No additive effects of inhaled iloprost and prone positioning on pulmonary hypertension and oxygenation in acute respiratory distress syndrome.

BACKGROUND: In acute respiratory distress syndrome (ARDS), pulmonary hypertension is associated with a poor prognosis. Prone position is effective to improve oxygenation whereas inhaled iloprost can treat pulmonary hypertension. However, combination of these interventions has not been examined before. The hypothesis was that this combination had additive effects on oxygenation and pulmonary hemodynamics as compared with each intervention alone. METHODS: In a prospective, randomized cross-over study, ten pigs were anesthetized, intubated and ventilated with volume controlled ventilation. Carotid, jugular venous and pulmonary artery catheters were inserted. ARDS was induced with oleic acid (0.20 mL/kg). Measurements were repeated in randomized different sequences of prone or supine positions with or without iloprost inhalation (220 ng/kg/min) (four combinations). Systemic and pulmonary arterial pressures; arterial and mixed venous blood gases; and Qs/Qt and the resistances were recorded. RESULTS: Iloprost decreased pulmonary artery pressures (for MPAP: P=0.034) in both supine (37±10 vs. 31±8 mmHg; P<0.05) and prone positions (38±9 vs. 29±8 mmHg; P<0.05); but did not obtain a significant improvement in oxygenation in both positions. Prone position improved the oxygenation (p<0.0001) compared to supine position in both with (361±140 vs. 183±158 mmHg, P<0.05) or without iloprost application (331±112 vs. 167±117 mmHg, P<0.05); but did not achieve a significant decrease in MPAP. CONCLUSION: Although iloprost reduced pulmonary arterial pressures, and prone positioning improved oxygenation; there are no additive effects of the combination of both interventions on both parameters. To treat both pulmonary hypertension and hypoxemia, application of iloprost in prone position is suggested.

A recruitment maneuver improves apneic oxygenation.

BACKGROUND: Apneic oxygenation (AO) is applied during surgery and in intensive care units. Even with AO, apnea is associated with progressive hypoxemia, limiting the tolerable amount of time in AO. This experimental study evaluates the effects of a recruitment maneuver (RM) on oxygenation, CO2 retention, and survival times during prolonged apnea, supported or not supported with intratracheal apneic oxygenation. METHODS: Following Ethic Committee approval, 15 male Sprague-Dawley rats were anesthetized and ventilated with PCV and FiO2:1 for 15 minutes. After obtaining a basal arterial blood-gas sample, the rats were randomized into 3 groups and disconnected from the ventilator: group (G) 1 (N.=6): AO with a cannula inserted into the carina; G2 (N=6): RM (40 cm H2O CPAP applied for 30 seconds) before AO; and G3 (N.=3): no application after disconnection (G3 was stopped after the first 3 subjects died within 3 minutes). Further arterial blood-gas samples were taken after 1, 3, and 6 minutes (T1, T3, and T6). Survival times after the start of AO were recorded. RESULTS: G2 was associated with significantly higher values of PaO2 at T3 and T6 when compared to G1 (345±56 vs. 233±65 mm Hg at T3 and 258±31 vs. 180±31 mm Hg at T6, respectively, P<0.05). There were significant changes in PaO2, pH, and PaCO2 over time in all subjects, but no differences were observed between G1 and G2 in pH or PaCO2. Survival time in G2 was significantly longer as opposed to G1 (G1: 10.3±2.3 min; G2: 14.3±3.6 min; P<0.05). CONCLUSION: RM prior to AO prolongs tolerance to apnea, probably by increasing the time before intolerable hypoxemia occurs, without a significant difference in PaCO2 levels.

Effects of thoracic epidural anaesthesia on pulmonary venous admixture and oxygenation during one-lung ventilation.

BACKGROUND: In this clinical randomized study, the effects of four anaesthesia techniques during one-lung ventilation [total intravenous anesthesia (TIVA) with or without thoracic epidural anaesthesia (TEA) (G-TIVA-TEA and G-TIVA), isoflurane anaesthesia with or without TEA (G-ISO-TEA and G-ISO)] on pulmonary venous admixture (Qs/Qt) and oxygenation (OLV) were investigated. METHODS: In 100 patients (four groups, 25 patients in each) undergoing thoracotomy, a thoracic epidural catheter was inserted pre-operatively. In G-TIVA-TEA and G-ISO-TEA, bupivacaine 0.1% + 0.1 mg/ml morphine was administered intra-operatively (10 ml of first bolus + 7 ml/h infusion). Propofol infusion or isoflurane concentration was adjusted to keep a bispectral index (BIS) of between 40 and 50 in all groups. FiO(2) was 0.8 during OLV and 0.5 before and after OLV. Partial arterial and central venous oxygen pressures (PaO(2) and PvO(2)), arterial and venous oxygen saturations and Qs/Qt values were recorded before, during and after OLV. RESULTS: During OLV, PaO(2) was significantly higher and Qs/QT significantly lower in G-TIVA-TEA and G-TIVA compared with G-ISO-TEA and G-ISO (PaO2: 188 +/- 36; 201 +/- 39; 159 +/- 33; 173 +/- 42 mmHg, respectively; Qs/Qt: 31.2 +/- 7.4; 28.2 +/- 7; 36.7 +/- 7.1; 33.7 +/- 7.7%, respectively). No statistical changes were observed in patients with TEA compared with without TEA in any measurement. CONCLUSION: During OLV, TEA does not significantly affect the oxygenation and Qs/Qt and can be used safely regardless of whether TIVA or inhalation techniques are used.

