Objective To analyze clinical and laboratory features, viral load and viral shedding period of patients with mild or severe H1N1 influenza A infection. Methods Seventy mild cases and 16 severe cases with concurrent pneumonia were included from Shcnzhen area for analysis.Nasopharyngeal-swab specimens of patients were collected and viral load was detected by real-time quantitative polymerase chain reaction (PCR) assay during their hospitalization. The viral load and viral shedding period were compared between patients over 14 years old and less than 14 years old, and between 70 mild cases without pneumonia and 16 severe cases with pneumonia. The statistic analysis was performed using t test and chi square test. Results The most common symptoms and signs of the patients were fever, cough and enlargement of tonsils. However, the severe cases suffered more frequently from cough, dyspnea and high fever compared with the mild cases (x2 = 10. 9 and 14.3, respectively, t=3.65; both P＜0.01 ). The levels of white blood cell (WBC) count and alanine arninotransferase (ALT) of severe patients were both significantly higher than those of mild patients(t= 3.2, 2.4,respectively; both P＜0.05). The chest radiology of the severe cases showed interstitial pneumonia,mostly with ground glass image. The viral load of patients under 14 years was significantly higher than those over 14 years [(4.86± 1.23) lg vs (4. 17±0.89) lg; t=2.3, P＜0.05], and the viral shedding period of patients under 14 years was significantly longer than those over 14 years [(5.33±0. 49) d vs(3. 63±0.28) d; t=3.4, P＜0.01]. The severe patients also displayed significantly higher viral load and prolonged viral shedding period than the mild patients [(6. 36±1. 44) lg vs (4. 35±0.99) lg, t=6.1,P＜0.01; (5.75±1.77) d vs (4. 24±1. 96) d, t=3.2, P＜0.01]. Conclusion Age anddisease severity of patients with H1N1 influenza A infection are significantly associated with viral load and viral shedding period.

Objective:To evaluate the efficacy of constant flow oxygen supply via laryngeal mask airway combined with a thin tube at the distal end of airway stenosis for intraoperative ventilation in the patients with severe tracheal stenosis undergoing bronchoscopy. Methods:Forty patients of either sex, aged 18-70 yr, scheduled for comprehensive interventional therapy with tracheoscope for severe tracheal stenosis, were allocated into 2 groups ( n=20 each) by a random number table method: test group and control group.After routine anesthesia induction, intermittent positive pressure ventilation was supplied via a laryngeal mask airway linked to four-way connector and anesthesia machine.In test group, a 6Fr suction tube was inserted through the four-way connector and placed at the distal end of the stenosis, with 1 L/min flow oxygen supply.Before ventilation with the thin tube (T 0), at 30 min after start of mechanical ventilation (T 1), and at the end of operation (T 2), SpO 2, P ETCO 2, mean airway pressure (Pmean), and minute ventilation (MV) were recorded, monitoring of lung ventilation was implemented using electrical impedance tomography, and the area percentages of the centre of ventilation (CoV), dependent silent spaces (DSS), and non-dependent silent spaces (NSS) were recorded.Blood gas analysis was performed at T 1 to record pH value, PaO 2 and PaCO 2.Hypoxemia was recorded during ventilation. Results:Compared with control group, MV, Pmean and area percentage of NSS were significantly increased and area percentage of DSS was decreased at T 1, 2, P ETCO 2 was decreased and SpO 2 and area percentage of CoV were increased at T 1, pH value and PaO 2 were increased, and PaCO 2 and the incidence of hypoxemia were decreased in test group ( P<0.05). Conclusion:Combination of laryngeal mask airway and a thin tube at the distal end of airway stenosis for constant flow oxygen supply can improve the ventilation efficacy by increasing the oxygen concentration at the distal end of the stenosis and by reopening the collapsed lung tissue at the distal end during interventional therapy with tracheoscope in the patients with severe tracheal stenosis.