Pulmonary Artery Cannulation Research Articles

Technical considerations for percutaneous pulmonary artery cannulation for mechanical circulatory support.

Percutaneous pulmonary artery cannulas, used as inflow for left ventricular venting or as outflow for right ventricular mechanical circulatory support, are easily and rapidly deployable with transesophageal and fluoroscopic guidance. We chose to review our institutional and technical experience with all right atrium to pulmonary artery cannulations. Based on the review, we describe 6 right atrium to pulmonary artery cannulation strategies. They are divided into total right ventricular assist support, partial right ventricular assist support, and left ventricular venting. A single limb cannula or a dual lumen cannula can be used for right ventricular support. In the right ventricular assist device configuration, percutaneous cannulation may prove beneficial in cases of isolated right ventricular failure. Conversely, pulmonary artery cannulation can be used for left ventricular venting as drainage to a cardiopulmonary bypass or extracorporeal membrane oxygenation circuit. This article can be used as a reference for the technical aspects of cannulation, decision-making in patient selection, and management of patients in these clinical scenarios.

Pulmonary Artery Cannulation Complicating Tube Thoracostomy.

Pulmonary Artery Cannulation Complicating Tube Thoracostomy.

Percutaneous Pulmonary Artery Cannulation to Treat Acute Secondary Right Heart Failure While on Veno-venous Extracorporeal Membrane Oxygenation.

Right heart failure (RHF) is a common, yet difficult to manage, complication of severe acute respiratory distress syndrome requiring extracorporeal membrane oxygenation (ECMO) that is associated with increased mortality. Reports of the use of percutaneous mechanical circulatory support devices for concurrent right heart and respiratory failure are limited. This series describes the percutaneous cannulation of the pulmonary artery for conversion from veno-venous to veno-pulmonary artery return ECMO in 21 patients who developed secondary RHF. All patients cannulated between May 2019 and September 2021 were included. Either a 19 or 21 French venous cannula was placed percutaneously into the pulmonary artery via the internal jugular or subclavian vein, providing a total of 821 days of support (median 23 [4-71] days per patient) with flows up to 6 L/min. Five patients underwent cannulation at the bedside, with the remainder performed in the cardiac catheterization laboratory. Pulmonary artery cannulation occurred after 12 [8.5-23.5] days of ECMO support. Vasoactive infusion requirements decreased significantly within 24 hours of pulmonary artery cannula placement (p = 0.0004). Nonetheless, 75% of these patients expired after a median of 12 [4-63] days of support, with three patients found to have had significant pericardial effusions peri-arrest. This cannulation technique may be an effective alternative to veno-arterial ECMO cannulation or the placement of a dual-lumen cannula for the treatment of RHF.

Cannulation Strategies in Ex Vivo Lung Perfusion.

