Biomedical subjects

Panagiotis K Behrakis

Publications and source records attributed to Panagiotis K Behrakis.

5 recordsLinked to original sources

PubMed2004

Immediate post-operative effects of tracheotomy on respiratory function during mechanical ventilation.

INTRODUCTION: Tracheotomy is widely performed in the intensive care unit after long-term oral intubation. The present study investigates the immediate influence of tracheotomy on respiratory mechanics and blood gases during mechanical ventilation. METHODS: Tracheotomy was performed in 32 orally intubated patients for 10.5 +/- 4.66 days (all results are means +/- standard deviations). Airway pressure, flow and arterial blood gases were recorded immediately before tracheotomy and half an hour afterwards. Respiratory system elastance (Ers), resistance (Rrs) and end-expiratory pressure (EEP) were evaluated by multiple linear regression. Respiratory system reactance (Xrs), impedance (Zrs) and phase angle (phirs) were calculated from Ers and Rrs. Comparisons of the mechanical parameters, blood gases and pH were performed with the aid of the Wilcoxon signed-rank test (P = 0.05). RESULTS: Ers increased (7 +/- 11.3%, P = 0.001), whereas Rrs (-16 +/- 18.4%, P = 0.0003), Xrs (-6 +/- 11.6%, P = 0.006) and phi rs (-14.3 +/- 16.8%, P = <0.001) decreased immediately after tracheotomy. EEP, Zrs, blood gases and pH did not change significantly. CONCLUSION: Lower Rrs but also higher Ers were noted immediately after tracheotomy. The net effect is a non-significant change in the overall Rrs (impedance) and the effectiveness of respiratory function. The extra dose of anaesthetics (beyond that used for sedation at the beginning of the procedure) or a higher FiO2 (fraction of inspired oxygen) during tracheotomy or aspiration could be related to the immediate elastance increase.

Adult↗

PubMed2003

Volume and flow dependence of respiratory mechanics in mechanically ventilated COPD patients.

Volume and flow dependencies of respiratory mechanics are examined in 10 COPD patients under mechanical ventilation (MV) at 3 levels of externally applied PEEP (PEEPe). Airways pressure (Paw), flow (V') and volume (V) data are analyzed according to (1) the linear and (2) a non-linear model, accounting for volume dependence of elastance and for flow and volume dependence of resistance. The models' fitness to data is assessed by the regression errors. Non-linear modelling fits significantly better to data, while the difference of fitness decreases with PEEPe. Linear mechanics are not significantly different between the 3 levels of PEEPe. A positive volume dependence of elastance observed at 0, decreases at 5 and increases again at 10 hPa of PEEPe. A seriously negative volume dependence of resistance at 0 turned to positive with PEEPe. These dependencies of respiratory mechanics during COPD under MV, show that the present non-linear respiratory mechanical monitoring may help for better and less risky adjustment of PEEPe.

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PubMed2003

Early phase changes by concurrent endurance and strength training.

To compare regimens of concurrent strength and endurance training, 26 male basketball players were matched for stature, body composition, and physical activity level. Subjects completed different training programs for 7 weeks, 4 days per week. Groups were as follows: (a) the strength group (S; n = 7) did strength training; (b) the endurance group (E; n = 7) did endurance training; (c) the strength and endurance group (S + E; n = 7) combined strength and endurance training; and (d) the control group (C; n = 5) had no training. The S + E group showed greater gains in Vo(2)max than the E group did (12.9% vs. 6.8%), whereas the S group showed a decline (8.8%). Gains were noted in strength and vertical jump performance for the S + E and S groups. The S + E group had better posttraining anaerobic power than the S group did (6.2% vs. 2.9%). No strength, power, or anaerobic power gains were present for the E and C groups. We conclude that concurrent endurance and strength training is more effective in terms of improving athletic performance than are endurance and strength training apart.

Adult↗

PubMed2002

Muscular mass assessed by ultrasonography after administration of low-dose corticosteroids and muscle relaxants in critically ill hemiplegic patients.

