Arterial Line Management for the Birthing Center

Objectives List reasons for Arterial Line monitoring in the OB setting. Identify equipment needed for insertion of an arterial line. Describe the process for Arterial Line monitoring.

What is Blood Pressure? Blood pressure (BP), sometimes referred to as arterial blood pressure, is the pressure exerted by circulating blood upon the walls of blood vessels, and is one of the principal vital signs. When used without further specification, "blood pressure" usually refers to the arterial pressure of the systemic circulation. During each heartbeat, blood pressure varies between a maximum (systolic) and a minimum (diastolic) pressure.[1] The blood pressure in the circulation is principally due to the pumping action of the heart.[2] Differences in mean blood pressure are responsible for blood flow from one location to another in the circulation. The rate of mean blood flow depends on the resistance to flow presented by the blood vessels. Mean blood pressure decreases as the circulating blood moves away from the heart through arteries and capillaries due to viscous losses of energy. Mean blood pressure drops over the whole circulation, although most of the fall occurs along the small arteries and arterioles.[3] Gravity affects blood pressure via hydrostatic forces (e.g., during standing) and valves in veins, breathing, and pumping from contraction of skeletal muscles also influence blood pressure in veins.[2] Other “Pressure” variables……… Resistance, tone, volume, fluids, viscosity, ………

History of BP Monitoring 1731 Reverend Stephen Hales cannulated a mare’s artery with a goose quill connected to a length of goose trachea. This was connected to an 8 ft. glass column manometer. 1905 Korotkoff proposed the auscultatory method.

Arterial Pressure Monitoring Indications: Continuous blood pressure evaluation Trends in blood pressure Efficacy of drugs, interventions Serial blood gas samples required Respiratory failure Mechanically ventilated patients Severe acid/base abnormalities

Why Arterial Line Monitoring? Continuous arterial blood pressure monitoring When there is a failure of indirect BP measurement When there is a need for arterial waveform analysis When there is a need for monitoring intravenous pharmacologic or mechanical cardiovascular support Arterial blood sampling Respiratory failure Mechanically ventilated patients Severe acid/base abnormalities

What types of patients require arterial line monitoring in the OB setting? Patients with cardiac disease Repaired congenital defects Cardiomyopathy CAD Patients with pulmonary issues Pulmonary Hypertension Cystic Fibrosis Patients with medical conditions where increase BP can result in catastrophic consequences Marfan’s syndrome Patients with acute changes in the OR Post-partum hemorrhage Sepsis

What Sites are used for Arterial Catheter Placement? Radial Brachial Femoral Axillary Dorsalis pedis The most common site used in the Birthing Center is the radial site.

Where will these lines be placed in the Birthing Center? Arterial lines may be placed in the patient’s room on 5700, the OR, triage or PACU.

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Getting Started: What Equipment will I need? Flush System 1000 ml bag of NS Pressure tubing with transducer Needless adapter Pressure bag

The Transduced Flush System: Provides a mechanism to maintain patency of invasive lines using high pressure with minimal flush delivery while transducing these lines to a monitor where intravascular and/or intracardiac pressure measurements can be taken.

Flush System set up Label fluid bag with date, time, initials and phrase “No additives.” Purge all air from the fluid bag. Insert pressurized tubing into fluid bag. Do not inflate pressure bag yet. Place fluid bag into pressure bag. Open the clamp and squeeze the drip chamber to fill the chamber ½ full.

Flush System set up continued 6. Flush tubing under gravity flow, checking that all air bubbles have been flushed out of tubing, transducer, and stopcocks. 7. Replace vented caps with “dead end” or occlusive caps on all stopcocks and assure that all connections on tubing are tight. 8. Inflate pressure bag to 300 mmHg. 9. Attach pressure tubing to end of catheter. 10. If new invasive lines are inserted, new pressurized tubing and flush bag should be set up and used.

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What Equipment will be needed? Insertion: Arterial catheter Chlorhexidine gluconate (CHG) swab (for CHG allergy, use 3 alcohol swabsticks and 3 povidone-iodine swabsticks) Sterile towels Sterile gloves Mask and cap

Allen’s Test Evaluate distal circulation prior to placement Allen’s test for radial catheter May be incorrect in as many as 14% of patients Requires continued evaluation of distal circulation!

Allen’s Test Occlude radial & ulnar artery Ask pt. to repeatedly squeeze hand into tight fist Ask pt. to relax hand – should be pale Lift finger off artery not being used Color should return within 5-10 seconds

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Arterial Line Insertion

Arterial Line Insertion Verify that patient consent has been obtained by the physician or physician designee. Reinforce physician’ explanation and provide reassurance to the patient during insertion. Provide assistance to inserter as needed. Connect pressure tubing to arterial catheter when insertion is complete, check that all connections are tight.

