Efficacy and safety of noninvasive positive pressure ventilation in the treatment of acute respiratory failure after cardiac surgery.

BACKGROUND: Although noninvasive positive pressure ventilation (NPPV) has been successfully used for various kinds of acute respiratory failure, the data are limited regarding its application in postoperative respiratory failure after cardiac surgery. Therefore, we conducted a prospective randomized control study in a university surgical intensive care unit to evaluate the efficacy and safety of NPPV in the treatment of acute respiratory failure after cardiac surgery, and explore the predicting factors of NPPV failure. METHODS: From September 2011 to November 2012 patients with acute respiratory failure after cardiac surgery who had indication for the use of NPPV were randomly divided into a NPPV treatment group (NPPV group) and the conventional treatment group (control group). The between-group differences in the patients' baseline characteristics, re-intubation rate, tracheotomy rate, ventilator associated pneumonia (VAP) incidence, in-hospital mortality, mechanical ventilation time after enrollment (MV time), intensive care unit (ICU) and postoperative hospital stays were compared. The factors that predict NPPV failure were analyzed. RESULTS: During the study period, a total of 139 patients who had acute respiratory failure after cardiac surgery were recorded, and 95 of them met the inclusion criteria, which included 59 males and 36 females with a mean age of (61.5 ± 11.2) years. Forty-three patients underwent coronary artery bypass grafting (CABG), 23 underwent valve surgery, 13 underwent CABG+valve surgery, 13 underwent major vascular surgery, and three underwent other surgeries. The NPPV group had 48 patients and the control group had 47 patients. In the NPPV group, the re-intubation rate was 18.8%, tracheotomy rate was 12.5%, VAP incidence was 0, and the in-hospital mortality was 18.8%, significantly lower than in the control group 80.9%, 29.8%, 17.0% and 38.3% respectively, P < 0.05 or P < 0.01. The MV time and ICU stay (expressed as the median (P25, P75)) were 18.0 (9.2, 35.0) hours and 4.0 (2.0, 5.0) days, which were significantly shorter than in the control group, 96.0 (26.0, 240.0) hours and 6.0 (4.0, 9.0) days respectively, P < 0.05 or P < 0.01. The postoperative hospital stays of the two groups were similar. The univariate analysis showed that the NPPV success subgroup had more patients with acute lung injury (ALI) (17 vs. 0, P = 0.038), fewer patients with pneumonia (2 vs. 7, P < 0.001) and lower acute physiology and chronic health evaluation II (APACHE II) scores (16.1 ± 2.8 vs. 21.8 ± 3.2, P < 0.001). Multivariate analysis showed that pneumonia (P = 0.027) and a high APACHE II score >20 (P = 0.002) were the independent risk factors of NPPV failure. CONCLUSIONS: We conclude that NPPV can be applied in selected patients with acute respiratory failure after cardiac surgery to reduce the need of re-intubation and improve clinical outcome as compared with conventional treatment. Pneumonia and a high APACHE II score >20 might be the independent risk factors of NPPV failure in this group of patients.

[Postoperative acute renal failure in adult patients with cardiac surgery: evaluation of the RIFLE classification].

OBJECTIVE: To evaluate the ability of the RIFLE classification to predict hospital mortality in adult patients who underwent cardiac surgery. METHODS: From October 1st 2006 to December 31st 2006, five hundred and nine adult patients who underwent coronary artery bypass grafting and/or valve operation were enrolled in this study. Renal function was assessed daily according to the RIFLE classification, meanwhile, APACHE II score and SOFA score were also evaluated, as well as the maximum scores were recorded. RESULTS: Mean duration of ventilation support was 18 (14-19) hours, the time of ICU stay was 1.4 +/- 1.0 days, and the time of postoperative hospital stay was 12.0 (10.0-15.0) days. 167 patients (32.8%) incurred postoperative ARF according to the RIFLE classification. The overall mortality was 4.3% (22/502). A significant increase (P < 0.01) was observed for mortality based on RIFLE classification. By applying the area under the receiver operating characteristic curve, the RIFLE classification had more powerful discrimination power [0.933, (95% CI 0.872-0.995), P < 0.001]. CONCLUSIONS: ARF is one of the major complications in postcardiotomy patients. Analytical data suggested the good discriminative power of the RIFLE classification for predicting inpatient mortality of adult postoperative patient with ARF, and the RIFLE classification is simple and practically performed. According to the RIFLE classification, patients with RIFLE class I or class F incur a significantly increased risk of in-hospital mortality compared with those who never develop ARF.

[Extracorporeal membrane oxygenation support in acute cardiorespiratory function failure patients after cardiac surgery].

