You Do Need power plug adapter while traveling from Brazil to Laos.

Here is Why You Need An Adapter

The outlet and plug type used in Laos are A, B, C, E and F and in Brazil are C and N. This is how they look like.

Brazil

In Brazil, outlets of type C and N are in use.

Type C

Type N

Laos

In Laos, outlets of type A, B, C, E and F are in use.

Type A

Type B

Type C

Type E

Type F