Acute hemodynamic effects of inhaled nitric oxide, dobutamine and a combination of the two in patients with mild to moderate secondary pulmonary hypertension.

INTRODUCTION: The use of low-dose dobutamine to maintain hemodynamic stability in pulmonary hypertension may have a detrimental effect on gas exchange. The aim of this study was to investigate whether inhaled nitric oxide (INO), dobutamine and a combination of the two have beneficial effects in patients with end-stage airway lung disease and pulmonary hypertension. METHOD: Hemodynamic evaluation was assessed 10 min after the administration of each drug and of their combination, in 28 candidates for lung transplantation. RESULTS: Administration of INO caused a reduction in mean pulmonary arterial pressure (MPAP), an increase in PaO2 with a significant reduction in venous admixture effect (Qs/Qt).Dobutamine administration caused an increase in cardiac index and MPAP, with a decrease in PaO2 as a result of a higher Qs/Qt. Administration of a combination of the two drugs caused an increase in the cardiac index without MPAP modification and an increase in PaO2 and Qs/Qt. CONCLUSION: Dobutamine and INO have complementary effects on pulmonary circulation. Their association may be beneficial in the treatment of patients with mild to moderate pulmonary hypertension.

Hemodynamic and oxygenation changes of combined therapy with inhaled nitric oxide and inhaled aerosolized prostacyclin.

OBJECTIVE: To evaluate hemodynamic and oxygenation changes of combined therapy with inhaled nitric oxide (iNO) and inhaled aerosolized prostcyclin (IAP) during lung transplantation. DESIGN: Prospective study. SETTING: University hospital. PARTICIPANTS: Ten patients scheduled for lung transplantation. INTERVENTIONS: Ten patients, with a mean age of 38 years (range, 24 to 56 years), were scheduled for lung transplantation (2 single-lung transplantations and 8 double-lung transplantations). During first lung implantation with single-lung perfusion and ventilation, hemodynamic and oxygenation data were analyzed in 3 phases: (1) baseline, 5 minutes after pulmonary artery clamping; (2) inhaled NO phase, 15 minutes after inhaled NO administration (20 ppm) in 100% oxygen; and (3) IAP-inhaled NO phase, 15 minutes after combined administration of inhaled NO (20 ppm) and IAP (10 ng/kg/min) in 100% oxygen. MEASUREMENTS AND MAIN RESULTS: During the inhaled NO phase, reductions of mean pulmonary arterial pressure (p < 0.05) and intrapulmonary shunt (p < 0.05) were noted. After the start of prostacyclin inhalation, a further decrease in mean pulmonary arterial pressure (p < 0.05) was observed. PaO2/FIO2 increased during the IAP-inhaled NO phase (p < 0.05), whereas intrapulmonary shunt decreased (p < 0.05). CONCLUSION: This study confirms the action of inhaled NO as a selective pulmonary vasodilator during lung transplantation. Combined therapy with IAP and inhaled NO increases the effects on pulmonary arterial pressure and oxygenation compared with inhaled NO administered alone without any systemic changes.

Inhaled nitric oxide administration during one-lung ventilation in patients undergoing thoracic surgery.

OBJECTIVE: To evaluate the effects of inhaled nitric oxide (iNO) on hemodynamics and oxygenation during one-lung ventilation (OLV) in the lateral decubitus position in patients undergoing elective thoracic surgery. DESIGN: Prospective study. SETTING: University hospital. PARTICIPANTS: Thirty consecutive patients scheduled for thoracotomy. INTERVENTIONS: Anesthesia consisted of thoracic epidural analgesia combined with general anesthesia (isoflurane, fentanyl, and vecuronium bromide). Systemic and pulmonary circulations were monitored with a radial artery catheter and a pulmonary artery catheter. Inhaled NO, 40 ppm, was administered during OLV, and the inhaled gas mixture was monitored for NO and nitrogen dioxide (NO2). Hemodynamic and oxygenation data were collected before and during inhaled NO administration. MEASUREMENTS AND MAIN RESULTS: Inhaled NO caused a reduction of pulmonary vascular resistance index from 249 +/- 97.6 dyne. sec. cm(-5) to 199.3 +/- 68.9 dyne. sec. cm(-5) (p < 0.05), without effects on systemic hemodynamics or impairment of oxygenation. A stratification of the patients according to values of QS/QT (< 30%, 30% to 44%, > or = 45%), PaO(2)/fraction of inspired oxygen (> or = 200, 100 to 199, < 100), and pulmonary hypertension (mean pulmonary arterial pressure < 24 or > or = 24 mmHg) showed that inhaled NO causes a significant reduction of mean pulmonary artery pressure in patients with pulmonary hypertension, mainly as a result of a reduction of pulmonary vascular resistance index, and improves oxygenation by reducing intrapulmonary shunt in patients with severe hypoxemia during OLV. CONCLUSIONS: Inhaled NO administration neither significantly decreased mean pulmonary arterial pressure in patients with normal pulmonary artery pressure nor improved oxygenation in nonhypoxic patients. Nevertheless, inhaled NO is effective in patients with pulmonary hypertension and hypoxemia during OLV.

Pulmonary hemodynamics contribute to indicate priority for lung transplantation in patients with cystic fibrosis.

OBJECTIVE: Lung transplantation is a viable option for patients with cystic fibrosis. The current strategy of selection, based on spirometry and deterioration of quality of life, results in a high mortality on the waiting list. We reviewed the case histories of patients with cystic fibrosis accepted for lung transplantation to ascertain whether pulmonary hemodynamics could contribute to predict life expectancy. METHODS: Forty-five patients with cystic fibrosis were accepted: 11 died on the waiting list (group I), 24 underwent transplantation (group II), and 10 are still waiting (group III). During evaluation we recorded spirometry, oxygen requirement, ratio of arterial oxygen tension to inspired oxygen fraction (PaO (2)/FIO (2)), arterial carbon dioxide tension (PaCO (2)), 6-minute walk test results, right ventricular ejection fraction, echocardiography, and pulmonary hemodynamics. We compared data from group I, II, and III patients. A comparison was also made within group II between the data collected at the time of evaluation and at the time of transplantation to quantify the deterioration during the waiting time. RESULTS: The waiting time, spirometry, 6-minute walk test results, and right ventricular ejection fraction did not differ among the three groups. A statistically significant difference was found for PaO (2)/FIO (2), PaCO (2), mean pulmonary artery pressure, cardiac index, pulmonary arterial wedge pressure, and intrapulmonary shunt between groups I and II. Groups I and III showed statistically significant differences for mean pulmonary artery pressure, PaO (2)/FIO (2), and systemic vascular resistance indexed. No differences were observed between groups II and III. The comparison within group II showed a significant deterioration of pulmonary hemodynamics during the waiting time. CONCLUSIONS: Pulmonary hemodynamics are worst in patients dying on the waiting list and deteriorate significantly during the waiting time. They may thus contribute to establish priority for lung transplantation in patients with cystic fibrosis.