PER-1- and OXA-10-like beta-lactamases in ceftazidime-resistant Pseudomonas aeruginosa isolates from intensive care unit patients in Istanbul, Turkey.

The presence of PER-1- and OXA-10-like beta-lactamases was investigated by PCR in 49 ceftazidime-resistant Pseudomonas aeruginosa isolates from patients hospitalised in the 24-bed general intensive care unit of the Istanbul Faculty of Medicine during a 12-month period between February 1999 and February 2000. The clonal relatedness of the isolates was investigated by random amplified polymorphic DNA (RAPD) analysis, and the sequences of the PER-1 and OXA genes from all isolates were determined. The rates of resistance of the isolates to imipenem, aztreonam and cefepime were 98%, 92% and 96%, respectively, and to piperacillin and piperacillin-tazobactam were 41% and 37%, respectively. Using the double-disk synergy test, 37% (18/49) of the isolates were identified as extended-spectrum beta-lactamase producers. The PER-1 gene was identified in 86% (42/49) and the OXA-10 gene in 55% (27/49) of the ceftazidime-resistant isolates. Of isolates carrying the PER-1 gene, 48% (20/42) also carried the OXA-10 gene. The respective nucleotide sequences were identical for each isolate. Sixteen RAPD patterns were detected among the PER-1-positive isolates, but 60% (25/42) of the PER-1-positive isolates belonged to two distinct patterns, while the remainder exhibited a wide clonal diversity. The results indicated that the prevalence of PER-1- and OXA-10-like beta-lactamases remains high among ceftazidime-resistant P. aeruginosa isolates in Turkey.

Reliability of procalcitonin as a severity marker in critically ill patients with inflammatory response.

Procalcitonin (PCT) is increasingly recognised as an important diagnostic parameter in clinical evaluation of the critically ill. This prospective study was designed to investigate PCT as a diagnostic marker of infection in critically ill patients with sepsis. Eighty-five adult ICU patients were studied. Four groups were defined on the basis of clinical, laboratory and bacteriologic findings as systemic inflammatory response syndrome (SIRS) (n = 10), sepsis (n = 16), severe sepsis (n = 18) and septic shock (n = 41). Data were collected including C-reactive protein (CRP), PCT levels and Sequential Organ Failure Assessment and Acute Physiology and Chronic Health Evaluation II scores on each ICU day. PCT levels were significantly higher in patients with severe sepsis and septic shock (19.25 +/- 43.08 and 37.15 +/- 61.39 ng/ml) than patients with SIRS (0.73 +/- 1.37 ng/ml) (P < 0.05 for each comparison). As compared with SIRS patients, plasma PCT levels were significantly higher in infected patients (21.9 +/- 47.8 ng/ml), regardless of the degree of sepsis (P < 0.001). PCT showed a higher sensitivity (73% versus 35%) and specificity (83% versus 42%) compared to CRP in identifying infection as a cause of the inflammatory response. Best cut-off levels were 1.31 ng/ml for PCT and 13.9 mg/dl for CRP. We suggest that PCT is a more reliable marker than CRP in defining infection as a cause of systemic inflammatory response.

[The effect of pentaglobin therapy on prognosis in patients with severe sepsis]. / Agir sepsis hastalarinda Pentaglobin tedavisinin prognoz üzerine etkisi.

This study was designed to assess the effects of polyclonal immunoglobulin administration on septic shock incidence and prognosis in patients with severe sepsis. Patients with severe sepsis were randomly allocated into two groups. One group (n = 21) received 5 ml/kg/day IgM enriched immunoglobulin preparation (Pentaglobin) for 3 days. Other group did not receive immunoglobulins (n = 18). Simplified Organ Failure Assessment (SOFA) scores, leucocyte count, duration of mechanical ventilation, ICU stay, duration of severe sepsis did not show significant differences between the groups, as regards to septic shock incidence and mortality. However, a significant decrease in procalcitonin levels were detected only in patients who received pentaglobin (p = 0.001). Mortality rate was 5/21 (23.8%) in pentaglobin group and 5/18 (27.7%) in the control group. Although pentaglobin therapy could not achieve a statistically significant improvement in septic shock occurrence and mortality, the constant reduction in procalcitonin levels indicated the beneficial effects of immunotherapy on the severity of inflammatory response to infection in severe sepsis.