[1] Univ Puerto Rico, Sch Med, Med, San Juan, PR 00936 USA
[2] Auxilio Mutuo Hosp, Surg, San Juan, PR USA
[3] Univ Pittsburgh, Med Ctr, Surg, Pittsburgh, PA USA
[4] Las Palmas Med Ctr, Surg, El Paso, TX USA
[5] LifeLink Puerto Rico, San Juan, PR USA
[6] UPR, Sch Nursing, Continuing Educ, San Juan, PR USA
[7] Univ Puerto Rico Rio Piedras Campus, Nat Sci, San Juan, PR USA