Left ventricular overloading identified by critical care echocardiography is key in weaning-induced pulmonary edema.

PURPOSE: To assess the role of left ventricular overload and cumulated fluid balance in the development weaning-induced pulmonary edema (WIPO). METHODS: Ventilated patients in sinus rhythm with COPD and/or heart failure (ejection fraction ≤ 40%) were studied. Echocardiography was performed immediately before and during a 30-min spontaneous breathing trial (SBT) using a T-tube. Patients who failed were treated according to echocardiography results before undergoing a second SBT. RESULTS: Twelve of 59 patients failed SBT, all of them developing WIPO. Patients who succeeded SBT had lower body weight (- 2.5 kg [- 4.8; - 1] vs. + 0.75 kg [- 2.95; + 5.57]: p = 0.02) and cumulative fluid balance (- 2326 ml [- 3715; + 863] vs. + 143 ml [- 2654; + 4434]: p = 0.007) than those who developed WIPO. SBT-induced central hemodynamic changes were more pronounced in patients who developed WIPO, with higher E wave velocity (122 cm/s [92; 159] vs. 93 cm/s [74; 109]: p = 0.017) and E/A ratio (2.1 [1.2; 3.6] vs. 0.9 [0.8; 1.4]: p = 0.001), and shorter E wave deceleration time (85 ms [72; 125] vs. 147 ms [103; 175]: p = 0.004). After echocardiography-guided treatment, all patients who failed the first SBT were successfully extubated. Fluid balance was then negative (- 2224 ml [- 7056; + 100] vs. + 146 ml [- 2654; + 4434]: p = 0.005). Left ventricular filling pressures were lower (E/E': 7.3 [5; 10.4] vs. 8.9 [5.9; 13.1]: p = 0.028); SBT-induced increase in E wave velocity (+ 10.6% [- 2.7/ + 18] vs. + 25.6% [+ 12.7/ + 49]: p = 0.037) and of mitral regurgitation area were significantly smaller. CONCLUSION: In high-risk patients, WIPO appears related to overloaded left ventricle associated with excessive fluid balance. SBT-induced central hemodynamic changes monitored by CCE help in guiding therapy for successful weaning.

Prevalence and prognostic value of acute cor pulmonale and patent foramen ovale in ventilated patients with early acute respiratory distress syndrome: a multicenter study.

PURPOSE: We sought to determine the prevalence of and factors associated with acute cor pulmonale (ACP) and patent foramen ovale (PFO) at the early phase of acute respiratory distress syndrome (ARDS), and to assess their relation with mortality. METHODS: In this prospective multicenter study, 200 patients submitted to protective ventilation for early moderate to severe ARDS [PaO2/F(I)O2: 115 ± 39 with F(I)O2: 1; positive end-expiratory pressure (PEEP): 10.6 ± 3.1 cmH2O] underwent transthoracic (TTE) and transesophageal echocardiography (TEE) <48 h after admission. Echocardiograms were independently interpreted by two experts. Factors associated with ACP, PFO, and 28-day mortality were identified using multivariate regression analysis. RESULTS: TEE depicted ACP in 45/200 patients [22.5%; 95% confidence interval (CI) 16.9-28.9%], PFO in 31 patients (15.5%; 95% CI 10.8-21.3%), and both ACP and PFO in 9 patients (4.5%; 95% CI 2.1-8.4%). PFO shunting was small and intermittent in 27 patients, moderate and consistent in 4 patients, and large or extensive in no instances. PaCO2 >60 mmHg was strongly associated with ACP [odds ratio (OR) 3.70; 95% CI 1.32-10.38; p = 0.01]. No factor was independently associated with PFO, with only a trend for age (OR 2.07; 95% CI 0.91-4.72; p = 0.08). Twenty-eight-day mortality was 23%. Plateau pressure (OR 1.15; 95% CI 1.05-1.26; p < 0.01) and air leaks (OR 5.48; 95% CI 1.30-22.99; p = 0.02), but neither ACP nor PFO, were independently associated with outcome. CONCLUSIONS: TEE screening allowed identification of ACP in one-fourth of patients submitted to protective ventilation for early moderate to severe ARDS. PFO shunting was less frequent and never large or extensive. ACP and PFO were not related to outcome.

