Objective   To investigate the improvement of oxygenation after the treatment of prone position in patients with severe acute respiratory distress syndrome (ARDS) caused by pneumocystis jirovecii pneumonia (PJP) after kidney transplantation.

  Methods  Clinical data of 5 cases of moderate and severe ARDS caused by PJP after kidney transplantation were analyzed retrospectively, and clinical characteristics, treatment regimen and prognosis were summarized.

  Results  Clinical manifestations of 5 patients were fever, dry cough, chest tightness, shortness ofbreath,sweating and fatigue, and body temperature fluctuated between 38 ℃ and 39 ℃, percutaneous arterial oxygen saturation(SpO₂) was gradually decreased, and respiratory distress symptoms were worsened. Pulmonary CT scan showed diffuse ground-glass shadow. After transfer to intensive care unit (ICU), immunosuppressive drugs were terminated, and all patients were given with compound sulfamethoxazole, caspofungin, low-dose glucocorticoids against pneumocystis jirovecii (PJ), oxygen therapy and other symptomatic supportive treatments. Four patients diagnosed with severe ARDS upon admission to ICU were treated in a prone position. One patient with moderate ARDS was not kept in a prone position. At 1 d after treatment in a prone position, partial pressure of arterial oxygen (PaO₂) and oxygenation index were increased, whereas alveolar-arterial oxygen difference (A-aDO₂) was decreased compared with before treatment (allP<0.05). Compared with 1 d after treatment, SpO₂, PaO₂ and oxygenation index were all increased, while A-aDO₂ was decreased at 4 d after treatment (all P<0.05). Box diagram showed that oxygenation index showed an overall upward trend after prone-position treatment, whereas A-aDO₂ showed an overall downward trend. The length of ICU stay of 5 patients was 14 (8, 29) d. All patients in a prone position did not develop complications, such as skin pressure sore, tube detachment and tube displacement, etc. Among 5 patients, 4 patients were mitigated, and 1 patient died of septic shock and multiple organ failure.

  Conclusions  For both conscious and intubated patients, a prone position may significantly improve oxygenation and prognosis of patients with severe ARDS caused by PJP after kidney transplantation. Early diagnosis and accurate and standardized treatment play a pivotal role in enhancing cure rate.