Non-invasive ventilation in patients with acute lupus pneumonitis: A case report and review of literature.

Acute lupus pneumonitis is an uncommon but life threatening condition associated with systemic lupus erythematosus. We report the case of a young female who presented to us with acute hypoxemic respiratory failure secondary to acute lupus pneumonitis as initial presenting manifestation of lupus. She was managed with non-invasive ventilation and pulse steroids, with which she had dramatic improvement.

INTRODUCTION

Systemic lupus erythematosus (SLE) is an autoimmune disease. The tissue-binding autoantibodies and immune complexes mediate the cellular and organ dysfunction found in this disease. SLE affects 9 times as many women as men. It may occur at any age, but appears most often in people between the ages of 20 and 45 years. Prevalence of SLE in the United States is 15–50 per 100,000. SLE is rare in India with a point prevalence of 3 per 100,000.[1]

SLE has the potential to affect any organ however, the lungs are commonly involved later in the course of the disease. The prevalence of pleuro-pulmonary manifestations of lupus has been variable, depending on the diagnostic methods used. An autopsy study of 90 patients with SLE found, some degree of pleuropulmonary involvement in 97.8% of cases.[2] However, in a series of 216 consecutive patients with SLE, lung involvement was found in only 25% cases based on clinical judgment and imaging.[3]

Acute lupus pneumonitis is an uncommon manifestation of lupus affecting less than 2% of cases. It is often life threatening, once ventilator failure sets in, with a mortality rate of more than 50%, despite treatment.[4]

Herein, we report perhaps the first case in English literature of acute lupus pneumonitis with acute hypoxemic respiratory failure managed successfully with Noninvasive ventilation (NIV) and steroids.

CASE REPORT

A 24-year-old woman was admitted in the medical intensive care unit with a five day history of fever, dry cough, and shortness of breath. At admission she had central cyanosis, a respiratory rate of 40 breaths/min, and an oxygen saturation of 48% while breathing room air which improved to 78% on re-breathing mask. She had a temperature of 102°F, pulse of 140/min and a blood pressure of 110/50 mmHg. She was irritable but oriented to time, place, and person. Respiratory examination revealed diffuse bilateral fine inspiratory crackles. The rest of the physical examination was unremarkable.

Investigations revealed hemoglobin of 11.6 gm/dL, total leukocyte count of 14,600/μL and platelet count of 68,000/μL and an erythrocyte sedimentation rate of 94 mm in the 1st hour. Liver and renal function tests were normal. A chest radiograph showed bilateral lower zone alveolar opacities [Figure 1].

Figure 1

Chest radiograph showing bilateral lower zone alveolar opacities

Arterial blood gas analysis showed hypoxemia with respiratory alkalosis [Table 1] with a PaO2/FiO2 score of 180. Echocardiography revealed moderate amount of pericardial effusion with normal left ventricular ejection fraction.

Table 1

Arterial blood gas of the patient at baseline and after application of non – invasive ventilation

A diagnosis of acute respiratory distress syndrome (ARDS) was made and the patient was initiated on NIV (Evita 2 Dura, Draeger Medical, Lubeck, Germany) with an inspiratory/expiratory positive airway pressure of 16/6 cm of H2O with a FiO2 of 0.7. After sending the cultures she was started on injectable antibiotics (co-moxyclav and azithromycin) keeping the possibility of severe community acquired pneumonia. Later, her blood culture, sputum gram smear, Ziehl–Neelsen (ZN) stain and pyogenic culture and serology for infection were negative. Nonenhanced computed tomography (NCCT) chest revealed bilateral lower lobe air-space disease, pericardial effusion [Figure 2].

Figure 2

NCCT chest showing bilateral lower lobe air-space disease

Broncho-alveolar lavage was clear (non-hemorrhagic) did not show any organism on gram smear, ZN Stain and potassium hydroxide (KOH) mount and culture was sterile. In view of negative cultures, polyserositis, poor response to initial antibiotics possibility of an autoimmune disease was kept and her auto-immune panel was sent, which revealed high titres of antinuclear antibody (ANA) and ds double-stranded DNA (dsDNA) antibodies. Diagnosis of systemic lupus erythematosis was made.

A diagnosis of acute lupus pneumonitis was made after rigorously excluding infections (negative cultures and serology for infection), myocarditis and pulmonary embolism (normal left ventricular ejection fraction on echocardiography). Diffuse alveolar hemorrhage was excluded by the absence of- hemoptysis, falling serial hematocrit and worsening RBC counts on sequential BAL sample.

She was given pulse methylprednisolone (1 g iv/daily) for three days. Besides this NIV was given with close clinical and laboratory monitoring till steroids had their beneficial effects. After 72 hours of continuous ventilation (with short breaks for daily activities), there was a significant improvement in the lung injury scores [Table 1].

A repeat chest radiograph at 7th day revealed clearing of lower lobe opacities. She was gradually weaned off the ventilator and discharged after a total hospital stay of 10 days.

DISCUSSION

Various causes of acute respiratory failure in SLE include severe community-acquired or pneumonia in immunocompromised host, diffuse alveolar hemorrhage, acute lupus pneumonitis, pulmonary embolism, and volume overload state.

The reported incidence of acute lupus pneumonitis varies from 0.9% to 11.7%.[4] It usually presents with fever, cough, pleurisy, dyspnea, pleural effusions, pulmonary infiltrates, especially in the lower lung fields and hypoxia. Usually these patients have high anti-dsDNA antibody titres.

Various mechanism of type I respiratory failure in lupus pneumonitis include alveolitis, alveolar necrosis, alveolar hemorrhage, edema, interstitial pneumonitis, hyaline membranes, interstitial pneumonitis, capillary thrombosis, and deposition of immunoglobulin and complement.[56]

NIV has revolutionized the management of acute respiratory failure and it can decrease the endotracheal intubation rates and even mortality. A recent prospective multicenter survey found that when NIV was used as first-line therapy for selected ALI/ARDS patients (those with >2 organ failures, hemodynamic instability, or encephalopathy were excluded), 54% avoided intubation and had excellent outcomes.[7] NIV has been successfully used in ALI/ARDS which are rapidly reversible with treatment.[89] In the index case the patient had features of ARDS at time of presentation and was initiated on NIV as adjunctive besides definitive treatment. NIV must be applied by well-trained professionals who are familiar with NIV equipment and can identify features of early NIV ineffectiveness, in which case intubation should be considered.

The mainstay of acute lupus pneumonitis treatment is systemic corticosteroids (prednisone 1–1.5 mg/kg/d in divided doses), although the mortality of lupus pneumonitis remains high despite corticosteroids.[4] If the response to oral corticosteroids is not adequate within 72 hours or the patient has marked tachypnea, hypoxemia, or suspected diffuse alveolar hemorrhage, treatment should include intravenous pulse corticosteroids (i.e., 1 g methylprednisolone per day for 3 days). In addition, immunosuppressants such as cyclophosphamide should be considered.

In conclusion, acute lupus pneumonitis can be the initial presenting manifestation of SLE.

Differentiating it from severe community-acquired, diffuse alveolar hemorrhage, pulmonary embolism and volume overload state, due either to renal failure or to congestive heart failure is important. Early institution of NIV in acute hypoxemic respiratory failure secondary to acute lupus pneumonitis is fruitful till immunosuppressive have their effect.