Arterial Line Insertion Assess wave form and set monitor alarms.

Secure transducer level to the phlebostatic axis. The phlebostatic axis is found at the intersection of the 4th intercostal space and the mid-axillary line.

Leveling and Zeroing Why zero? Possible transducer locations: Performed to eliminate the effects of atmospheric pressure on the transducer. Should be performed after connecting the pressure system to the patient and whenever there is significant change in hemodynamic numbers. Possible transducer locations: Mounted on manifold on IV pole Within the fluid line Directly affixed to the patient

Zeroing the Transducer Closed Open Atmospheric Pressure = 0 mmHg

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The Arterial Waveform Systolic Upstroke Systolic Peak Systolic Decline Dicrotic Notch Diastolic Runoff

Discrepancies w/ Cuff and A-line Problems with the cuff Cuff does not fit (must 20% longer than arm circumference) Deflating too quickly (>3mmHg/second) Regional arterial tree differences (coarctation, dissection) Blood Pressure at extremes

Discrepancies w/ Cuff and A-line Overdamping Attenuation of the waveforms Underestimation of blood pressure Underdamping Amplification of oscillations/waveforms Overestimation of blood pressure Overdamped Normal Underdamped

Square Wave Test Otherwise known as “dynamic response testing” Usually performed once per shift Done to determine if the monitoring system can accurately reproduce a patient's cardiovascular pressures Identifies problems such as: air bubbles, kinking in the tubing, loose connections or catheter patency

Square Wave Test When the fast-flush is pulled - the waveform should Have a sharp upstroke which terminates in a flat line which is followed by a rapid downstroke extending below baseline with 1 or 2 rapid oscillations A quick return to baseline

Square Wave Test Problems: Troubleshooting: Overdampened sluggish or no oscillations with a fast flush Falsely ↓ SBP and ↑ DBP Underdampened undulations in the square wave with the fast flush Falsely ↑ SBP and ↓ DBP Troubleshooting: Check for bubbles, blood clots, kinks, loose connections or decrease the length of tubing

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Assessment and Maintenance Assess for signs of complications at least every 4 hours and prn. Any signs of complications should be reported to the physician immediately. Change dressing when it becomes loose, moist, or soiled. Cleanse area with CHG, allow to air dry, and apply sterile dressing. Monitor waveform and blood return to assure arterial catheter patency. Set alarm parameters according to the patient’s current blood pressure. Keep arterial alarms on at all times since large blood volume may be lost quickly if any part of the system is loose or disconnected.

Complications of Arterial Lines Pain Infection Hemorrhage Hematoma Arterial Insufficiency (<0.1%) Arterial Embolus Misuse and Misinterpretation

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Withdrawing Blood Samples What equipment will I need? Alcohol wipes Saline-filled syringe 2 empty syringes Blood transfer device (for vacutainer® tubes) Vacutainer® tubes

Procedure Scrub the needleless adapter with alcohol x 15 seconds. A 10 ml syringe to the needleless adapter. Turn the stopcock off to the pressure tubing (on the patient). Aspirate 5ml blood into the 10 ml syringe. Turn the stopcock off to syringe. Detach syringe and discard. Turn stopcock off to all ports. Scrub the needleless adapter with alcohol x 15 seconds. Attach another 10 ml syringe to the needleless adapter on the stopcock. Turn the stopcock to the pressure tubing.

Procedure continued Withdraw enough blood needed for blood samples. Turn stopcock off to syringe. Scrub needleless adapter with alcohol x 15 seconds. Attach flush syringe containing 5 or 10 ml normal saline. Attach blood transfer device to syringe with blood. Fill vacutainer® tubes with blood needed for labs. Label blood sample(s) with patient addressograph or lab barcode label, then date, time, and initial the label.(BEFORE LEAVING THE PATIENT’S BEDSIDE)

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Arterial Line Removal Patients who deem appropriate candidates for post partum recovery on 5700 will have their A-line removed. Any patient that requires additional monitoring will be transferred to an ICU setting.

Arterial Line Removal Assess the patient’s coagulation profile (PT, PTT, INR, platelets) prior to removal of the arterial catheter. Wash hands and don gloves. Turn pressure system off by clamping tubing or turning stopcock off to the patient. Remove dressing and sutures (if present). Place sterile gauze pad over site and remove catheter, immediately apply direct pressure to site. Hold pressure until hemostatis is obtained (5-10 minutes). Longer times may be needed for anticoagulated patients. Check for bleeding and presence of pulse 15 minutes post removal.

Arterial Line Removal Reportable Conditions: Bleeding or hematoma at site. Loss of pulse distal to insertion site. Absence of blood return. Signs of infection.

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You may now close the module. This concludes you’re online training for A-Line Management in the Birthing Center. Please print your certificate of completion to bring to your hands-on training session. You may now close the module.