Ultrasonography for Screening and Follow-Up of Diaphragmatic Dysfunction in the ICU: A Pilot Study.

PURPOSE: Reversibility and impact of diaphragmatic dysfunction (DD) are unknown. The principal aim was to describe diaphragmatic function as assessed by ultrasonography during weaning trials. MATERIALS AND METHODS: The present study is a 6-month single-center prospective study. All patients under mechanical ventilation for more than 7 days and eligible for a spontaneous breathing trial (SBT) were enrolled prospectively. INTERVENTION: Two blinded ultrasonographers evaluated each hemidiaphragm during SBT. Prevalence of DD among weaning failure and death and interobserver reproducibility have been evaluated. RESULTS: The 34 included patients had a mean Simplified Acute Physiology Score version II of 55.7 ± 14 and a median intensive care unit (ICU) stay length of 17 days (13-30). Diaphragmatic dysfunction was found in 13 (38%) patients, on both sides in 8. Bilateral DD resolved before ICU discharge in 5 of the 7 reevaluated patients. No weaning failures were recorded. The ICU mortality was higher in patients with DD (37% vs 5%, P = .048). Mean interobserver agreement rate was 91%. Reproducibility was better with M-mode. CONCLUSION: The ICU-acquired DD usually improves before ICU discharge but might constitute a marker for greater disease severity. The present preliminary results require confirmation in a larger prospective multicenter study.

Group A Escherichia coli-related purpura fulminans: an unusual manifestation due to an unusual strain?

We describe an exceptional case of life-threatening group A Escherichia coli-induced purpura fulminans. Genotyping of common polymorphisms in genes involved in innate immunity or coagulation did not reveal known susceptibility to such a manifestation. Genetic analysis of the strain revealed an unusual conserved virulence plasmidic region, pointing out its potential virulence.

Role of kinin B2 receptors in opioid-induced hyperalgesia in inflammatory pain in mice.

Postoperative pain management is a clinical challenge that can be complicated by opioid-induced hyperalgesia (OIH). Kinin receptors could mediate both the acute and chronic phases of inflammation and pain. A few recent studies suggest that dynorphin A could maintain neuropathic pain by activating the bradykinin (BK) receptor. Thus, the effect of a single administration of sufentanil (a µ-opioid receptor agonist) was investigated in a model of carrageenan-induced inflammatory pain using three strains of mice, i.e., knockout mice for one kinin receptor, B1R or B2R (B1KO, B2KO), and wild-type C57/BL6J mice (WT) treated with either a B1R (R954) or a B2R antagonist (HOE140) or a KKS inhibitor (aprotinin). Pain was assessed and compared between the different groups using two behavioral tests exploring mechanical (von Frey filaments) and thermal (Hargreaves test) sensitivity. Pretreatment with sufentanil induced a sustained increase in pain sensitivity with a delayed return to baseline values characterizing an OIH in carrageenan-injected mice only. Sufentanil-induced OIH was not observed in B2KO but persisted in B1KO and was blunted by aprotinin and the B2R antagonist only. Collectively, our data indicate that the B2R receptor and BK synthesis or availability are essential peripheral steps in the mechanism leading to OIH in a pain context.

Oxygen challenge test in septic shock patients: prognostic value and influence of respiratory status.

Transcutaneous oxygen pressure (PtcO2) value in response to an increase of FiO2 or oxygen challenge test (OCT) in ventilated patients has been reported to be related to peripheral perfusion and outcome during septic shock. However, patients with sepsis-related acute respiratory distress syndrome could demonstrate compromised arterial oxygenation with OCT impairment decoupled to circulatory failure. The aims of this study were to confirm the prognostic value of OCT and to explore the influence of respiratory status on OCT results. This was a prospective study set in an intensive care unit of a tertiary teaching hospital. Fifty-six mechanically ventilated patients with septic shock criteria were studied. Transcutaneous oxygen pressure was measured at baseline and after OCT, at intensive care unit admittance (T0), and 24 h later (T24). Survival at day 28 and hemodynamic and respiratory parameters were analyzed and compared according to outcome and respiratory status. Central hemodynamic parameters or static transcutaneous data did not differ between survivors and nonsurvivors at enrollment. The OCT was statistically different at T24 according to outcome (P < 0.001), but sensitivity was low (53%). Moreover, patients with low OCT results at T24 exhibited more severe respiratory failure (P < 0.01). The OCT at T24 is related to outcome but is influenced by the severity of respiratory failure. Our results suggest considering with caution hemodynamic management based on OCT in septic shock patients with altered pulmonary function.

Guidewire localization by transthoracic echocardiography during central venous catheter insertion: a periprocedural method to evaluate catheter placement.

PURPOSE: To evaluate the feasibility of guidewire detection in right cardiac cavities by transthoracic echocardiography (TTE) in order to detect catheter misplacement and to optimize central venous catheter (CVC) positioning. Ultrasonic control for catheter tip positioning was compared to that by chest X-ray (CXR). METHODS: We conducted a monocentric prospective observational study (January-November 2010). All consecutive patients undergoing CVC insertion were included. The puncture was performed using the landmark method or ultrasound guidance. TTE was performed during the procedure to follow the arrival of the guidewire in the right cardiac cavities. Catheter misplacement was defined as an aberrant position on the postprocedural CXR (catheter positioning in ipsilateral or contralateral veins). The primary endpoint was the prediction of catheter misplacement by guidewire detection in the cardiac cavities. The secondary endpoint was the optimization of the catheter tip placement in the superior vena cava. RESULTS: A total of 98 patients received 101 CVC. The guidewire was visualized in 92 cases. In five cases, the guidewire was not seen in the right cardiac cavities and CXR showed catheter misplacement. In four cases, poor echogenicity led to the ultrasound examination being abandoned. Catheter misplacement was detected by TTE with a sensitivity of 96% (CI 90-98%), a specificity of 83% (CI 44-97%), a positive predictive value of 98%, and a negative predictive value of 55%. Likelihood ratios were LR+ 5.7 (CI 0.96-34.4) and LR- 0.05 (CI 0.02-0.14). Guidewire removal under TTE avoided an excessively distal position of the catheter tip in all cases. CONCLUSION: TTE is a reliable tool to detect catheter misplacement and to optimize catheter tip positioning during the procedure of CVC insertion.