Number of supervised studies required to reach competence in advanced critical care transesophageal echocardiography.

PURPOSE: To determine the minimum number of supervised transesophageal echocardiography (TEE) that intensivists should perform to reach competence in performing and interpreting a comprehensive hemodynamic assessment in ventilated intensive care unit patients. METHODS: Prospective and multicentric study. Skills of 41 intensivists (trainees) with no (level 0) or little (level 1) experience in echocardiography was evaluated over a 6-month period, using a previously validated skills assessment score (/40 points). Trainees were evaluated at 1 (M1), 3 (M3) and 6 months (M6) by their tutor while performing 2 TEE examinations in ventilated patients. Competence was a priori defined by a skills assessment score >35/40 points. RESULTS: No difference in the score was observed between level 0 and level 1, except at M1 (22.2 ± 6.2 vs. 25.9 ± 4.4 points, p = 0.03). After 6 months, trainees performed a mean of 31 ± 9 supervised TEE. The score gradually increased from M1 to M6 (24 ± 6, 32 ± 3, and 35 ± 3 points, p < 0.001), regardless of trainees' initial level. A correlation was found between the number of supervised TEE and the skills assessment score (r (2) = 0.60; p < 0.001). The number of supervised TEE examinations which best predicted a score >35/40 points was 25, with a sensitivity of 81 % and a specificity of 93 % (area under the ROC curve: 0.91 ± 0.04). A number of 31 supervised TEE examinations predicted a score >35/40 points with a specificity close to 100 %. CONCLUSION: The performance of at least 31 supervised examinations over 6 months is required to reach competence in TEE driven hemodynamic evaluation of ventilated patient.

A pilot study on safety and clinical utility of a single-use 72-hour indwelling transesophageal echocardiography probe.

PURPOSE: To evaluate the hemodynamic monitoring capability and safety of a single-use miniaturized transesophageal echocardiography (TEE) probe left in place in ventilated critically ill patients. METHODS: The probe was inserted in 94 patients and designed to be left in place for up to 72 h. Three views were obtained: the superior vena caval transverse, the mid-esophageal four-chamber, and the transgastric mid-papillary short-axis views. Observational data on the feasibility of insertion, complications, image quality, and influence on management were recorded and analyzed. RESULTS: No failure of probe insertion was observed. The nasogastric tube had to be removed in 17 % of cases. Image quality was judged as adequate or optimal in 91/94 (97 %) of cases in the superior vena caval view, 89/94 (95 %) of cases in the four-chamber view, and 86/94 (91 %) of cases in the short-axis view. The duration of monitoring was 32 ± 23 h, allowing 2.8 ± 1.6 hemodynamic evaluations per patient that led to a mean of 1.4 ± 1.5 therapeutic changes per patient. Among the 263 hemodynamic assessments, 132 (50 %) had a direct therapeutic impact in 62 patients (66 %). Two patients developed lip ulceration from the probe, and two patients had self-limited gastric bleeding. CONCLUSION: The single-use miniaturized probe could be inserted in all patients. Image quality was acceptable in the majority of cases, and the information derived from the device was useful in making management decisions in patients with hemodynamic failure on ventilatory support. Further studies are needed to confirm the good tolerance and to compare the new device with other hemodynamic monitoring techniques.

Monitoring of metformin-induced lactic acidosis in a diabetic patient with acute kidney failure and effect of hemodialysis.

Metformin associated lactic acidosis (MALA) is a serious complication occurring especially in elderly patients given high doses of the drug. We report a non-fatal case of MALA with pronounced acidosis (pH 6.76, lactate 30.81 mmol/l) and high metformin concentrations (127 mg/l) in a patient who had developed acute renal failure after undergoing an operation. Multiple measurements of biological parameters and metformin blood concentrations showed the effectiveness of repeated hemodialysis sessions on metformin elimination. Cases previously reported with such a severe MALA were associated with a high mortality rate. We show that close monitoring in an intensive care unit together with prompt and repeated dialysis sessions can lead to a favorable outcome.