BACKGROUND AIMS: The present study investigates the influence of low-dose and short- term administration of corticosteroids and muscle relaxants on the muscular mass (MM) in hemiplegic ICU patients, with the aid of ultrasonography (U/S). METHODS: Thirty-seven patients hospitalised in the ICU for 18.6+/-3.6 days, were included in the study. Sixteen patients did not receive either drug (group A), five patients received dexamethasone (24 mg/day) for 4 days (group B), eight patients received dexamethasone (24 mg/day) for 4 days and atracurium (0.3-0.6 mg/kg/h) for 2.8+/-0.4 days (group C), whereas eight other non-hemiplegic ICU patients comprised the control group. MM was measured in cm by U/S and serum Albumin (ALB, g/l) at the first and the tenth ICU hospitalisation day. The corresponding differences (DeltaMM, DeltaALB) were compared between the four groups of patients. RESULTS: MM and ALB decreased significantly in all groups. DeltaMM was significantly higher in group C in comparison to all other groups, while DeltaMM was also higher in group B, when compared to the control and A groups. DeltaALB did not show significant inter-group differences. DeltaMM was significantly related to patients' age (r=0.41,P =0.001). CONCLUSIONS: Muscular atrophy of the ICU hemiplegic patients is significantly influenced by the synchronous treatment with muscle relaxants and corticosteroids at low doses and for short term. This myopathy should be taken into account for the better prognosis and the safer outcome of the patient and U/S is suitable for accurate and non-invasive monitoring of MM.

APACHE↗

PubMedDate not supplied

Postoperative changes on pulmonary function after laparoscopic and open cholecystectomy.

BACKGROUND/AIMS: We examined 28 patients who underwent cholecystectomy for acute or chronic cholecystitis and/or cholelithiasis in order to evaluate the effect of surgical technique on respiratory functional parameters. METHODOLOGY: We compared lung volume, flow parameters and blood gas indices in two groups of patients, eighteen of which underwent laparoscopic and ten of which open cholecystectomy, specifically on the 2nd and 8th postoperative day lung function indices were compared to preoperative values. The same anesthetic protocol was administered for all patients. No underlying illness other than the cholecystitis and/or cholelithiasis was present. RESULTS: From the results of lung volume parameters, ERV (%pred) data indicate a better expiratory ability for the Open Cholecystectomy [preop.: 93.10 (38.80), 8th day: 116.90 (63.69) compared to the Laparoscopic Cholecystectomy group (preop.: 105.39 (31.51), 8th day: 98.72 (35.80). For IC (%pred.) parameter, in the Open Cholecystectomy group a marked but not statistically significant decrease remained into the 8th day (preop.: 86.70 (16.40). 8th day: 68.40 (16.98)] whereas for the Laparoscopic Cholecystectomy group, IC %pred value reflected a better respiratory performance [preop.: 92.83 (17.87), 8th day: 82.50 (18.82)]. For RV and RV/TLC parameter measurements a marked increase in the %pred value was observed for the Laparoscopic Cholecystectomy group on the 8th postoperative day as compared to preoperative data [RV: 122.94 (42.80), 109.22 (33.23) respectively, RV/TLC: 122.68 (31.10), 109.14 (21.56) respectively]. From the analysis of the flow parameters, a distinct difference was evident for PEF between the preoperative and 8th postoperative day data with the Laparoscopic Cholecystectomy group showing statistically significant better flow rates [preop.: 93.72 (15.91), 8th day: 84.33 (20.67)] as compared to the Open Cholecystectomy group [preop.: 82.30 (22.98), 8th day: 59.10 (15.23)]. CONCLUSIONS: Having compared the 8th postoperative day with preoperative data for the two surgical methods, open cholecystectomy presented a better expiratory performance as compared to the laparoscopic method. However, laparoscopic cholecystectomy resulted in an overall better postoperative respiratory function.

Adult↗