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Positive end-expiratory pressure (PEEP)-induced increase in central venous pressure (CVP) has been suggested to be a robust indicator of fluid responsiveness, with heart rhythm having minimal influence. We compared the ability of PEEP-induced changes in CVP with passive leg raising (PLR)-induced changes in stroke volume index (SVI) in patients with atrial fibrillation after valvular heart surgery.In 43 patients with atrial fibrillation after cardiac surgery, PEEP was increased from 0 to 10 cm H2O for 5 min and changes in CVP were assessed. After returning the PEEP to 0 cm H2O, PLR was performed for 5 min and changes in SVI were recorded. Finally, 300 ml of colloid was infused and haemodynamic variables were assessed 5 min after completion of a fluid challenge. Fluid responsiveness was defined as an increase in SVI ≥10% measured by a pulmonary artery catheter.Fifteen (35%) patients were fluid responders. There was no correlation between PEEP-induced increases in CVP and changes in SVI after a fluid challenge (β coefficient -0.052, P=0.740), whereas changes in SVI during PLR showed a significant correlation (β coefficient 0.713, P0.001). The area under the receiver operating characteristic curve of the PEEP-induced increase in CVP and changes in SVI during PLR for fluid responsiveness was 0.556 [95% confidence interval (CI) 0.358-0.753, P=0.549) and 0.771 (95% CI 0.619-0.924, P=0.004), respectively.A PEEP-induced increase in CVP did not predict fluid responsiveness in patients with atrial fibrillation after cardiac surgery, but increases in SVI during PLR seem to be a valid predictor of fluid responsiveness in this subset of patients.

Background. The classic increase in P wave size, known as ‘P-atriale', is a widely accepted criterion for determination of proper positioning of central venous catheter tips. Recent transoesophageal echocardiography (TOE) studies did not confirm intra-atrial position despite advancing the central venous catheter further than indicated by ECG guidance. We postulate that the pericardial reflection rather than the entry into the right atrium corresponds to the ECG changes. In order to test our hypothesis we sought to determine the anatomical substrate for the electrical changes in an animal study. Subsequently, a modified version of the study was undertaken in man and is also reported. Methods. In six juvenile pigs the left external jugular vein and right carotid artery were cannulated. A triple-lumen central venous catheter was positioned by ECG guidance using a Seldinger wire as an exploring electrode. The venous and arterial catheters were suture fixed 2 cm beyond the onset of an increase in P wave size. The corresponding anatomical catheter tip position was determined by open exploration of the vessels and the heart. Subsequently the catheter tip position (during advancement) of a pulmonary artery catheter and the corresponding electrical ECG changes were examined in 10 patients during open chest cardiac surgery. Results. All catheters—arterial and venous, in animals and humans—revealed an increase in size of the P wave as well as the QRS complex. All venous catheters were positioned in the superior vena cava, beyond the pericardial reflection but outside the right atrium. All arterial catheters were positioned in the ascending aorta thus also beyond the pericardial reflection. Conclusions. The start of an increase in P wave size does not correspond with the entrance of the right atrium. The anatomic equivalent for the electrophysiological changes of the ECG is the pericardial reflection. ECG guidance is unable to distinguish between venous and arterial catheter position.

Pulmonary artery catheters are widely used in intensive care, but evidence to support their widespread use is sparse. Some published data suggest that greater mortality is associated with use of these catheters. The largest study to date looked at >5500 patients in several centres in America and found a greater 30 day mortality in those patients receiving a pulmonary artery catheter. We tested the hypothesis that, on our intensive care unit, mortality was greater for those patients receiving a pulmonary artery catheter. Using a propensity score to account for severity of illness, the odds ratio for mortality in those patients receiving a pulmonary artery catheter was 1.08 (95% confidence interval 0.87–1.33). We believe that continued use of the pulmonary artery catheter is safe; a large randomized controlled trial examining outcome is unlikely to provide an adequate answer.

Although, guidelines related to length of insertion of a pulmonary artery catheter to reach a particular cardiac chamber are available, these are not backed by clinical studies. We measured the length of insertion of pulmonary artery catheters to locate the right ventricle, pulmonary artery and pulmonary capillary wedge positions in 300 adult patients undergoing elective cardiac surgery.The pulmonary artery catheters were inserted using a standard technique through the right internal jugular vein. The right ventricle, pulmonary artery and wedge position of the catheter were confirmed by the characteristic waveforms, and the length of insertion to these points was measured.The right ventricle was reached at 24.6 (3) cm (95% CI 24.2-24.9 cm), pulmonary artery at 36 (4) cm (95% CI 35.6-36.5 cm) and wedge position at 42.8 (5.7) cm (95% CI 42.2-43.5 cm). The length of catheter to reach the right ventricle, pulmonary artery and wedge position was significantly more in patients undergoing valve surgery as compared with those undergoing coronary artery bypass grafting [26 (3.8) and 24 (2.5) cm; 38.5 (4.6) and 35 (3.2) cm; and 47.8 (6.9) and 41.2 (4.1) cm, respectively, P0.001]. The length of insertion to reach pulmonary artery and pulmonary capillary wedge position was directly related to height of the patient (Pearson's correlation 0.157 and 0.15, respectively).We have provided the norms related to length of insertion of pulmonary artery catheter, which should be useful in accurate placement of the catheter and minimize complications related to coiling of the catheter.