The rendu-osler-weber disease revealed by a refractory hypoxemia and severe cerebral fat embolism.

The Rendu-Osler-Weber disease is a genetic disease which may lead to severe hemorrhage and less frequently to severe organ dysfunction. We report the case of a 22-year-old patient with no personal medical history who was involved in a motorcycle accident and exhibited severe complications related to large arteriovenous pulmonary shunts during his ICU stay. The patient developed an unexplained severe hypoxemia which was attributed to several arteriovenous shunts of the pulmonary vasculature by a contrast study during a transesophageal echocardiographic examination. The course was subsequently complicated by a prolonged coma associated with hemiplegia which was attributed to a massive paradoxical fat embolism in the setting of an untreated femoral fracture. In addition to hemorrhagic complications which may lead to intractable shock, arteriovenous malformations associated with the Rendu-Osler-Weber disease may involve the pulmonary vasculature and result in unexpected complications, such as hypoxemia or severe cerebral fat embolism in high-risk patients.

Initial resuscitation guided by the Surviving Sepsis Campaign recommendations and early echocardiographic assessment of hemodynamics in intensive care unit septic patients: a pilot study.

OBJECTIVE: To compare therapeutic interventions during initial resuscitation derived from echocardiographic assessment of hemodynamics and from the Surviving Sepsis Campaign guidelines in intensive care unit septic patients. DESIGN AND SETTING: Prospective, descriptive study in two intensive care units of teaching hospitals. METHODS: The number of ventilated patients with septic shock who were studied was 46. Transesophageal echocardiography was first performed (T1<3 hrs after intensive care unit admission) to adapt therapy according to the following predefined hemodynamic profiles: fluid loading (index of collapsibility of the superior vena cava≥36%), inotropic support (left ventricular fractional area change<45% without relevant index of collapsibility of the superior vena cava), or increased vasopressor support (right ventricular systolic dysfunction, unremarkable transesophageal echocardiography study consistent with sustained vasoplegia). Agreement for treatment decision between transesophageal echocardiography and Surviving Sepsis Campaign guidelines was evaluated. A second transesophageal echocardiography assessment (T2) was performed to validate therapeutic interventions. RESULTS: Although transesophageal echocardiography and Surviving Sepsis Campaign approaches were concordant to manage fluid loading in 32 of 46 patients (70%), echocardiography led to the absence of blood volume expansion in the remaining 14 patients who all had a central venous pressure<12 mm Hg. Accordingly, the agreement was weak between transesophageal echocardiography and Surviving Sepsis Campaign for the decision of fluid loading (κ: 0.37 [0.16;0.59]). With a cut-off value<8 mm Hg for central venous pressure, κ was 0.33 [-0.03;0.69]. Inotropes were prescribed based on transesophageal echocardiography assessment in 14 patients but would have been decided in only four patients according to Surviving Sepsis Campaign guidelines. As a result, the agreement between the two approaches for the decision of inotropic support was weak (κ: 0.23 [-0.04;0.50]). No right ventricular dysfunction was observed. No patient had anemia and only three patients with transesophageal echocardiography documented left ventricular systolic dysfunction had a central venous oxygen saturation<70%. CONCLUSIONS: A weak agreement was found in the prescription of fluid loading and inotropic support derived from early transesophageal echocardiography assessment of hemodynamics and Surviving Sepsis Campaign guidelines in patients presenting with septic shock.

Localized cardiac tamponade after open-heart surgery.

