I feel the code 516 .0 is self sufficient to decribe the major diagnostic condition.
If your physician wants to go for more deeper intrigate diagnosis with the surfactant and the responsiveness an dso on , let me give a suggestion with the pathophysiological factor related to it.
Try one of the codes in the series 279.xx series which deals with the combines metabolic and immnune mediated deceased statuses
It is autosomal recessive disorder of immune mediated deceased condition, wherein the cytokine /and or interleukine component of the plasma protein metabolism( of the Gamma Globulin chain ) gets deranged. Variety of conditions are met with.
Until we have a better knowledge of the intricate network of interactions among energy regulation, immune surveillance and vital organ functions could in the near future lead to valuable strategies for managements in several immune-mediated diseases, we cannot pin point and assign a code for this ( as far my knowledge goes).
But the ICD -9 CM of the Endocrine ,nutritiona,l Metabolic and Immunity Chapter can find a way, since this is a immune mediated disease with plasma protein metabolism(Gamma globulin fraction difficient status) and an Autosomal recessive disorder, I would like to think of 279.2 to the closest specificity.
If you or your physician have any other suggestion while pondering into the details of its pathophysiology, may be you can be more closer than what I suggested.