To the Editor: Shukrallah et al.1 describe the use of donor aorta as an adjunct conduit to facilitate pulmonary artery cannulation for ex vivo lung perfusion (EVLP). As challenges pertaining to cannulation are inherent to EVLP, the article provides helpful practical content, but only considers cannulation challenges related to the pulmonary artery, and offers just a single solution that may not always suffice. In prior EVLP studies, we recognized lung cannulation challenges at both the pulmonary artery and atrial cuff and developed several novel cannulation strategies, which have been extensively described in methods and supplementary sections https://links.lww.com/ASAIO/A752.2,4–6 In ex vivo lungs, a shortened main pulmonary artery can be managed with a donor artery, vein, and/or synthetic (e.g., Dacron) graft.2 In the absence of a main pulmonary artery, donor aorta can be fashioned end-to-end to bridge the left and right pulmonary arteries, then a second graft can be anastomosed end-to-side to the donor aorta to serve as the inflow conduit (Supplemental Figure 1A https://links.lww.com/ASAIO/A752). Although optimal cannulation and perfusion strategies remain to be determined, configurations with a closed atrium have been shown to result in less edema and enhanced lung physiology.3 For EVLP circuits with a closed atrium, a shortened atrial cuff can be reconstructed using donor pericardium (Supplemental Figure 1B https://links.lww.com/ASAIO/A752), vein, or commercial soft tissue or pericardial patch products, thus enabling connection to the circuit. While many protocols use collared polymer tubing, we previously described2,4–6 the use of donor vessel as an organ-to-circuit “bio-bridge” (Supplemental Figure 1C https://links.lww.com/ASAIO/A752) to facilitate venous drainage and enable: (1) tight regulation of vascular flow, (2) consistent maintenance of pulmonary venous drainage despite differing anatomy and distribution of pulmonary veins across studies, (3) optimal placement of ex vivo lungs in prone or supine position, and (4) evaluation of oxygenation and ventilation separately in left and right lungs.4 To better understand flow characteristics through the bio-bridge, we performed computational fluid dynamics modeling, which indicated smooth laminar flow through the bio-bridge into the venous drainage cannula (Supplemental Figure 1D https://links.lww.com/ASAIO/A752).6 Immunohistochemical staining confirmed that the endothelium of the bio-bridge was intact and viable after 36 hours of normothermic cross-circulation EVLP.6 Based on these and other studies, we posit that use of the donor vessel bio-bridge as a natural vascular conduit between the organ and circuit confers demonstrable advantages due to: (1) non-thrombogenic surface and (2) intrinsic elasticity, which provides vasoprotective capacitance to dampen abrupt changes in circuit pressures.4 After more than a decade of clinical practice, the EVLP field has made remarkable progress, but still lacks standardization not only in cannulation techniques but also across platforms (e.g., commercial, custom), circuit configurations (e.g., open, closed atrium), perfusates (e.g., acellular, cellular), flow and ventilation settings, and reported parameters and outcomes. In the future, consensus guidelines should be established to help standardize cannulation and perfusion techniques and data reporting in order to facilitate rigorous cross-study comparisons and inform best practices.

Dynamic extracorporeal life support: A novel management modality in temporary cardio-circulatory assistance.

Extracorporeal life support (ECLS) is a temporary mechanical assistance method employed in acute respiratory, cardiocirculatory, and cardio-respiratory failure, refractory to conventional treatments. Patient's hemodynamic, respiratory and metabolic condition, or situations related to ECLS support or performance, may change during ECLS treatment. Provision of an additional drainage or perfusion cannula, or even of an additional associated device, for example, transaortic suction device or intra-aortic balloon pump (IABP), may be required to improve the ECLS/patient interaction and effects. Besides such a modified ECLS mode, however, a potential asset is represented by the "dynamic ECLS," which is the change of the flow direction (drainage or perfusion) in the already implanted cannula during the ECLS run. This particular management may be achieved in venous femoral or jugular cannulation, but it finds an even more appealing potential with the pulmonary artery (PA) cannulation. The PA allows the institution of a multitasking ECLS circuit, ranging from enhanced left ventricle (LV) unloading (drainage from the PA) to a right ventricular support or "central" veno-venous ECLS (perfusing the PA), tailored according to the patient hemodynamic, gas exchange, metabolic state, underlying cardiac involvement, and ECLS performance. Dynamic ECLS may, therefore, represent an additional option in ECLS management, particularly including the PA cannulation. Based on this new dynamic management of ECLS mode, we propose the Extracorporeal Life Support Organization nomenclature update.

Less Invasive Reoperative Ventricular Assist Device Insertion for Patients With Patent Bypass Grafts

We report our technique for left ventricular assist device insertion that is useful in patients with patent coronary artery bypass grafts or mediastinal adhesions from other previous surgeries. An inverted-T upper hemisternotomy is made at the level of the second or third intercostal space, and with the left sternal section retracted, dissection is carried along the chest wall into the left pleural space. The device is implanted in the left ventricular apex via a left thoracotomy in the fifth or sixth intercostal space. The outflow graft is routed through the left pleural space and anastomosed to the ascending aorta.

