For polymyxin B injection, based on the evidence provided and the IV and IVT joint scheme, colistin is an ideal drug because it has good antibacterial activity against MDR or XDR A. baumannii, but clinicians need to be mindful of mucin-related complications, including chemical meningitis inflammation, chemical ventricle inflammation, seizures and horsetail nerve syndrome (there have been reported incidences of 21.7%) [5]. The gene discussed is MUC5AC; the disease is inflammatory response.