Exhibit 4.4.1  AMENDMENT NO. 2  TO  EQUITYHOLDERS AGREEMENT  AMENDMENT
(this Amendment),
dated as of February 26, 2008, to the EQUITYHOLDERS AGREEMENT (the Agreement), dated as
of February 10, 2005, among Emergency Medical Services L.P., a Delaware
limited partnership (the Company),
Onex Partners LP, a Delaware limited partnership (Onex Partners), the
equityholders signatory thereto and such other equityholders of the Company as
may, from time to time, become parties to the Agreement in accordance with the
provisions thereof.  Any capitalized term
used herein and not defined shall have the meaning given to such term in the
Agreement.  Pursuant to Section 6.13 of the Agreement, the
Company, the Majority Onex Investors and the Management Representatives desire
to amend the Agreement as set forth herein.  The parties agree hereby as follows:  1.Amendments.  (a)           The definition of Pre-QPO Units is
hereby amended to read in its entirety as follows:  The term Pre-QPO
Units, as to any Person, means the Units held by that Person
immediately prior to the consummation of a Qualified Public Offering, but
excluding any Units issued or issuable upon the exercise of any option held by
that Person immediately prior to the consummation of a Qualified Public Offering.  (b)           Section 1.6 is
hereby amended to read in its entirety as follows:  Termination.  The
provisions of this Article 1 shall terminate automatically upon the
earlier to occur of (a) an Approved Sale and (b) the 181st day
following a Qualified Public Offering; provided
however, that notwithstanding the foregoing, in the case of a
Restricted Employee Investor the provisions of this Article 1 shall
continue, but only as to Pre-QPO Units, and shall terminate as to
Pre-QPO Units automatically upon the earlier to occur of (a) an Approved
Sale and (b) the fifth anniversary of a Qualified Public Offering.  2.Governing Law.  This Amendment shall be governed by, and
interpreted in accordance with, the laws of the State of Delaware.  3.Counterparts.  This Amendment may be executed in any number
of counterparts which together shall constitute one and the same instrument.


4.No Further
Amendment.   Except as
expressly amended in paragraph 1 of this Amendment, the terms and conditions of
the Agreement shall remain in full force and effect, and are hereby ratified
and confirmed in all respects.  *  *  *  IN WITNESS WHEREOF, the parties
have caused this Amendment to be executed by their respective officers
thereunto duly authorized, as of the date first above written.  EMERGENCY
MEDICAL SERVICES CORPORATION, 
as successor to the issuer of the Units   By:
  /s/  Todd
  G. ZimmermanName:   Todd
  G. ZimmermanTitle:     Executive
  Vice President  EMERGENCY
MEDICAL SERVICES L.P.  By:
  Emergency
  Medical ServicesCorporation,
  its general partnerBy:
  /s/  Todd
  G. ZimmermanName:   Todd
  G. ZimmermanTitle:     Executive
  Vice President   MANAGEMENT
REPRESENTATIVES:  /s/
  William A. SangerWilliam
  A. Sanger, Chief Executive Officer/s/
  Randel G. OwenRandel
  G. Owen, Chief Financial Officer/s/
  Todd G. ZimmermanTodd
  G. Zimmerman, Executive Vice President 
  and Secretary


ONEX
  PARTNERS LP (as a Majority Onex Investor)
  ONEX
  PARTNERS LLC (as a Majority Onex 
  Investor)By:
  Onex
  Partners GP LP, its GeneralPartner
  By:
  /s/
  Robert M. Le BlancBy:
  Onex
  Partners Manager LP, its Agent
  
  Name:   Robert M. Le BlancBy:
  Onex
  Partners Manager GP Inc., its
  
  Title:
      DirectorGeneral
  PartnerBy:
  /s/
  Donald F. WestName:
    Donald F. WestBy:
  /s/ Robert M. Le Blanc
  
  Title:     DirectorName:  Robert M. Le BlancTitle:    PresidentBy:
  /s/
  Donald F. WestName:  Donald
  F. WestTitle:    Vice
  President  [SIGNATURE PAGE TO AMENDMENT NO. 2 TO EQUITYHOLDERS AGREEMENT]