Pulmonary artery cannulation to enhance extracorporeal membrane oxygenation management in acute cardiac failure.

Pulmonary artery (PA) cannulation during peripheral venoarterial extracorporeal membrane oxygenation (ECMO) has been shown to be effective either for indirect left ventricular (LV) unloading or to allow right ventricular (RV) bypass with associated gas-exchange support in case of acute RV with respiratory failure. This case series reports the results of such peculiar ECMO configurations with PA cannulation in different clinical conditions. All consecutive patients receiving PA cannulation (direct or percutaneous) from January 2015 to September 2018 in 3 institutions were retrospectively reviewed. Isolated LV unloading or RV support, as well as dynamic support including initial drainage followed by perfusion through the PA cannula, was used as part of the ECMO configuration according to the type of patient and the patient's haemodynamic/functional needs. Fifteen patients (8 men, age range 45-73 years, EuroSCORE log range 14.45-91.60%) affected by acute LV, RV or biventricular failure of various aetiologies, were supported by this ECMO mode. Percutaneous PA cannulation was performed in 10 patients and direct PA cannulation, in 5 cases. Dynamic ECMO management (initially draining and then perfusing through the PA cannula) was carried out in 6 patients. Mean ECMO duration was 9.1 days (range 6-17 days). One patient exhibited pericardial fluid during the implant of a PA cannula (no lesion found when the chest was opened), and weaning from temporary circulatory support was achieved in 14 patients (1 who received a transplant). Three patients (20%) died in-hospital, and 12 patients were successfully discharged without major complications. Effective indirect LV unloading in peripheral venoarterial ECMO as well as isolated RV support can be achieved by PA cannulation. Such an ECMO configuration may allow the counteraction of common venoarterial ECMO shortcomings or allow dynamic/adjustable management of ECMO according to specific ventricular dysfunction and haemodynamic needs. Percutaneous PA cannulation was shown to be safe and feasible without major complications. Additional investigation is needed to confirm the safety and efficacy of such an ECMO configuration and management in a larger patient population.

Reoperation for residual aneurysm of coronary anastomosis after Bentall procedure

Objective: To introduce a new operative method for residual aneurysm of coronary anastomosis after Bentall procedure. Methods: Between March 2011 and December 2012, six patients in Beijing Anzhen Hospital with residual aneurysm of coronary anastomosis (CT showed goldfish eye sign at the openings of coronary) after Bentall procedure underwent the operation of concentric circular patch procedure under cardiopulmonary bypass. Femoral artery, right atrium and upper right pulmonary artery cannulation were used for cardiopulmonary bypass, and the artificial vessel was transected after cardiac arrest. A concentric circular patch was pruned, whose outside diameter was slightly larger than the aneurysm and the inside diameter was equal to the openings of coronary. The outer edge of the patch was anastomosed to the outer edge of the aneurysm (opening of artificial vessel in primary surgery) with 4-0 prolene. The inner edge of the patch was anastomosed to the openings of coronary with 5-0 prolene. Results: All patients had clinical recovery. Postoperative CT demonstrated the disappearance of residual aneurysm during follow-up (the goldfish eye sign disappeared). Conclusion: The concentric circular patch procedure is a feasible treatment for residual aneurysm of coronary anastomosis.

