Semifluorinated alkanes and the use thereof

A method for liquid artificial respiration by intubation, comprising administering at least one semifluorinated alkane of the general formula

• RFRH or RFRHRF
• wherein RF is a linear or branched perfluoralkyl group and RH is a linear or branched, saturated alkyl group, wherein the linear semifluorinated alkane has the formula:
• F(CF2)n(CH2)mH
• or
• F(CF2)n(CH2)m(CF2)nF,
• the branched semifluorinated alkane includes within the perfluoralkyl groups —FCX— units where X=C2F5, C3F7 or C4F9 and within the alkyl groups —HCY— units where Y=C2H5, C3H7 or C4H9, contained within a perfluoralkyl chain is a —CX2— group and contained within an alkyl chain is a —CY2— group, and wherein further the total number of the carbon atoms in the perfluoralkyl part is between 1 and 20, and in the alkyl part the number of the carbon atoms is between 3 and 20.