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

Here is Why You Need An Adapter

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

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

Nepal

In Nepal, outlets of type C, D and M are in use.

Type C

Type D

Type M