(674) - Ambulatory Extracorporeal Membrane Oxygenation with Right Atrium to Pulmonary Artery Cannulation Through Hemisternotomy for Long-term Support

Veno-venous (VV) extracorporeal membrane oxygenation (ECMO) is being used with increasing frequency for acute respiratory failure, as a bridge to recovery or lung transplantation. Traditionally, VV ECMO was performed using femoral venous cannulas; but recently, development of the bi-caval dual lumen catheter has enabled ambulatory ECMO, allowing early rehabilitation to avoid deconditioning. In cases with dysfunction of the right ventricle (RV) which is common in this setting, we have found that ECMO with right atrium (RA) to pulmonary artery (PA) cannulation can provide stable and reliable support while allowing the RV to recover. Between Feb 2013 and Aug 2013, nine patients were supported using a right ventricular assist device (RVAD) with an oxygenator, with inflow from the RA, and outflow to the main PA. The cannulas were placed through an upper hemisternotomy, then tunneled and brought out in the right upper quadrant. The underlying pathology included pulmonary embolism in four patients, idiopathic pulmonary fibrosis in four patients, and acute respiratory distress syndrome in one patient. Three patients were female and six were male. Mean age was 50 (range 27 to 66). The patients were maintained on RA-PA ECMO for 1 to 77 days (mean 26). Total duration of mechanical support was 10 to 99 days (mean 38). Four patients had RA-PA ECMO as the initial form of support, and five patients had veno-arterial or other VV ECMO first and were transitioned to RA-PA ECMO. Flows were maintained between 3 to 5 L/min with adequate O2 delivery and CO2 removal. After RA-PA ECMO initiation, patients were able to participate in physical therapy and rehabilitation, and some were able to ambulate. Three patients were bridged to lung transplantation, and four recovered; these seven patients survived to discharge. Two patients died. Seven patients developed pneumonia, and two had intracranial hemorrhage. RA-PA ECMO provides reliable mechanical support that can be used in acute pulmonary failure, with the advantage of oxygenating all of the cardiac output, while also functioning as an RVAD. This strategy should be considered when other forms of support do not provide optimal results. RA-PA ECMO makes long term support and RV recovery possible, while also allowing ambulation and rehabilitation.

Neonatal Cavopulmonary Assist: Pulsatile Versus Steady-Flow Pulmonary Perfusion

Morbidity and mortality associated with single-ventricle physiology decrease substantially once a systemic venous, rather than systemic arterial, source of pulmonary blood flow is established. Cavopulmonary assist has potential to eliminate critical dependence on the problematic systemic-to-pulmonary shunt as a source of pulmonary blood flow in neonates. We have previously demonstrated feasibility of neonatal cavopulmonary assist under steady-flow conditions. We hypothesized that pulsatile pulmonary perfusion would further improve pulmonary hemodynamics. Lambs (weight 7.2 +/- 1.1 kg, age 7.9 +/- 1.5 days) underwent total cavopulmonary diversion using bicaval venous-to-main pulmonary artery cannulation. A miniature centrifugal pump was used to augment cavopulmonary flow. Pulsatility was created with an intermittently compressed compliance chamber in the circuit. Hemodynamic and gas exchange data were measured for 8 hours. Pulsatile (n = 6), steady-flow (n = 13), and control (n = 6) groups were compared using two-way analysis of variance with repeated measures. All animals remained physiologically stable with normal gas exchange function. Mean pulmonary arterial pressure was elevated in pulsatile and steady-flow groups compared with the control group and within-group baseline values. Pulmonary vascular resistance was elevated initially in both assist groups but decreased significantly over the last 4 hours of the study and normalized after hour 4 in the pulsatile perfusion group. Pulmonary vascular resistance also normalized to control in the steady-flow group after hour 7. Both steady-flow and pulsatile pulmonary perfusion demonstrated normalization of pulmonary vascular resistance to control in a neonatal model of univentricular Fontan circulation. These results suggest that there is no benefit to pulsatile flow in this model.

