<PAGE>
                                                                     Exhibit 4.8


                          SUPPLEMENTAL INDENTURE NO. 2


        SUPPLEMENTAL INDENTURE NO. 2 (this "Supplemental Indenture"), effective
as of September 30, 2005 among Global Medical Response, Inc., a Delaware
corporation (the "Guaranteeing Subsidiary"), a subsidiary of American Medical
Response, Inc. (or its permitted successor), a Delaware corporation, the Issuers
(as defined in the Indenture referred to herein), the other Guarantors (as
defined in the Indenture) and U.S. Bank Trust National Association, as trustee
under the Indenture referred to below (the "Trustee").


                               W I T N E S S E T H

        WHEREAS, the Issuers and the Guarantors party thereto have heretofore
executed and delivered to the Trustee an indenture (the "Indenture"), dated as
of February 10, 2005, as supplemented by the Supplemental Indenture, dated April
15, 2005, providing for the issuance of 10% Senior Subordinated Notes due 2015
(the "Notes");

        WHEREAS, the Indenture provides that under certain circumstances the
Guaranteeing Subsidiary shall execute and deliver to the Trustee a supplemental
indenture pursuant to which the Guaranteeing Subsidiary shall unconditionally
guarantee all of the Issuers' Obligations under the Notes and the Indenture on
the terms and conditions set forth herein (the "Subsidiary Guarantee"); and

        WHEREAS, pursuant to Section 9.01 of the Indenture, the Trustee is
authorized to execute and deliver this Supplemental Indenture.

        NOW THEREFORE, in consideration of the foregoing and for other good and
valuable consideration, the receipt of which is hereby acknowledged, the
Guaranteeing Subsidiary and the Trustee mutually covenant and agree for the
equal and ratable benefit of the Holders of the Notes as follows:

        1. Capitalized Terms. Capitalized terms used herein without definition
shall have the meanings assigned to them in the Indenture.

        2. Agreement to Guarantee. The Guaranteeing Subsidiary hereby agrees as
follows:

               (a) Along with all other Guarantors, to jointly and severally
        unconditionally Guarantee to each Holder of a Note authenticated and
        delivered by the Trustee and to the Trustee and its successors and
        assigns, irrespective of the validity and enforceability of the
        Indenture, the Notes or the obligations of the Issuers hereunder or
        thereunder, that:

                      (i) the principal of and interest on the Notes will be
               promptly paid in full when due, whether at maturity, by
               acceleration, redemption or otherwise, and interest on the
               overdue principal of and interest on the Notes, if any, if
               lawful, and all other obligations of the Issuers to the Holders
               or the Trustee hereunder or thereunder will be promptly paid in
               full or performed, all in accordance with the terms hereof and
               thereof; and

                      (ii) in case of any extension of time of payment or
               renewal of any Notes or any of such other obligations, that same
               will be promptly paid in full when due or performed in accordance
               with the terms of the extension or renewal, whether at stated
               maturity, by acceleration or otherwise. Failing payment when due
               of any amount so
<PAGE>

               guaranteed or any performance so guaranteed for whatever reason,
               the Guarantors shall be jointly and severally obligated to pay
               the same immediately. Each Guarantor agrees that this is a
               guarantee of payment and not a guarantee of collection.

               (b) The obligations hereunder shall be unconditional,
        irrespective of the validity, regularity or enforceability of the Notes
        or the Indenture, the absence of any action to enforce the same, any
        waiver or consent by any Holder of the Notes with respect to any
        provisions hereof or thereof, the recovery of any judgment against the
        Issuers, any action to enforce the same or any other circumstance which
        might otherwise constitute a legal or equitable discharge or defense of
        a Guarantor. Subject to Section 6.06 of the Indenture, each Guarantor
        hereby waives diligence, presentment, demand of payment, filing of
        claims with a court in the event of insolvency or bankruptcy of an
        Issuer, any right to require a proceeding first against an Issuer,
        protest, notice and all demands whatsoever and covenant that this
        Subsidiary Guarantee shall not be discharged except by complete
        performance of the obligations contained in the Notes and the Indenture.

               (c) If any Holder or the Trustee is required by any court or
        otherwise to return to the Issuers, the Guarantors, or any Custodian,
        Trustee, liquidator or other similar official acting in relation to
        either the Issuers or the Guarantors, any amount paid by either to the
        Trustee or such Holder, this Subsidiary Guarantee, to the extent
        theretofore discharged, shall be reinstated in full force and effect.

