When the commutation is ordered, the workers’ compensation commissioner shall fix the lump sum to be paid at an amount which will equal the total sum of the probable future payments capitalized at their present value and upon the basis of interest at the rate provided in section 535.3 for court judgments and decrees. Upon the payment of such amount, the employer shall be discharged from all further liability on account of the injury or death, and be entitled to a duly executed release. Upon the filing of the release, the liability of the employer under any agreement, award, finding, or judgment shall be discharged of record.