DAH is a syndrome characterized by multicausal alveolar capillary injury and blood accumulation in the alveoli from the pulmonary microcirculation. Clinical manifestations include nonspecific severe dyspnea, hemoptysis, anemia, and diffuse alveolar infiltrates in both lungs[2, 6, 7]. The most common histopathology of DAH is the presence of erythrocytes, fibrin, and iron-containing heme formed by macrophage phagocytosis in the alveoli[6]. DAH is represented by pulmonary capillaritis, benign pulmonary hemorrhage, diffuse alveolar damage, and other histological changes[7]. Wegener granulomatosis (32%), Goodpasture syndrome (13%), idiopathic pulmonary hemosiderosis (13%), collagen vascular disease (13%), and microscopic polyangiitis (9%) are the most prevalent causes of DAH[6, 7].
The pathogenesis of DAH during the perioperative period may be related to negative pressure pulmonary edema (NPPE). NPPE, also known as postobstruction pulmonary edema, was first reported in 1973[10]. The first case of negative-pressure-related postextraction laryngospasm was reported in 1989[11], and the diagnosis of postoperative negative-pressure-related DAH was primarily established after 2006. Postoperative negative-pressure-related DAH is a potentially fatal complication of general anesthetic surgery with an incidence of 0.05% to 0.1% and is associated with laryngospasm occurring in over 50% of cases in adults[8, 12].
It is now generally accepted that the acute upper airway obstruction triggered by the patient’s NPPE causes an increase in negative intrathoracic pressure (up to 140 cm H2O compared to the normal 4 cm[13]), which is the mechanism of NPPE-associated DAH. Then, because of this event, hydrostatic pressure rises, as well as venous return, pulmonary blood volume, and hydrostatic pressures. Pulmonary edema results from hydrostatic pressure transmission to the interstitium and alveoli, facilitating fluid transport from the pulmonary capillaries into these tissues. The alveolar-capillary membrane may be damaged and ruptured in severe cases, leading to diffuse alveolar hemorrhage[2, 8, 9, 14]. Young and healthy adults are more likely to have negative-pressure-related DAH as they have powerful inspiratory muscles that can generate higher intrapleural negative pressures[15].
In this case, the differential diagnoses included pulmonary embolism, cardiogenic pulmonary edema, negative pressure-associated DAH, sevoflurane-associated lung injury, airway trauma, arteriovenous malformation, connective tissue disease, or vasculitic processes, such as Wegener granulomatosis or Goodpasture syndrome. Multiple aspects can be used to deduce the cause of this circumstance. Initial suspicions were of pulmonary embolism. Most patients affected by a potential pulmonary embolism caused by silicone leakage from a prosthesis exhibit clinical symptoms within 24 hours[16, 17]. In addition to a mild postoperative inflammatory response and the absence of neurological involvement and inconsistent chest CT imaging with silicone embolism in the lungs (bilateral peripheral ground glass shadows and thickening of the lobular septa[16]), our patient presented with a sudden onset of dyspnea within a short period of time after surgery. The placement of the breast implant during breast augmentation may have damaged the adipose tissue of the thorax, resulting in the formation of fat emboli in the pulmonary microvasculature and pulmonary fat embolism[18]. The patient’s mental clarity returned rapidly after receiving oxygen therapy. There were also no manifestations of central nervous system involvement, such as headache, disorientation, or spasticity, despite her acute respiratory distress symptoms. Moreover, the patient lacked a petechial rash on her body.
The most prevalent cardiac causes of DAH are congestive heart failure and mitral valve diseases[19]. Our patient had no history of cardiovascular disease and was in good health. The patient's clinical indications, electrocardiogram, and transthoracic echocardiogram systematically ruled out left ventricular systolic or diastolic dysfunction, as well as valvular pathology. The postoperative cardiac enzyme levels and echocardiogram were nonspecific, and the COVID-19 test was negative. Therefore, cardiogenic pulmonary edema was also ruled out.
The patient underwent a strict fast, and no history of aspiration was present. A total of 700 mL of the equilibrium solution was administered at a constant rate to compensate for preoperative fluid loss and achieve equilibrium. During the duration of the perioperative period, there was no drug-related allergy. Throughout the perioperative period, the patient's immunobiological, microbiological, and coagulation assays were negative, with no drug-related allergic reactions. Negative-pressure-related DAH was diagnosed based on the patient's clinical symptoms, imaging results, and recovery after excluding the aforementioned causes. Bronchoalveolar lavage revealed persistent or increased lavage hemorrhage, a crucial part of diagnosing DAH[6]. However, our patient refused bronchoalveolar lavage due to the improvement of her symptoms.
Multiple anesthetic factors predisposed our patient to develop DAH. Sevoflurane as an inhaled anesthetic has been reported in some cases to induce postoperative DAH[4, 20, 21]. Although the mechanism of action is unknown, high concentrations of sevoflurane and propofol may cause airway obstruction, and sevoflurane's toxic effects bear a risk of alveolar wall damage, which can partly contribute to DAH[22, 23]. At concentrations between 100 and 300 g/ (kg × min), esmolol does not cause significant bronchospasm. However, at doses 40 to 100 times higher, esmolol can inhibit β2-adrenergic receptor in bronchial and vascular smooth muscle, increasing airway resistance. Our patient consumed 80 mg of esmolol throughout the procedure, which is above the normal dose range. However, there are no studies detailing the clinical impact of putative esmolol properties.
The treatment of negative- pressure-related DAH is aimed at rectifying upper airway obstruction and hypoxia. The treatment mainstay consists of preserving airway patency, ensuring adequate oxygenation via supplemental oxygen, and increasing positive end-expiratory pressure or continuous positive pressure, guided by physical examination, oxygen saturation, and arterial blood gas testing. Within 12 to 48 hours, patients' clinical symptoms and pulmonary edema typically improve[7, 24]. In cases of extreme severity, patients can be treated with noninvasive or invasive mechanical ventilation (high-flow nasal cannula oxygen therapy or noninvasive or invasive mechanical ventilation[2, 9]). Other drugs, such as diuretics and steroids, should be determined on a case-by-case basis due to the lack of consensus regarding their action[25]. In our instance, an anti-inflammatory corticosteroid regimen was administered systemically. Our patient responded well to symptomatic and supportive care and recovered spontaneously without developing secondary symptoms.
This case reminds us that this rare but potentially catastrophic complication can occur after breast augmentation. Therefore, we summarize the following guidelines to facilitate the effective prevention, diagnosis, and treatment of negative-pressure-related DAH in our clinical work:
1) Negative-pressure-related DAH is difficult to diagnose, and failure to promptly identify and treat underlying causes may result in acute respiratory failure. Surgeons should pay adequate attention to patients with any postanesthetic upper airway obstruction condition.
2) Negative-pressure-related DAH should be considered in patients with acute upper airway obstruction, hemoptysis, and bilateral diffuse pulmonary infiltrative shadows on chest CT after other causes have been ruled out.
3) Negative-pressure-induced DAH is treated with airway obstruction relief, oxygen supplementation, and assisted ventilation.
Negative-pressure-related DAH after breast augmentation is a rare but life-threatening clinical entity that occurs most frequently in healthy adults presenting with laryngospasm following surgical anesthesia. Systematic management strategies can prevent further deterioration and reduce the risk of death from DAH through early recognition, diagnosis, and aggressive intervention.