This article highlighted the invaluable expertise of Academician TONG Xiaolin in managing severe cases of COVID-19， thereby providing ideas for the treatment of severe and critically ill patients with SARS-CoV-2 infection by integrating traditional Chinese and western medicine. It is believed that COVID-19 belongs to the “cold dampness epidemic” in traditional Chinese medicine， which is caused by pathogenic qi of cold and dampness. The course of the disease can be divided into four stages： constraint， block， collapse， and deficiency， and the severe cases are mainly in the block and collapse stages. The pathogenesis at the block stage is described as epidemic toxins blocking the lung， which should be treated by diffusing the lung and unblocking the bowels， resolving phlegm and unblocking collaterals. The primary formula used is Zilong Xuanbai Chengqi Decoction （子龙宣白承气汤） with modifications based on individual condition. The pathogenesis at the collapse stage is described as internal block and external collapse， which should be treated by restoring yang to save from collapse， boosting qi to relieve collapse， diffusing the lung and unblocking the bowels， resolving phlegm and unblocking collaterals， usually with the formula Poge Zilong Xuanbai Chengqi Decoction （破格子龙宣白承气汤） with modifications.

Epidemic cerebrospinal meningitis shows a high degree of consistency with the law of transmission among wei （卫）-qi-ying （营）-blood， in terms of the onset of the season， contagiousness， symptoms， pathogenesis， as well as characteristics of the transmission. It is proposed to use epidemic cerebrospinal meningitis as an example to explore the underlying disease of wei-qi-ying-blood syndrome differentiation system. Epidemic meningitis invades the brain from the upper respiratory tract along the nervous system， and its overall pathogenesis follows from entering the lung system （prodromal period） to entering the blood （bacteremia period， sepsis period） and then entering the brain （shock period）. According to the four-dimensional qualitative principle of epidemic pathogen tropism， it corresponds to disease of both wei and qi syndrome， then blazing of both qi and ying syndrome， and then heat blocking pericardium， exuberant heat stirring wind， and internal block and external collapse syndrome. This article explored the laws of transmission among wei-qi-ying-blood and its underlying diseases described in On Warm Heat （《温热论》）， and revealed the original appearance of the disease model under the laws of transmission among wei-qi-ying-blood to guide the clinical practice.

We report a case of a long-term survivor of heart transplant who developed severe COVID-19 and was treated with a traditional Chinese medicine combined with conventional medicine. Throughout the treatment， the patient received active conventional medical treatment， and traditional Chinese medicine interventions included tonifying qi， invigorating the spleen and transforming phlegm， promoting yang and eliminating stagnation， resolving dampness and dissipating phlegm， and promoting blood circulation and eliminating stasis. The main therapeutic principles adopted were to recuperating depleted yang and rescuing the patient from collapse and to resolve phlegm and promote water. Pogezilong Xuanbai Chengqi Decoction （破格子龙宣白承气汤） with modifications was administered. In summary， it is crucial to the timely adjust the immunosuppressive regimen， combine use of various anti-infective agents with a focus on COVID-19， to protect of cardiac and renal function， and to integrate traditional Chinese medicine in the entire treatment process. As this case is rare， the diagnostic and therapeutic methods in traditional Chinese medicine， the use of immunosuppressive agents， and follow-up monitoring strategies can be a valuable reference.

Traditional Chinese medicine (TCM) has played an important role in the prevention and treatment of Coronavirus disease 2019 (COVID-19) epidemic in China. The integration of Chinese and Western medicine is an important feature of Chinese COVID-19 prevention and treatment. According to a series of evidence-based studies, TCM can reduce the infection rate of severe acute respiratory syndrome coronavirus 2 in high-risk groups. For patients with mild and moderate forms of COVID-19, TCM can relieve the related signs and symptoms, shorten the period of nucleic-acid negative conversion, and reduce conversion rate to the severe form of the disease. For COVID-19 patients with severe and critical illnesses, TCM can improve inflammatory indicators and blood oxygen saturation, shorten the hospital stay, and reduce the mortality rate. During recovery, TCM can improve patients' symptoms, promote organ function recovery, boost the quality of patients' life, and reduce the nucleic-acid repositive conversion rate. A series of mechanism research studies revealed that capability of TCM to treat COVID-19 through antiviral and anti-inflammatory effects, immune regulation, and protection of organ function via a multicomponent, multitarget, and multipathway approach.
Humans ; COVID-19 ; Medicine, Chinese Traditional ; Drugs, Chinese Herbal/therapeutic use* ; SARS-CoV-2 ; Epidemics