Nasal CPAP therapy: effects of different CPAP levels on pressure transmission into the trachea and pulmonary oxygen transfer (original) (raw)
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Monaldi archives for chest disease = Archivio Monaldi per le malattie del torace / Fondazione clinica del lavoro, IRCCS [and] Istituto di clinica tisiologica e malattie apparato respiratorio, Università di Napoli, Secondo ateneo, 2008
Due to an increasing incidence of respiratory failure after cardiac surgery we wanted to study whether nasal continuous positive airway pressure (NCPAP) may improve pulmonary oxygen transfer and may avoid reintubation after coronary operations. Additionally, we compared this protocol to non-invasive positive pressure ventilation (NPPV). For a period of 2 years we analyzed all patients that were extubated within 12 hours after coronary surgery, and in whom oxygen transfer (PaO2/FIO2) deteriorated without hypercapnia so that all these patients met predefined criteria for reintubation: group A=immediate reintubation (n=88), group B=NCPAP-treatment (n=173), group C=NPPV (n=18). 25.4% of group B- and 22.2% of group C-patients were also intubated after a period of NCPAP or NPPV. All other patients of groups B and C could be weaned from these devices (B = 34.3 +/- 5.9 hours; C = 26.4 +/- 4.4 h; p < 0.05) and were well oxygenated by face mask at ambient pressure (Ratio PaO2/FIO2: B, 138 ...
Continuous positive airway pressure by mask in patients after coronary surgery
Acta Anaesthesiologica Scandinavica, 1994
Thirty patients who underwent coronary artery bypass grafting were randomized to receive 30% oxygen by mask either with an ambient airway pressure or with 7.4 mmHg (1 kPa) continuous positive airway pressure (CPAP) for 8 h after extubation. Arterial blood oxygen tension (PaO2) decreased remarkably in the control group after extubation (from 19.2 +/- 5.3 kPa to 12.4 +/- 2.7 kPa) but less in the CPAP group (from 16.4 +/- 3.3 kPa to 14.0 +/- 2.1 kPa). On the second postoperative morning PaO2 was equally low in both groups (control: 8.4 +/- 1.5 kPa, CPAP: 8.9 +/- 1.9 kPa). Atelectatic areas were seen with similar frequency in both groups, 17% (whole material) on the first and 50% on the second postoperative morning. Atelectasis was more common in patients with internal thoracic artery grafting and/or pleural drainage. In conclusion, CPAP therapy was well tolerated, and minimized the decrease in PaO2 after extubation, but could not prevent the poor oxygenation or the late development of atelectatic areas on the second postoperative day.
Turkish Journal of Anesthesia and Reanimation, 2015
The aim of our study is to investigate the effect of two different methods of continuous positive airway pressure (CPAP) and bilevel positive airway pressure (BIPAP) and oxygen support under spontaneous ventilation on respiration mechanics, gas exchange, dry mouth and face mask lesion during an early postoperative period in patients undergoing upper abdominal surgery. Methods: Eighty patients undergoing elective abdominal surgery with laparotomy, between the age of 25 and 75 years and American Society of Anesthesiologists Physical Status score (ASA) II-III with chronic obstructive pulmonary disease (COPD) diagnosis were included to the study. Subjects were randomly allocated in to four groups. During the first postoperative hour, the first group received BIPAP, second group received high-flow CPAP, third group received low-flow CPAP and fourth group received deep breathing exercises, respiratory physiotherapy and O 2 therapy. Preoperative, postoperative before and after treatment PaO 2 , PaCO 2 , SpO 2 , tidal volume (TV), respiratory rate (RR) levels were recorded. Subjects with dry mouth or face mask lesion were recorded. Results: In all groups, PaO 2 and TV measurements were higher at the postoperative first hour than the postoperative zero hour. We found that low-flow CPAP increased PaO 2 and SpO 2 values more, and TV levels were higher in the postoperative period than the preoperative period. PaCO 2 levels were elevated at the zero hour postoperatively and at the end of the first hour; they decreased approximately to preoperative values, except in the fourth group. Conclusion: Administration of prophylactic respiratory support can prevent the deterioration of pulmonary functions and hypoxia in patients with COPD undergoing upper abdominal surgery. In addition, we found that low-flow CPAP had better effects on PaO 2 , SpO 2 , TV compared to other techniques.
CHEST Journal, 1995
started on N-CPAP before surgery, were put on N-CPAP as soon as extubated, on a near-continuous basis, for 24 to 48 h and thereafter for all sleep periods. None of them had major complications. The intensive care unit and hospital stays were the normal ones for each type of surgery in our institution. We conclude that N-CPAP started before surgery and resumed immediately after extubation allowed us to safely manage a variety of surgical procedures in patients with OSAS, and to freely use sedative, analgesic, and anesthetic drugs without major complications. Every effort should be made to identify patients with OSAS and institute N-CPAP therapy before surgery.
2016
Context: Prolonged mechanical ventilation and intensive care unit (ICU) stay increases morbidity and mortality. Objective: To evaluate the effects of biphasic positive airway pressure versus continuous mandatory ventilation (CMV), synchronized intermittent mandatory ventilation (SIMV) and continuous positive airway pressure (CPAP) in patients receiving elective post operative ventilation Methods and Material: 40 patients of age group 20 yrs and older of American society of anesthesiologists (ASA) physical status 1-3 who underwent elective abdominal surgery under general anesthesia were divided into 2 groups, group B(n=20) comprised of patients who were put on BIPAP mode and group C(n=20) who were put on CMV, SIMV, CPAP mode. Outcomes measured were ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2), duration of mechanical ventilation, sedation requirement, and hemodynamic instability. Patients were put on ventilator and ventilated according to protocol. Results: The duration of mechanical ventilation was significantly reduced [p – 0.005] in group B [6.82.8 hours] than group C [9.93.6 hours]. Sedation requirement with midazolam was significantly reduced [p – 0.0001] in group B (42.71 mg) than group C (8.052.45 mg). There was no difference with respect to PaO2/FiO2 ratio and hemodynamic stability between both the groups. Conclusions: BIPAP as compared to CMV, SIMV and CPAP mode reduces the duration of mechanical ventilation and sedation requirement which in turn reduces morbidity. Pulmonary gas exchange was similar between the two groups.
