Though the extent of its benefits can be difficult to quantify, it isn’t impossible. Since hemodynamic monitoring can predict future cardiovascular insufficiency (CVI), experts at HPC will brief you on tools and techniques for effective hemodynamic monitoring.
Modalities: Dictators of Success
By considering the modalities for patients with specific indications, which range from invasive to less- and non-invasive, it’s possible to assess perfusion adequacy and guide goal-directed therapy—two indicators of effective treatment.
With this type of monitoring, the goal is to lower potential sources of error because the overuse of IV fluids can lead to many complications. These can create problems during recovery, such as muscle weakness, and lead to prolonged hospital stays.
Avoiding such errors can be challenging since the occurrence of clinically relevant endpoints of variables that demonstrate sufficiency emerge long after it is achieved, leading to excessive drug exposure. It may be avoided by monitoring mixed venous oxygen saturation (SvO2) and arterio-venous O2 and CO2 (v-aCO2), which require the insertion of a pulmonary artery catheter.
Current literature shows that invasive monitoring assists in the diagnosis and assessment of a patient’s response to therapy and may thus potentially allow for better titration of care. However, it can give rise to iatrogenic complications. That’s why it’s important to be familiar with different approaches and their safety profiles.
Which Technique Should Be Used?
Here’s a look into some devices and techniques used for hemodynamic monitoring:
Pulse Oximetry
Pulse oximetry goes beyond oxygen saturation and pulse rate. It’s an indisputable standard of care for assessing respiratory and circulatory status by measuring arterial hemoglobin saturation (SpO2). It also plays an important role in the monitoring of neonates (preterm or term) as it helps determine the perfusion and pulse variability index while providing accurate measurements that predict hemodynamic changes.
However, it does not demonstrate any difference in cardiovascular, respiratory, neurologic, or infectious complications, so it’s best to restrict it to tested use cases.
Esophageal Doppler
Esophageal Doppler is a minimally invasive way to assess cardiac function and obtain other hemodynamic information safely at the bedside. It is highly sensitive to changes in flow, so clinicians have access to the right measurement of blood flow velocity and real-time cardiac output at all times, enabling more informed decisions.
A randomized trial also showed that it is associated with a reduction in the length of hospital stay and the optimization of circulatory status perioperatively.
Electrocardiogram (ECG)
According to a 2004 guideline, electrocardiographic monitoring with immediately available defibrillation could improve survival and patient outcomes. However, its efficacy is restricted to patients with arrhythmias (acute coronary syndrome). Much less is known about its impact on ST-segment ischemia or QT interval monitoring.
Pulmonary Artery Catheter (PAC)
Pulmonary artery catheterization is considered the optimal form of hemodynamic monitoring in clinical settings. It is placed in the central vein (the femoral, jugular, or subclavian vein), allowing the almost continuous, simultaneous recording of pulmonary artery and cardiac filling pressures, cardiac output, and SvO2.
That said, some published data suggests that it brings a greater risk of mortality. Non-specific use of this technique also leads to the increased utilization of resources.
Thus, it is best reserved for patients who are high-risk or undergoing major surgery. However, in cases where the cardiac output varies, it becomes the go-to choice though it requires accurate calibration to ensure it works in low pressures.
Transpulmonary Thermodilution (TPTD)
Transpulmonary thermodilution offers an assessment of the cardiopulmonary condition and changes in the redistribution of the extravascular water in the thorax.
It can be carried out in multiple ways, such as the use of the PiCCO system, which combines it with pulse contour analysis to guide hemodynamic management in critically ill patients when the shock is unresponsive to the initial therapy. This can provide an assessment of the benefit/risk balance of fluid infusion.
For instance, extravascular lung water (EVLW) and pulmonary vascular permeability index (PVPI) can be helpful for assessing the risk of pulmonary edema. However, they require central access, so they can be more invasive.
Transesophageal Echocardiography (TEE)
Transesophageal echocardiography is an operator-dependent modality of hemodynamic monitoring. It’s a valuable diagnostic tool that uses ultrasound to provide the required information quickly, with relative accuracy and low risk.
It also has a shorter time to resolution of hemodynamic instability which explains why it’s becoming popular in healthcare, but it has no clear impact on prognosis.
Moreover, it tends to be expensive.
As such, professionals rely heavily on the practice guidelines to dictate use cases, such as for critical care patients with persistent hypotension or hypoxia.
What’s the Verdict on Effective Hemodynamic Monitoring?
Effective hemodynamic monitoring depends on the patient’s cardiovascular state. To identify the most likely clinical trajectory and clinically relevant decompensation earlier and optimize resuscitation, it’s best to use dynamic hemodynamic monitoring approaches. These entail assessing the pathophysiological process of disease to facilitate diagnosis and management while guiding fluid therapy. Research shows that it can lead to less fluid administration with similar or superior outcomes.
It’s also important to measure cardiac output [CO] and its components, such as contractility, heart rate, preload, and afterload, using the Fick principle—the gold standard. It can guide fluid resuscitation and de-resuscitation (in case of fluid overload) to achieve a negative fluid balance. However, bear in mind that it requires the insertion of a special central venous or arterial line so it can be invasive.
Improve Outcomes with Hospital Procedures Consultants
Hemodynamic instability is common among critically ill patients. Hence, it’s important for healthcare professionals to educate themselves about the different techniques for better patient management. Even though literature has yet to record an instance where one device proved superior over another, it does offer insights into which techniques minimize complications and reduce the length of hospital stay.
Hospital Procedures Consultants teaches participants techniques that enable hemodynamic monitoring such as brachial arterial catheterization and ultrasound-guided radial arterial line placement. Browse through our wide range of courses to learn more.
Resources
O’Rourke, M. C. Goldstein, S. Mendenhall, B. R. Transesophageal Echocardiogram. StartPearls – CME -8,2023
Huygh, J. Peeters, Y. Bernards, J. Malbrain, M. L. N. G. Hemodynamic monitoring in the critically ill: an overview of current cardiac output monitoring methods. Version 1. F1000Res. 2016; 5: F1000 Faculty Rev-2855. Dec 16. doi: 10.12688/f1000research.8991.1
Rali, A. S. Butcher, A. Tedford, R. J. Sinha, S. Mekki, P. Van Spall, H. Sauer, A. J. Contemporary Review of Hemodynamic Monitoring in the Critical Care Setting. USC Cardilogy Review 2022, 16:e12.
Pinsky, M. R. Cecconi, M. Chew, M. S. De Backer, D. Douglas, I. Edwards, M. Hamzaoui, O. Hernandez, G. Martin, G. Monnet, X. Saugel, B. Scheeren, T. W. L. Teboul, J. L. Vincent, J. L. Effective hemodynamic monitoring. Crit Care. 2022 Sep 28;26(1):294. doi: 10.1186/s13054-022-04173-z.
Saugel, B. Vincent, J. L. Cardiac output monitoring: how to choose the optimal method for the individual patient. Curr Opin Crit Care. 2018 Jun;24(3):165-172. doi: 10.1097
Wallace, H. A. Regunath, H. Fluid Resuscitation. StatPearls. CME. 06/2023
Torp, K. D. Modi, P. Pollard, E. J. Simon, L. V. Pulse Oximetry. StatPearls. CME. 07/2023
Rodriguez Ziccardi, M. Khalid, N. Pulmonary Artery Catheterization. StatPearls. CME. 08/2023
Messina, A. Alicino, V. Cecconi, M. Transpulmonary thermodilution. Curr Opin Crit Care. 2023 Jun 1;29(3):223-230. doi: 10.1097