Treatment of particle-associated pulmonary aspiration with bronchoscopic lavage: report of two cases

Editor, Aspiration pneumonia after regurgitation is a severe complication associated with general anaesthesia [1]. Aspiration of vomit may result in respiratory insufficiency and circulatory collapse, which contribute to the high mortality rate [1]. Recent studies [2] indicated that the incidence of perioperative pulmonary aspiration is not only very infrequent (1 in 2000–3000 in elective surgery in adults), but that it is still associated with significant pulmonary morbidity and mortality. In general, careful suctioning of aspirated materials is useful to decrease the volume remaining in the lungs, but lavage with physiological saline is discouraged, because it may increase the spread of aspirate [3]. We present two cases of regurgitation during anaesthetic induction. In both of these cases, treatments of pulmonary particle-associated aspiration with prompt bronchoalveolar lavage under bronchoscopy did not result in severe subsequent pneumonia. Case 1 A 62-year-old (82 kg; 162 cm) man developed a sudden headache and nausea. He was brought to the hospital and was diagnosed with subarachnoid haemorrhage (SAH). More than 15 h after the onset, he was transferred to an operating room for cerebral aneurysm clipping. His consciousness had been clear, and he was fasted. Anaesthesia was induced with thiopental, 200 mg, and vecuronium, 8 mg. When his mouth was opened for tracheal intubation, regurgitation was observed. The vomit was suctioned, and the patient was intubated tracheally. Then, intratracheal vomit was suctioned. The lungs were ventilated with 100% oxygen. Oxygen saturation (Spo2) and Pao2 were 94% and 69 mmHg, respectively. Chest radiograph demonstrated atelectasis of the total area of the left lung (Fig. 1). Bronchial toilet for 45 min brought about no improvements in chest radiographic findings.Fig. 1About 1 h after aspiration, bronchoalveolar lavage (BAL) with physiological saline was performed under bronchoscopy. All of the left pulmonary segments were washed. Finally, all food particles identified were washed out, and the vomit was no longer seen bronchoscopically. Spo2 was elevated to 100% and Pao2 was 122 mmHg in 40% oxygen without positive end expiratory pressure (PEEP). From the findings of chest radiography, pulse oximeter, and arterial gas analysis, a decision was made to proceed with the surgery. Throughout the surgery, all measurements such as arterial gases were within normal levels. After the surgery, a chest radiograph demonstrated no atelectasis (Fig. 1). No abnormal respiratory sounds were noted. The patient was transferred into the ICU, and ventilation was mechanically assisted. Tracheal intubation was maintained for 5 days with a sedative, midazolam, to ensure faultless respiratory management because of insufficient respiratory drive from unknown factor (the extubation criteria was not fulfilled by the decrease in minute volume without the mechanical ventilation) but not lung damage. At the fifth postoperative day, the tracheal tube was removed (Fig. 1). At the seventh postoperative day, the patient was transferred to an ordinary ward without any sequela. Two weeks thereafter, the patient was discharged from the hospital. Case 2 A 57-year-old man (57 kg; 163 cm) was diagnosed with sigmoid cancer accompanied by stenosis. Circulatory and renal function (hypotension and need for a diuretic) was recovering, and sigmoid stenosis had progressed to ileus. A gastric tube had been inserted in advance, and gastric juice, about 100 ml, had been excreted. The patient was prepared for emergency sigmoidectomy. The lungs were ventilated with 100% oxygen, and general anaesthesia by rapid sequence induction with cricoid pressure was employed with intravenous 300 μg fentanyl, 120 mg thiopental, and 10 mg vecuronium. On tracheal intubation, regurgitation and aspiration were noted. The bronchus was extensively suctioned for 20 min, but the level of Spo2 (92%) and Pao2 (89 mmHg) were insufficient. Chest radiograph showed bilateral atelectasis. BAL was carefully performed under bronchoscopy. All the aspirated particles found bronchoscopically were washed out. After BAL, both levels of Spo2 (100%) and Pao2 (477 mmHg) had recovered to within normal levels. Under laparotomy, sigmoid perforation and panperitonitis were confirmed. Haemodynamics during surgery were poor: intermittent ephedrine (10 mg) was required on several occasions and continuous dopamine (8–12 μg kg−1 min−1) was given to maintain haemodynamics. During anaesthesia, hydroxyethyl starch, 1500 ml, and acetated Ringer solution, 4560 ml, were infused. After the operation, chest radiography did not show signs of pneumonia. The patient was admitted to the ICU to receive intestinal and cardiopulmonary care, which lasted 10 days for recovery from circulatory dysfunction. Mechanical ventilation was needed for haemodynamic instability and the patient's tracheal tube was removed 11 days after surgery. The patient was then transferred to an ordinary ward. The patient's abdominal status did not improve as readily. Overall, the patient was discharged 51 days after surgery with complete improvement in his intestinal status. BAL under bronchoscopy immediately after particle-associated aspiration had completely corrected atelectasis, even though the initial chest radiographs in both cases showed serious findings. Consequently, in case 1, fever and increases in white blood cell (WBC) and C-reactive protein (CRP) due to aspiration pneumonia were slight or nonexistent. In case 2, these measurements were elevated because of severe panperitonitis, but the patient recovered and was discharged from the hospital. If respiratory distress due to aspiration pneumonia were evident in addition to circulatory and renal dysfunction, the patient would not have recovered. In both cases, pneumonia might be minimal or not exist despite aspiration with prompt BAL. Rat models of aspiration pneumonia have demonstrated a biphasic feature of pathogenesis [4]. Several kinds of chemical substances are produced by acid aspiration in the early phase [4–6]. The early phase triggers the development of the late phase [5], and the late-phase reactions may not only produce more severe respiratory distress but also systemic dysfunction, including circulatory collapse and multiple organ failure. Therefore, prompt BAL under bronchoscopy is important for two reasons. First, the BAL eliminates aspirated particles that obstruct the airway to produce atelectasis. Second, the BAL washes out the early phase chemical substances. These two cleaning procedures may block progression from early phase to late-phase events, avoiding catastrophic outcomes. Some practitioners have suggested that bronchial toilet or BAL should not be performed because it can spread the disease focus [1,3]. Ordinary bronchial toilet does not clean up the lung completely, but may widely spread vomit. Also, delayed BAL may spread inflammatory cytokines along with vomit particles throughout the lungs. However, exhaustive BAL immediately after aspiration under bronchoscopy could eliminate particles and the early phase chemical substances. In the cases of particle-associated aspiration, the careful elimination of all particles with bronchoscopy is recommended [2]. It also indicates that lavage might be more effective in these cases than conventional bronchoscopic cleaning. In both cases presented in this report, ordinary suctioning technique did not improve the status of patients. The prompt BAL under bronchoscopy removing all of particles along with the early phase of chemical substances may prevent severe subsequent pneumonia, although we did not measure these substances in the BAL fluid. In summary, prompt BAL under bronchoscopy after pulmonary particle-associated aspiration did not result in a severe subsequent pneumonia in both of the cases presented here. This case report suggests that a subsequent pneumonia after pulmonary particle-associated aspiration might be prevented by prompt BAL under bronchoscopy.