Original articleHaemodynamic monitoring with pulse-induced contour cardiac output (PiCCO) in critical care
Introduction
Management of critically ill patients is based on knowledge of fundamental physiological variables. Monitoring techniques of the haemodynamic status of these patients have developed from the non-invasive monitoring of single parameter to more invasive monitoring of multiple parameters. This leads to a far more comprehensive analysis allowing clinicians to anticipate events and provide more effective treatment.
Jacobsen (1995) states that in the critically ill and haemodynamically unstable patients the nearest measurable parameters to tissue oxygenation are cardiac output, arterial blood pressure, central venous pressure, arterial and central venous oxygenation and haemoglobin. Therefore, the measurement of these parameters is seen as essential in the management of these patients. Burchell et al. (1997) considered that the measurement of cardiac output is now accepted as a routine part of bedside monitoring. In the authors’ unit, three main methods of monitoring the patient’s haemodynamic status have evolved. The pulmonary artery catheter (PAC) was the initial method, this was superseded by non-invasive oesophageal Doppler and most recently the unstable patients have been monitored using the pulse-induced continuous cardiac output (PiCCO). These three techniques are compared in Table 1.
Section snippets
Pulse-induced continuous cardiac output
PiCCO is a device that quantifies several parameters, including continuous (pulse contour) cardiac output, cardiac preload, systemic vascular resistance and extravascular lung water (EVLW). The patient requires a central venous line ideally sited in the internal jugular or subclavian vein, and an arterial catheter with a thermister is placed in one of the larger systemic arteries, e.g. the femoral or brachial artery. As Salukhe and Wyncoll (2002) explain the PiCCO system works on the principle
Intrathoracic blood volume
The PiCCO offers the possibility to assess ITBV derived from global end diastolic volume (GEDV) determined by thermodilution measurement. GEDV correlates well with ITBV in both experimental and clinical studies. Bindels et al. (2000) found that ITBV is more reliable and therefore a superior indicator of cardiac preload in the clinical situation than pulmonary artery wedge pressure (WP). Buhre et al. (2000) support this by concluding that the measurement of ITBV by indicator dilution enables
Extravascular lung water
EVLW correlates to extravascular thermal volume in the lungs and is evaluated by the PiCCO through the mean transit time method.The quantification of EVLW correlating to pulmonary oedema is not possible with routine clinical studies and examinations. The early accumulation of interstitial oedema and small changes in water content of the lungs are not reliably detected or quantified with chest X-ray or arterial blood gases. The chest X-ray
Cardiac function index
Evaluation of the contractile state of the heart is a crucial task in critical care. This can be measured via a left ventricular catheter, and by using the reference standard dP/dt max. dP/dt is a direct measurement of contractility. It calculates how fast the pressure is rising during systole. If pressure close to the aortic valve is measured, the rise in blood pressure during ventricular systole is proportional to the force of contraction.
It is not possible within the general Critical Care
Calibration of the PiCCO
As already stated, the PiCCO requires calibration by thermodilution determination. If the patient is stable, it is recommended this is repeated every 8 hours. However, this is very patient dependant and the manufacturers suggest that it may be necessary to recalibrate every hour in the initial stages of resuscitation. Recalibration is also recommended if the continuous cardiac output has changed consistently in the same direction for 15 minutes or if there are large or sudden changes in the
Advantages and disadvantages of the PiCCO
The PiCCO is now the monitoring system which is being used more frequently in the authors’ unit, but its advantages and disadvantages need to be examined. The main advantages over the PAC is that it is considered to be far less invasive, requiring only a central line and arterial line which the majority of critical care patients have as a matter of course. This in turn leads to far less risk of complications. Sakka et al. (2000) state that in comparison to the PAC the PiCCO system is considered
The role of the nurse
As the scope of nursing evolves the profession must be self-determining, influencing the boundaries of practice, and the development of new skills, roles and knowledge. Wright et al. (1996) state that nurses play a pivotal role in individualising patient care and Taylor (1996) explains that doctors and nurses working together in a non-hierarchical manner can contribute to decision making regarding patient treatment. The relationship is characterised by trust and mutual respect.
