I am sorry that your mother is sick.
Your brother could apply for a B-2 visitor visa at the U.S. Consulate. he will need to show strong ties to his home country including employment, residence etc. he will need to prove that he is only visiting to see his mother and is not a risk to stay in the U.S. permanently..
It may also be helpful to provide a letter and provide any documents concerning your mother's health.
With so much of his family already in the U.S., the big challenge for him will be to docuemnt and prove that he will only visit.
See:
http://barbados.usembassy.gov/visa-tourist.html
Regards,
Andrew M. Wilson, Esq.
Serotte Reich Wilson, LLP
www.srwlawyers.com
awilson@srwlawyers.com
Answered on Sep 07th, 2012 at 5:52 PM