Echocardiographic assessment of pulmonary artery occlusion pressure in ventilated patients: a transoesophageal study.

BACKGROUND: Non-invasive evaluation of left ventricular filling pressure has been scarcely studied in critically ill patients. Accordingly, we prospectively assessed the ability of transoesophageal echocardiography (TEE) Doppler to predict an invasive pulmonary artery occlusion pressure (PAOP) < or = 18 mmHg in ventilated patients. METHODS: During two consecutive 3-year periods, TEE Doppler parameters were compared to right heart catheterisation derived PAOP used as reference in 88 ventilated patients, haemodynamically stable and in sinus rhythm (age: 63 +/- 14 years; simplified acute physiologic score (SAPS) II: 45 +/- 12). During the initial period (protocol A), threshold values of pulsed-wave Doppler parameters to predict an invasive PAOP < or = 18 mmHg were determined in 56 patients. Derived Doppler values were prospectively tested during the subsequent period (protocol B) in 32 patients. RESULTS: In protocol A, Doppler parameters had similar area under the receiver operating characteristic (ROC) curve. In protocol B, mitral E/A < or = 1.4, pulmonary vein S/D > 0.65 and systolic fraction > 44% best predicted an invasive PAOP < or = 18 mmHg. Lateral E/E' < or = 8.0 or E/Vp < or = 1.7 predicted a PAOP < or = 18 mmHg with a sensitivity of 83% and 80%, and a specificity of 88% and 100%, respectively. Areas under ROC curves of lateral E/E' and E/Vp were similar (0.91 +/- 0.07 vs 0.92 +/- 0.07: p = 0.53), and not significantly different from those of pulsed-wave Doppler indices. CONCLUSION: TEE accurately predicts invasive PAOP < or = 18 mmHg in ventilated patients. This further increases its diagnostic value in patients with suspected acute lung injury/acute respiratory distress syndrome.

Cardiac morphological and functional changes during early septic shock: a transesophageal echocardiographic study.

OBJECTIVE: The objective was to prospectively evaluate cardiac morphological and functional changes using transesophageal echocardiography (TEE) during early septic shock. DESIGN: Prospective, observational study. SETTING: Medical-surgical intensive care unit of a teaching hospital. PATIENTS AND PARTICIPANTS: Ventilated patients with septic shock, sinus rhythm and no cardiac disease underwent TEE within 12h of admission (Day0), after stabilization of hemodynamics by fluid loading (median volume: 4.9l [lower and upper quartiles: 3.7-9.6l]) and vasopressor therapy, and after vasopressors were stopped (Dayn). MEASUREMENTS AND RESULTS: Thirty-five patients were studied (median age: 60 years [range 44-68]; SAPS II: 53 [46-62]; SOFA score: 9 [8-11]) and 9 of them (26%) died while on vasopressors. None of the patients exhibited TEE findings of cardiac preload dependence. Between Day0 and Dayn (7 days [range 6-9]), mean left ventricular (LV) ejection fraction (EF) increased (47 +/- 20 vs. 57 +/- 14%: p < 0.05), whereas mean LV end-diastolic volume decreased (97 +/- 25 vs. 75 +/- 20ml: p < 0.0001). Out of 16 patients (46%) with LV systolic dysfunction on Day0, 12 had normal LVEF on Dayn and 4 patients fully recovered by Day28. Only 4 women had LV dilatation (range, LV end-diastolic volume: 110-148ml) on Day0, but none on Dayn. Doppler tissue imaging identified an LV diastolic dysfunction in 7 patients (20%) on Day0 (3 with normal LVEF), which resolved on Dayn. CONCLUSIONS: This study confirms that LV systolic and diastolic dysfunctions are frequent, but LV dilatation is uncommon in fluid-loaded septic patients on vasopressors. All abnormalities regressed in survivors, regardless of their severity. DESCRIPTORS: Shock: clinical studies (38), Cardiovascular monitoring (34).

Focused training for goal-oriented hand-held echocardiography performed by noncardiologist residents in the intensive care unit.