Video-assisted transcatheter lung perfusion regional chemotherapy

To establish a technique for performing isolated lung perfusion (ILP) under video-assisted thoracic surgery (VATS) to treat unresectable lung malignancies. Under fluoroscopic and thoracoscopic guidance, five canine left lungs were isolated by means of an endovascular technique comprising pulmonary artery cannulation through the right femoral vein and pulmonary vein cannulation through the left auricular appendage (VATS-ILP). ILP was performed for 20 min at a flow rate of 30 ml/min with a high-dose cisplatin solution (50 microg/ml). Toxicity and pharmacokinetics of VATS-ILP were compared with those of conventional ILP performed in five additional lungs. VATS-ILP was performed safely without adverse reaction. Both VATS-ILP and conventional ILP delivered a high dose of cisplatin to the treated lung (total platinum concentration: 48+/-17 microg/g tissue for VATS-ILP vs. 51+/-19 microg/g tissue for conventional ILP, P>0.1) without significant systemic leakage (total platinum concentration: 0.4+/-0.1 microg/ml plasma vs. 0.5+/-0.2 microg/ml plasma, P>0.1). In addition, no significant differences were observed between the groups in the serum lactate dehydrogenase level, serum angiotensin-converting enzyme level, body weight change, or mid-term histological change following ILP. A significantly smaller thoracotomy was used for VATS-ILP than for conventional ILP (4.7+/-0.4 cm for VATS-ILP vs. 12+/-0.7 cm for conventional ILP, P<0.001) because VATS-ILP required neither arteriotomy nor venotomy. We established a canine VATS-ILP model that showed pharmacokinetic potential similar to that of conventional ILP. A clinical trial of VATS-ILP with cytotoxic drugs is warranted.

Neonatal cavopulmonary assist: Benefit of pulsatile pulmonary perfusion

Abstract Introduction: A systemic venous source of pulmonary blood flow reduces the instability associated with Stage I Norwood physiology. We have previously demonstrated neonatal cavopulmonary assist under steady flow conditions. We hypothesized that pulsatile pulmonary perfusion would improve pulmonary hemodynamics. Methods: Lambs (7.2 +/− 1.1 SD kg, age 7.9 +/− 1.5 days) underwent cavopulmonary diversion using bicaval venous-to-main pulmonary artery cannulation. The proximal main pulmonary artery was clamped and the right ventricle vented for egress of coronary venous blood. A miniature centrifugal pump was used to assist cavopulmonary blood flow. Control animals (n = 4) underwent sham surgery. 13 animals received steady flow pulmonary perfusion, and six animals received pulsatile pulmonary perfusion. Hemodynamic and gas exchange data were measured for eight hours. Groups were compared using ANOVA. Results: All animals remained physiologically stable. Cardiac index, systemic arterial pressure, mean pulmonary arterial pressure, vena caval pressure, mean circulatory filling pressure, pO2, and pCO2 were not statistically different between the steady flow and pulsatile flow groups after 8 hours of cavopulmonary assist (P Conclusions: Pulsatile pulmonary perfusion yields a pulmonary vascular resistance comparable to control and lower than steady flow perfusion in a neonatal animal model of univentricular Fontan circulation.

A new method of pulmonary artery cannulation with minimally invasive decannulation for right ventricular assistance:an animal experiment

To create a new method of pulmonary artery cannulation during operation for right ventricular assistance, for which minimally invasive decannulation can be done after operation. A specially-made disassemblable composite graft consisting of a woven dacron tube and a bovine pericardial tube (composite graft) was anastomosed to the pulmonary artery as a pathway in seven dogs by median sternotomy. The end of the woven dacron tube and a link-thread for connecting the two tubes in the composite graft were drawn outside the body through an intercostal tunnel. A predisposed drawing-tieing thread in the composite graft was drawn outside through another intercostal tunnel and then tightened. An inflow cannula was placed into the left femoral vein or jugular vein via an incision of skin so as to establish a right ventricular assist system. By means of the centrifugal pump, the right ventricular bypass was established. After stopping the pumping, the 2 sets of predisposed prolene thread in the composite graft were tied by catheter and knotting tool via the small skin incision, 8 knots for each set, to close the bovine pericardial tube, and then the drawing-tieing thread, link-thread, and the dacron tube in the composite graft were removed. Median sternotomy was performed again to observe the anastomotic stoma, the closure of the stump of bovine pericardial tube, and whether hemorrhage occurred. The mean maximum output of right ventricular assist system from left femoral or jugular vein to pulmonary artery was (64.4 +/- 12.3) ml.min(-1).kg(-1). The second sternotomy showed satisfactory knotting on the bovine pericardial tube except in one case, whose second set of drawing-tieing thread was tied in the seventh knot and failed to be drawn out, thus partially remained in the body. No bleeding was found in all cases. The new cannulating methods with minimally invasive decannulation after operation created in this study is simple, easy and effective.

