Do I need a malpractice lawyer

Depends on the nature and extent of your husband's injuries. In order for there to be negligence, conduct below the applicable standard of care has to cause injury. If there were injuries, get a free consultation with a PA medical malpractice lawyer. They can order your husband's medical records and determine if there was conduct below the standard of care.

If your husband sustained a permanent injury, but almost won't support a lawsuit.

Malpractice is basically care and treatment that is below the acceptable standard of care that causes injury. Even if there is negligence unless there is a injury--an a a severe and permanent injury there is no claim to pursue. You mention that the "hospital almost overdosed" your husband. The law does not typically compensate for what might have happened only for what did happen. If your husband was not injured there is no claim to pursue.

In order to determine whether there is a case more information would have to be provided. It is difficult to determine if you have a case based on a few sentences the more thorough discussion would be necessary.