               (f) The Guaranteeing Subsidiary shall not be entitled to any
        right of subrogation in relation to the Holders in respect of any
        obligations guaranteed hereby until payment in full of all obligations
        guaranteed hereby. The Guaranteeing Subsidiary further agrees that, as
        between the Guarantors, on the one hand, and the Holders and the
        Trustee, on the other hand, (x) the maturity of the obligations
        guaranteed hereby may be accelerated as provided in Article 6 of the
        Indenture for the purposes of this Subsidiary Guarantee, notwithstanding
        any stay, injunction or other prohibition preventing such acceleration
        in respect of the obligations guaranteed hereby, and (y) in the event of
        any declaration of acceleration of such obligations as provided in
        Article 6 of the Indenture, such obligations (whether or not due and
        payable) shall forthwith become due and payable by the Guarantors for
        the purpose of this Subsidiary Guarantee. The Guarantors shall have the
        right to seek contribution from any non-paying Guarantor so long as the
        exercise of such right does not impair the rights of the Holders under
        the Guarantee.

               (i) Pursuant to Section 10.02 of the Indenture, after giving
        effect to any maximum amount and any other contingent and fixed
        liabilities that are relevant under any applicable Bankruptcy or
        fraudulent conveyance laws, and after giving effect to any collections
        from, rights to receive contribution from or payments made by or on
        behalf of any other Guarantor in respect of the obligations of such
        other Guarantor under Article 10 of the Indenture shall result in the
        obligations of such Guarantor under its Subsidiary Guarantee not
        constituting a fraudulent transfer or conveyance.

        3. Execution and Delivery. Each Guaranteeing Subsidiary agrees that the
Subsidiary Guarantees shall remain in full force and effect notwithstanding any
failure to endorse on each Note a notation of such Subsidiary Guarantee.

        4. Releases.

        (a) The Subsidiary Guarantee of a Subsidiary Guarantor shall be
released:


                                     2
<PAGE>

               (i) in connection with any sale or other disposition of all or
        substantially all of the assets of that Subsidiary Guarantor (including
        by way of merger or consolidation), if the Issuer that directly or
        indirectly owns such Subsidiary Guarantor applies the Net Proceeds of
        such sale or other disposition, in accordance with the applicable
        provisions of the Indenture;

               (ii) in connection with the sale of all of the capital stock of a
        Subsidiary Guarantor, if the Issuer that directly or indirectly owns
        such Subsidiary Guarantor applies the Net Proceeds of that sale, in
        accordance with the applicable provisions of the Indenture;

               (iii) in connection with any transaction which results in a
        Subsidiary Guarantor ceasing to be a Restricted Subsidiary of an Issuer,
        if the transaction is not in violation of the applicable provisions of
        the Indenture;

               (iv) if an Issuer designates any Restricted Subsidiary of such
        Issuer that is a Subsidiary Guarantor as an Unrestricted Subsidiary, in
        accordance with the applicable provisions of the Indenture; or

               (v) if a Subsidiary Guarantor has no outstanding Indebtedness
        after giving effect to such release other than pursuant to clause (2),
        (4), (5), (6) (with respect to Permitted Refinancing Indebtedness in
        respect of Indebtedness initially incurred under clause (2) or (5)
        only), (7), (10), (11), (12), (13), (14) or (15) of Section 4.09 of the
        Indenture or pursuant to clause (9) of Section 4.09 of the Indenture
        (with respect to Indebtedness incurred under any of the foregoing
        clauses) and an Officers' Certificate certifying the foregoing is
        presented to the Trustee together with a request to release such
        Subsidiary Guarantor from its Subsidiary Guarantee.

        Upon delivery by the Issuers to the Trustee of an Officers' Certificate
and an Opinion of Counsel to the effect that such sale or other disposition was
made by the Issuers in accordance with the provisions of the Indenture,
including without limitation Section 4.10 of the Indenture, the Trustee shall
execute any documents reasonably required in order to evidence the release of
any Subsidiary Guarantor from its obligations under its Subsidiary Guarantee.