As already
Conclusion
Accurate monitoring of the haemodynamic status of the critically ill patient is essential to effective management. The PiCCO offers a method of obtaining detailed information with relatively few additional risks to the patients. The PiCCO allows the clinician to measure three parameters, which are relatively new, ITBV, EVLW and CFI. These allow for a far more holistic view of the haemodynamic status of the patient and allows for the applied treatment to be evaluated continuously. This should
Ros Cottis Senior Sister Critical Care, BSc (Hons) Specialist Nursing Practice ENB 100, Critical Care Unit, Southend Hospital, Prittlewell Chase, Southend on Sea, Essex SS0 ORY, UK. Tel: +44 1702 221351; E-mail: [email protected]
(Requests for offprints to RC)
References (18)
- et al.
Pulmonary artery wedge pressure and extravascular lung water in patients with acute cardiogenic pulmonary oedema requiring mechanical ventilation
American Journal of Cardiology
(1999) - et al.
Effects of the sitting position on the distribution of blood volume in patients undergoing neurosurgical procedures
British Journal of Anaesthesia
(2000) - et al.
Relationship between volume and pressure measurements and stroke volume in critically ill patients
Critical Care
(2000) - et al.
Efficacy and safety of prone positioning for patients with acute respiratory distress syndrome
Journal of Advanced Nursing
(2000) - et al.
Invasive techniques for the estimation of cardiac output
International Journal of Intensive Care
(1997) - et al.
Continuous cardiac output by femoral arterial thermodilution calibrated pulse contour analysis: comparison with pulmonary arterial thermodilution
Critical Care Medicine
(1999) - et al.
Transoesophageal Doppler for continuous haemodynamic monitoring
British Journal of Intensive Care
(1993) Invasive cardiac output monitoring. Costs, complications and benefits of new systems
International Journal of Intensive Care
(1995)- et al.
Intrathoracic blood volume accurately reflects circulatory volume status in critically ill patients with mechanical ventilation
Intensive Care Medicine
(1992)
Cited by (44)
Global end-diastolic volume index vs CVP goal-directed fluid resuscitation for COPD patients with septic shock: a randomized controlled trial
2017, American Journal of Emergency MedicineCitation Excerpt :Therefore, it is speculated that when septic shock is associated with COPD, CVP-based fluid resuscitation can lead to a relatively significant error. The PiCCO monitor is a comparably new minimally invasive hemodynamic monitoring technique that can not only accurately detect GEDI but also visually represent heart preload [17-19]. It does not wrongly replace whole-heart preload with right ventricular preload [20,21].
Acupuncture for heart failure: A systematic review of clinical studies
2016, International Journal of CardiologyCitation Excerpt :The normal range of the cardiac index is 2.4–4.2 l/min/m2 and stroke volume index (SI) is 35–70 ml/m2, depending on the size of the individual. The normal range of the left cardiac work index (LCWI) is 3.4–4.2 kg/min/m2 which is a normalized value for the amount of work per minute required for the left ventricle to pump blood [31,32]. The normal value of the LVEF is 62 ± 6% [33] and a 5% improvement is related to long term mortality [34].
Vagus-preserving technique during minimally invasive esophagectomy: The effects on cardiac parameters in a swine model
2014, Surgery (United States)Citation Excerpt :Using a Leycom device, the pressure-volume loop was measured under the following load conditions: Afterloading by the brief inflation of a balloon catheter in the ascending aorta and preloading by a brief increase of intrapulmonary pressure. These methods are described in detail elsewhere.16-18 To ensure that the recorded goal criteria were not affected by hypovolemia, all animals received a comparable infusion volume.
Mixed venous oxygen saturation monitoring revisited: Thoughts for critical care nursing practice
2012, Australian Critical Care
Ros Cottis Senior Sister Critical Care, BSc (Hons) Specialist Nursing Practice ENB 100, Critical Care Unit, Southend Hospital, Prittlewell Chase, Southend on Sea, Essex SS0 ORY, UK. Tel: +44 1702 221351; E-mail: [email protected]
(Requests for offprints to RC)
Neil Magee Staff Nurse Critical Care, Southend Hospital, ENB 100 Southend Hospital, Prittlewell Chase, Southend on Sea, Essex SS0 ORY, UK. Tel: +44 1702 221351; E-mail: [email protected]
David J. Higgins FRCA, Director of Critical Care, Southend Hospital, Prittlewell Chase, Southend on Sea, Essex SS0 ORY, UK. Tel: +44 1702 221351; E-mail: [email protected]