Single Needle Hemodialysis

Caution: Federal Law (USA) restricts this device to sale,by or on the order of a physician.

Read Instruction for Use prior to patient application.Trademarks used herein are owned by or licensed to Gambro

2006 Gambro 306050356 Rev B

Objectives

Rationale for Single Needle (SN) Dialysis

History of SN Dialysis Systems

Phoenix SN

Stroke Volume & Clearance Efficiency

Effects of Changing Pressure Limits & Blood Flow

Why Single Needle?

Consistent access to the blood is the weakest link in the hemodialysis process.

History of SN Dialysis Control Systems

Pressure – Time• Continuous Pump

Vital Assists

Average Pressure• Intermittent Pump

COBE Centry® SNC (C2)

Pressure – Pressure• Intermittent Pump

Centrysystem® 3/3+Phoenix®

Continuous Pump (Double Blood Pump)

• AK 10• Fresenius

+ =LOW HIGH

LOW HIGH

AVERAGE

SN CYCLE

All SN systems have two operating Phases

Arterial Phase• Blood drawn FROM the patient

Venous Phase• Blood returned TO the patient

The combination of the two is referred to as a “CYCLE”

Phoenix® Single Needle

Utilizes a Pressure – Pressure control device incorporating the intermittent blood pump and A/V clamping device

The operator sets a SN Pressure Max (venous pressure) limit to end the Arterial Phase

AND

a SN Pressure Min (venous pressure) limit to end the Venous Phase

Note: SN Pressure Min/Max = Venous Pressure Min/Max

Arterial Phase Description

Blood Pump is ON

Arterial Clamp is Open

Venous Clamp is Closed

When the SN Pressure Max (venous pressure) limit is reached the machine switches to the Venous Phase

Venous Phase Description

Blood Pump is OFF

Arterial Clamp is Closed

Venous Clamp is Open

Blood returns to the patient until the SN Pressure Min (venous pressure) limit is reached triggering another Arterial Phase(The blood is returned by the pressure built up in the system)

Stroke Volume & Clearance Efficiency

Clearance Efficiency in single needle dialysis is a function of:• Stroke Volume• Access Recirculation • Average Blood Flow Rate• Blood Tubing Compliance

Stroke Volume

Is the quantity of blood removed from the patient in one Arterial Phase

Is relative to how high the SN Pressure Max (venous pressure)

limit is set

Optimum Stroke Volume = 20 – 30 mls

Stroke Volume (continued)

By increasing the volume of blood pumped with one stroke, the percent of that volume being recirculated is Decreased

Stroke Volume is optimized on the Phoenix® system using a unique Cartridge Blood Set configuration which includes 1 or 2 pumping chambers and the operator’s ability to manipulate blood side pressure limits

Stroke Volume Calculation

The Phoenix® system calculates the Stroke Volume:

Arterial Phase Time X Pump Speed

60

Sources of Recirculation

Poor blood flow from patient’s access

Common space in the Access Device• Fistula needle or Single Lumen Catheter

Compliance of the blood lines

Recirculation

Recirculation is the drawing of dialyzed blood from the Venous Line into the Arterial Line before it circulates through the patient

Dialyzed blood has a lower concentration of solutes than the blood in the patient’s circulatory system, therefore Recirculation can adversely affect clearance efficiency

Common Space

Is the space from the tip of the needle to the start of the Y where venous and arterial blood mix

Use of standard Fistula needle is not recommended due to the common space volume

•Optimum volume of common space is 0.5 mL

1.

2.

Common Space = Recirculation

A/V Fistula needle with a Y adapter attached is not recommended • 12” Fistula Needle w/ tubing = 2.6 – 2.9 ml volume

Use an Access Device designed for Single Needle

Common Space = Recirculation

This chart illustrates Common Space Volume as related to % of Recirculation at a certain Stroke Volume

Stroke Volume 20 30 40.5ml 2.5% 1.7% 1.2%

1.0ml 5.0% 3.3% 2.5%2.0ml 10.0% 6.7% 5.0%4.0ml 20% 13% 10%

Common Space % of Recirculation

Access Device designed for Single Needle

Pictured below is a fistula needle designed for SN as compared to a standard fistula needle

As you can see the common space is vastly different SN ”Y “ Set Fistula Needle

Standard Fistula Needle with 12” Tubing

Blood Flow Rate

Phoenix® system calculates Blood Flow rate as:

Pump Speed x Active Time of Blood Pump

Cycle Time

Blood Tubing Compliance

Recirculation may be caused by the compliance of the blood tubing set during single needle procedures

Pressure differentials as great as 600 mmHg (-200 mmHg arterial, +380 mmHg venous) may occur between venous and arterial phases, causing expansion and contraction of the tubing

Blood Tubing Compliance continued

This expansion and contraction causes backflow during the arterial and venous phases

Lastly, due to the configuration of the Cartridge Blood Set, blood flow is continuous through the dialyzer

Effects of Adjusting Pressure Limits

Increase

SN Pressure Max to:

Stroke Volume

Average Blood Flow Rate

Arterial Phase Time

Decrease

SN Pressure Max to:

Stroke Volume

Average Blood Flow Rate

Arterial Phase Time

Effects of Adjusting Pressure Limits

Increase

SN Pressure Min to:

Stroke Volume

Average Blood Flow Rate

Venous Phase Time

Decrease

SN Pressure Min to:

Stroke Volume

Average Blood Flow Rate

Venous Phase Time

Raising or Lowering Pump Speed will:

1. Change blood flow rate

2. speed, arterial phase time

3. speed, arterial phase time

4. Possible change in stroke volume

Effects of Adjusting Pump Speed

Gambro® Product Offerings

Cartridge Blood Sets:• Single Needle Set P/N 003-409-400• Single Needle Set w/prime line attached P/N 003-409-410• Single Needle Conversion Kit P/N 003-429-500

Y Connector P/N S-194C• For use with a Single Lumen Catheter