PURPOSE: To describe the clinical presentation and echocardiographic findings associated with localized tamponade after open-heart surgery. METHODS: Retrospective analysis of a case series with a surgically proven diagnosis. RESULTS: Among 23 patients with surgically proven localized cardiac tamponade after elective open-heart surgery, 5 patients (22%) died in the ICU from multiorgan failure. At the time of diagnosis (median delay: 2 days; range: 0-8 days), shock was present in 19 patients, 8 of them being hypotensive. Transthoracic echocardiography (TTE) depicted the localized cardiac tamponade in 3 of 4 examined patients, whereas transesophageal echocardiography (TEE) was always conclusive. The right atrium was primarily involved, solely (n = 11) or with the right ventricle (n = 5), whereas the left cardiac cavities were less frequently compressed (left atrium: n = 6, left ventricle: n = 1). The free wall curvature of the involved cardiac chamber was consistently inverted, and blood flow turbulences were depicted in 12 patients. Surgical removal of the compressive hematoma improved the clinical status of 18 patients (78%) who were discharged from the hospital. CONCLUSION: Since localized tamponade complicating open-heart surgery has various, non-specific clinical presentations and TTE is not diagnostic, indications of TEE must be liberal in this setting to prompt diagnosis and surgical reoperation.

Assessment of left ventricular ejection fraction using an ultrasonic stethoscope in critically ill patients.

INTRODUCTION: Assessment of cardiac function is key in the management of intensive care unit (ICU) patients and frequently relies on the use of standard transthoracic echocardiography (TTE). A commercially available new generation ultrasound system with two-dimensional imaging capability, which has roughly the size of a mobile phone, is adequately suited to extend the physical examination. The primary endpoint of this study was to evaluate the additional value of this new miniaturized device used as an ultrasonic stethoscope (US) for the determination of left ventricular (LV) systolic function, when compared to conventional clinical assessment by experienced intensivists. The secondary endpoint was to validate the US against TTE for the semi-quantitative assessment of left ventricular ejection fraction (LVEF) in ICU patients. METHODS: In this single-center prospective descriptive study, LVEF was independently assessed clinically by the attending physician and echocardiographically by two experienced intensivists trained in critical care echocardiography who used the US (size: 135×73×28 mm; weight: 390 g) and TTE. LVEF was visually estimated semi-quantitatively and classified in one of the following categories: increased (LVEF>75%), normal (LVEF: 50 to 75%), moderately reduced (LVEF: 30 to 49%), or severely reduced (LVEF<30%). Biplane LVEF measured using the Simpson's rule on TTE loops by an independent investigator was used as reference. RESULTS: A total of 94 consecutive patients were studied (age: 60±17 years; simplified acute physiologic score 2: 41±15), 63 being mechanically ventilated and 36 receiving vasopressors and/or inotropes. Diagnostic concordance between the clinically estimated LVEF and biplane LVEF was poor (Kappa: 0.33; 95% CI: 0.16 to 0.49) and only slightly improved by the knowledge of a previously determined LVEF value (Kappa: 0.44; 95% CI: 0.22 to 0.66). In contrast, the diagnostic agreement was good between visually assessed LVEF using the US and TTE (Kappa: 0.75; CI 95%: 0.63 to 0.87) and between LVEF assessed on-line and biplane LVEF, regardless of the system used (Kappa: 0.75; CI 95%: 0.64 to 0.87 and Kappa: 0.70; CI 95%: 0.59 to 0.82, respectively). CONCLUSIONS: In ICU patients, the extension of physical examination using an US improves the ability of trained intensivists to determine LVEF at bedside. With trained operators, the semi-quantitative assessment of LVEF using the US is accurate when compared to standard TTE.

Extracorporeal albumin dialysis in three cases of acute calcium channel blocker poisoning with life-threatening refractory cardiogenic shock.

We describe 3 patients admitted to the medical-surgical ICU in a university hospital with life-threatening cardiogenic shock after the ingestion of high doses of calcium channel blockers (8.4 g sustained-release diltiazem, 4.2 g sustained-release diltiazem, and 14.4 g slow-release verapamil). Cardiovascular failure and cardiac conduction disturbances were unresponsive to the usual therapy (eg, intravenous injection of high doses of calcium, glucagon, hyperinsulinemia-euglycemia therapy, fluid resuscitation) and to increasing doses of simultaneous infusions of adrenergic agonists. Albumin dialysis with Molecular Adsorbents Recirculating System (MARS) therapy was performed because of its unique ability to selectively remove from circulation protein-bound toxins (and potentially drugs) that are not cleared by conventional hemodialysis. A single procedure was successfully performed in each patient, which was followed by rapid weaning of adrenergic agonist agents and full recovery of the life-threatening cardiovascular failure. At 2-year follow-up, patients were asymptomatic. Albumin dialysis with MARS therapy may be effective when used as a rescue procedure in patients presenting with sustained, life-threatening cardiogenic shock as a result of massive calcium channel blocker poisoning.

