Clinical Research on SMI
SFI has often been used to treat shock caused by various factors, COPD, systematic inflammatory response syndrome and other diseases in clinical practice (see  Table 3 ). SMI has been recommended in China’s SARS Diagnosis and Treatment Scheme (Version 2004) and MERS Diagnosis and Treatment Scheme (Version 2015).
Biao Deng et al. studied 71 patients with shock and found that SMI in combination with conventional Western medicine had definite therapeutic efficacy, shortened the course of disease, reduced the length of hospital stay, and lowered the fatality rate (Deng et al., 2006). Hefeng Qin observed 68 patients with infectious shock and found that SMI had good clinical efficacy. It significantly improved CRP, PCT and TNF-α serum levels, and shortened the recovery time of vital signs with few adverse reactions (Qin, 2014). Wang Xian’an et al. observed 80 patients treated for infectious shock, and discovered that SMI in combination with ulinastatin had a significant therapeutic effect, enhancing immune function, and alleviating the inflammatory response (Wang et al., 2017). X. Huang et al. evaluated 23 RCTs with a total of 1,804 participants to study the impact of SMI on COPD. The results showed that SMI not only increased the total clinical response rate, but also improved pulmonary function, blood gas, and IgG indexes, and shortened the time for disappearance of lung rales. The results indicated that SMI in combination with Western medicine might have a positive effect in the treatment of COPD (Huang et al., 2019). Zongjun Fang et al. studied 38 patients with COPD. The control group (18 cases) received conventional Western medicine, while 20 cases (the treatment group) received SMI in addition. The results showed that patients in the treatment group had better vital capacity, forced expiratory volume in 1 s (FEV1), maximal breathing capacity (MBC), maximal inspiratory pressure (MIP), load breathing time, arterial blood gas analysis, and Burp dyspnea scores than the control group or the pre-treatment patients. The treatment group also had significantly improved respiratory function and clinical symptoms (Fang et al., 1998). Changxing Guo et al. randomized 33 patients with systemic inflammatory response syndrome into a conventional Western medicine treatment group (15 cases) and SMI + conventional treatment group (18 cases). After treatment, patients in the SMI treatment group had increased prostacyclin PGI2 and PGI2/thromboxane A2 (TXA2) in blood to a certain extent compared to patients in the conventional treatment group. Patients in the SMI group also had decreased levels of TXA2, atrial natriuretic peptide (ANP) and endothelin, and there were significant differences between the two groups. The results indicated that SMI could play an active role in improving microcirculation, protecting organ functions, and preventing further occurrence and development of systemic inflammatory response syndrome (Guo et al., 2004).