Table 2 Grouping criteria.

SMPP group

The patients met the inclusion criteria and had any of the following performances:

 Poor general situation;

 Conscious disorder, cyanosis, respiratory dysfunction;

 Hypoxemia, assisted breathing (groan, flaring of alaenasi, three depressions sign), intermittent apnea, oxygen saturation < 92%;

 Persistent hyperpyrexia for more than 5 days or ultra-hyperpyrexia;

 Dehydration or food refusal;

 Chest imaging showed the following findings: unilateral lung infiltration ≥ 2/3, multilobular lung infiltration, pleural effusion, pneumothorax, atelectasis, lung necrosis, lung abscess;

 Extrapulmonary complications

GMPP group

The patients met the inclusion criteria and had no above performance