Successful treatment of anterior tracheal necrosis after total thyroidectomy using vacuum-assisted closure therapy.

Total thyroidectomy involving the adjacent structures of the trachea can cause tracheal damage such as early tracheal necrosis. The authors describe the first case of anterior tracheal necrosis following total thyroidectomy treated using vacuum-assisted closure device. After two weeks of VAC therapy, there was no evidence of ongoing infection and the trachea was partially closed around a tracheotomy cannula, removed after 3 months. The use of a VAC therapy to reduce and close the tracheal rent and to create a rapid granulation tissue over tracheal structure appeared as a good opportunity after anterior tracheal necrosis.

Value of liver stiffness measured by transient elastography in the liver transplant pre-operative evaluation of the potential deceased liver donors: preliminary study.

The selection of a liver graft is crucial for the success of a transplantation. One of the determinant factors in the selection of a liver graft of quality is to assess the degree of steatosis. The aim of this study was to evaluate the feasibility of a FibroScan(®) during the liver retrieval procedure and to determine the interest of measuring liver stiffness (LS) using the FibroScan(®) as a criterion of objective assessment in the pre-donation selection of liver grafts. Of 16 FibroScan(®) performed on 16 livers of donors meeting conventional French criteria for the selection of liver grafts, the LS values were considered as abnormal in three donors (18.75%). The correspondence with the histologic analysis of the biopsies in terms of elevated steatosis was excellent. For 13 other liver grafts, the values of LS were normal as were the histologic analyses of the biopsies. A supplementary multicenter study is required in order to position the transient elastography as the objective examination in the pre-operative selection of liver grafts.

Basic critical care echocardiography: validation of a curriculum dedicated to noncardiologist residents.

OBJECTIVE: To assess the efficacy of a limited, tailored training program for noncardiologist residents without experience in ultrasound to reach competence in basic critical care echocardiography. DESIGN: Prospective descriptive clinical study. SETTING: Medical-surgical intensive care unit of a teaching hospital. PATIENTS: 201 patients (125 men; age: 61 ± 16 yrs; Simplified Acute Physiologic Score II: 37 ± 17; 145 ventilated patients) who required a transthoracic echocardiography were studied. INTERVENTION AND MEASUREMENTS: The curriculum consisted of a 12-hr learning program blending didactics, interactive clinical cases, and tutored hands-on sessions. After completion of this tailored training program, all eligible patients subsequently underwent a transthoracic echocardiography performed in random order by a recently trained resident and an experienced intensivist with expertise in critical care echocardiography who was used as a reference. The agreement between responses to clinical questions provided by the two investigators who independently interpreted the transthoracic echocardiography study at bedside was used as an indicator of effectiveness of the tested curriculum. MAIN RESULTS: Residents performed a mean of 33 transthoracic echocardiograms during the study period (range: 29-38). Experienced intensivists had significantly fewer unaddressed clinical questions than did residents (57 [5.7%] vs. 111 [11.0%] of 1,005 clinical questions: p < .0001). When compared to residents, the experienced intensivists performed shorter transthoracic echocardiography examinations (3.0 ± 1.0 min vs. 7.0 ± 2.5 min: p < .0001) with more acoustic windows (888 vs. 828 of 1,005 potential windows: p < .0001). Residents adequately assess global left ventricle systolic function (κ: 0.84; 95% confidence interval: 0.76-0.92). They accurately identified dilated left ventricle (κ: 0.90; 95% confidence interval: 0.80-1.0), dilated right ventricle (κ: 0.76; 95% confidence interval: 0.64-0.89), dilated inferior vena cava (κ: 0.79; 95% confidence interval: 0.63-0.94), and pericardial effusion (κ: 0.79; 95% confidence interval: 0.58-0.99) and diagnosed two cases of tamponade. CONCLUSIONS: A 12-hr training program blending didactics, interactive clinical cases, and tutored hands-on sessions dedicated to noncardiologist residents without experience in ultrasound appears well suited for reaching competence in basic critical care echocardiography.

