal Defect (ASD) is a hole in the septum between the heart's two upper chambers (atria). This permits oxygen-rich blood from the left atrium to mix with oxygen-poor blood in the right atrium, leading to increased blood flow to the right side of the heart.

• Secondary mechanism: The excess blood flow from the right side of the heart is then sent to the lungs, causing an overload. The right atrium and ventricle may enlarge due to this additional volume. Over time, this can result in pulmonary hypertension.

• Key complication: If untreated, the increased pressure in the lungs and right heart enlargement can lead to heart failure, arrhythmias, and Eisenmenger syndrome, a severe form of pulmonary hypertension where the direction of blood flow through the ASD reverses.

Patient Profile

Demographics:

6-year-old male, kindergarten student

History:

• Key past medical history: Diagnosed with Atrial Septal Defect at 2 years old

• Current medications: Furosemide (Lasix), Digoxin

• Allergies: No known allergies

Current Presentation:

• Chief complaint: Increasing fatigue, shortness of breath and frequent respiratory infections

• Key symptoms: Reduced appetite, swelling in legs, difficulty in gaining weight

• Vital signs: Heart rate - 115 bpm, Blood pressure - 95/65 mmHg, Respiratory rate - 30 breaths per minute, Oxygen saturation - 92%

Section 1

Change in Patient Status:

In the following few days, the child's condition became progressively worse. His fatigue increased, and he was often too exhausted to participate in school activities. His shortness of breath became more pronounced even with minimal exertion, such as walking short distances. His appetite dwindled, and he lost 1.5 kg over a week. His oxygen saturation levels dropped to 88% despite supplemental oxygen administration. His respiratory rate increased to 35 breaths per minute, heart rate escalated to 125 bpm, and blood pressure remained relatively stable at 95/68 mmHg.

New Complications:

These changes indicated worsening of his condition, possibly progressing towards heart failure. He also developed a new onset of persistent cough and fever, indicative of a possible respiratory infection due to the increased blood flow to the lungs, making them more susceptible. Moreover, his leg swelling became more pronounced. On physical examination, an increase in liver size (hepatomegaly) was noted, indicating congestion from the right-sided heart failure. The child also showed signs of exercise intolerance and cyanosis, especially around the mouth and lips, suggesting severe oxygen deprivation. These new complications necessitate a reevaluation of the current treatment strategy and may indicate the need for surgical intervention.

Section 2

New Diagnostic Results:

Upon these alarming indications, the healthcare team proceeded with a series of diagnostic tests. The chest X-ray showed an enlarged heart and increased lung markings, suggesting pulmonary congestion. An echocardiogram confirmed the existence of a large atrial septal defect causing significant shunting from left to right. It also showed that the right side of the heart was severely dilated and the function of the right ventricle was compromised. An EKG showed sinus tachycardia and right bundle branch block, indicative of a strain on the right side of the heart. His CBC results showed a slightly increased white blood cell count of 11,500/µL, suggestive of an existing infection. This was further supported by the presence of elevated C-reactive protein levels in his blood test results.

Change in Patient Status:

With these new findings, the child was diagnosed with decompensated heart failure secondary to the large atrial septal defect. His oxygen saturation levels dropped further to 85% despite receiving a higher flow of supplemental oxygen. His extremities became cold to touch, and he developed a new onset of altered consciousness, becoming increasingly lethargic and unresponsive. The child was then transferred to the pediatric intensive care unit (PICU) for closer monitoring and management of his deteriorating condition. These findings suggest that the child's condition is critical, necessitating immediate and aggressive interventions to prevent further complications. The healthcare team must now consider the risks and benefits of surgical repair of the defect versus conservative management.

Section 3

New Complications:

Over the next 24 hours, the child's condition continued to deteriorate. He experienced worsening dyspnea and fatigue and his oxygen saturation levels dropped further to 80% despite being on high flow oxygen. A repeat echocardiogram indicated an increased right to left shunting through the atrial septal defect, suggesting the development of Eisenmenger's syndrome, a condition in which prolonged high pressure in the right side of the heart leads to the reversal of blood flow through the defect. His blood test results showed a hemoglobin level of 18.2 g/dL and a hematocrit of 54.8%, suggestive of secondary polycythemia, a compensatory response to chronic hypoxia.

Response to Interventions:

In response to the child's deteriorating condition, the healthcare team initiated aggressive management strategies. Intravenous diuretics were administered to reduce the volume overload on his heart and improve his breathing. Despite these interventions, the child's oxygen saturation remained persistently low and he continued to show signs of worsening heart failure. The team also initiated a trial of sildenafil to decrease the pulmonary vascular resistance and to reduce the right to left shunting. The healthcare team now faces the challenging decision of whether to proceed with a high-risk surgical repair of the atrial septal defect or to continue with medical management, which is unlikely to reverse the course of the disease.

Section 4

New Diagnostic Results:

A subsequent cardiac catheterization was performed to further assess the severity of the shunting and evaluate the pulmonary vascular resistance. The results revealed markedly elevated pulmonary artery pressures, confirming the diagnosis of Eisenmenger's syndrome. A complete blood count was repeated, which showed a further increase in the child's hemoglobin to 19.4 g/dL and hematocrit to 58.5%, indicating a worsening state of secondary polycythemia.

Change in Patient Status:

Despite aggressive medical interventions, the child's clinical condition continued to deteriorate. His oxygen saturation levels remained critically low at 78% and he developed signs of cyanosis, with a bluish discoloration noted on his lips and nail beds. He also became increasingly lethargic and was unable to tolerate feeds due to worsening dyspnea. His heart rate increased to 140 beats per minute, and his blood pressure dropped to 90/50 mmHg, suggestive of possible cardiogenic shock. The team was concerned about the risk of a potential cardiac arrest if his condition was not stabilized urgently. Given the gravity of the situation, the healthcare team decided to convene a meeting with the child's parents to discuss the possible need for emergency surgical intervention.

Section 5

New Complications:

During the meeting with the parents, the child's condition took a sudden turn for the worse. He started to exhibit signs of severe respiratory distress, with increased work of breathing, use of accessory muscles, and retractions. Crackles were heard on auscultation of the lungs, indicative of possible pulmonary edema. Additionally, his pulse oximetry reading dropped to 70%. The arrhythmia monitor indicated a new onset of tachyarrhythmia, with a heart rate spiking to 170 beats per minute.

In response, the healthcare team immediately initiated emergency resuscitation measures. The child was given supplemental oxygen via a non-rebreather mask. An arterial blood gas analysis was ordered, revealing a pH of 7.30, PaCO2 of 55 mmHg, PaO2 of 55 mmHg, and bicarbonate level of 24 mEq/L, indicating respiratory acidosis. The electrocardiogram showed signs of right ventricular hypertrophy and strain. The team quickly realized that the child was decompensating and an immediate surgical intervention was crucial to prevent further deterioration. This new development called for a rapid reassessment of the treatment plan and escalation of care.