OBJECTIVE: We sought to evaluate the efficacy of a limited training dedicated to residents without knowledge in ultrasound for performing goal-oriented echocardiography in ICU patients. DESIGN: Prospective pilot observational study. SETTING: Medical-surgical ICU of a teaching hospital. PATIENTS: 61 consecutive adult ICU patients (SAPS II score: 38 +/- 17; 46 ventilated patients) requiring a transthoracic echocardiography were studied. INTERVENTIONS: After a curriculum including a 3-h training course and 5 h of hands-on training, one of four noncardiologist residents and an intensivist experienced in ultrasound subsequently performed hand-held echocardiography (HHE), independently and in random order. Assessable "rule in, rule out" clinical questions were purposely limited to easily identifiable conditions by the sole use of two-dimensional imaging. MEASUREMENTS AND RESULTS: When compared with residents, the experienced intensivist performed shorter examinations (4 +/- 1 vs. 11 +/- 4 min: p < 0.0001) and had significantly less unsolved clinical questions [3 (0.8%) vs. 27 (7.4%) of 366 clinical questions: p < 0.0001]. When addressed, clinical questions were adequately appraised by residents: left ventricular systolic dysfunction [Kappa: 0.76 +/- 0.09 (95% CI: 0.59-0.93)], left ventricular dilatation [Kappa: 0.66 +/- 0.12 (95% CI: 0.43-0.90)], right ventricular dilatation [Kappa: 0.71 +/- 0.12 (95% CI: 0.46-0.95)], pericardial effusion [Kappa: 0.68 +/- 0.18 (95 CI: 0.33-1.03)], and pleural effusion [Kappa: 0.71 +/- 0.09 (95% CI: 0.53-0.88)]. The only case of tamponade was accurately diagnosed by the resident. CONCLUSIONS: Limited training of noncardiologist ICU residents without previous knowledge in ultrasound appears feasible and efficient to address simple clinical questions using point-of-care echography. Influence of the learning curve on diagnostic accuracy and potential therapeutic impact remain to be determined.

Diagnosis of left ventricular diastolic dysfunction in the setting of acute changes in loading conditions.

INTRODUCTION: Conventional pulsed wave Doppler parameters are known to be preload dependent, whereas newly proposed Doppler indices may be less influenced by variations in loading conditions. The aim of the present study was to evaluate the effects of haemodialysis-induced preload reduction on both conventional and new Doppler parameters for the assessment of left ventricular (LV) diastolic function. METHODS: This prospective observational study was conducted in a medical-surgical intensive care unit (ICU) and nephrology department of a teaching hospital. In total, 37 haemodialysis patients with end-stage renal disease (age [mean +/- standard deviation]: 52 +/- 13 years) and eight ventilated ICU patients with acute renal failure receiving vasopressor therapy (age 57 +/- 16 years; Simplified Acute Physiology Score II 51 +/- 17) were studied. Echocardiography was performed before and after haemodialysis. Conventional pulsed wave Doppler indices of LV diastolic function as well as new Doppler indices, including Doppler tissue imaging early diastolic velocities (E' wave) of the septal and lateral portions of the mitral annulus, and propagation velocity of LV inflow at early diastole (Vp) were measured and compared before and after ultrafiltration. RESULTS: The volume of ultrafiltration was greater in haemodialysis patients than in ICU patients (3.0 +/- 1.1 l versus 1.9 +/- 0.9 l; P = 0.005). All conventional pulsed wave Doppler parameters were altered by haemodialysis. In haemodialysis patients, E' velocity decreased after ultrafiltration when measured at the septal mitral annulus (7.1 +/- 2.5 cm/s versus 5.9 +/- 1.7 cm/s; P = 0.0003), but not at its lateral portion (8.9 +/- 3.1 cm/s versus 8.3 +/- 2.6 cm/s; P = 0.37), whereas no significant variation was observed in ICU patients. Vp decreased uniformly after ultrafiltration, the difference being significant only in haemodialysis patients (45 +/- 11 cm/s versus 41 +/- 13 cm/s; P = 0.04). Although of less magnitude, ultrafiltration-induced variations in Doppler parameters were also observed in haemodialysis patients with altered LV systolic function. CONCLUSION: In contrast to other Doppler parameters, Doppler tissue imaging E' maximal velocity measured at the lateral mitral annulus represents an index of LV diastolic function that is relatively insensitive to abrupt and marked preload reduction.

Oral nystatin prophylaxis of Candida spp. colonization in ventilated critically ill patients.