OBJECTIVE: To investigate the treatment experience of extracorporeal membrane oxygenation (ECMO) support after cardiac surgery. METHODS: Retrospectively analyze the clinical data of 117 postoperative patients supported with ECMO in cardiac intensive care unit from March 2005 to June 2008. There were 32 female and 85 male patients, with a mean age of (48.7 +/- 16.5) years old. The cardiac operations included coronary artery bypass grafting (n = 20), coronary artery bypass grafting and remodeling of left ventricle (n = 9), coronary artery bypass grafting and valvular operation (n = 5), repair of ventricular septal perforation following acute myocardial infarction (n = 2), valvular operation (n = 46), heart transplantation (n = 20), lung heart transplantation and repair of ventricular septal defect (n = 1), correction of congenital heart defects (n = 10), aortic operations (n = 4). Venoarterial bypass was instituted in 115 for hemodynamic failure and venovenous in 2 patient for hypoxemia following cardiac surgery. ECMO was established in 110 patients by cannulation of the right atrium and femoral artery, and 5 of the right atrium and ascending aorta. And 2 case added left atrial drainage to ECMO. Heparin was infused to maintain the whole blood activated coagulation time (ACT) of 160 to 200 s in centrifugal pump (14 cases), and 200 to 250 s in roller pump (3 cases) to avoid thrombotic events. This was administered until decannulation. Intra-aortic balloon pump was used in 15 patients and continuous renal replacement therapy in 29 cases. RESULTS: Mean ECMO duration was 61 h (ranged 3 to 225 h) and the mean duration of ICU stay was 5 d. 87 patients (74.4%) were successfully weaned from ECMO. 69 patients (59.0%) survived to discharge. The most common complications were re-exploration for bleeding (n = 24) and alimentary tract hemorrhage (n = 14), renal failure required renal replacement therapy (n = 29), infection(n = 32), limb ischemia (n = 5), plasma leak of oxygenators (n = 29), hemolysis (n = 7), neurological complication (n = 4). CONCLUSIONS: ECMO is an effective mechanical assistance method for short-term treatment of postoperative cardiorespiratory failure. Indication should be controlled strictly. Earlier institution of ECMO and prevent complication may improve outcome.

[The application of extracorporeal membrane oxygenation for surgical treatment of coronary artery disease].

OBJECTIVE: To summarize the results and experiences on extracorporeal membrane oxygenation (ECMO) for post-cardiac surgery of coronary artery disease. METHODS: From June 2004 to November 2006, sixteen patients with the mean age of (58 +/- 11) years old undergoing cardiac surgical procedures were placed on ECMO using a heparin-bonded circuit. Fourteen patients were male and two patients were female. Thirteen patients underwent on pump coronary artery bypass surgery (CABG) and three patients underwent off-pump coronary artery bypass grafting. The duration of ECMO support, stay of intensive care unit (ICU stay), complications and turnovers were recorded. RESULTS: The mean duration of ECMO support was 51 hours, and the mean duration of ICU stay was 5 days. Thirteen patients (81.3%) were successfully weaned form ECMO, ten patients (62.5%) were discharged from hospital. The main complications were bleeding, infection, renal failure and ischemia of the lower limbs with the incidence of 18.8%, 37.5%, 25% and 18.8% respectively. CONCLUSION: ECMO is an acceptable technique for shortterm treatment of refractory low cardiac output after cardiac surgery of coronary artery disease.

[Acute hemodynamic effects of intravenous diltiazem in patients with congenital heart defects and pulmonary hypertension post cardiac surgery].

OBJECTIVE: To observe the acute hemodynamic effects of intravenous diltiazem in patients with congenital heart defect (CHD) and severe pulmonary hypertension (HP) post cardiac surgery. METHODS: From November 2003 to September 2005, 12 patients with CHD and severe HP (4 male, mean age 17.8 +/- 9.8 years) after cardiac surgery received intravenous diltiazem (3 - 5 microg x kg(-1) x min(-1)) in the Intensive Care Unit. Mean pulmonary artery pressure (mPAP), mean arterial pressure (MAP), heart rate (HR), stroke volume (SV), systemic vascular resistance (SVR), pulmonary vascular resistance (PVR) were monitored with Swan-Ganz catheter before (T1) and 6 hours (T2) after diltiazem injection, before weaning patients off of ventilator (T3), 1 hour (T4) and 24 hour (T5) after extubation. RESULTS: All patients survived during the observation period and no patient developed pulmonary hypertension crisis. The average ventilation time was (88.7 +/- 50.1) hours. Mean ICU stay time was (5.8 +/- 3.1) days. Compared to T1, mPAP was significantly decreased at T3 and T5, MAP significantly increased at T4 and T5, HR significantly reduced at T2 and thereafter, SV significantly increased at T3, T4 and T5 and PVR significantly increased at T3 and T5 while SVR remained unchanged after diltiazem therapy. CONCLUSION: Intravenous use of diltiazem is safe and effective for patients with CHD with severe HP post cardiac surgery.