FIRST SUPPLEMENTAL INDENTURE

EXHIBIT 4.4

FIRST SUPPLEMENTAL INDENTURE

SUPPLEMENTAL INDENTURE (this “Supplemental Indenture”), dated as of September 18, 2008, among Northstar Hospital, LLC (the “Guaranteeing Subsidiary”), an indirect subsidiary of Symbion, Inc., a Delaware corporation (the “Issuer”), the Issuer and U.S. Bank National Association, as trustee under the Indenture referred to below (the “Trustee”).

WITNESSETH

WHEREAS, the Issuer has heretofore executed and delivered to the Trustee an indenture (the “Indenture”), dated as of June 3, 2008, providing for the issuance of 11.00%/11.75% Senior PIK Toggle 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 irrevocably and unconditionally guarantee all of the Issuer’s 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 to pro-vide an unconditional Guarantee on the terms and subject to the conditions set forth in the Subsidiary Guarantee and in this Indenture including but not limited to Article 11 thereof.

3. NO RECOURSE AGAINST OTHERS.  No past, present or future director, officer, employee, incorporator, stockholder or agent of the Guaranteeing Subsidiary, as such, shall have any liability for any obligations of the Issuer or any Guaranteeing Subsidiary under the Notes, any Subsidiary 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.

4. NEW YORK LAW TO GOVERN.  THIS SUPPLEMENTAL INDENTURE SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

5. COUNTERPARTS.  The parties may sign any number of copies of this Supplemental In-denture.  Each signed copy shall be an original, but all of them together represent the same agreement.

6. EFFECT OF HEADINGS.  The Section headings herein are for convenience only and shall not affect the construction hereof.

7. 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 Issuer.

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.

Dated:   September 18, 2008

	NORTHSTAR HOSPITAL, LLC
	By:	SMBI Northstar, LLC, the sole member
		of Northstar Hospital, LLC
		By:	/s/ Xxxxxx X. Xxxxxx
			Name:	Xxxxxx X. Xxxxxx
			Title:	Vice President
	SYMBION, INC.
	By:	/s/ Xxxxxx X. Xxxxxx
		Name:	Xxxxxx X. Xxxxxx
		Title:	Senior Vice President and Chief
			Financial Officer
	U.S. BANK NATIONAL ASSOCIATION,
	as Trustee
	By:	/s/ Xxxxx Xxxxxxxx
	Name:	Xxxxx Xxxxxxxx
	Title:	Vice President