Ventilator-associated pneumonia: evaluation of etiology, microbiology and resistance patterns in a tertiary respiratory center

Ventilator-associated pneumonia [VAP] has been reported as the most common hospital-acquired infection among patients requiring mechanical ventilation. This study aimed to determine the incidence of ventilator-associated pneumonia in a cardiopulmonary tertiary center, and to evaluate its etiology, resistance patterns, and outcome of admitted patients. In a retrospective study, patients admitted to the Masih Daneshvari Hospital, a tertiary cardiopulmonary center, were evaluated in a 7-month period. A total of 530 patients were admitted to the ICU out of which, 40 acquired VAP. Overall, 99 patients were evaluated [male 57, female= 42] including 40 VAP and 59 non- VAP cases. The incidence of VAP was estimated to be 7.5% in this unit. The underlying conditions included respiratory diseases [COPD, asthma, etc], and cardiac problems [post "coronary artery bypass graft" CABG, etc]. Also, patients in the thoracic surgery ward and those with renal, gastrointestinal, neurologic and other medical problems were evaluated. The patients were divided into two groups of VAP and non-VAP cases. The micro-organisms were recovered from the patients' bronchoalveolar lavage fluid. The most common micro-organisms recovered were Pseudomonas aeruginosa [17 cases] and Staph. aureus species [15 cases]. In VAP patients in whom S. aureus was recovered, 80 percent of species were methicillin-resistant [MRSA] but all were sensitive to Vancomycin. Moreover, resistance to two, three or four antibiotics was seen in 12, 10, and 5 patients, respectively, in whom P. aeruginosa was recovered. The prevalence of S. aureus in patients with respiratory problems was more than other groups [including MRSA species], but the prevalence of recovered P. aeruginosa was the lowest in respiratory patients, compared to other groups. Also the mortality rate in drug resistant S. aureus and P. aeruginosa groups were 42 and 47 percent, respectively. Length of stay for MRSA group was 80% and death rate was 50%. In P. aeruginosa group, there was a positive relationship between resistance to multiple drugs and mortality and also ICU stay. VAP is a common infection in ICU setting and certain interventions may affect its incidence. In our study, P. aeruginosa and S. aureus were more common in ICU patients. Pseudomonas species were associated with the highest mortality rate and were resistant to four antibiotics in the antibiogram testing. S. aureus species were more common in patients with underlying respiratory problems, compared to those with other conditions

Relationship between the severity of airway obstruction and inspiratory muscles dysfunction in COPD patients

COPD is known as the main cause of morbidity and mortality in the world. Morbidity in COPD patients is mainly due to the respiratory muscle dysfunction especially diaphragm and chest wall muscles. Respiratory muscle dysfunction is mostly seen in severe and progressive stages of the disease. COPD results in increased functional residual capacity [FRC]. In severe cases of COPD, respiratory muscle dysfunction and FRC raise lead to the deterioration of hyperinflation. In our study, 30 COPD patients [28 males, 2 females] referred to Masih Daneshvari Hospital were evaluated. All cases were studied with the exact same body plethysmography equipment and the same technician. The average age, height, weight and BMI of cases were 53 +/- 11 yrs,168.86 +/- 6.33 cm, 65.44 +/- 16.78 kg and 23.56 +/- 6.32, respectively. The mean FEV1 according to the GOLD criteria was in the range of moderate to severe. Hyperinflation noted characterized by RV and reverse RV/TLC, was clearly noticed in our study [RV=225.9 +/- 82.11, RV/TLC%= 195 +/- 34.49]. Based on our study results, there was a significant correlation between FEV1, hyperinflation [RV/TLC, RV], respiratory muscle function [PImax/P1] and respiratory time cycle Ti/Ttot .It should be mentioned that there was a significant correlation between PImax and Tension Time Index as well

Respiratory disturbance index and severity of airway obstruction in COPD patients

Chronic obstructive pulmonary disease [COPD] is a common disease and concomitant occurrence with obstructive sleep apnea [OSA] has been reported in some studies. This coincidence can result in exacerbation of common complications like exacerbated hypoxemia, hyperpnea and right-sided heart failure. Thus, we decided to evaluate and compare respiratory disturbance index [RDI] and sleep apnea in COPD patients. For this purpose, 50 COPD patients with OSA were studied between 2003 and 2004. OSA criteria included obstructive apnea and clinical symptoms of snoring, sleep disorder and RDI >/= 5. The patients were divided in to two groups: group 1 consisted of 11 patients [22%] with FEV1/FVC<70 with the mean age of 36.18 +/- 14 and group 2 was included 39 patients [78%] with FEV1/FVC >/= 70 with the mean of 84.75 +/- 6.6%. RDI was compared between the two groups using independent sample t-test. Multiple regression analysis was also used for comparing other variables like height, weight, age, etc. The understudy patients were included 19 females [38%] and 31 males [62%] with the mean age of 53.7 +/- 14.8 yrs. There were statistically significant differences in RDI and height between the two groups [p=0.028 and p=0.00, respectively]. However, no significant difference was detected between the two groups in terms of weight and body mass index [BMI]. The possibility of concomitant occurrence of COPD and OSA should be considered due to co-occurrence of significant respiratory symptoms [like dyspnea, sleepiness, etc.] and assessed by adding RDI to important indices like height and so on