<PAGE>
                                                                     EXHIBIT 4.3






                          FIRST SUPPLEMENTAL INDENTURE

                           Dated as of October 8, 2003

                                       TO

                                    INDENTURE

                          Dated as of February 25, 1998


                                      Among


                       UNIVERSAL HOSPITAL SERVICES, INC.,


                                   as Issuer,


                                       and


                         U.S. BANK NATIONAL ASSOCIATION
               (as successor to FIRST TRUST NATIONAL ASSOCIATION),

                                   as Trustee.
<PAGE>
      FIRST SUPPLEMENTAL INDENTURE, dated as of October 8, 2003, between
UNIVERSAL HOSPITAL SERVICES, INC., a Delaware corporation (as successor to
Universal Hospital Services, Inc. a Minnesota corporation) (the "Company"), and
U.S. BANK NATIONAL ASSOCIATION, as trustee (the "Trustee").

                             RECITALS OF THE COMPANY

      The Company has heretofore executed and delivered to the Trustee a certain
Indenture, dated as of February 25, 1998 (the "Indenture"), pursuant to which
the Company issued $135,000,000 aggregate principal amount of its 10-1/4%
Senior Notes due 2008 (the "Notes"). All terms used in this First Supplemental
Indenture that are defined in the Indenture shall have the respective meanings
assigned to them in the Indenture.

      Section 9.02 of the Indenture provides that, subject to certain
exceptions, the Indenture may be amended or supplemented with the written
consent of at least a majority in aggregate principal amount of the outstanding
Notes.

      The Board of Directors of the Company, by Written Consent effective as of
September 26, 2003, authorized (i) the solicitation, in connection with a tender
offer to purchase all the outstanding Notes for cash, of consents to certain
proposed amendments to the Indenture and (ii) the execution and delivery of this
First Supplemental Indenture upon receipt of the necessary consents.

      The Company has received the necessary consents and desires and has
requested that the Trustee join with it in the execution and delivery of this
First Supplemental Indenture.

      In accordance with Sections 9.02, 9.06 and 11.04 of the Indenture, the
Company has furnished the Trustee with (i) copies of the Written Consent of the
Board of Directors of the Company authorizing the execution of this First
Supplemental Indenture, certified by the Secretary of the Company, and (ii) an
Officers' Certificate and an Opinion of Counsel, each stating that the execution
of this First Supplemental Indenture is authorized or permitted by the
Indenture.

      All things have been done that are necessary to make this First
Supplemental Indenture a valid agreement of the Company and the Trustee and a
valid amendment of and supplement to the Indenture.

      NOW, THEREFORE, THIS FIRST SUPPLEMENTAL INDENTURE WITNESSETH:

      For and in consideration of the premises, the Company and the Trustee
agree for the benefit of the other parties and for the equal and ratable benefit
of the Holders of the outstanding Notes:

                                   ARTICLE ONE

      SECTION 1.01. The following definitions are eliminated in their entirety
from Section 1.01 of the Indenture, "Affiliate Transaction," "Change of
Control," "Change of Control Offer," "Change of Control Payment Date," "incur,"
"Net Proceeds Offer," "Net Proceeds Offer Amount," "Net Proceeds Offer



                                       2
<PAGE>
Payment Date," "Net Proceeds Offer Trigger Date," "Refinancing Indebtedness,"
"Replacement Assets" and "Restricted Payment."

      SECTION 1.02. The following are eliminated in their entirety from the
Indenture: Section 4.03, Section 4.04, Section 4.05, Section 4.06, Section 4.07,
Section 4.08, Section 4.09, Section 4.10, Section 4.11, Section 4.12, Section
4.13, Section 4.14, Section 4.15, Section 4.16, Section 4.17, Section 4.18,
Section 4.19, Section 5.01, Section 6.01(3), Section 6.01(4), Section 6.01(5),
Section 6.01(6), Section 6.01(7), Section 6.02(b) and Article 10.

      SECTION 1.03. The parenthetical statement in Section 6.01(2) of the
Indenture is eliminated in its entirety.

      SECTION 1.04. References to any of the defined terms, Sections and
Articles eliminated above are eliminated in their entirety.

      SECTION 1.05.

            (a) This First Supplemental Indenture shall only become operative
upon the delivery by the Company to the Trustee of an Officers' Certificate
certifying that the Company has purchased all Notes validly tendered and not
withdrawn in the Tender Offer prior to the Consent Payment Deadline (as such
terms are defined in the Company's Offer to Purchase For Cash and Consent
Solicitation Statement dated September 24, 2003 (the "Offer to Purchase")).

            (b) In the event that the Company shall not have delivered such an
Officers' Certificate on or before October 31, 2003, or in the event that on or
before such date the Company shall have delivered an Officers' Certificate
stating that the Company will not purchase the Notes validly tendered and not
withdrawn in the Tender Offer prior to the Consent Payment Deadline, this First
Supplemental Indenture shall be null and void, nunc pro tunc.

            (c) In its determination as to whether this First Supplemental
Indenture has become operative, the Trustee shall be entitled to rely on an
Officers' Certificate delivered pursuant to (a) or (b) above, or the failure to
deliver such an Officers' Certificate described in (b) above.

                                   ARTICLE TWO

      SECTION 2.01. Except as expressly amended by this First Supplemental
Indenture, the Indenture is in all respects ratified and confirmed and all of
its terms, conditions and provisions shall remain in full force and effect.

      SECTION 2.02. This First Supplemental Indenture shall form a part of the
Indenture for all purposes and shall, after it becomes effective, bind every
Noteholder.

      SECTION 2.03. This First Supplemental Indenture may be executed in any
number of counterparts, each of which shall be deemed to be an original, but all
such counterparts shall together constitute but one and the same instrument.

      SECTION 2.04. The Trustee makes no representation as to the validity or
sufficiency of this First Supplemental Indenture.



                                       3
<PAGE>
      SECTION 2.05. The recitals contained herein shall be taken as the
statements of the Company and the Trustee assumes no responsibility for their
correctness.

      SECTION 2.06. THIS FIRST SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK WITHOUT GIVING
EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAWS TO THE EXTENT THAT THE
APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE REQUIRED THEREBY.





                                       4
<PAGE>
      IN WITNESS WHEREOF, the parties have caused this First Supplemental
Indenture to be duly executed as of the date first above written.

                                    UNIVERSAL HOSPITAL SERVICES, INC.


                                    By:  /s/ Gary D. Blackford
                                         ---------------------------------------
                                    Name:  Gary D. Blackford
                                    Title: President and Chief Executive Officer





                                    U.S. BANK NATIONAL ASSOCIATION,
                                    AS TRUSTEE

                                    By: /s/ Richard H. Prokosch
                                        ----------------------------------------
                                    Name: Richard H. Prokosch
                                    Title: Vice President



                                       5