Question

1. The critical care nurse is mentoring a new nurse on hemodynamic monitoring at the bedside of a critically ill patient. The patient has a right radial intra-arterial line, and a right subclavian pulmonary artery pressure monitoring system with a thermodilution catheter. The critical care nurse demonstrates proper management of the invasive hemodynamic monitoring lines to the new nurse and obtains the ordered parameters (mean arterial pressure [MAP], central venous pressure [CVP], pulmonary artery systolic [PAS], pulmonary artery diastolic [PAD], pulmonary artery wedge pressure [PAWP], cardiac output [CO], and cardiac index [CI] measurement). The critical care nurse meets with the new nurse afterward at the nurses’ station and encourages the new nurse to share what the new nurse understands in regard to invasive hemodynamic monitoring. The new nurse is currently taking critical care classes on hemodynamic monitoring.

a.     What are the indications for the hemodynamic monitoring methods (intra-arterial line) and the pulmonary artery pressure monitoring system?

b.     What are the various ordered parameters used for in the case study? (MAP, CVP, PAS/PAD, PAWP, CO, CI).

c.     Indicate why a patient’s MAP, CVP, PAS/PAD, PAWP, CO, and CI would be measured. Include information on various types of patients.

d.     Indicate why MAP, CVP, PAS/PAD, PAWP, CO, and CI would be elevated and how the nurse would respond to each or how an elevated reading would be corrected.

e.     Indicate why MAP, CVP, PAS/PAD, PAWP, CO, and CI would be elevated and how the nurse would respond to each or how an elevated reading would be corrected.

f.      What are the nursing responsibilities when caring for the patient with hemodynamic monitoring system. Include arterial line and pulmonary artery catheter. (Include the zeroing/flushing/square wave test, etc.)

g.     Of what potential complications should the nurse be aware when caring for the patient with hemodynamic monitoring?

Answer 1

Hemodynamic monitoring

Critically ill patients requires continues assessment of their cardiovascular system to diagnose and manage their complex medical conditions. This is most commonly achieved by the use of direct pressure monitoring system. Often refered to as hemodynamic monitoring. Heart function is the main focus of hemodynamic studies.

Definition

Using invasive technology to provide quantitative information about vascular capacity, blood volume, pump effectiveness and tissue perfusion.

a. Indications for hemodynamic monitoring

* Any deficits or loss of cardiac function such as myocardial infarction, congestive heart failure, cardiomyopathy

* All type of shock : cardiogenic shock, neurogenic shock or anaphylactic shock

* Decresed urine output from dehydrarion, hemorrhage, GI bleed, burns or surgery

Indications of pulmonary artery pressure monitoring

* pulmonary hypertension

* Assessment of volume status in severe shock

* Evaluation of pericardial illness such as cardiac tamponade or constricitve pericarditis

* Assessment of rightsided valvular disease, congenital heart disease, cardiac shunts , when surgical repair is planned.

* frequent blood sampling.

b. Various ordered parameters

Mean Arterial Pressure(MAP )

* MAP=[{2×diastolic}+systolic]+3

* A MAP of about 60 is necessary to perfuse coronary arteries, brain, kidneys

* Usual range 70-110

Cardiac output(CO)

* The amount of blood ejected from ventricle in one minute

* 4-8 litres per minute

Cardiac index(CI)

* It is an adjusted cardiac output for the patients body surface area

* C.O/BSA=CI

Cardiac Venous Pressure(CVP)

*It describes the pressure of blood in the thoracic venecava

*Normal value 2-6 mmHg

Pulmonary Cappilary Wedge Pressure(PCWP)

*An indirect indication of left atrial pressure

*Normal 5 -10 mmHg

Pulmonary Artery Pressure (PAP)

*Pulmonary artery is always Venous blood because it is leaving the right ventricle on its way to the lungs to receive oxygen.

*PA:25/10mmHg

THE RULE!

PAD>PAWP>CVP

f. Nursing responsibilities

* Site care and catheter safety

* A sterile dressing is placed over the insertion site and the catheter is tapped in place. The insertion site should assesssed for infection and the dressing changed every 72 hrs .

*The placement of the catheter, stated in cm should be documented and assessed every shift

* The integrity of the sterile sleeve must be maintained so the catheter can be advanced or pulled back with out contamination

* The catheter tubing should be labeled and all the connections secure

* The balloon should always be deflated and syringe closed and locked unless you are taking a PCWP measurement.

For zeroing

* Ensure the transducer pressure tubing and flush solution are correctly assembled and free of air bubbles.

* place transducer at level of right atrium

* press zero , sets atmospheric pressure as zero reference point

* when ever patient position is altered the transducer height should be altered.

For square wave test

* snap flush to generate square wave

* check for oscillations as an indicator of the harmonic characters of the system.

* Usually only only one oscillations before returning to base line.

* 2 or more oscillations before returning to base line ( Underdamped)

* If no oscillations ( overdamped - response speed is too low.)

g. Complications

* Infection

* pulmonary artery rupture

* pulmonary thrombo embolism

* Pulmonary infarction

* catheter kinking

* Dysarhythmias

* Local destruction with distal ischemia

* External hemorrhage

* Massive ecchymosis

* Dissection

* Air embolism

* Blood loss

* Pain

* Arteriospasam