Bleeding Complications Associated With Percutaneous Tracheostomy Insertion in Patients Supported With Venovenous Extracorporeal Membrane Oxygen Support: A 10-Year Institutional Experience.

OBJECTIVES: To evaluate the bleeding complications associated with percutaneous tracheostomy while a patient is receiving venovenous extracorporeal membrane oxygen (VV ECMO) support. DESIGN: Retrospective, observational analysis. SETTING: Single-center, tertiary, academic institution. PARTICIPANTS: All consecutive patients on VV ECMO over a 10 year-period undergoing percutaneous tracheostomy. INTERVENTIONS: Percutaneous tracheostomy. MEASUREMENTS AND MAIN RESULTS: Fifty percutaneous tracheostomies were performed in patients requiring VV ECMO support over the 10-year period. The authors observed a 40% incidence of bleeding, with 32% of these incidences characterized as minor (self-limiting, localized stomal ooze) and 8% characterized as significant (necessitating surgical control and frequent packing or accompanied by a decrease in hemoglobin >20%). CONCLUSIONS: Bleeding is associated with percutaneous tracheostomy and is self-limiting in the majority of patients.

Patients Discharged From the Intensive Care Unit on a Dopamine Infusion-A Retrospective, Observational Study.

OBJECTIVE: To assess the safety of discharging cardiac surgical patients from the intensive care unit (ICU) to wards while the patients are still receiving a dopamine infusion. DESIGN: Retrospective, observational study. SETTING: Cardiothoracic ICU of a tertiary academic hospital in the United Kingdom. PARTICIPANTS: The study comprised all cardiac surgical patients older than 18 years and admitted between September 1, 2015 and September 16, 2016 to the ICU and subsequently discharged to a surgical ward. Patients were divided in the following 2 groups: a dopamine group with patients discharged with a dopamine infusion and a control group with patients discharged without any dopamine infusion. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The hospital mortality rate was comparable in both groups (0.7% in the dopamine group v 0.2% in the control group [p = 0.11]), despite that the median logistic EuroSCORE was significantly higher in the dopamine group (7.0 v 3.8 [p < 0.01]). The ICU readmission rate was higher in the dopamine group (6.6% v 2.4%; p < 0.01). ICU and hospital lengths of stay were longer in the dopamine group (1.7 v 0.9 days [p < 0.01] and 11.4 v 8.0 days [p < 0.01], respectively). CONCLUSIONS: Despite a higher ICU readmission rate, ICU discharge of patients on dopamine infusion was not associated with increased mortality.

Preload-adjusted left ventricular dP/dtmax: a sensitive, continuous, load-independent contractility index.

The classical indicators of left ventricular (LV) performances have been derived from pressure-volume (PV) and stroke work-volume plots obtained during various loading or pharmacological interventions. More recently, the preload-adjusted maximal change in pressure over time (PAdP/dtmax), derived from single beat PV analysis, has been shown to reflect the LV systolic performance accurately in varying conditions of inotropy and afterload. The objective of this study was to address whether PAdP/dtmax is a valid indicator of LV function in the setting of large preload variations, compared with the classical dP/dtmax-end-diastolic volume (EDV) and stroke work-EDV (preload recruitable stroke work) relationships. Nine anaesthetized and mechanically ventilated rats were instrumented with a ventricular conductance catheter. Stepwise preload reduction was achieved by repeated blood withdrawals (up to a total of 5 ml). Steady-state and dynamic PV loops were recorded during brief occlusion of the inferior vena cava, and LV function parameters were derived from these recordings. Our results demonstrate that PAdP/dtmax behaved in a similar manner to preload recruitable stroke work, reflecting well-maintained LV contractility during controlled haemorrhage until mean arterial pressure decreased below 40 mmHg. In contrast, dP/dtmax-EDV increased significantly and exhibited a curvilinear response that was associated with a large inter- and intra-animal variability. In a model of acute preload reduction, PAdP/dtmax was found to be the best indicator of systolic LV function. Given its simplicity, this real-time index derived from single beat analysis should be tested further in clinical settings.

Superiority of desflurane over sevoflurane and isoflurane in the presence of pressure-overload right ventricle hypertrophy in rats.

BACKGROUND: Pulmonary hypertension and associated pressure-overload right ventricular (RV) hypertrophy represent a tremendous challenge for the anesthesiologist, as optimal perioperative management is mandatory. However, the ideal anesthetic agent remains unknown because scientific evidence is lacking. METHODS: Twenty-eight rats were randomly assigned to a control or a monocrotaline group (60 mg kg). Four weeks later, animals were anesthetized, instrumented with a RV conductance catheter, and underwent well-controlled dose-responses to isoflurane, desflurane, and sevoflurane inhalation (minimum alveolar concentrations 0.5, 1.0, 1.5). RESULTS: Compared with controls, rats injected with monocrotaline presented with RV hypertrophy, increased afterload, and contractility, without change in cardiac output. The ratio of pressures in the right over the left circulation increased. The halogenated volatiles differently altered hemodynamics. Sevoflurane reduced RV contractility (more than 50%) and the right over left pressures ratio increased (from 0.41 ± 0.08 [SD] to 0.82 ± 0.14; P < 0.0001) secondary to profound concomitant systemic vasodilation, demonstrating a critical pressure gradient between right and left circulations. Despite significantly higher RV systolic pressures and afterload, desflurane decreased RV contractility much less (<10%; P < 0.0001 vs. sevoflurane) and maintained the right over left pressures ratio at more favorable values (0.47 ± 0.07; P < 0.0001 vs. sevoflurane). Isoflurane presented intermediate effects. CONCLUSION: In the presence of pressure-overload RV hypertrophy, hemodynamics are better preserved under desflurane inhalation, whereas sevoflurane-and to a lesser extent isoflurane-cause large discrepancies on the left and right circulations, raising the right over left pressures ratio to critical levels despite a conserved cardiac output.