        (b) Any Subsidiary Guarantor not released from its obligations under its
Subsidiary Guarantee shall remain liable for the full amount of principal of and
interest on the Notes and for the other obligations of any Guarantor under the
Indenture as provided in Article 11 of the Indenture.

        6. No Recourse Against Others. No past, present or future director,
officer, employee, incorporator, stockholder or agent of Parent or the
Guaranteeing Subsidiary, as such, shall have any liability for any obligations
of the Issuers, Parent or any Guaranteeing Subsidiary under the Notes, any
Guarantees, the Indenture or this Supplemental Indenture or for any claim based
on, in respect of, or by reason of, such obligations or their creation. Each
Holder of the Notes by accepting a Note waives and releases all such liability.
The waiver and release are part of the consideration for issuance of the Notes.
Such waiver may not be effective to waive liabilities under the federal
securities laws and it is the view of the SEC that such a waiver is against
public policy.

        7. NEW YORK LAW TO GOVERN. THE INTERNAL LAW OF THE STATE OF NEW YORK
SHALL GOVERN AND BE USED TO CONSTRUE THIS SUPPLEMENTAL INDENTURE BUT WITHOUT
GIVING EFFECT TO APPLICABLE PRINCIPLES OF CONFLICTS OF LAW TO THE EXTENT THAT
THE APPLICATION OF THE LAWS OF ANOTHER JURISDICTION WOULD BE REQUIRED THEREBY.


                                       3
<PAGE>

        8 Counterparts. The parties may sign any number of copies of this
Supplemental Indenture. Each signed copy shall be an original, but all of them
together represent the same agreement.

        9. Effect of Headings. The Section headings herein are for convenience
only and shall not affect the construction hereof.

        10. The Trustee. The Trustee shall not be responsible in any manner
whatsoever for or in respect of the validity or sufficiency of this Supplemental
Indenture or for or in respect of the recitals contained herein, all of which
recitals are made solely by the Guaranteeing Subsidiary and the Issuers.


                          [Signature pages to follow.]



                                       4
<PAGE>

                                                                     Exhibit 4.8


        IN WITNESS WHEREOF, the parties hereto have caused this Supplemental
Indenture No. 2 to be duly executed and attested, all as of the date first above
written.


                              GLOBAL MEDICAL RESPONSE, INC.

                                By: /s/ William A. Sanger
                                    ---------------------------------
                                    Name: William A. Sanger
                                    Title: Chief Executive Officer


                              AMR HOLDCO, INC.

                                By: /s/ William A. Sanger
                                    ---------------------------------
                                    Name: William A. Sanger
                                    Title: Chief Executive Officer


                              EMCARE HOLDCO, INC.

                                By: /s/ William A. Sanger
                                    ---------------------------------
                                    Name: William A. Sanger
                                    Title: Chief Executive Officer


                [Signature Page to Supplemental Indenture No. 2]
<PAGE>

                              EMERGENCY MEDICAL SERVICES L.P.

                                By: Emergency Medical Services
                                    Corporation, its general partner


                                By: /s/ William A. Sanger
                                    ---------------------------------
                                    Name: William A. Sanger
                                    Title: Chairman and Chief Executive Officer

