In those undergoing cardiac surgery, monitoring of pulmonary artery pressures in the presence of pulmonary hypertension remains the commonest indication for the use of a PAC. Thermodilution cardiac output determination in the perioperative period has been described, but the technique is rarely used ².

In patients with cyanotic heart disease, catheter lumens must be meticulously de-aired before insertion and carbon dioxide should be used for balloon inflation.

The catheter can either be placed transthoracically or percutaneously. Transthoracic placement can be performed at the time of operation with few problems related to insertion, a similar degree of risk for thrombosis and infection, but possibly more complications related to bleeding and cardiac tamponade at removal than the percutaneous technique ^{3, 4}.

The transthoracic technique is predominantly used for the measurement of PAP and wedging is not performed. For this reason, balloon-tipped catheters are usually not used - particularly as in the presence of pulmonary hypertension the risk of PA rupture may be higher. More commonly a catheter is placed directly into the left atrium (often via the superior pulmonary vein) to measure LAP. Again, tamponade is a potential complication after removal, as well as systemic embolisation of air or catheter-tip thrombus. Flori et al ¹² have recently reviewed the complcations of transthoracically-placed catheters in a large series of paediatric patients.

Percutaneous insertion may be difficult or impossible in conditions such as tricuspid or pulmonary stenosis, or in any condition where pulmonary blood flow is reduced. A 'combination' technique of PAC placement using surgical manipulation of a previously percutaneously inserted, non-flotation catheter has recently been described ⁵. In this study, the pre-incision PA placement rate was 7%. Echocardiography can also be used to assist in the placement of a PAC ⁶.

In the presence of a significant intracardiac shunt, the interpretation of catheter data may be very difficult. Refer to the section entitled 'Contraindications to Pulmonary Arterial Catheterisation' for further discussion.

The development of paediatric echocardiographic techniques has virtually eliminated any role for the catheters in the diagnosis of residual defects following correction of congenital anomalies.

The catheters have a limited role in the Paediatric Intensive Care Unit. Cardiac output measurement can be performed using thermodilution, but other techniques such thoracic bioimpedance have been shown to be reasonably accurate ⁷. The treatment of refractory shock which is unresponsive to volume resuscitation - for example in cases of sepsis or major burns ⁸, may be aided by PAC guided fluid resuscitation and circulatory support. The catheters may also be useful in the assessment of the effect of high positive airway pressure support on deteriorating cardiovascular function in children with severe lung disease who require ventilation ⁹.

The care of a paediatric patient with a PAC is best done in a paediatric intensive care setting with experienced intensivists involved in insertion, supervision, interpretation of results and subsequent management ¹.

Several sizes of PAC are available for children ¹⁰ . The 7F (adult) catheter is suitable for older children and teenagers. A 6F catheter can be used in those over 18kg and 4 or 5F catheters in those in the weight range 10 - 18kg. 3.5F injectate catheters with 2.5F thermodilution probes which can be placed during cardiac surgery are available for those weighing less than 10kg. A 3F catheter has recently been developed for use in children with pulmonary valve stenosis ¹¹.

Pacing catheters are of little use in children due to difficulty in positioning in hearts of different sizes.

1. Thompson AK. Pulmonary artery catheterization in children. New Horizons 1997;5: 244 - 250.

2. Weyland A, Buhre W, Wietasch G et al Clinical value of aortic thermodilution monitoring of cardiac output in a small child after surgical correction of tetralogy of Fallot. J Cardiothorac Vasc Anesth, 1995:435 - 437

3. Wheedon D, Shore DR, Lincoln C. Continuous monitoring of pulmonary artery pressure after cardiac surgery in infants and children. J Cardiovasc Surg 1981; 22: 307-311.

4. Gold GP, Jonas RA, Land P. et al. Trans thoracic intracardiac monitoring lines in pediatric surgical patients: a ten year experience. Ann Thorac Surg 1986; 42: 185-191.

5. Muralidhar K, Dixit MD, Shetty DP A safe technique to monitor pulmonary artery pressure during and after paediatric cardiac surgery. Anaesth Intensive Care 1997 Dec;25(6):634-6

6. Rimensberger PC, Beghetti M Pulmonary artery catheter placement under transoesophageal echocardiography guidance. Paediatr Anaesth 1999;9(2):167-70

7. O'Connell AJ, Tibballs J. Coulthard M. Improving agreement between thoracic bioimpedance and dye dilution cardiac output estimation in children. Anaesth Intens Care 1991; 19:434 - 440.

8. Reynolds EM, Ryan DP, Sheridan RL, et al. Left ventricular failure complicating severe pediatric burn injuries. J Pediatr Surg 1995; 30: 264-270.

9. De Bruin W. Notterman DA, Magid M, et al. Acute hypoxemic respiratory failure in infants and children: Clinical and pathological consequences. Crit Care Med 1992; 20: 1223-1234.

10. Lake CL. Monitoring of the pediatric cardiac patient. In: Pediatric Cardiac Anesthesia. 3rd ed, Appleton & Lange, Connecticut, 1998.

11. Mori Y, Nakanishi T, Satoh M et al Catheterization of the pulmonary artery using a 3 French catheter in patients with congenital heart disease. Cathet Cardiovasc Diagn 1998 Sep;45(1):45-50

Last edited on: 13/11/2000