<PAGE>

                                                                    Exhibit  2.3


                         AGREEMENT AND PLAN OF MERGER
                         ----------------------------


     This Agreement of Merger (this "Agreement") is entered into effective as of
October 31, 1999, (the "Effective Date") by and between the following Texas
limited liability companies: Hemo Dialysis of Amarillo, LLC, Dialysis
Specialists of South Texas, LLC, Amarillo Acute Dialysis Specialists, LLC and
Dialysis Specialists of Corpus Christi, LLC (collectively, the "Constituent
Entities") and North Buckner Dialysis Center, Inc., a Delaware corporation (the
"Surviving Corporation").

     WHEREAS, the parties hereto deem that the purposes and objectives of the
Constituent Entities and the Surviving Corporation may be effectively achieved
and promoted within a single corporate structure; and

     WHEREAS, in order to accomplish this objective, the parties now desire to
merge the Constituent Entities with and into the Surviving Corporation (the
"Merger") on the terms and conditions hereinafter set forth and in accordance
with the provisions of (S)264 of the Delaware General Corporation Law (the
"DGCL") and the provisions of (S)10.02 of the Texas Limited Liability Company
Act (the "TLLCA");

     NOW THEREFORE, BE IT RESOLVED, that in consideration of the mutual
covenants and agreements contained herein and other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties agree as follows:


                                   ARTICLE I
                                   ---------

                                Terms of Merger
                                ---------------

     The Constituent Entities shall be merged into the Surviving Corporation in
a statutory merger in accordance with the DGCL, the TLLCA and the terms of this
Agreement.


                                  ARTICLE II
                                  ----------

                               Effect of Merger
                               ----------------

     Upon the Effective Date:

     (1)  the Constituent Entities and the Surviving Corporation shall be a
single corporation;
<PAGE>

     (2) the Surviving Corporation shall possess all the rights, privileges,
immunities and franchises of each of the Constituent Entities, and all property,
real, personal and mixed, and debts due on whatever account, and every other
interest belonging to or due to each of the Constituent Entities (including, but
not limited to, liability for any fees or franchise taxes due and owing to the
Secretary of State of the State of Texas as of the Effective date) shall be
deemed to be transferred to and vested in the Surviving Corporation, without
further act, deed or transfer;
     (3) the Surviving Corporation shall thenceforth be responsible for and
subject to all of the debts, liabilities and obligations of each of the
Constituent Entities in the same manner as if the Surviving Corporation had
itself incurred them;
     (4) any claim, existing action, or proceeding pending by or against any of
the Constituent Entities may be prosecuted to judgment by the Surviving
Corporation; and
     (5) neither the rights of creditors nor any liens upon the property of
either of the Constituent Entities shall be impaired by the Merger.


                                  ARTICLE III
                                  -----------

                     Manner and Basis of Converting Shares
                     -------------------------------------

     The manner and basis of converting the membership interests of the
Constituent Entities into the shares or other securities of the Surviving
Corporation shall be as follows: upon the Effective Date, all of the membership
interests of the Constituent Entities shall then be immediately canceled and
shall cease to exist and the outstanding shares of the Surviving Corporation
shall remain in effect.

                                  ARTICLE IV
                                  ----------

Certificate of Incorporation, By-laws, Directors and Officers of the Surviving
------------------------------------------------------------------------------
                                  Corporation
                                  -----------

     The Certificate of Incorporation and By-laws (collectively, the "Charter
Documents") of the Surviving Corporation in effect on the Effective Date shall
be the Charter Documents of the Surviving Corporation until duly amended or
changed in accordance with their internal provisions and those of the DGCL.

     The directors and officers of the Surviving Corporation on the Effective
Date will continue as directors and officers of the Surviving Corporation until
their successors have been duly elected and qualified pursuant to the Charter
Documents.
<PAGE>

                                   ARTICLE V
                                   ---------

                                 Miscellaneous
                                 -------------

     The parties hereto each agree to do, execute, acknowledge and deliver all
such further acts, instruments and assurances, and to take all such further
action, including, without limitation, the execution and filing of such
instruments in the States of Delaware and Texas and any other State as should be
necessary or desirable to carry out this Agreement and to consummate and effect
the Merger.

     This Agreement shall be governed by and construed in accordance with the
laws of Illinois.



               [Remainder of this page intentionally left blank.]
<PAGE>

     IN WITNESS WHEREOF, the Surviving Corporation and the Constituent Entities
have each caused this Agreement to be effective as of the day and the year first
written above.


