PAWP readings

jenadox · Jul 9, 2001

Dawn,

In the CCU I work in we only do it once a shift(when we do cardiac output) unless:

1. There is an order specifying how often the MD wants it done

2. A change in the patient's condition warrents that it be checked ie, if you think they are going into pulmonary edema

It is usually left up to us though. I personally don't wedge anymore than I have to for the exact reasons you mentioned above.

Hope that helps some!

dewp_63 · Jul 10, 2001

Thank you so much for your reply, Jena. Hopefully, I can take this information back to the unit, where maybe we'll be able to write an appropriate policy addressing this.

PatriceM · Jul 21, 2001

A pulmonary artery occlusive pressure (wedge) is best done after any therapeutic intervention to determine its effectiveness. Also the lifespan of the balloon is only 72 wedges. The paop should be compared to the pad and determine if they are correlating. A pad may be used to determine the paop. All paop should be read from the end expiration. A patient that is not vented should be read at peak, and a vented patient at valley. (P-peak (patient) and V-valley (vent).

A PA line can be a very handy determinate of patient therapy--but only if read right.

Good luck with determining a policy. A PAOP should be read with interventions. On our unit, with tailored therapy for our cardiomyopathy patients, these measurements provide a guide for medications. That is exactly how all PA pressures should be done!

:)

mdslabod · Aug 16, 2001

If zeroed when inserted, the PA diastolic is the same as the wedge. CVP readings give you volume status.

When in doubt, set priorities. What information do you need. Never forget, the best policy is to go by the hospital policy.

MicheleRN

Critical Care

Columbus, Ohio

patches · Aug 21, 2001

At the CCU I work in, we rarely keep Swans in place for more than a few days and we check PAWP q4 hours. I also work in a CCU that are acuity of patients is the sickest of the sick. The only people other than acute problems are our Cardiomyopathy pts, who have them while in the unit waiting on a Heart and their meds are based on the pressures. Most of our docs want an actual wedge pressure, not the PA diastolic, only if their is a question of it validity can we use the PA diastolic and then usually they insert a new Swan-Ganz catheter if it is vital to the pts care.

cvicu rn · Sep 10, 2001

I work in a post open heart unit and we do wedge pressures and cvp readings q2 hrs and prn when indicated, and manual cardiac output readings q4 hrs and prn, but the swans are usually d/c'd 1-2 days post-op.Some docs do use the cco swans, which are great when they work correctly!

szerch · Oct 13, 2001

In our CVICU, all of our OHS patients have swans. One of our surgeons only wedges in the OR for placement, and then asks the RN's not to wedge on a routine basis, especially for the valve patients. He thinks the risks outweigh the benefits, and we use the pa diastolic pressure for cardiac profiles. With the other surgeons, we wedge on arrival from the OR, and q4hrs after that. We wedge more often if we are titrating gtts, or if he calls for a reading.:)

Cheryl ~ STH · Mar 30, 2002

I'm new to the CCU where I work and our hospital policy is to wedge q 1 hr on fresh hearts and if meds are titrated or new cardiac meds are added then go to q 2 hrs. and prn.

CindyCCRN · Mar 30, 2002

...I think I submitted twice... Sorry!

hoolahan, ASN, RN · Mar 30, 2002

In the CT ICU where I used to work, we also only used the PAD as a wedge.

I once saw a surgical resident reposition a swan while we were in report, and she wedged it. I don't know if she forgot to unwedge it, but not 2 minutes later, the pt asked our manager who was walking by for a tissue, which our manager handed her as she proceeded to cough up frank red blood, she went out moments later, coded and died. Made an impression on me, that's for sure! I am perfectly OK using the PAD as a wedge pressure!

CindyCCRN · Mar 31, 2002

Hi, Cheryl!

I have worked ICU/CCU for many years - lots of Hemodynamics (love them... teach them!). We have very specific standards for all policies and proceedures, according to recommended critical care safety guidelines. Routinely, PA lines are never wedged more frequently than q4hrs - often less, per individual Dr's order. Actual occlusion of pulmonary artery can cause rapid and severe distress in some patients. (have seen some patients develop immediate chest pain, ST elevation, dysrrhythmias, BP changes, respiratory problems, etc. with pulm artery occlusion - PCW). PADP should always be 0 to 4 less than PCW, if line properly positioned... can use initial PADP minus 0-4 per Dr ok, for PCWP/LVEDP/LAP estimation and calculations, most of time...

If in proper position (optimal = lung zone 3), should wedge with between 1 to 1.5cc air - never more... If a catheter wedges with less than 1 cc - indicative of tip being too distal and line usually needs to be retracted. If no wedge obtained with full 1.5 cc air - usually tip too proximal and line needs to be advanced... After insertion and Xray confirmation, nursing should mount strip recording of PA and PCW waveform - helps future detection of trouble... and always note exact depth of insertion to tip of hub (and communicate to next shift). Most all catheters are 110 cm long with markings every 10 cm = thin black line and 50 cm markings = thick black line... Also, great to know normal insertion distances, depending on site ... from Int. Jug. - PA normally 40-55 cm, from SCV - PA 35-50, from Fem vein - PA insertion normally about at 60 cm, from right antecubital - PA shouild be at about 70 cm, and from left antecub - PA line should be inserted to about 80 cm. for proper pacement and accuracy..

When wedging, we always have respiratory pattern visible and never leave catheter wedged for more than 2 full respiratory cycles - often less, if acceptable PCW waveform visible. We then edit all PCW waveforms for ventillatory effects and artifacts from pleural pressures. To avoid artifact, always read the waves at end expiration (when pleural pressures and atmospheric pressures are about equal) - choose the last clear wave that is not affected by breathing - before next inspiratory dip (when wave starts to be pulled down). And as explained by PatriceM, depending on pt. - spontaneous breathing = "peak" vs. mechanically controlled ="valley"...

Then, we determine accurate PCWP by interpreting hemodynamic waveform...

Each PCWP may contain 3 waves -

1. "a" wave (pressure rise due to atrial contraction) - usually the largest wave; occurs near the end or after the QRS.

2. "c" wave (mitral valve closure... rarely visible with PCW - more visible with right sided CVP waveform and tricuspid closure) -

3. "v" wave (atrial filling - vent systole) - located after the T wave.( the T- P).

The 2 Acceptable Methods to read PCWP are:

1. "Mean of The "a" wave - most accurate method of reading the PCWP is to average the top and bottom values of the of "a" wave; unreliable with mitral stenosis, AV Blocks (at fib, flutter, paced rhythms = absent "a" wave, or junct rhythm, "cannon a waves", etc...

...Then must use alternative for correlating with EKG strip... (Remember, electrical activity always occurs before mechanical)...

2. Z point Technique - useful when "c" wave is not visible and the "a" wave is abnormal. This method assumes that 0.08 seconds (or longer) after the end of the QRS complex correlates with LVEDP... So to read the PCWP via Z point- simply find .08 sec from the end of the QRS and draw a straight line down to the EKG - this the PCW value!

...Cheryl, Oops! ...I think I got carried away. But I do love hemodynamics and this is only a small piece of understanding

them... I hope I helped with your question.... Cindy