Exhibit 4.18


 


SUPPLEMENTAL INDENTURE NO. 12


 


THIS SUPPLEMENTAL INDENTURE NO.
12 (this “Supplemental Indenture”), dated as of March 28, 2008, is
among River Medical Incorporated, an Arizona corporation and a wholly owned
subsidiary of Arizona Oasis Acquisition, Inc. (the “Guaranteeing
Subsidiary”); 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
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 guarantee of the Guaranteeing Subsidiary is referred to
herein as a “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 with respect to its Subsidiary Guarantee:


 


(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 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.


 


(d)           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.


 


(e)           Pursuant
to Section 11.03 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 11 of the Indenture 


 


2

















 


shall result in the
obligations of such Guarantor under its Subsidiary Guarantee not constituting a
fraudulent transfer or conveyance.


 


3.                                      Execution and Delivery.  The Guaranteeing Subsidiary agrees that the
Subsidiary Guarantee 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:


 


(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 


 


3

















 


Notes and for the
other obligations of any Guarantor under the Indenture as provided in Article 11
of the Indenture.


 


5.             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 the 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.


 


6.             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.


 


7.             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.


 


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


 


9.             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 Page Follows}


 


4

















 


IN WITNESS WHEREOF, the parties
hereto have caused this Supplemental Indenture to be duly executed and
attested, all as of the date first above written.


 


 


	
  RIVER MEDICAL INCORPORATED

  	
   

  
	
   

  	
   

  	
   

  
	
  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

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  EMERGENCY MEDICAL SERVICES L.P.

  	
   

  
	
  By: Emergency Medical Services Corporation, its general partner

  	
   

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  By:

  	
  /s/ William A. Sanger

  	
   

  
	
  Name:

  	
  William A. Sanger

  	
   

  
	
  Title:

  	
  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.

  



 


 


[Signature Page to Supplemental Indenture No. 12]


 

















 


	
  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.

  
	
  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.

  



 


 


[Signature Page to Supplemental Indenture No. 12]


 

















 


	
  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.

  
	
  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.

  



 


 


[Signature Page to Supplemental Indenture No. 12]


 

















 


	
  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.

  
	
  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.

  
	
  EMERGENCY MEDICAL SERVICES CORPORATION

  
	
  EMS MANAGEMENT LLC 

  
	
  By: AMR Holdco, Inc. and EmCare Holdco, Inc., its members

  
	
  HELIX PHYSICIANS MANAGEMENT, INC.

  
	
  NORMAN BRUCE JETTON, INC.

  
	
  PACIFIC EMERGENCY SPECIALISTS MANAGEMENT, INC.

  
	
  AMERICAN EMERGENCY PHYSICIANS MANAGEMENT, INC.

  
	
  PHYSICIAN ACCOUNT MANAGEMENT, INC.

  



 


 


[Signature Page to Supplemental Indenture No. 12]


 

















 


	
  PROVIDER ACCOUNT MANAGEMENT, INC.

  
	
  CHARLES T. MITCHELL, M.D., INC.

  
	
  GLOBAL MEDICAL RESPONSE, INC.

  
	
  AIR AMBULANCE SPECIALISTS, INC.

  
	
  EHR MANAGEMENT CO.

  
	
  EMCARE OF MARYLAND LLC,

  
	
  By: EmCare Holdings Inc. and EmCare, Inc., its members

  
	
  NEVADA RED ROCK HOLDINGS, INC.

  
	
  NEVADA RED ROCK AMBULANCE, INC.

  
	
  MEDICWEST HOLDINGS, INC.

  
	
  MEDICWEST AMBULANCE, INC.

  
	
  MISSION CARE
  SERVICES, LLC 

  
	
  By: American
  Medical Response, Inc., its manager

  
	
  MISSION CARE
  OF ILLINOIS, LLC 

  
	
  By: Mission
  Care Services, Inc., its manager 

  
	
  By: American
  Medical Response, Inc., its manager

  
	
  MISSION CARE
  OF MISSOURI, LLC 

  
	
  By: Mission
  Care Services, Inc., its manager 

  
	
  By: American
  Medical Response, Inc., its manager

  
	
  ACCESS2CARE,
  LLC 

  
	
  By: Mission
  Care Services, Inc., its manager 

  
	
  By: American
  Medical Response, Inc., its manager

  
	
  ABBOTT
  AMBULANCE, INC.

  
	
  ARIZONA
  OASIS ACQUISITION, INC.

  
	
  RADIOLOGY
  STAFFING SOLUTIONS, INC. 

  
	
  RADSTAFFING
  MANAGEMENT SOLUTIONS, INC.

  
	
   

  
	
   

  
	
  By:

  	
  /s/ William A. Sanger

  	
   

  
	
  Name:

  	
  William A. Sanger

  	
   

  
	
  Title:

  	
  Chief Executive Officer

  	
   

  
	
   

  
	
   

  
	
  U.S. BANK TRUST NATIONAL ASSOCIATION, as Trustee

  
	
   

  	
   

  	
   

  
	
   

  	
   

  	
   

  
	
  By:

  	
  /s/ John J. Doherty

  	
   

  
	
  Name:

  	
  John J. Doherty

  	
   

  
	
  Title:

  	
  Vice President

  	
   

  



 


 


[Signature Page to Supplemental Indenture No. 12]