Serafeim Nanas

Patterns of dynamic hyperinflation during exercise and recovery in patients with severe chronic obstructive pulmonary disease

Background: Not all patients with severe chronic obstructive pulmonary disease (COPD) progressively hyperinflate during symptom limited exercise. The pattern of change in chest wall volumes (Vcw) was investigated in patients with severe COPD who progressively hyperinflate during exercise and those who do not. Methods: Twenty patients with forced expiratory volume in 1 second (FEV1) 35 (2)% predicted were studied during a ramp incremental cycling test to the limit of tolerance (Wpeak). Changes in Vcw at the end of expiration (EEVcw), end of inspiration (EIVcw), and at total lung capacity (TLCVcw) were computed by optoelectronic plethysmography (OEP) during exercise and recovery. Results: Two significantly different patterns of change in EEVcw were observed during exercise. Twelve patients had a progressive significant increase in EEVcw during exercise (early hyperinflators, EH) amounting to 750 (90) ml at Wpeak. In contrast, in all eight remaining patients EEVcw remained unchanged up to 66% Wpeak but increased significantly by 210 (80) ml at Wpeak (late hyperinflators, LH). Although at the limit of tolerance the increase in EEVcw was significantly greater in EH, both groups reached similar Wpeak and breathed with a tidal EIVcw that closely approached TLCVcw (EIVcw/TLCVcw 93 (1)% and 93 (3)%, respectively). EEVcw was increased by 254 (130) ml above baseline 3 minutes after exercise only in EH. Conclusions: Patients with severe COPD exhibit two patterns during exercise: early and late hyperinflation. In those who hyperinflate early, it may take several minutes before the hyperinflation is fully reversed after termination of exercise.

Bone mass loss in chronic heart failure is associated with secondary hyperparathyroidism and has prognostic significance

Chronic heart failure (CHF) is associated with increased risk of osteoporosis. We investigated the relationship between severity of CHF and bone loss, underlying pathophysiological mechanisms, and the prognostic significance of bone mass changes in heart failure.

Serum S100B protein is increased and correlates with interleukin 6, hypoperfusion indices, and outcome in patients admitted for surgical control of hemorrhage.

ABSTRACT S100B protein, an acknowledged biomarker of brain injury, has been reported to be increased in hemorrhagic shock. Also, acute hemorrhage is associated with inflammatory response. The aim of this study was to investigate the concentrations of serum S100B and the potential relationships with interleukin 6 (IL-6), severity of tissue hypoperfusion, and prognosis in patients admitted for surgical control of severe hemorrhage. Patients undergoing elective abdominal aortic aneurysm surgery participated as control subjects. Serum samples were drawn before, at the end of surgery, and after 6 and 24 h. Sixty-four patients with severe hemorrhage (23 trauma and 41 nontrauma) and 17 control subjects were included. Increased preoperative concentrations of S100B protein (1.70 ± 2.13 and 0.81 ± 1.23 &mgr;g/L) and IL-6 (241 ± 291 and 226 ± 238 pg/mL) were found in patients with traumatic and nontraumatic reason, respectively, and remained elevated throughout 24 h. Compared with nontrauma, trauma patients exhibited higher preoperative S100B levels (P < 0.05). Overall mortality was 47%. In control subjects, preoperative S100B and IL-6 levels were within normal limits and increased at the end of surgery (P < 0.001 and P < 0.01, respectively). Preoperative S100B correlated with IL-6 (r = 0.78, P < 0.01), arterial lactate (r = 0.50, P < 0.01), pH (r = −0.45, P < 0.01), and bicarbonate (r = −0.40, P < 0.01). Multiple analysis revealed that preoperative S100B in trauma and lactate in nontrauma patients were independently associated with outcome. In predicting death, preoperative S100B yielded receiver operator characteristics curve areas of 0.75 for all patients and 0.86 for those with trauma. These results indicate that severe hemorrhage in patients without brain injury is associated with increased serum levels of S100B, which correlates with IL-6 and tissue hypoperfusion. Moreover, the predictive ability of S100B for mortality, suggests that it could be a marker of potential clinical value in identifying, among patients with severe hemorrhage, those at greater risk for adverse outcome.

Anemia in heart failure: pathophysiologic insights and treatment options.

Anemia has been recognized as a very common and serious comorbidity in heart failure, with a prevalence ranging from 10 to 79%, depending on diagnostic definition, disease severity and patient characteristics. A clear association of anemia with worse prognosis has been confirmed in multiple heart failure trials. This finding has recently triggered intense scrutiny in order to identify the underlying pathophysiology and the best treatment options. Etiology is multifactorial, with iron deficiency and cytokine activation (anemia of chronic disease) playing the most important roles. Treatment is aimed at not only restoring hemoglobin values back to normal, but also at improving the patients symptoms, functional capacity and hopefully the outcome. Iron supplementation and erythropoietin-stimulating agents have been used for this purpose, either alone or in combination. In this review, the recent advances in elucidating the mechanisms leading to anemia in the setting of heart failure are presented and the evidence supporting the use of different treatment approaches are discussed.

