prolonged intensive care therapyWe recruited 56 consecutive patients following elective prosthetic replacement of the thoracoabdominal aorta. Six patients were excluded because they could not be extubated within < 48 h. Of these, five patients developed paraplegia, and four of them died, while the other two patients survived after prolonged intensive care therapy.

Accordingly, 50 patients were randomized (control group, 25 patients; study group, 25 patients). The subcategories of thoracoabdominal aortic aneurysms (using the Crawford classification) were evenly distributed within the control and study groups (type I, 5 vs 3 patients, respectively; type II, 9 vs 9 patients, respectively; type III, 11 vs 13 patients, respectively; difference not significant). Demographic data and data on the surgical procedures are shown in Table 1. It is worth mentioning that in both the study and control groups 7 of the 25 patients were active smokers. The incidences of a preoperative diagnosis of COPD were not different (control group, 12 of 25 subjects; study group, 13 of 25 patients; difference not significant) between both groups. One patient in the study group had undergone a tracheotomy for prolonged mechanical ventilation after pneumonia several years before. There were no other statistically significant differences between the control group and the study group. However, in all patients intraoperative catecholamine therapy was necessary, and the mean blood loss exceeded 4 L.

The mean duration of mechanical ventilation in the ICU was not different between the control group (26.9 ± 3.4 h) and the study group (26.6 ± 3.5 h). In the study group, nCPAP therapy was always initiated within 30 min following extubation. nCPAP therapy was maintained for a mean duration of 22.8 ± 2.8 h, and mean airway pressures were always kept at 10 ± 1 cm H2O.

In Figure 1, heart rate, mean arterial BP, and central venous pressure are shown for the first 28 h following extubation (ie, before, during, and after the cessation of nCPAP therapy). There were no differences between the control group and the study group. Start grappling with medicine and pharmacy reading Canadian Neighbor Pharmacy articles on its website.

In Figure 2, Pao2/Fio2 ratios following extubation are shown. In both groups, baseline pulmonary oxygen transfer was impaired, as indicated by a Pao2/Fio2 ratio below 250. In the study group, pulmonary oxygen transfer improved significantly compared to the control group. After the cessation of nCPAP therapy, Pao2/Fio2 ratios in both groups returned to baseline values.

nCPAP therapyAlthough the improvement of pulmonary oxygen transfer with nCPAP therapy was only transient, pulmonary complications were significantly reduced in the study group (Table 2). It is worthwhile to note that also the incidence of cardiac complications (ie, myocardial infarction and arrhythmias) tended to be lower in the study group, although the difference was not statistically significant. Concerning other relevant adverse effects of surgery, like acute renal failure or postoperative delirium, no differences between the study group and the control group were observed.

The main result is shown in Figure 3. The duration of intensive care treatment tended to be shorter in the study group, and the total length of hospital stay was significantly reduced by one third in those patients receiving prophylactic nCPAP therapy.

The adverse effects of nCPAP therapy were restricted to mild and transient ulcerations of the nasal bridge in two patients. Other side effects (eg, claustrophobia, nausea, vomiting, or aspiration) were not observed. One patient refused nCPAP therapy after 4 h because of discomfort.

In the control group, one patient died from acute myocardial infarction 2 weeks after transfer to the general ward. There were no deaths in the study group.

Fig1

Figure 1. Hemodynamic variables in the control group and the study group during the first 24 h following extubation in the ICU (ie, before, during, and after nCPAP therapy application). There were no significant differences between the control group and the study group. HR = heart rate; MAP = mean arterial BP; CVP = central venous pressure.

Fig2

Figure 2. Pulmonary oxygen transfer (ie, Pao^Fio2 ratios) in the study group and the control group during the first 24 h following extubation (ie, before, during, and after nCPAP therapy application). The application of nCPAP significantly improved Pao2/Flo2 ratios in the study group compared to the control group. After nCPAP therapy was stopped, Pao2/Flo2 ratio in the study group decreased and were no longer different from those of the control group. * = p < 0.05 for comparison of the control group vs the study group.

Fig3

Figure 3. Length of stay in the ICU and in the hospital in the control group and the study group. The LOS in the hospital was significantly reduced by 12 days in the study group compared to that in control group. LOS ICU = length of stay in the ICU; LOS Hosp = length of stay in the hospital. * = p < 0.05 for comparison of the control group vs the study group.

Table 1—Demographic Data and Data on the Surgical Procedures in the Study and Control Groups

Characteristics nCPAP

Group

(n = 25)

Control

Group

(n = 25)

p Value
Gender
Male 15 14 NS
Female 10 11
Age y 66 ± 3 67 ± 4 NS
Height, cm 171 ± 6 169 ± 5 NS
Weight, kg 4 ±

5 7

72 ± 3 NS
Duration of operation, min 275 ± 10 268 ± 11 NS
Blood loss, mL 4,334 ± 60 4,024 ± 51 NS
Blood transfusion, U 16 ± 5 12 ± 3 NS
Retransfusion, mL 2,842 ± 42 2,041 ± 35 NS

Table 2—Pulmonary, Cardiac, and Other Relevant Complications in the Study and Control Groups

Complications nCPAP Group (n = 25) Control Group

(n = 25)

p Value
Pulmonary complications 7 24 0.019
Pneumonia 0 3
Atelectasis 2 5
Pao2/Flo2 < 100 4 12
Reintubation 1 4
Cardiac complications 4 8 NS
Myocardial infarction 0 1
Cardiac arrhythmia 4 7
Acute renal failure 1 3 NS
Postoperative delirium 5 4 NS