Question: Applying the OLD CART mnemonic

Expert answer

Introduction

The case study of S.M., a 24-year-old patient with a history of asthma, who presents with a 4-day history of cough, congestion, and breathing difficulties, offers a significant opportunity to explore respiratory system pathophysiology, particularly in the context of asthma and its possible exacerbation. S.M.'s symptoms, compounded by potential exposure to COVID-19, add layers of complexity to the assessment, diagnosis, and management of the condition. This essay critically examines the scenario, using clinical mnemonics such as OLD CART (Onset, Location, Duration, Characteristics, Aggravating factors, Relieving factors, and Treatments), and delves into various aspects such as the necessary clarifying questions, the review of systems, expected respiratory findings, and appropriate nursing diagnoses and interventions.

The respiratory system is vital in maintaining gas exchange in the body, and when compromised, as in the case of asthma, it can result in decreased oxygen saturation and increased respiratory effort. This case presents multiple issues, including potential asthma exacerbation, possible respiratory infection (COVID-19), and impaired gas exchange, all of which need to be systematically evaluated and managed. Through a thorough assessment of S.M.'s presenting symptoms, medical history, and vital signs, it becomes crucial to apply evidence-based clinical reasoning, guided by mnemonics like OLD CART, to explore potential underlying respiratory issues. Using a structured approach will allow healthcare professionals to develop a comprehensive problem list, with appropriate nursing diagnoses and interventions aimed at improving respiratory function and overall patient well-being.

Additional Clarifying Questions for S.M.

To obtain a fuller picture of S.M.'s condition, three pertinent questions should be asked:

1. Has your asthma worsened in the past few days, and are you experiencing more frequent or severe attacks?
   This question seeks to identify any patterns of asthma exacerbation beyond the current episode, which could suggest a deteriorating baseline respiratory function or a need for adjustments in asthma management.

2. Can you describe your "breathing medication" and how frequently you’ve been using it?
   It is essential to clarify which medications (e.g., short-acting beta-agonists, inhaled corticosteroids) S.M. is referring to, as different types of medication are used for long-term control versus quick relief. This will help determine whether S.M. is adhering to the correct treatment plan or if overuse or misuse is contributing to the current condition.

3. Do you have any history of exposure to other respiratory irritants, allergens, or significant stress in recent days?
   Asthma exacerbations can be triggered by allergens, pollutants, or even psychological stress. Identifying these factors will help in managing S.M.'s triggers effectively and prevent future exacerbations.

OLD CART Mnemonic for S.M.'s Chief Complaint

Applying the OLD CART mnemonic allows a systematic exploration of S.M.’s symptoms:

• Onset:
  "When did your symptoms start?"
  This aims to confirm the duration and timeline of S.M.'s symptoms. While S.M. has reported a 4-day history, understanding if the symptoms began suddenly or gradually can help in differentiating between asthma exacerbation and other possible conditions like viral respiratory infections.

• Location:
  "Where do you feel the most discomfort or trouble when you breathe?"
  The answer could point towards localized issues such as chest tightness, which is often associated with asthma, or other areas of discomfort that might suggest additional complications like pleuritic pain in cases of pneumonia or pulmonary embolism.

• Duration:
  "How long do your breathing difficulties last? Are they constant or do they come and go?"
  Asthma exacerbations often present with episodic breathing difficulties. If S.M. is experiencing constant shortness of breath, it may suggest a more severe or worsening condition.

• Characteristics:
  "Can you describe the cough and breathing difficulties—are you producing any sputum or is it dry?"
  This will help distinguish between productive and non-productive coughs, which are indicative of different conditions. A dry cough is more typical of asthma, while a productive cough might suggest an infection or mucus buildup.

• Aggravating factors:
  "What seems to make your symptoms worse?"
  Identifying specific aggravating factors such as physical activity, cold air, allergens, or even emotional stress can guide management strategies.

• Relieving factors:
  "Is there anything that helps ease your symptoms?"
  Knowing what alleviates symptoms—whether medication or environmental changes—can help assess the effectiveness of S.M.’s current treatment plan.

• Treatments:
  "Have you tried any treatments besides your breathing medication?"
  This question aims to identify any additional interventions S.M. may have tried, including over-the-counter remedies, home treatments, or even alternative therapies.

Social History

For a patient like S.M., it is critical to gather a detailed social history that encompasses:

1. Smoking history: "Do you smoke or have you ever smoked?" Smoking can significantly exacerbate asthma and other respiratory conditions. Even secondhand smoke exposure can be a critical factor.

2. Living environment: "Can you describe your living situation, including any exposure to pets, mold, or dust?" Allergens like pet dander and dust mites are common asthma triggers, and poor living conditions can exacerbate respiratory symptoms.

3. Occupational hazards: "Do you work in an environment with potential respiratory irritants?" S.M. reports recent exposure to a coworker who tested positive for COVID-19, but additional exposure to chemicals or other airborne irritants could contribute to asthma exacerbation.