Cavopulmonary assist in the neonate: an alternative strategy for single-ventricle palliation

Background Cavopulmonary blood flow, rather than a systemic arterial source of pulmonary blood flow, stabilizes Norwood physiology. We hypothesized that pump-assisted cavopulmonary diversion would yield stable pulmonary and systemic hemodynamics in the neonate. This was tested in a newborn animal model of total cavopulmonary diversion and univentricular Fontan circulation. Methods Lambs (n = 13; mean weight, 5.6 ± 1.5 kg; mean age, 6.8 ± 4.0 days) were anesthetized and mechanically ventilated. Baseline hemodynamic parameters were measured. Total cavopulmonary diversion was performed with bicaval venous-to-main pulmonary artery cannulation. A miniature centrifugal pump was used to assist cavopulmonary flow. Support was titrated to normal physiologic parameters. Hemodynamic data, arterial blood gases, and lactate values were measured for 8 hours. Baseline, 1-hour, and 8-hour time points were compared by using analysis of variance. Results All animals remained stable without the use of volume loading, inotropic support, or pulmonary vasodilator therapy. Cardiac index, systemic arterial pressure, left atrial pressure, and lactate values were similar to baseline values 8 hours after surgery. Mean pulmonary arterial pressure and pulmonary vascular resistance were modestly increased 8 hours after surgery. Mean arterial pH, P o 2, and P co 2 values remained stable throughout the study. Conclusions Cavopulmonary assist is feasible in a neonatal animal model of total cavopulmonary diversion and univentricular Fontan circulation with acceptable pulmonary arterial pressures and without altering regional volume distribution or cardiac output. Pump-assisted cavopulmonary diversion, in combination with Norwood aortic arch reconstruction, could solve several major problems associated with a systemic shunt–dependent univentricular circulation, including hypoxemia, impaired diastolic coronary perfusion, and ventricular volume overload.

Third-trimester arterial blood gas and acid base values in normal pregnancy at moderate altitude

To report arterial blood gas and acid base values of normal nulliparous patients at moderate altitude for commonly used maternal positions. Ten normotensive nulliparous women between 36 and 38 weeks' gestation volunteered to undergo radial and pulmonary artery cannulation as part of a larger study. Following instrumentation, baseline assessments were made in the left lateral recumbent position after a 30-minute stabilization period. Sequential measurements were then obtained in the left lateral, right lateral, supine, knee-chest, sitting, and standing positions. Blood samples were analyzed in duplicate for oxygen content on a blood gas analyzer. Statistical analysis was performed by analysis of variance of repeated measures with significance defined at P < or = .05. There was no significant difference in arterial blood gas or acid base values between any positions in this antepartum population of term healthy women. The composite mean values were as follows: pH 7.46, arterial carbon dioxide pressure (PaCO2) 26.6 mmHg, arterial oxygen pressure 88.3 mmHg, bicarbonate 18.2 mEq/L, saturated arterial hemoglobin level 0.96. Arterial blood gas and acid base values are not altered by maternal position in the late third trimester of pregnancy. The PaO2 in these women studied at moderate altitude was lower than previously reported for healthy pregnant women studied at sea level. Appropriate interpretation of arterial blood specimens of pregnant women should take into account both the pregnancy and altitude at which the women reside.

