Last updated on December 28th, 2023

Basic hemodynamic monitoring (e.g., BP, HR, Temp, CRT) is an integral part of our nursing practice. But when the patient becomes critically ill, we need more advanced and invasive means to closely and accurately observe the hemodynamic status.

A clear understanding of hemodynamic parameters along with their purposes and normal values is crucial to spot any deviation from normal and to initiate treatment ASAP. Thereby, preventing life-threatening complications and unwarranted deterioration. 

Here, we’ll discuss

• hemodynamic monitoring
• purpose of hemodynamic monitoring
• main hemodynamic parameters
• Normal values of hemodynamic parameters
• hemodynamic instability

What is hemodynamic monitoring?

The term “hemo” means blood and “dynamic” denotes movements and pressure. Thus, hemodynamics can be defined as movements and pressures of blood flow within blood vessels as the heart contracts and relaxes.  

More precisely, hemodynamic monitoring includes measuring and interpreting intravascular pressure, oxygenation, and blood flow within the circulatory system.

In the clinical context, hemodynamic monitoring refers to close observation of the functions of the cardiovascular system and circulatory status of critically ill patients.

Hemodynamic parameters give vital information about blood volume, contractility of the heart, and fluid balance. All of which are necessary to evaluate the effectiveness of the treatment and overall condition of the critically ill patient.

What is the purpose of hemodynamic monitoring?

The main purposes of hemodynamic monitoring are:

• to maintain adequate perfusion of the internal organs
• early identification of preventable complications and life-threatening conditions (e.g., heart failure)
• to guide course of treatment and administration of fluids
• to accurately determine the effectiveness of therapeutic interventions
• to precisely assess the cardiovascular function of the critically ill patients 

What are the main hemodynamic parameters?

Most commonly measured hemodynamic parameters in general settings include blood pressure (BP), heart rate (HR), body temperature (Temp), and capillary refill time (CRT).

Commonly measured hemodynamic parameters in critical care settings include:

• Mean Arterial Pressure (MAP)
• Cardiac Output (CO)
• Cardiac Index (CI)
• Central Venous Pressure (CVP) which is also referred as Right Atrial Pressure (RAP)
• Pulmonary Artery Pressure (PAP)
  • Systolic (PAS [normal: 15–30 mmHg])
  • Diastolic (PAD [normal: 5–15 mmHg])
• Mean Pulmonary Artery Pressure (MPAP)
• Pulmonary artery wedge pressure (PAWP) also known as Pulmonary capillary wedge pressure (PCWP) or Pulmonary Artery Occlusion Pressure (PAOP)
• Pulmonary Vascular Resistance (PVR)
• Right Ventricular Pressure (RVP)
  • RV Systolic (normal: 20-30 mmHg)
  • RV Diastolic (normal: 0-5 mmHg)
• Stroke Volume (SV)
• Stroke Index (SI) also called Stroke Volume Index (SVI)
• Systemic Vascular Resistance (SVR)

Normal Hemodynamic Parameters

Following are the most commonly monitored hemodynamic parameters with their abbreviations and normal ranges.