This study aimed to investigate the effects of planned respiratory cares and Continuous Positive Airway Pressure (CPAP) on atelectasis and arterial blood oxygen levels in Coronary Artery Bypass Graft (CABG) patients. pulmonary complications and oxygenation impairment after Coronary Artery Bypass Surgery (CABS) are prevalent and lead to increased hospitalization and treatment costs. Planned respiratory cares and the application of ventilation with CPAP mode are among the proceedings that are conducted in most of the health centers, but there are not sufficient scientific evidences to confirm the effectiveness of one of these proceedings after CABS. The preset study was a three-group clinical trial with the sample size of 120 patients (40 patients in each group) candidate for CABG based on permuted-block randomization. This study was conducted at ShahidRajaei Hospital, Iran in 2015. Patients in experimental group (1) received planned respiratory cares; patient in experimental group (2) received noninvasive ventilation with CPAP mode and; patients in control group received conventional respiratory cares. Other treatments were similar for all three groups. The groups of interest were compared regarding the percentages of measured arterial oxygen saturation before surgery and days one, two, and three after surgery. Also, chest X-rays of patients both before and after surgery (day 3) were compared in terms of atelectasis. Data were analyzed by SPSS 16 using Chi-square tests, Kruskal-Wallis, and Friedman. the results showed that there is not any significant difference between three groups in terms of demographic variables, disease background, and arterial oxygen saturation values before surgery. In day (1), before intervention in patients of group 3, the arterial oxygen saturation values were higher compared to other two groups (p=0.03) and (p=0.001). In the case of atelectasis incidence, patients in group 2 had lowest incidence rate compared to other groups. However, there was no significant difference between three groups of the study. the results of this study showed that those patients who received noninvasive ventilation with CPAP mode after surgery, have better oxygenation status compared to patients receiving planned respiratory cares and patients receiving conventional cares. Also, oxygenation and recovery procedures are faster in these patients. The incidence of atelectasis in this group is lower compared to other groups. Therefore, it is recommended to use this noninvasive method to have better ventilation for patients under open heart surgery.
Continuous positive airway pressure does not improve lung function after cardiac surgery
Canadian Journal of Anesthesia/Journal canadien d'anesthésie, 2006
Despite the well-documented impairment of pulmonary function after cardiopulmonary bypass, effective precautions and ideal management strategies for this problem are still under debate. This study aimed to evaluate the effects of continuous positive airway pressure (CPAP) applied during cardiopulmonary bypass on respiratory and hemodynamic variables. Methods: In this randomized, prospective, controlled trial, 120 male patients, aged 45 to 70 yr undergoing first-time elective bypass surgery, were randomly assigned to receive either 10 cm H 2 O of CPAP (Group I; n = 60) during cardiopulmonary bypass, or serve as control (Group II; n = 60), where the patient's lungs were vented to atmosphere during the bypass period. Results: Alveolar-arterial oxygen partial pressure difference and shunt fraction were significantly higher in the control group compared with the CPAP group after cardiopulmonary bypass (T 2) and after closure of sternum (T 3), (P < 0.05). No differences between groups with respect to hemodynamic variables were observed at any time. Postoperative pulmonary function variables were lower in both groups compared to baseline values. Conclusions: Continuous positive airway pressure administered during cardiopulmonary bypass decreased shunt fraction and alveolar-arterial oxygen partial pressure difference during surgery, but had no sustained effect on either variable postoperatively. We conclude that, in patients with normal preoperative pulmonary function, application of 10 cm H 2 O CPAP does not improve lung function after cardiac surgery.
CPAP at 10 cm H2O during cardiopulmonary bypass does not improve postoperative gas exchange
Revista Brasileira De Cirurgia Cardiovascular, 2008
OBJECTIVE: To compare postoperative (PO) pulmonary gas exchange indexes in patients submitted to myocardial revascularization (MR) with or without the application of continuous positive airway pressure (CPAP) during cardiopulmonary bypass (CPB). METHODS: Thirty adult patients submitted to MR with CPB between March and September 2005 were randomly allocated to two groups: CPAP (n=15), patients that received CPAP at 10 cmH2O during CPB, and control (n=15), patients that didn't receive CPAP. PaO2/FiO2 and P(A-a)O2 were analyzed at four moments: Pre (just before CPB, with FiO2=1.0 ); Post (30min post-CPB, with FiO2=1.0); immediate PO period (12h post-surgery, with FiO2=0.4 by using a Venturi® facial mask) and first PO day (24h post-surgery, with FiO2=0.5 by a facial mask). RESULTS: PaO2/FiO2 and P(A-a)O2 tend to get significantly worst as time elapsed during the postoperative period in both groups, but no differences were observed between them at any moment. When PaO2/FiO2 was subdivided into three categories, a greater prevalence of patients with values between 200 mmHg and 300mmHg were observed in CPAP group only at moment Post (30min post-CPB; p = 0.02). CONCLUSION: CPAP at 10cmH2O administered during CPB, although had lightly improved PaO2/FiO2 at 30 minutes post-CPB, had no significant sustained effect on postoperative pulmonary gas exchange. We concluded that in patients submitted to MR, application of 10 cmH2O CPAP does not improve postoperative pulmonary gas exchange.