Survival from Catastrophic Intraoperative Pulmonary Embolism

Survival from Catastrophic Intraoperative Pulmonary Embolism

Ischemia-reperfusion arrhythmias and lipids: Effect of human high- and low-density lipoproteins on reperfusion arrhythmias

The effect of high- and low-density lipoproteins separated from human serum on the postischemic reperfusion arrhythmias was investigated. The hearts were perfused by working heart mode with Krebs Henseleit bicarbonate buffer containing arachidonic acid (1 microgram/ml) for 5 minutes. Whole heart ischemia was induced by the use of a one-way ball valve, and hearts were perfused for 15 minutes followed by 20 minutes of reperfusion. Physiologic concentrations of high- and low-density lipoproteins were constantly infused through the atrial route during ischemic perfusion. Coronary effluent was collected via pulmonary artery cannulation for subsequent radioimmunoassay of thromboxane B2 and 6-keto-prostaglandin F1 alpha, the major stable metabolites of thromboxane A2 and prostacyclin, respectively. The incidence of ventricular arrhythmias during reperfusion was 6/6 (100%), 1/6 (17%), and 6/6 (100%) in control, high-density lipoprotein and low-density lipoprotein infusion groups, respectively. There was no significant difference in coronary flow among the three groups throughout the perfusion. Both thromboxane B2 and 6-keto-prostaglandin F1 alpha increased significantly during ischemia compared with preischemic values in all groups of hearts. However, the ratio of these two parameters varied in control and low-density lipoprotein infusion groups during ischemia, while there was no significant change in the high-density lipoprotein infusion group. These results provide the possibility that arachidonate metabolites may be involved in the regulation of ischemia-reperfusion arrhythmias and that high-density lipoprotein that was infused during ischemia markedly inhibits the incidence of ischemia-reperfusion-induced ventricular arrhythmias, due in part at least, to stabilizing the arachidonate metabolites during ischemic perfusion.

Acid-base changes in ischemic myocardium and intervention with hypothermia or bicarbonate.

Effects of ischemia and reperfusion on acid-base changes in relation to myocardial contractility, and the effects of correcting H+ were studied by lowering PCO2 or increasing HCO3- levels. The hearts were perfused by working heart mode and whole heart ischemia was induced by use of a one way valve followed by myocardial warming (37 degrees C, normothermia), cooling (18 degrees C, hypothermia) or warming plus 2.1 mM NaHCO3 for 15 min. The hearts were then reperfused for 20 min. Coronary effluent was collected through pulmonary artery cannulation and used for the measurement of acid-base changes. There were close correlations between the decrease in coronary flow and LV pressure, LV dP/dt. Close correlations were also observed between the decline in LV pressure and the rise in PCO2, H+, and the decline in HCO3-. A highly significant correlation was seen between H+ and lactate production. Myocardial contractility decreased to the same extent in 3 groups during ischemia, whereas its recovery rate in both the hypothermia and HCO3- -treated groups were significantly higher than in the normothermia group. The increment of H+ was significantly less in both the hypothermia and HCO3- -treated groups than in normothermia. These results indicate that lactate production is the major H+ producing source and the correction of H+ could minimize the ischemic insult and at the same time contribute to the reperfusion injury.

Acute complications of pulmonary artery catheter insertion in critically ill patients.

Of 142 critically ill patients undergoing pulmonary artery catheter (PAC) insertion, 1.4% suffered pneumothorax and 7.7% experienced arterial puncture during central venous access. Catheterization was successful in all cases; however, 8.4% of patients required special maneuvers for pulmonary artery cannulation. The 52.3% incidence of cardiac arrhythmias during PAC insertion was primarily due to ventricular arrhythmia (VA), which was more common among patients with complicated myocardial infarction (p less than .01) and less common in patients with sepsis (p less than .05). The development of VA was significantly related to the duration of PAC insertion. Our study suggests that PAC placement carries certain risks and complications which should be weighed against the advantages of a PAC in each patient.

Percutaneous pulmonary artery cannulation

Percutaneous pulmonary artery cannulation