Echocardiography: a help in the weaning process.

INTRODUCTION: To evaluate the ability of transthoracic echocardiography (TTE) to detect the effects of spontaneous breathing trial (SBT) on central hemodynamics and to identify indices predictive of cardiac-related weaning failure. METHODS: TTE was performed just before and at the end of a 30-min SBT in 117 patients fulfilling weaning criteria. Maximal velocities of mitral E and A waves, deceleration time of E wave (DTE), maximal velocity of E' wave (tissue Doppler at the lateral mitral annulus), and left ventricular (LV) stroke volume were measured. Values of TTE parameters were compared between baseline (pressure support ventilation) and SBT in all patients and according to LV ejection fraction (EF): >50% (n = 58), 35% to 50% (n = 30), and <35% (n = 29). Baseline TTE indices were also compared between patients who were weaned (n = 94) and those who failed (n = 23). RESULTS: Weaning failure was of cardiac origin in 20/23 patients (87%). SBT resulted in a significant increase in cardiac output and E/A, and a shortened DTE. At baseline, DTE was significantly shorter in patients with LVEF <35% when compared to other subgroups (median [25th-75th percentiles]: 119 ms [90-153]; vs. 187 ms [144-224] vs. 174 ms [152-193]; P < 0.01) and E/E' was greater (7.9 [5.4-9.1] vs. 6.0 [5.3-9.0] vs. 5.2 [4.7-6.0]; P < 0.01). When compared to patients who were successfully weaned, those patients who failed exhibited at baseline a significantly lower LVEF (36% [27-55] vs. 51% [43-55]: P = 0.04) and higher E/E' (7.0 [5.0-9.2] vs. 5.6 [5.2-6.3]: P = 0.04). CONCLUSIONS: TTE detects SBT-induced changes in central hemodynamics. When performed by an experienced operator prior to SBT, TTE helps in identifying patients at high risk of cardiac-related weaning failure when documenting a depressed LVEF, shortened DTE and increased E/E'. Further studies are needed to evaluate the impact of this screening strategy on the weaning process and patient outcome.

Efficacy of and tolerance to mild induced hypothermia after out-of-hospital cardiac arrest using an endovascular cooling system.

INTRODUCTION: We evaluated the efficacy of and tolerance to mild therapeutic hypothermia achieved using an endovascular cooling system, and its ability to reach and maintain a target temperature of 33 degrees C after cardiac arrest. METHODS: This study was conducted in the medical-surgical intensive care unit of an urban university hospital. Forty patients admitted to the intensive care unit following out-of-hospital cardiac arrest underwent mild induced hypothermia (MIH). Core temperature was monitored continuously for five days using a Foley catheter equipped with a temperature sensor. Any equipment malfunction was noted and all adverse events attributable to MIH were recorded. Neurological status was evaluated daily using the Pittsburgh Cerebral Performance Category (CPC). We also recorded the mechanism of cardiac arrest, the Simplified Acute Physiologic Score II on admission, standard biological variables, and the estimated time of anoxia. Nosocomial infections during and after MIH until day 28 were recorded. RESULTS: Six patients (15%) died during hypothermia. Among the 34 patients who completed the period of MIH, hypothermia was steadily maintained in 31 patients (91%). Post-rewarming 'rebound hyperthermia', defined as a temperature of 38.5 degrees C or greater, was observed in 25 patients (74%) during the first 24 hours after cessation of MIH. Infectious complications were observed in 18 patients (45%), but no patient developed severe sepsis or septic shock. The biological changes that occurred during MIH manifested principally as hypokalaemia (< 3.5 mmol/l; in 75% of patients). CONCLUSION: The intravascular cooling system is effective, safe and allows a target temperature to be reached fairly rapidly and steadily over a period of 36 hours.