                              AMERICAN MEDICAL RESPONSE, INC.
                              HANK'S ACQUISITION CORP.
                              FOUNTAIN AMBULANCE SERVICE, INC.
                              MEDLIFE EMERGENCY MEDICAL SERVICE, INC.
                              AMERICAN MEDICAL RESPONSE NORTHWEST, INC.
                              AMERICAN MEDICAL RESPONSE WEST
                              METROPOLITAN AMBULANCE SERVICE
                              AMERICAN MEDICAL RESPONSE OF INLAND EMPIRE
                              DESERT VALLEY MEDICAL TRANSPORT, INC.
                              SPRINGS AMBULANCE SERVICE, INC.
                              AMERICAN MEDICAL RESPONSE OF COLORADO, INC.
                              INTERNATIONAL LIFE SUPPORT, INC.
                              MEDEVAC MIDAMERICA, INC.
                              MEDEVAC MEDICAL RESPONSE, INC.
                              AMERICAN MEDICAL RESPONSE OF OKLAHOMA, INC.
                              AMERICAN MEDICAL RESPONSE OF TEXAS, INC.
                              KUTZ AMBULANCE SERVICE, INC.
                              AMERICAN MEDICAL RESPONSE HOLDINGS, INC.
                              AMERICAN MEDICAL RESPONSE MANAGEMENT, INC.
                              A1 LEASING, INC.
                              FLORIDA EMERGENCY PARTNERS, INC.
                              MOBILE MEDIC AMBULANCE SERVICE, INC.
                              METRO AMBULANCE SERVICE, INC.
                              METRO AMBULANCE SERVICE (RURAL), INC.
                              MEDIC ONE AMBULANCE SERVICES, INC.
                              AMERICAN MEDICAL RESPONSE OF SOUTH CAROLINA, INC.
                              AMERICAN MEDICAL RESPONSE OF NORTH CAROLINA, INC.
                              AMERICAN MEDICAL RESPONSE OF GEORGIA, INC.
                              TROUP COUNTY EMERGENCY MEDICAL SERVICES, INC.
                              RANDLE EASTERN AMBULANCE SERVICE, INC.
                              MEDI-CAR SYSTEMS, INC.
                              MEDI-CAR AMBULANCE SERVICE, INC.
                              AMERICAN MEDICAL RESPONSE OF TENNESSEE, INC.
                              PHYSICIANS & SURGEONS AMBULANCE SERVICE, INC.
                              AMERICAN MEDICAL RESPONSE OF ILLINOIS, INC.
                              MIDWEST AMBULANCE MANAGEMENT COMPANY
                              PARAMED, INC.

                [Signature Page to Supplemental Indenture No. 2]
<PAGE>



                              MERCY AMBULANCE OF EVANSVILLE, INC.
                              TIDEWATER AMBULANCE SERVICE, INC.
                              AMERICAN MEDICAL RESPONSE OF CONNECTICUT,
                                 INCORPORATED
                              AMERICAN MEDICAL RESPONSE OF MASSACHUSETTS, INC.
                              AMERICAN MEDICAL RESPONSE MID-ATLANTIC, INC.
                              AMBULANCE ACQUISITION, INC.
                              METRO AMBULANCE SERVICES, INC.
                              BROWARD AMBULANCE, INC.
                              ATLANTIC AMBULANCE SERVICES ACQUISITION, INC.
                              ATLANTIC/KEY WEST AMBULANCE, INC.
                              ATLANTIC/PALM BEACH AMBULANCE, INC.
                              SEMINOLE COUNTY AMBULANCE, INC.
                              LIFEFLEET SOUTHEAST, INC.
                              AMERICAN MEDICAL PATHWAYS, INC.
                              ADAM TRANSPORTATION SERVICE, INC.
                              ASSOCIATED AMBULANCE SERVICE, INC.
                              PARK AMBULANCE SERVICE INC.
                              FIVE COUNTIES AMBULANCE SERVICE, INC.
                              SUNRISE HANDICAP TRANSPORT CORP.
                              STAT HEALTHCARE, INC.
                              LAIDLAW MEDICAL TRANSPORTATION, INC.
                              MERCY, INC.
                              AMERICAN INVESTMENT ENTERPRISES, INC.
                              LIFECARE AMBULANCE SERVICE, INC.
                              TEK, INC.
                              MERCY LIFE CARE
                              HEMET VALLEY AMBULANCE SERVICE, INC.
                              AMERICAN MEDICAL RESPONSE OF SOUTHERN CALIFORNIA
                              MEDIC ONE OF COBB, INC.
                              PUCKETT AMBULANCE SERVICE, INC.

                [Signature Page to Supplemental Indenture No. 2]
<PAGE>

                              AMERICAN MEDICAL RESPONSE DELAWARE VALLEY, LLC
                              By: American Medical Response Mid-Atlantic, Inc.,
                                  its sole member

                              REGIONAL EMERGENCY SERVICES, LP
                              By: Florida Emergency Partners, Inc., its general
                                  partner

                              PROVIDACARE, L.L.C.
                              By: American Medical Pathways, Inc., its sole
                                  member

                              AMR BROCKTON, L.L.C.
                              By: American Medical Response of Massachusetts,
                                  Inc., its manager

                              By: /s/ Randel G. Owen
                                  ----------------------------------------------
                                  Name:  Randel G. Owen
                                  Title: Vice President

