Exhibit 3.45
                            CERTIFICATE OF FORMATION
                                       OF
                     ACUTE EXTRACORPOREAL SERVICES, L.L.C.



FIRST:  The name of the limited liability company is ACUTE EXTRACORPOREAL
        SERVICES, L.L.C. (the "Company").

SECOND: The address of the Company's registered office in the State of Delaware
        is 1209 Orange Street, Wilmington, Delaware 19801 in the county of New
        Castle. The name of the Company's registered agent is The Corporation
        Trust Company.

THIRD:  The latest date on which the Company is to dissolve is December 31,
        2050.

FOURTH: The debts, obligations and liabilities of the Company, whether arising
        in contract, tort or otherwise, shall be solely the debts, obligations
        and liabilities of the Company; and no member or manager of the Company
        shall be obligated personally for any such debt, obligation or liability
        of the Company solely by reason of being a member or acting as a manager
        of the Company.


     IN WITNESS WHEREOF, the undersigned has executed this Certificate of
Formation of ACUTE EXTRACORPOREAL SERVICES, L.L.C. this 1st day of December,
1998.

                                              /s/ Margaret M. Scholand       
                                       ---------------------------------------
                                       Margaret M. Scholand, Authorized Person