Parameter	Abbreviation	Normal Value
Pulmonary Artery Systolic	PAS	15–30 mm Hg
Pulmonary Artery Diastolic	PAD	5–15 mm Hg
Pulmonary ArteryWedge Pressure(Pulmonary CapillaryWedge Pressure) (Pulmonary Artery Occlusion Pressure)	PAWP (PCWP) (PAOP)	4–12 mm Hg
Central Venous Pressure (Right Atrial Pressure)	CVP (RAP)	2–6 mm Hg
Mean Arterial Pressure	MAP	70–105 mm Hg
Cardiac Output	CO	4–8 L/min
Cardiac Index	CI	2.5–4.0 L/min/m2
Stroke Volume	SV	60–120 mL/beat
Stroke Volume Index (Stroke Index)	SVI (SI)	30–65 mL/beat/m2
Left Ventricular Stroke Work Index	LVSWI	40–70 g–m/m2
Right Ventricular Stroke Work Index	RVSWI	5–12 g–m/m2
Pulmonary Vascular Resistance	PVR	50–250 dynes/s/ cm–5
Pulmonary Vascular Resistance Index	PVRI	45–200 dynes/s/ cm–5/m2
Systemic Vascular Resistance	SVR	800–1400 dynes/s/ cm–5
Systemic Vascular Resistance Index	SVRI	1700–2600 dynes/s/cm–5/m2
Systolic Blood Pressure	SBP	90–130 mm Hg
Diastolic Blood Pressure	DBP	60–85 mm Hg
Heart Rate	HR	60–100 bpm
Temperature	Temp	97.8–99.1°F; 36.5–37.3°C
Respiratory Rate	RR	12–20 bpm
Left Ventricular End-Diastolic Pressure	LVEDP	4 to 12 mm Hg
Mean Right Atrial Pressure	Mean RAP	1 to 8 mm Hg
Right Ventricular Diastolic Pressure (Peak Systolic Pressure)	RVDP	1 to 8 mm Hg (15 to 30 mm Hg)
RV Systolic Pressure	RVSP	20–30 mm Hg
RV Diastolic Pressure	RVDP	3–7 mm Hg
Ejection Fraction	EF	>60%
Mixed Venous Oxygen Saturation	SvO2	60–80%
Arterial Oxygen Saturation	SaO2	≥95%
Central Venous Oxygen Saturation	ScvO2	≥70%
Oxygen Delivery	DO2	900-1100 mL/min
Oxygen Delivery Index	DO2	360-600 mL/min/m2
Oxygen Consumption	VO2	200-250 mL/min
Oxygen Consumption Index	VO2I	108-165 mL/min/m2
Oxygen Extraction Ratio	O2ER	22%-30%

Sources: (Burns & Delgado, 2019, p72: Landrum, 2012, p243-4: www.uptodate.com: www.sciencedirect.com)

Hemodynamic Instability

Hemodynamic instability refers to a state where the circulatory function of the heart is compromised; i.e., there is not enough pressure and/or volume of circulating blood in the intravascular space for adequate tissue perfusion.

If hemodynamic instabilities are not corrected in time, it can progress from mild tissue hypoperfusion to organ failure and death. Therefore, the key to managing hemodynamic instabilities is early detection and prompt treatment.

Following are the key signs and symptoms you would see in patients with compromised hemodynamic status.

Signs and symptoms of hemodynamic instability include:

• Hypotension
• Abnormal heart rates
• Abnormal heart rhythm
• shortness of breath
• Sluggish capillary refill time (CTR)
• Cold extremities
• pheripheral cyanosis
• Decreased urine output
• Loss of consciousness
• Changes in mental status

Bonus Tips

While assessing a patient’s hemodynamic parameters, always correlate hemodynamic waveform with electrocardiogram (ECG) waveform timings.

Accurate interpretation of right heart hemodynamics in relation to the cardiac cycle gives valuable data to prevent foreseeable complications. 

While interpreting abnormal hemodynamic waveforms, remember to rule out cardiac arrhythmia or ventricular pacing.

Conclusion

In conclusion, hemodynamic monitoring refers to the observation of cardiovascular functions such as blood pressure (BP), heart rate (HR), blood flow, vascular volumes, ventricular function, etc.

Especially as a critical care nurse, you should have a good understanding of how to obtain accurate hemodynamic parameters. Also how to analyze, interpret, and incorporate the findings into prompt action.

Reference

Burns, S., & Delgado, S. (2019). AACN Essentials of Critical Care Nursing (4th ed.). The McGraw-Hill Companies.

Landrum, M. (2012). Fast Facts for the Critical Care Nurse. Springer Pub. Co.

O’Toole, M. (2013). Mosby’s medical dictionary (9th ed.). Elsevier.