A new indicator dilution technique for measurement of cardiac output is described. Lithium chloride is injected via a central venous catheter and its dilution curve measured in arterial blood using a lithium-selective electrode. We assessed the lithium dilution cardiac output measurement (LiDCO) and a conventional thermodilution cardiac output measurement (ThDCO) by comparing the results of both with cardiac output determined by electromagnetic flowmetry (EMCO) under controlled laboratory conditions in 10 swine. They were monitored with a pulmonary artery catheter, femoral artery catheter and electromagnetic flowmeter placed around the ascending aorta. LiDCO, ThDCO and EMCO measurements were determined at baseline, in a hyperdynamic state produced by administration of dobutamine, at a second baseline and finally in a hypodynamic state induced by propranolol during deep anaesthesia. Data were analysed by linear regression analysis and the comparison method described by Bland and Altman; bias and precision of both LiDCO and ThDCO compared with EMCO were calculated by the method of Sheiner and Beal. The correlation coefficient between LiDCO and EMCO (0.95) was higher than that between ThDCO and EMCO (0.87). The precision value of LiDCO (0.04) was significantly less (i.e. better) than that of ThDCO (0.09). The results of this study indicated that LiDCO was more reliable compared with conventional ThDCO.

Background Pulse-contour analysis method (PCM) cardiac output (CO) monitors are increasingly used for CO monitoring during anaesthesia and in the critically ill. Very recently, several systems have been introduced that do not need calibration; among them the pressure recording analytical method (PRAM). Sparse data comparing the accuracy of the PRAM-CO with conventional thermodilution CO (ThD-CO) in cardiac surgery patients are available. Methods In this prospective comparison study, paired CO measurements with a pulmonary artery catheter and a PRAM monitoring set were obtained 20–30 min apart (t1, t2) in 23 extubated patients on the first postoperative day after cardiac surgery. Data were analysed by the Bland–Altman method. Results A total of 46 paired CO measurements (23 for each interval) were collected. The Bland–Altman analysis showed a mean difference (bias) of 0.0 litre min−1 and limits of agreement (1.96 sd ) of 4.53 to −4.54 litre min−1 [upper 95% confidence interval (CI), 3.26–5.80; lower 95% CI, −5.8 to −3.27]. The percentage error (1.96 sd /mean of the reference method) was 87%. Conclusions These results question the reliability of the PRAM technology for the determination of CO in postoperative cardiac surgery patients.

We describe a new indicator dilution method of measuring cardiac output in man. A bolus injection of lithium chloride 0.6 mmol was given via a central venous catheter and arterial plasma [Li + ] recorded using a specially developed sensor incorporating an Li + -selective electrode. Cardiac output was derived from the lithium dilution curve, with a correction for packed cell volume. Lithium dilution cardiac output (LiDCO) was compared with thermodilution cardiac output (TD) using 22 lithium sensors in nine patients. For each sensor, one LiDCO was measured immediately before and one immediately after three TD estimations and mean values of LiDCO and TD derived. The correlation coefficient, r , was 0.89; slope of the regression 0.84; Y intercept 0.72; bias 0.3 (0.5) litre min −1 (mean (TD-LiDCO) (1 SD). LiDCO appeared to be a safe, simple and accurate technique which does not require insertion of a pulmonary artery catheter.

There is concern over the safety of the use of pulmonary artery flotation catheters (PAFC) in the United Kingdom.1 We were unable to find any data directly applicable to practice in the United Kingdom and Ireland. The aim of our study was to assess the practice in this country by the use of a telephone questionnaire. A standardised questionnaire was used and answered by senior medical personnel. We phoned 48 intensive care units who had more than 8 beds and we stipulated that the answers reflected practice in the unit. We found that a trainee routinely passes the pulmonary artery flotation catheter however the decision to pass a PAFC was only made by a consultant in 30% of cases. In more than 80% of intensive care units less than 40% of patients had a PAFCin situ. The incidence of indications for placing a PAFC are sited in Table 27. In the intensive care units in our survey the main forms of measurement of cardiac output were cold injectate (77%), continuous thermodilution (48%), echocardiography and Doppler methods (4%), and thoracic bioimpedance (2%). In over 90% of cases the measurements routinely taken with the PAFC were pulmonary artery pressure, pulmonary capillary wedge pressure, cardiac output, central venous pressure and systemic vascular resistance. Oxygen delivery (48%), oxygen consumption (40%), mixed venous saturation (50%) and right and left stroke work index ( Our data suggest that in only 20% of the units we studied was a pulmonary artery flotation catheter routinely used. In addition it appears that not all clinicians in the United Kingdom and Ireland feel that a PAFC is indicated in a number of well documented clinical situations.

Haemoptysis occurred in a patient in whom a Swan-Ganz catheter was inserted for the induction of anaesthesia for hemicolectomy. It is suggested that acute pulmonary hypertension, superimposed on existing chronic pulmonary hypertension, superimposed on existing chronic pulmonary hypertension associated with mitral stenosis, was an important aetiological factor in the haemoptysis.

Percutaneous insertion of a Swan-Ganz catheter through the internal jugular vein is presumed to have resulted in lodgement of the catheter tip in the wall of the internal carotid artery.

A Swan—Ganz catheter, employed for haemodynamic monitoring, was put to a use not described previously. Pulmonary angiography was performed through the catheter at the bedside with minimal discomfort or complication. In this case it was possible to determine that a lung abscess was responsible for a translucency in sthe right lower lobe. This was subsequently confirmed at postmortem examination.

SUMMARY A patient developed pulmonary damage following the insertion of a Swan-Ganz catheter into the pulmonary artery. Suggestions are made on how to avoid this complication.