OBJECTIVE: Colonization of multiple body sites is a leading risk factor for Candida spp. infection in intensive care unit (ICU) patients. We evaluated whether oral nystatin prophylaxis reduces Candida spp. colonization in ventilated ICU patients. DESIGN AND SETTING: Prospective, randomized, open-label study with blinded assessment of the objective primary evaluation criterion in the medical-surgical ICU of a teaching hospital. PATIENTS: The study included 98 consecutive patients mechanically ventilated for at least 48 h (mean age 58+/-19 years; mean SAPS II 40+/-11), assigned to either treatment group (n=51) or control group (n=47). Study groups were comparable for age, SAPS II, reason for admission, and immune status. INTERVENTIONS: Patients were randomized to receive oral nystatin (treatment group; 3x10(6) U per day) or no nystatin (control group). Multiple body sites (trachea, stomach, rectum, urine, groin, and blood) were tested for Candida spp. on admission and then every 3 days by mycologists blinded to group assignment, and the colonization index was determined. RESULTS: Colonization by Candida spp. developed in 25% of controls but in none of the treated patients. In multivariate analysis, the absence of nystatin prophylaxis and ICU length of stay were independently associated with Candida spp. colonization. No invasive candidiasis was diagnosed in either study group. CONCLUSIONS: Oral nystatin prophylaxis efficiently prevented Candida spp. colonization in ICU patients at low risk of developing invasive candidiasis. Further studies are needed to determine whether this strategy remains efficient in reducing Candida spp. infections in higher risk ICU patients.

Quantitative assessment of pleural effusion in critically ill patients by means of ultrasonography.

OBJECTIVE: To assess the ability of ultrasonography to identify the presence and assess the volume of pleural effusion in the intensive care unit setting. DESIGN: Prospective descriptive clinical study. SETTING: Medical-surgical intensive care unit of a teaching hospital. PATIENTS: Initial study group (group I) consisted of 97 patients (mean [+/-SD] Simplified Acute Physiology Score II, 40 +/- 14) with clinically suspected pleural effusion. Fifty-one patients were mechanically ventilated and 55 patients underwent a unilateral or bilateral thoracentesis (58 procedures). All patients underwent supine chest radiography and pleural ultrasonography at bedside. The testing group (group II) consisted of 19 additional patients (17 under ventilation) who underwent thoracentesis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Maximal interpleural distance was measured at the base and apex of the pleural space, at both end-expiration and end-inspiration. In group I, interpleural distances were compared to actual volume of fluid in the subset of patients who underwent a complete thoracentesis (n = 49). Prediction of the volume of pleural effusion was subsequently tested prospectively in group II (25 complete thoracenteses). Portable chest radiography and pleural ultrasonography yielded discordant results for 47 patients (48%) in the diagnosis of pleural effusion. The expiratory interpleural distance measured at the thoracic base with ultrasonography was significantly correlated with the volume of fluid (p < .0001; coefficient of determination: right, 0.78; left, 0.51). A pleural effusion > or =800 mL was predicted when this distance was >45 mm (right) or >50 mm (left), with a sensitivity of 94% and 100% and a specificity of 76% and 67%, respectively. In group II, the mean bias between the predicted and observed volumes of pleural effusion determined by thoracentesis was 24 +/- 355 mL, and this decreased to 28 +/- 146 mL for the prediction of pleural effusion <1400 mL. CONCLUSIONS: Bedside ultrasonography is well suited for the quantitative assessment of unloculated pleural effusions in intensive care unit patients.

Transesophageal echocardiography and therapeutic management of patients sustaining blunt aortic injuries.

BACKGROUND: No objective criteria have been described to help selecting patients with major blunt aortic injury (BAI) for postponed surgical repair. The efficacy of conservative management of minor BAI needs further evaluation. METHODS: We studied 31 patients (Injury Severity Score, 48 +/- 15) who sustained a BAI diagnosed using transesophageal echocardiography (TEE). In patients with major BAI, the timing of surgery was made on the basis of clinical findings (grade 2) or TEE results (grade 3). We retrospectively separated patients into group I (rapid surgery, < or = 12 hours; n = 13) and group II (late or no surgery; n = 11). All major BAIs were confirmed by alternative imaging modalities or surgery. Patients with minor BAI (grade 1; n = 7) prospectively underwent conservative management with serial TEE follow-up. RESULTS: All patients with grade 3 BAI (n = 4) were promptly operated on. No group II patient died as a result of aortic rupture, and all of them exhibited a small false aneurysm formation (ratio between the maximal diameter of the injured aortic isthmus and the diameter of the normal descending aorta < 1.4) and hemomediastinum (< 7.2 mm). TEE follow-up of group II patients (mean, 5 months) showed stable BAI, whereas follow-up of patients with minor BAI (mean, 15 months) disclosed total healing (n = 3) or stable lesions (n = 4). CONCLUSION: Conservative management of minor BAI with serial follow-up appears to be appropriate. In patients with a grade 2 BAI and small false aneurysm formation and hemomediastinum, postponed surgical repair appears to be safe. However, these TEE criteria remain to be tested prospectively.