Effect of perioperative systemic α2 agonists on postoperative morphine consumption and pain intensity: systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Systemic α2 agonists are believed to reduce pain and opioid requirements after surgery, thus decreasing the incidence of opioid-related adverse effects, including hyperalgesia. METHODS: The authors searched for randomized placebo-controlled trials testing systemic α2 agonists administrated in surgical patients and reporting on postoperative cumulative opioid consumption and/or pain intensity. Meta-analyses were performed when data from 5 or more trials and/or 100 or more patients could be combined. RESULTS: Thirty studies (1,792 patients, 933 received clonidine or dexmedetomidine) were included. There was evidence of postoperative morphine-sparing at 24 h; the weighted mean difference was -4.1 mg (95% confidence interval, -6.0 to -2.2) with clonidine and -14.5 mg (-22.1 to -6.8) with dexmedetomidine. There was also evidence of a decrease in pain intensity at 24 h; the weighted mean difference was -0.7 cm (-1.2 to -0.1) on a 10-cm visual analog scale with clonidine and -0.6 cm (-0.9 to -0.2) with dexmedetomidine. The incidence of early nausea was decreased with both (number needed to treat, approximately nine). Clonidine increased the risk of intraoperative (number needed to harm, approximately nine) and postoperative hypotension (number needed to harm, 20). Dexmedetomidine increased the risk of postoperative bradycardia (number needed to harm, three). Recovery times were not prolonged. No trial reported on chronic pain or hyperalgesia. CONCLUSIONS: Perioperative systemic α2 agonists decrease postoperative opioid consumption, pain intensity, and nausea. Recovery times are not prolonged. Common adverse effects are bradycardia and arterial hypotension. The impact of α2 agonists on chronic pain or hyperalgesia remains unclear because valid data are lacking.

Relevance of the volume-axis intercept, V0, compared with the slope of end-systolic pressure-volume relationship in response to large variations in inotropy and afterload in rats.

The end-systolic pressure-volume relationship (ESPVR) is proposed and used as a reliable index of left ventricular (LV) contractility despite the fact that its afterload independence has been challenged. Furthermore, the physiological relevance of its volume-axis intercept, V(0), remains unclear. Systemic haemodynamics and pressure-volume loops obtained by inferior vena cava occlusion were recorded in 21 rats anaesthetized by isoflurane inhalation and instrumented with a conductance pressure-volume catheter in response to incremental I.V. doses of adrenaline, dobutamine, phenylephrine, metoprolol, papaverine and isoflurane inhalation. In conditions with large variations (± 100%) of both inotropy and afterload, infusion of negative inotropic drugs was associated with a dose-dependent rightward shift of ESPVR accompanied by a decrease in its slope (end-systolic elastance, E(es)), whereas positive inotropic agents produced an isolated decrease in V(0). With the predominant vasoactive drugs, there was a dose-dependent change in E(es) without major horizontal shifts, demonstrating that this slope mainly represents LV afterload rather than inotropy. When contractility was altered, V(0) was negatively correlated to the preload-adjusted contractility index, PAdP/dt(max), demonstrating that a reduced V(0) provides a good reflection of increased LV contractility. From these results, we computed a logarithmically adjusted E(es)/V(0) ratio, which resulted in reasonably strong concordance with PAdP/dt(max), including all the investigated drugs and dosages [n = 288; bias, 0.8 ± 16.2% (SD)]. Concordance with E(es) (bias, 7.2 ± 58.7%) or V(0) (bias, -0.6 ± 33.4%), used alone or with other commonly used contractility indices, was far less significant. In contrast to E(es), V(0) provides a relatively good LV contractility index because it is much less sensitive to afterload.

[Cardiac biomarkers and pulmonary embolism: prognostic stratification]. / Biomarqueurs cardiaques et embolie pulmonaire: stratification pronostique.

In hemodynamically stable patients with signs of right ventricular dysfunction, the mortality related to acute pulmonary embolism (PE) may be as high as 10%. In the absence of any haemodynamic and cardiac repercussion, the clinical evolution is benign and outpatient treatment may be contemplated. It is therefore mandatory to develop tools for early prognostic stratification in order to improve efficient patient care. This article discusses more specifically the role of cardiac biomarkers (natriuretic peptides and troponin) in assessing PE prognosis and severity at the time of the diagnosis.