Risk factors for tracheobronchial acquisition of resistant Gram-negative bacterial pathogens in mechanically ventilated ICU patients.

Abstract The aim of this study was to identify risk factors for tracheobronchial acquisition with the most common resistant Gram-negative bacteria in the intensive care unit (ICU) during the first week after intubation and mechanical ventilation. Tracheobronchial and oropharyngeal cultures were obtained at admission, after 48 hours, and after 7 days of mechanical ventilation. Patient characteristics, interventions, and antibiotic usage were recorded. Among 71 eligible patients with two negative bronchial cultures for resistant Gram-negative bacteria (at admission and within 48 hours), 41 (58%) acquired bronchial resistant Gram-negative bacteria by day 7. Acquisition strongly correlated with presence of the same pathogens in the oropharynx: Acinetobacter baumannii [odds ratio (OR) = 20·2, 95% confidence interval (CI): 5·5–73·6], Klebsiella pneumoniae (OR = 8·0, 95% CI: 1·9–33·6), and Pseudomonas aeruginosa (OR = 27, 95%: CI 2·7–273). Bronchial acquisition with resistant K. pneumoniae also was associated with chronic liver disease (OR = 3·9, 95% CI: 1·0–15·3), treatment with aminoglycosides (OR = 4·9, 95% CI: 1·4–18·2), tigecycline (OR = 4·9, 95% CI: 1·4–18·2), and linezolid (OR = 3·9, 95% CI: 1·1–15·0). In multivariate analysis, treatment with tigecycline and chronic liver disease were independently associated with bronchial resistant K. pneumoniae acquisition. Our results show a high incidence of tracheobronchial acquisition with resistant Gram-negative microorganisms in the bronchial tree of newly intubated patients. Oropharynx colonization with the same pathogens and specific antibiotics use were independent risk factors.

Comparative evaluation of Acute Physiology and Chronic Health Evaluation II and Sequential Organ Failure Assessment scoring systems in patients admitted to the cardiac intensive care unit.

PURPOSE To assess and compare the performance of Acute Physiology and Chronic Health Evaluation (APACHE) II and Sequential Organ Failure Assessment (SOFA) scores in the cardiac intensive care unit (CICU). METHODS A single-center, prospective cohort study in a CICU admitting patients with acute cardiovascular diseases was conducted. Both APACHE II and SOFA were calculated on admission. The area under the receiver operating characteristic curve (AUC) was used to evaluate the discriminative ability for predicting CICU survival, hospital survival, and survival 6 months after hospital discharge. Goodness of fit was assessed using the Hosmer-Lemeshow and the Brier scores. All analyses were conducted separately for the patients with acute coronary syndrome. RESULTS Of the 300 consecutively admitted patients, 206 had acute coronary syndrome. Both scores exhibited good discriminative ability (AUC range, 0.84-0.92), and their AUCs did not differ significantly. The Hosmer-Lemeshow test P values were numerically higher (.151-.949 vs .033-.531), and the Brier score closer to zero (0.0864-0.1570 vs 0.1039-0.1264) for APACHE II compared with SOFA score models. The Acute Physiology and Chronic Health Evaluation was the best single risk factor for CICU mortality (odds ratio, 1.24; 95% confidence interval, 1.13-1.37; P < .001). CONCLUSION Both APACHE II and SOFA scores have good and comparable discriminative ability for predicting outcome. Calibration and accuracy indices are superior for APACHE II.

Determinants of prolonged intensive care unit stay in patients after cardiac surgery: a prospective observational study

BACKGROUND Prolonged intensive care unit (ICU) stay of patients after cardiac surgery has a major impact on overall cost and resource utilization. The aim of this study was to identify perioperative factors which prolong stay in ICU. METHODS All adult patients from a single, specialized cardiac center who were admitted to the ICU after cardiac surgery during a 2-month period were included. Demographic and clinical characteristics, comorbidities, preoperative use of drugs, intraoperative variables, and postoperative course were recorded. Hemodynamic and blood gas measurements were recorded at four time intervals during the first 24 postoperative hours. Routine hematologic and biochemical laboratory results were recorded preoperatively and in the first postoperative hours. RESULTS During the study period 145 adult patients underwent cardiac surgery: 65 (45%) underwent coronary artery bypass graft surgery, 38 (26%) valve surgery, 26 (18%) combined surgery and 16 (11%) other types of cardiac operation. Seventy nine (54%) patients had an ICU stay of less than 24 hours. Random forests analysis identified four variables that had a major impact on the length of stay (LOS) in ICU; these variables were subsequently entered in a logistic regression model: preoperative hemoglobin [odds ratio (OR) =0.68], duration of aortic clamping (OR =1.01) and ratio of arterial oxygen partial pressure to inspired oxygen fraction (PaO2/FiO2) (OR =0.99) and blood glucose during the first four postoperative hours (OR =1.02). ROC curve analysis showed an AUC =0.79, P<0.001, 95% CI: 0.71-0.86. CONCLUSIONS Low preoperative hemoglobin, prolonged aortic clamping time and low PaO2/FiO2 ratio and blood glucose measured within the first postoperative hours, were strongly related with prolonged LOS in ICU.