                         North Buckner Dialysis Center, Inc.
                         Hemo Dialysis of Amarillo, LLC
                         Dialysis Specialists of South Texas LLC
                         Amarillo Acute Dialysis Specialists, LLC
                         Dialysis Specialists of Corpus Christi, LLC


                         By:/S/ Lawrence D. Damron
                            ----------------------------------------------------
                            Lawrence D. Damron, Chief Financial Officer of the
                            Surviving Corporation and of Home Dialysis of
                            America, Inc., the sole member of each of the
                            Constituent Entities
<PAGE>

                                                                       Exhibit A
                                                                       ---------

                      CERTIFICATE AND ARTICLES OF MERGER


     The undersigned entities hereby certify:

     FIRST:  That the name and jurisdiction of incorporation of each of the
constituent entities to the Merger (as defined below) are as follows:

<TABLE>
<CAPTION>
                                                                 Jurisdiction  of
                          Name                                   Incorporation               Type of Entity
                          ----                                   -------------              -------------
<S>                                                              <C>                        <C>
North Buckner Dialysis Center, Inc. ("N. Buckner")               Delaware                   corporation

Hemo Dialysis of Amarillo, LLC ("Hemo")                          Texas                      limited liability
                                                                                            company

Dialysis Specialists of South Texas, LLC ("DSST")                Texas                      limited liability
                                                                                            company

Amarillo Acute Dialysis Specialists, LLC                         Texas                      limited liability
("Amarillo")                                                                               company

Dialysis Specialists of Corpus Christi, LLC                      Texas                      limited   liability
("Corpus")                                                                                  company
</TABLE>

     SECOND: That immediately prior to the effectiveness of this certificate of
merger (this "Certificate"), the sole stockholder of N. Buckner and the sole
member of each of Hemo, DSST, Amarillo and Corpus  is Home Dialysis of America,
Inc., an Arizona corporation ("HDA"), and that HDA shall remain the sole
stockholder of N. Buckner immediately following the effectiveness of this
Certificate.

     THIRD:  That an Agreement and Plan of Merger (the "Agreement") between the
constituent entities to the Merger (the "Parties") has been approved, adopted,
certified, executed and acknowledged by the Parties in accordance with the
requirements of the Delaware General Corporation Law, the Texas Limited
Liability Company Act (the "TLLCA") and the internal documents of the Parties.
In accordance with the TLLCA, a copy of the Agreement is attached hereto as
Exhibit A for filing with the Secretary of State of the State of Texas.
---------

     FOURTH: That pursuant to the Agreement, Hemo, DSST, Amarillo and Corpus
shall merge with and into N. Buckner (the "Merger") and that N. Buckner shall
survive the Merger.

     FIFTH:  That the name N. Buckner upon consummation of the Merger shall
remain "North Buckner Dialysis Center, Inc."
<PAGE>

     SIXTH:    That the Certificate of Incorporation of N. Buckner, shall be the
Certificate of Incorporation of the surviving corporation.

     SEVENTH:  That an executed copy of the Agreement is on file at an office of
N. Buckner, the address of which is c/o Katten Muchin & Zavis, 525 West Monroe
Street, Suite 1600, Chicago, Illinois 60661.

     EIGHTH:   That a copy of the Agreement has been furnished by N. Buckner to
HDA, the sole stockholder of N. Buckner and the sole member of the other
constituent entities to the Merger.  If HDA desires, an additional copy of the
Agreement will be supplied to it upon request without cost.

     NINTH:    The membership interests of each of Hemo, DSST, Amarillo and
Corpus shall be immediately cancelled upon the effectiveness of this Certificate
and shall cease to exist, and the outstanding shares of N. Buckner shall remain
in effect.

     TENTH:    That this Certificate shall be effective on October 31, 1999.



               [Remainder of this page intentionally left blank.]
<PAGE>

     IN WITNESS WHEREOF, the undersigned have executed this Certificate on
October __, 1999.



                              North Buckner Dialysis Center, Inc.
                              Hemo Dialysis of Amarillo, LLC
                              Dialysis Specialists of South Texas LLC
                              Amarillo Acute Dialysis Specialists, LLC
                              Dialysis Specialists of Corpus Christi, LLC


                              /s/ Lawrence D. Damron
                              ------------------------------------------------
                              By: Lawrence D. Damron, Chief Financial Officer of
                              N. Buckner and of Home Dialysis of America, Inc.,
                              the sole member of each of Hemo, DSST, Amarillo
                              and Corpus