4. Substance use: "Do you use any recreational drugs or substances?" Some inhaled substances, such as marijuana or vaping products, can irritate the lungs and worsen respiratory conditions.

5. Physical activity: "How physically active are you, and do you notice any changes in your ability to exercise?" Asthma can limit physical activity, and understanding S.M.’s baseline function can help gauge the severity of the current episode.

Focused Review of Systems (ROS)

For a focused ROS, the respiratory system should be the primary concern. Additional systems to assess include the cardiovascular, neurological, and integumentary systems, given the potential for multisystem involvement in severe asthma exacerbations or COVID-19 infection.

1. Respiratory System:

   • Presence of wheezing, shortness of breath, chest tightness, and cough (productive or dry)
   • Any recent exposure to respiratory irritants or allergens
   • Impact on daily activities, such as difficulty speaking in full sentences due to breathlessness

2. Cardiovascular System:

   • Palpitations, dizziness, or chest pain, which may be indicative of hypoxia or increased work of breathing

3. Neurological System:

   • Headaches or confusion could be signs of hypoxia, especially with an oxygen saturation (SpO2) of 87%, which indicates moderate hypoxemia.

4. Integumentary System:

   • Any cyanosis (bluish discoloration of the skin), especially around the lips or fingertips, as this can indicate poor oxygenation.

Respiratory Findings in Asthma

Adventitious Lung Sounds

In a client with asthma, the most commonly encountered adventitious lung sound is wheezing. Wheezing is a high-pitched, musical sound typically heard during expiration, although it may be heard during both inhalation and exhalation in severe cases. The sound results from the turbulent flow of air through narrowed airways, a hallmark of asthma exacerbation.

Pathophysiologic Changes Leading to Wheezing

Asthma is characterized by chronic inflammation of the airways, bronchoconstriction, and increased mucus production. During an exacerbation, these changes result in airway narrowing, leading to increased resistance to airflow, especially during expiration when airways tend to be smaller. This narrowing creates the characteristic wheezing sound. In more severe exacerbations, reduced airflow may lead to diminished or absent breath sounds, signaling a critical reduction in ventilation, often termed a "silent chest."

Inhalation to Exhalation Ratio in Asthma Exacerbation

In normal breathing, the inhalation-to-exhalation (I) ratio is approximately 1:2. However, in asthma exacerbations, exhalation becomes more prolonged due to airway obstruction, resulting in a ratio closer to 1:3 or 1:4. This prolonged exhalation is an attempt by the body to overcome the increased resistance and expel air from the lungs, which is more difficult due to the constricted bronchi.

Problem List, Nursing Diagnoses, and Interventions

Based on S.M.'s clinical presentation, the following problems can be identified:

1. Impaired Gas Exchange (SpO2 87%)

• Nursing Diagnosis: Impaired gas exchange related to airway obstruction as evidenced by low oxygen saturation and dyspnea.
• Intervention: Administer supplemental oxygen as prescribed to maintain SpO2 above 92%. Evaluate response to bronchodilator therapy (e.g., albuterol). Encourage the patient to sit upright and practice pursed-lip breathing to improve ventilation.

2. Ineffective Airway Clearance (Cough, Congestion)

• Nursing Diagnosis: Ineffective airway clearance related to increased mucus production and bronchoconstriction as evidenced by cough and congestion.
• Intervention: Encourage fluid intake to thin secretions. Administer bronchodilators and expectorants as prescribed. Monitor for productive versus non-productive cough and use chest physiotherapy if indicated.

3. Risk for Infection (Recent COVID-19 Exposure)

• Nursing Diagnosis: Risk for infection related to exposure to a coworker with COVID-19.
• Intervention: Implement isolation precautions if needed based on COVID-19 testing. Educate the patient about the importance of hand hygiene, mask-wearing, and other infection control measures. Monitor for signs of worsening infection, such as increased fever or respiratory distress.

4. Activity Intolerance (Dyspnea and Increased Respiratory Rate)

• Nursing Diagnosis: Activity intolerance related to dyspnea and increased work of breathing as evidenced by tachypnea and reported difficulty breathing.
• Intervention: Assist the patient with activities of daily living (ADLs) to conserve energy. Gradually increase activity as tolerated. Monitor vital signs and oxygen saturation during exertion.

Conclusion

In conclusion, the case study of S.M. demonstrates the need for a comprehensive and structured approach to respiratory assessment, particularly in patients with asthma. By applying the OLD CART mnemonic and conducting a focused review of systems, clinicians can gather crucial information to guide diagnosis and treatment. The identification of adventitious lung sounds like wheezing, and understanding their pathophysiological basis, helps in managing asthma exacerbations effectively. A well-developed problem list, with corresponding nursing diagnoses and interventions, ensures a holistic approach to care, focusing on improving respiratory function, preventing complications, and optimizing patient outcomes.