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                                                                    EXHIBIT 18
                                   FORM OF
                     FIRST AMENDMENT TO THE TRUST AGREEMENT
                        FOR THE RESTATED PURITAN-BENNETT
                           DEFERRED COMPENSATION PLAN

         THIS AMENDMENT is made by the Puritan-Bennett Corporation (which,
together with its subsidiaries and affiliates, shall be referred to herein as
the "Corporation"), and the Wachovia Bank of North Carolina, N.A. (the
"Trustee"), effective as of the _____ day of _______________, 1994.

         WHEREAS, the Corporation established the 1985 Deferred Compensation
Plan (the "1985 Plan"), consisting of separate but identical Deferred
Compensation Agreements with a select group of management or highly compensated
employees of the Corporation and Policy Guidelines developed by the
Corporation; and

         WHEREAS, the Corporation established a trust fund pursuant to an
agreement with the Trustee, dated May 22, 1992 (the "Trust Agreement") for
receipt of contributions pursuant to the 1985 Plan; and

         WHEREAS, the Corporation and each participant desired to amend the
terms of the 1985 Plan by voiding the Deferred Compensation Agreements and the
Policy Guidelines, and amending and restating the 1985 Plan in its entirety to
become the Restated Puritan-Bennett Deferred Compensation Plan (the "Restated
Plan"), effective as of September 1, 1993; and

         WHEREAS, the Corporation desires to amend the Trust Agreement to
revise the definition of "Change in Control" and replace references to the 1985
Plan with references to the Restated Plan, and to make such other changes as
are necessary to reflect changes made pursuant to the restatement of the 1985
Plan.

         NOW, THEREFORE, the Trust Agreement is hereby amended as follows:

                 1.       All references to the "1985 Deferred Compensation
         Plan" are hereby deleted and replaced with the "Restated
         Puritan-Bennett Deferred Compensation Plan."

                 2.       Section 1.1 is amended to read in its entirety as
         follows:

                 (c)      Change in Control.  A "Change in Control" shall be
                          deemed to have occurred at any of the following times:

                          (i)              Upon the acquisition (other than
                                           from the Corporation) by any person,
                                           entity or "group," within the
                                           meaning of Section 13(d)(3) or
                                           14(d)(2) of the Securities Exchange
                                           Act of 1934 (the "Exchange Act")
                                           (excluding, for this purpose, the
                                           Corporation or its affiliates, or
                                           any employee benefit plan of the
                                           Corporation or its affiliates which
                                           acquires beneficial ownership of
                                           voting securities of the
                                           Corporation) of beneficial ownership
                                           (within the





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                                           meaning of Rule 13d-3 promulgated 
                                           under the Exchange Act) of 50% or 
                                           more of either the then outstanding 
                                           shares of common stock of the 
                                           Corporation or the Combined Voting 
                                           Power of the Corporation's then 
                                           outstanding voting securities. 
                                           "Combined Voting Power" means the
                                           combined voting power of the
                                           Corporation's then outstanding
                                           voting securities generally entitled
                                           to vote in the election of
                                           directors.

                          (ii)             At the time individuals who, as of
                                           the date hereof, constitute the
                                           Board (as of the date hereof, the
                                           "Incumbent Board") cease for any
                                           reason to constitute at least a
                                           majority of the Board, provided that
                                           any person becoming a director
                                           subsequent to the date hereof whose
                                           election, or nomination for election
                                           by the Corporation's shareholders,
                                           was approved by a vote of at least a
                                           majority of the directors then
                                           comprising the Incumbent Board
                                           (other than an election or
                                           nomination of an individual whose
                                           initial assumption of office is in
                                           connection with an actual or
                                           threatened election contest relating
                                           to the election of the directors of
                                           the Corporation, as such terms are
                                           used in Rule 14a-11 of Regulation
                                           14A promulgated under the Exchange
                                           Act) shall be, for purposes of this
                                           subsection 1.3.2, considered as
                                           though such person were a member of
                                           the Incumbent Board; or

                          (iii)            Upon the approval by the
                                           shareholders of the Corporation of a
                                           reorganization, merger,
                                           consolidation (in each case, with
                                           respect to which persons who were
                                           the shareholders of the Corporation
                                           immediately prior to such
                                           reorganization, merger or
                                           consolidation do not, immediately
                                           thereafter, own more than 50% of the
                                           Combined Voting Power of the
                                           reorganized, merged or consolidated
                                           company's then outstanding voting
                                           securities) or a liquidation or
                                           dissolution of the Corporation or of
                                           the sale of all or substantially all
                                           of the assets of the Corporation; or

                          (iv)             The occurrence of any other event
                                           which the Incumbent Board in its
                                           sole discretion determines
                                           constitutes a Change in Control.

                 3.       Section 1.3 is deleted in its entirety and Sections
         1.4 and 1.5 are renumbered to become 1.3 and 1.4, respectively.  A new
         Section 1.5 is added to read as follows:  "Plan" means the
         Puritan-Bennett Restated Deferred Compensation Plan, effective
         September 1, 1993.





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                 4.       The term "Investment Account" in new section 1.4 is
         amended to read "Account Balance" and all references to "Investment
         Account" throughout the Trust Agreement are hereby replaced with
         "Account Balance."

                 5.       All references to a "Participating Agreement" or the
         "Participating Agreements" are hereby deleted and replaced with the
         "Restated Plan."  Further, all references to "Policy Guidelines" or
         "Guidelines" are hereby deleted.

                 6.       The second sentence of Section 4.1 is deleted in its
         entirety.

                 7.       The last sentence of Paragraph (d) of Section 5.2 is
         deleted in its entirety.

         IN WITNESS WHEREOF, the parties have executed this Amendment,
effective as of the date written above.

                                        PURITAN-BENNETT CORPORATION
                                        ("GRANTOR")


                                        By:_____________________________
                                        Title:__________________________
                                        Date:___________________________

ATTEST:

By:______________________________
Title:___________________________
Date:____________________________



                                        WACHOVIA BANK OF NORTH
                                        CAROLINA, N.A. ("TRUSTEE")

                                        By:_____________________________
                                        Title:__________________________
                                        Date: __________________________

ATTEST:


By:______________________________
Title:___________________________
Date:____________________________