الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Patients with acute respiratory acidosis caused by an AECOPD are the group that benefits most from noninvasive ventilation. NIPPV with pressure support was shown to improve gas exchange, TV, RR, and diaphragmatic activity. In addition, it was associated with reduced risk of nosocomial infection, shorter ICU and hospital stay, and decreased mortality compared with endotracheal intubation.
The aim of the present study was first to emphasize the superiority of NIV in acute hypercapneic respiratory failure in patients with an AECOPD in comparison to conventional therapy alone. The second purpose was to identify early predictors of NIV failure in same patients and parameters of shifting to invasive ventilation.
After approval of the local Ethical Committee and having an informed written consent from every patient included in the study, the present study was carried out on fifty adult patients; all of them presenting with AECOPD.
Patients were randomly allocated into 2 equal groups
group I: 25 patients received standard medical treatment only.
group II: 25 patients received standard medical treatment plus NPPV.
All patients in the present study were subjected to full history taking and full clinical examination. ABG, CBC, serum urea and creatinine, RBS, CRP, ECG, and Chest X-ray have been recorded.
Patients of group I were subjected to standard medical treatment and controlled oxygen therapy (venturi mask) to maintain SpO2 88–92 %, nebulized salbutamol )2.5–5 mg(, nebulized ipratroprium )500 μg(, systemic glucocorticosteroids (prednisolone 40 mg/day), with or without antibiotics. Those in group II were subjected to standard medical treatment together with NIPPV which was considered within the first 60 minutes of hospital arrival for all patients in group II. All patients started on an IPAP of 10 and EPAP of 5 cmH2O. The pressures gradually adjusted as tolerated based on continuous pulse-oximetry, arterial blood gases, alleviation of patients’ dyspnea, decrease in respiratory rate and good patient–ventilator synchrony. Noninvasive ventilation was applied for an average duration of 15.32 ± 7.4 h/day and an average FiO2 of 34.08 ± 24.90 %.
Follow up was done for all the following parameters: RR, VAS, GCS, and ABG were followed at 1, 4, 12, 24 and 48 h after start of treatment. CRP and TLC were followed after 24 and 48 h. Outcome measures were also assessed and recorded as follows: treatment success or failure, intolerance to NPPV, dyspnic (breathlessness) scores, number and types of treatment complications, endotraceal intubation, mortality, length of hospital or ICU stay and dropouts/ withdrawals.
Results of the present study cleared that there were predictors of treatment success or failure since admission of cases in each group, which were as follows:
In group I, the parameters that showed significant correlation to treatment outcome were; age (p<0.001), pH on admission (p<0.001), pH after 1 h (p<0.001), PaCO2 after 1 h (p<0.001), SaO2 on admission (p<0.001), SaO2 after 1 h (p=0.001), baseline level of consciousness using (GCS) (p<0.001), GCS after 1 h of treatment (p<0.001), baseline heart rate (p<0.001), baseline breathlessness using (VAS) (p<0.001), VAS after 1 h of treatment (p<0.001), baseline severity scores using [BAP 65 (p<0.001) and APACHE II score (p=0.001)], number of comorbidities (p=0.003), number of ICU hospitalizations due to AECOPD (p=0.007), positive abdominal paradox sign (p=0.015), pack year index (p=0.025), RBS (p=0.032) and male sex (p=0.038).
In group II, these parameters were; pH on admission (p<0.001), pH after 1 h (p<0.001), PaCO2 on admission (p<0.001) PaCO2 after 1 h (p<0.001), BAP 65 score (p<0.001), positive pedal edema (p<0.001), RBS (p<0.001), baseline respiratory rate (p<0.001), baseline GCS (p<0.001), GCS after 1 h (p=0.001), BMI (p<0.001), number of comorbidities (p<0.001), type of comorbidities; CKD (p=0.001), diabetes (p=0.005), IHD (p=0.005), and hypertention (p=0.023), baseline VAS (p= 0.041), VAS after 1 h of treatment (p= 0.003), number of ICU hospitalizations due to AECOPD (p=0.004), central cyanosis (p=0.009), TLC (p=0.014), positive abdominal paradox sign (p=0.023), APACHE II score (p= 0.024), pack year index (p=0.026), SaO2 on admission (p=0.012) and SaO2 after 1 h (p=0.006).
Regarding the outcome measures, early NPPV had a success rate 19/25 (76.0 %) while in medical group the success rate was only 5/25 (20 %) which was of high statistical significance (p< 0.001); (Odds ratio= 0.0789, confidence interval= 0.021 – 0.302 and p<0.001).
Only 6 (24 %) out of the total number of patients treated with face mask BiPAP needed MV by ETI, whereas 15 (60 %) of the patients receiving conventional therapy underwent intubation and MV. Statistical analysis showed a significant difference (p = 0.010) in the occurrence of ETI between the 2 groups; (Odds ratio= 4.75, confidence interval= (1.40 – 16.051) and p=0.012).
The number of complications associated with treatment was significantly lower with NPPV (8/25, 32.0 %) vs medical group (23/25, 92.0 %); p < 0.001. (Odds ratio =24.437, confidence interval= (4.59 – 130.01) and p= 0.002. Most of complications occurred because of intubation, suggesting that avoidance of intubation is the major benefit of NPPV.
The length of ICU and hospital stay, both were significantly longer in medical group (I) than in NIPPV group (II) with p value < 0.001 which reflects that NIV is a highly cost effective treatment that both reduced total costs and improved in hospital mortality.
In-hospital survival rate was significantly higher in the NIPPV versus group I (92 % vs 68 % respectively, p = 0.034). 8/25 (28 %) of cases in group I died while in NIPPV group the non survived cases were only 2 /25 (8 %) of total number of patients included in the study; (Odds ratio= 5.411, confidence interval= (1.017 – 28.79) and p=0.047).
Parameters which showed significant correlation to in-hospital mortality were as follows:
In group I; GCS (p<0.001), APACHE II score (p<0.001), BAP 65 (p<0.001), heart rate (p=0.002), abdominal paradox (p=0.002), RBS (p=0.004), pneumonia (p=0.006), TLC= (p=0.008), pedal edema (p=0.010), stroke (p=0.024) and VAS (p=0.038).
In group II, BAP 65 (p<0.001), urea (p<0.001) , pH (p=0.002) ,RBS (p=0.002), AF (p=0.003), central cyanosis (p=0.010), PaCO2 (p=0.011), PaO2 (p=0.013), CKD (p= 0.020), number of comorbidities (p=0.021), APACHE II score (p=0.024), creatinine (p=0.024) and pedal edema (p=0.050).
To recapitulate, the present study confirms that NIPPV is clearly a superior alternative to standard medical therapy with oxygen therapy during the initial phase of management of such patients. It is extremely useful in an emergency department setting as a first line treatment for acute respiratory distress. NIV should be considered for all the patients with AECOPD with respiratory acidosis unless there is a contraindication to its use. The application of NIPPV together with regular medical treatment in patients with COPD and hypercapnic ARF reduces the incidence of complications, orotracheal intubation, hospital mortality and hospital stay with very high success rate reached 76 % in the present study. The measurement of certain parameters may be of value not only in terms of predicting the effectiveness of NIV treatment but also in predicting associated in-hospital mortality.