Hand-held echocardiography with Doppler capability for the assessment of critically-ill patients: is it reliable?

OBJECTIVE: To evaluate the diagnostic capability of a hand-carried ultrasound device (HCU) in critically ill patients when using conventional transthoracic echocardiography (TTE) as a reference. DESIGN: Prospective, descriptive study. SETTING: Medical-surgical intensive care unit of a teaching hospital. PATIENTS: All patients requiring a TTE study were eligible. INTERVENTIONS: Each patient underwent an echocardiographic examination using a full-feature echocardiographic platform (Sonos 5500, Philips Medical Systems, Andover, MA) and a small battery-operated device (SonoHeart Elite, SonoSite, Bothell, WA). The operators (level III training in echocardiography) were randomized (HCU vs. TTE) and they independently interpreted the echocardiograms at the patient bedside. RESULTS: During a 2-month period, 55 consecutive patients (age: 61+/-16 years, simplified acute physiology score 46+/-15, body mass index 26+/-7) were studied, 40 of them being mechanically ventilated (73%). The number of acoustic windows was comparable using HCU and TTE (2.3+/-0.8 vs. 2.4+/-0.8: P=0.24). The overall diagnostic accuracy of HCU was lower compared with conventional TTE (137/171 vs. 158/171 clinical questions solved: P=0.002), reaching 80% and 92%, respectively. Despite its spectral Doppler capability, HCU missed diagnoses that were adequately identified by TTE: elevated left ventricular pressure ( n=2), relevant valvulopathy ( n=2) and moderate ( n=4) or severe ( n=2) pulmonary hypertension. Acute management was altered by HCU and TTE findings in 27 patients (49%) and 28 patients (51%), respectively. CONCLUSIONS: In this study, HCU had a lower diagnostic accuracy compared with conventional TTE, despite its spectral Doppler capability. Further studies are needed to validate these evolving diagnostic tools in critical care settings.

Diagnostic ability of hand-held echocardiography in ventilated critically ill patients.

STUDY OBJECTIVES: To compare the diagnostic capability of recently available hand-held echocardiography (HHE) and of conventional transthoracic echocardiography (TTE) used as a gold standard in critically ill patients under mechanical ventilation. DESIGN: A prospective and descriptive study. SETTING: The general intensive care unit of a teaching hospital. PATIENTS: All mechanically ventilated patients requiring a TTE study with a full-feature echocardiographic platform (Sonos 5500; Philips Medical Systems, Andover, MA, USA) also underwent an echocardiographic examination using a small battery-operated device (33 x 23 cm2, 3.5 kg) (Optigo; Philips Medical Systems). INTERVENTIONS: Each examination was performed independently by two intensivists experienced in echocardiography and was interpreted online. For each patient, the TTE videotape was reviewed by a cardiologist experienced in echocardiography and the final interpretation was used as a reference diagnosis. RESULTS: During the study period, 106 TTE procedures were performed in 103 consecutive patients (age, 59 +/- 18 years; Simplified Acute Physiology Score, 46 +/- 14; body mass index, 26 +/- 9 kg/m2; positive end-expiratory pressure, 8 +/- 4 cmH2O). The number of acoustic windows was comparable using HHE and TTE (233/318 versus 238/318, P = 0.72). HHE had a lower overall diagnostic capacity than TTE (199/251 versus 223/251 clinical questions solved, P = 0.005), mainly due to its lack of spectral Doppler capability. In contrast, diagnostic capacity based on two-dimensional imaging was comparable for both approaches (129/155 versus 135/155 clinical questions solved, P = 0.4). In addition, HHE and TTE had a similar therapeutic impact in 45 and 47 patients, respectively (44% versus 46%, P = 0.9). CONCLUSIONS: HHE appears to have a narrower diagnostic field when compared with conventional TTE, but promises to accurately identify diagnoses based on two-dimensional imaging in ventilated critically ill patients.