Poststernotomy sternal osteomyelitis and mediastinitis by Trichosporon asahii: a rare occurrence with a grave prognosis

Post‐sternotomy infectious complications, including superficial and deep wound infections, sternal osteomyelitis and mediastinitis, are rarely caused by fungi. Trichosporon asahii is the main Trichosporon species that causes systemic infection in humans. Most cases involved neutropenic patients with hematologic malignancies. We report a unique case of a non‐cancer, non‐neutropenic but severely ill patient who developed an ultimately lethal T. asahii infection after sternotomy. We speculate that our patient had been colonized with the fungus and his surgical site infection may have been related to his emergency revascularization surgery. Therapy with liposomal amphotericin failed to sterilize the bloodstream despite in vitro susceptibility results. The addition of voriconazole helped sterilizing the bloodstream without changing the outcome. Physicians must be aware of the continuously expanding spectrum of infections with this emerging difficult‐to‐treat fungal pathogen.

A novel mortality prediction model for the current population in an adult intensive care unit

Background: The accurate and reliable mortality prediction is very useful, in critical care medicine. There are various new variables proposed in the literature that could potentially increase the predictive ability for death in ICU of the new predictive scoring model. Objective: To develop and validate a new intensive care unit (ICU) mortality prediction model, using data that are routinely collected during the first 24 h of ICU admission, and compare its performance to the most widely used conventional scoring systems. Methods: Prospective observational study in a medical/surgical, multidisciplinary ICU, using multivariate logistic regression modeling. The new model was developed using data from a medical record review of 400 adult intensive care unit patients and was validated on a separate sample of 36 patients, to accurately predict mortality in ICU. Results: The new model is simple, flexible and shows improved performance (ROC AUC = 0.85, SMR = 1.25), compared to the conventional scoring models (APACHE II: AUC = 0.76, SMR = 2.50, SAPS III: AUC = 0.76, SMR = 1.50), as well as higher predictive capability regarding ICU mortality (predicted mortality: 41.63 ± 31.61, observed mortality: 41.67%). Conclusion: The newly developed model is a quite simple risk‐adjusted outcome prediction tool based on 12 routinely collected demographic and clinical variables obtained from the medical record data. It appears to be a reliable predictor of ICU mortality and is proposed for further investigation aiming at its evaluation, validation and applicability to other ICUs.

Microcirculatory alterations during continuous renal replacement therapy in ICU: A novel view on the 'dialysis trauma' concept.

OBJECTIVE The purpose of this study was to evaluate microcirculation over 24 h renal replacement therapy (CRRT) in critically ill patients. METHODS We conducted a single-center, prospective, observational study, measuring microcirculation parameters, monitored by near infrared spectroscopy (NIRS) before hemodiafiltration onset (H0), and at six (H6) and 24 h (H24) during CRRT in critically ill patients. Serum Cystatin C (sCysC) and soluble (s)E-selectin levels were measured at the same time points. Twenty-eight patients [19 men (68%)] were included in the study. RESULTS Tissue oxygen saturation (StO2, %) [76.5 ± 12.5 (H0) vs 75 ± 11 (H6) vs 70 ± 16 (H24), p = 0.04], reperfusion rate, indicating endothelial function (EF, %/sec) [2.25 ± 1.44 (H0) vs 2.1 ± 1.8 (H6) vs 1.6 ± 1.4 (H24), p = 0.02] and sCysC (mg/L) [2.7 ± 0.8 (H0) vs 2.2 ± 0.6 (H6) vs 1.8 ± 0.8 (H24), p < 0.0001] significantly decreased within the 24 h CRRT. Change of EF positively correlated with changes of sCysC within 24 h CRRT (r = 0.464, p = 0.013) while in patients with diabetes the change of StO2 correlated with dose (r = − 0.8, p = 0.01). No correlation existed between hemoglobin and temperature changes with the deteriorated microcirculation indices. sE-Selectin levels in serum were elevated; no difference was established over the 24 h CRRT period. A strong correlation existed between the sE-Selectin concentration change at H6 and H24 and the mean arterial pressure change in the same period (r = 0.77, p < 0.001). CONCLUSIONS During the first 24 h of CRRT implementation in critically ill patients, deterioration of microcirculation parameters was noted. Microcirculatory alterations correlated with sCysC changes and with dose in patients with diabetes.