A 16-year old boy underwent laparoscopic surgery for varicocele. His past medical history was uneventful, except for febrile seizures during early childhood. He had no allergies, history of recurrent pneumonia or other chronic respiratory diseases. Likewise, his family history was unremarkable. Smoking habits were asked but not disclosed. Complete blood cells count, liver and kidney function tests and first level coagulation studies (platelets count, prothrombin time test, activated partial thromboplastin time, and fibrinogen) were all normal before the general anesthesia. According to the American Society of Anesthesiologists (ASA) risk classification1, he was a healthy patient (ASA 1).
Prior to the operation, the patient was given general anesthesia consisting of propofol (2 mg/kg) and rocuronium (0.6 mg/kg), with remifentanil (0.25 mcg/kg/min) for intubation. General anesthesia was maintained with 2% sevoflurane and remifentanil (0.25-0.125 mcg/kg/min). Sugammadex (2 mg/Kg) was administered before extubation (TOF ratio > 0.9). Both surgery and extubation were conducted without any complications and the patient had no obvious signs of upper airway obstruction, neither cough nor laryngospasm.
Thirty minutes after waking up, he manifested hemoptysis, dyspnea, and ARF. He was alert, tachypnoeic, and normothermic. His Glasgow Coma Scale was 15, and his initial vital signs were: pulse 80 bpm, blood pressure 90/60 mmHg and oxygen saturation averaging 73% on room air. Arterial blood gas analysis revealed: pH 7.37; pCO2 39.6 mmHg (5.27 kPa); pO2 39.5 mmHg (5.26 kPa); oxyhemoglobin (oxyHb) 73.7%; and HCO3- 23.1 mEq/L. Otorhinolaryngoiatric evaluation with nasal and laryngeal fibro-endoscopy unveiled no evidence of previous bleeding from the upper respiratory tract. Respiratory auscultation revealed diffuse rhonchi, with no other remarkable signs. His initial chest x-ray (Figure 1) showed infiltrative opacification pattern mainly seen in the mid zones with apical sparing suggestive for impaired pulmonary microcirculation, raising the suspect of DAH. To further investigate our hypothesis, a chest CT scan (Figure 2) was performed, which revealed multiple dense opacities with blurred, confluent margins due to diffuse alveolar involvement in the pulmonary lobes.
Given the evidence of hypoxemic respiratory failure and the suspect of DAH, the patient was transferred to the Intensive Care Unit, where he was subjected to immediate bronchoalveolar lavage, revealing the presence of abundant blood, but after the bronchoalveolar lavage with 0.9% sodium chloride solution, the bronchial mucosa appeared without signs of pathological lesions. More specifically, three lavage of 50 mLs each were done and afterwards 35, 35, and 50 mLs of BAL fluid were retrieved. Direct microscopic examination showed leucocytes, macrophages and bronchial epithelial cells. Further confirmation arrived from cytologic analysis of his bronchoalveolar lavage secretions which described the presence of blood, 85% of alveolar macrophages and 15% of granulocytes. Hemosiderin was not assessed because hemoptysis started 4 h before and the endoscopic appearance of the bleeding itself appeared to be very recent, undergoing from <48 h. The patient was given fraction inspired oxygen (FiO2) (40%; 12 L/min) by means of a Venturi mask for ARF, intravenous ceftriaxone 2 g per day as antibiotic prophylaxis and intravenous methylprednisolone 1 g per day for anti-inflammatory action for 5 days, while waiting for the results of microbial studies and autoimmune diseases screening.
Initial blood tests performed at Day 1 revealed: hemoglobin levels 13.5 g/dl (135 g/L); leukocytosis 14.540 mm-3 (14.54 109/L), of which 83.7% were neutrophils, and normal platelet count (221 x 109 /L). Renal function, liver function, electrolytes, coagulation studies (prothrombin time, activated partial thromboplastin time, and fibrinogen) were all normal. Von Willebrand factor deficiency was also ruled out on the basis of Von Willebrand factor antigen and Ristocetin cofactor activities which resulted within normal range (Von Willebrand factor antigen was 90%, with a normal reference range between 57 and 147%; Ristocetin cofactor was 120% with a normal reference range of 51-147% considering our patient's specific age group). Urinalysis was unremarkable, and direct microscopic exam did not reveal any dysmorphic red blood cells (RBCs). The diagnostic work-up, which included serological exams and blood and sputum cultures for Streptococcus pneumoniae, Haemophilus influenzae, Legionella pneumophila, Aspergillus, Mycobacterium tuberculosis, Nocardia spp., Chlamydia pneumoniae, Mycoplasma pneumoniae, Pneumocystis Jirovecii, Herpesviruses, and the complete respiratory viral panel, ruled out any pulmonary infections. An extensive rheumatological serologic evaluation including CRP, c-ANCA, p-ANCA, ANA, and ENA panel came back negative as well. Lastly, the echocardiography was completely normal, excluding any congenital or acquired cardiomyopathy as well as pulmonary hypertension.
Questioned on smoking habits, the boy revealed to be a frequent cannabis smoker since few years. He admitted to have smoked about 1-2 joints per day in the last month before surgery and to have used a marijuana smoking device known as "water bong" at least once. Moreover, he denied having used any other type of street drugs. We therefore performed a toxicological urine test that resulted positive for cannabinoids. Cocaine was not tested since the patient's parents declined their consent.
The patient's general conditions rapidly improved after 24 h: he was no longer dyspneic, and oxygen supplementation was stopped on day 2 of hospitalization after a second chest radiograph (Figure 3) revealed the resolution of DAH. He was discharged after 6 days with tapering prednisone. Although he was recommended an ambulatory follow-up, his parents declined.