                              EMCARE HOLDINGS INC.
                              EMCARE, INC.
                              EMCARE OF ALABAMA, INC.
                              EMCARE CONTRACT OF ARKANSAS, INC.
                              EMCARE OF ARIZONA, INC.
                              EMCARE OF CALIFORNIA, INC.
                              EMCARE OF COLORADO, INC.
                              EMCARE OF CONNECTICUT, INC.
                              EMCARE OF FLORIDA, INC.
                              EMCARE OF GEORGIA, INC.
                              EMCARE OF HAWAII, INC.
                              EMCARE OF INDIANA, INC.
                              EMCARE OF IOWA, INC.
                              EMCARE OF KENTUCKY, INC.
                              EMCARE OF LOUISIANA, INC.
                              EMCARE OF MAINE, INC.
                              EMCARE OF MICHIGAN, INC.
                              EMCARE OF MINNESOTA, INC.
                              EMCARE OF MISSISSIPPI, INC.
                              EMCARE OF MISSOURI, INC.
                              EMCARE OF NEVADA, INC.
                              EMCARE OF NEW HAMPSHIRE, INC.
                              EMCARE OF NEW JERSEY, INC.
                              EMCARE OF NEW MEXICO, INC.
                              EMCARE OF NEW YORK, INC.
                              EMCARE OF NORTH CAROLINA, INC.
                              EMCARE OF NORTH DAKOTA, INC.
                              EMCARE OF OHIO, INC.


                [Signature Page to Supplemental Indenture No. 2]
<PAGE>

                              EMCARE OF OKLAHOMA, INC.
                              EMCARE OF OREGON, INC.
                              EMCARE OF PENNSYLVANIA, INC.
                              EMCARE OF RHODE ISLAND, INC.
                              EMCARE OF SOUTH CAROLINA, INC.
                              EMCARE OF TENNESSEE, INC.
                              EMCARE OF TEXAS, INC.
                              EMCARE OF VERMONT, INC.
                              EMCARE OF VIRGINIA, INC.
                              EMCARE OF WASHINGTON, INC.
                              EMCARE OF WEST VIRGINIA, INC.
                              EMCARE OF WISCONSIN, INC.
                              EMCARE PHYSICIAN PROVIDERS, INC.
                              EMCARE PHYSICIAN SERVICES, INC.
                              EMCARE SERVICES OF ILLINOIS, INC.
                              EMCARE SERVICES OF MASSACHUSETTS, INC.
                              EMCARE ANESTHESIA SERVICES, INC.
                              ECEP, INC.
                              COORDINATED HEALTH SERVICES, INC.
                              EM-CODE REIMBURSEMENT SOLUTIONS, INC.
                              EMERGENCY MEDICINE EDUCATION SYSTEMS, INC.
                              EMERGENCY SPECIALISTS OF ARKANSAS, INC. II
                              FIRST MEDICAL/EMCARE, INC.
                              HEALTHCARE ADMINISTRATIVE SERVICES, INC.
                              OLD STAT, INC.
                              REIMBURSEMENT TECHNOLOGIES, INC.
                              STAT PHYSICIANS, INC.
                              THE GOULD GROUP, INC.
                              TIFTON MANAGEMENT SERVICES, INC.
                              TUCKER EMERGENCY SERVICES, INC.
                              HELIX PHYSICIANS MANAGEMENT, INC.
                              NORMAN BRUCE JETTON, INC.
                              PACIFIC EMERGENCY SPECIALISTS MANAGEMENT, INC.
                              AMERICAN EMERGENCY PHYSICIANS MANAGEMENT, INC.
                              PHYSICIAN ACCOUNT MANAGEMENT, INC.
                              PROVIDER ACCOUNT MANAGEMENT, INC.
                              CHARLES T. MITCHELL, INC.

                              EMCARE OF MARYLAND LLC,
                              By: EmCare Holdings Inc. and EmCare, Inc., its
                                  members

                              EMS MANAGEMENT LLC
                              By: AMR HoldCo, Inc. and EmCare HoldCo, Inc., its
                                  members

                              By: /s/ William A. Sanger
                                  ----------------------------------------------
                                  Name:  William A. Sanger
                                  Title: Chief Executive Officer

                [Signature Page to Supplemental Indenture No. 2]
<PAGE>


U.S. BANK TRUST NATIONAL ASSOCIATION
  as Trustee

By: /s/ Cheryl L. Clarke
    -------------------------------------------------
    (Authorized Signatory)