[Transesophageal echocardiography for diagnosis of traumatic injuries to the major intrathoracic vessels in 150 patients: the effect of the learning curve]

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.

Echocardiography in the Intensive Care Unit

As ultrasound technology improves and ultrasound availability increases, echocardiography utilization is growing within intensive care units. Although not replacing the often-needed comprehensive echocardiographic evaluation, limited bedside echocardiography promises to provide intensivists with enhanced diagnostic ability and improved hemodynamic understanding of individual patients. Routine and emergency echocardiography within the intensive care unit focuses on identifying and optimizing medically treatable conditions in a timely manner. Methods for such goal-directed assessments are presented.

[Blunt traumatic aortic injury: importance of transesophageal echocardiography]

Traumatic injury of the aorta can be a fatal complication of blunt thoracic trauma and if it is survived and diagnosed, surgery will be necessary. A prerequisite is a prompt imaging diagnosis of the injury in order to plan an optimal therapeutic procedure for the patient, depending on the severity of the injury. Digital angiography has now been replaced by non-invasive methods, such as computer tomography (CT) or transesophageal echocardiography (TEE). Using TEE it is possible to carry out a staging of the injury and this classification together with the corresponding clinical symptoms determines the therapeutic treatment regime. In many cases a staged treatment is standard procedure. In addition to the establishment of an adequate blood pressure (for prophylaxis of the open rupture), monitoring during the course of treatment may be necessary. The main advantage of TEE is that the examination of these mostly multiple traumatised patients can be carried out at the bedside. This review describes the use of TEE as a diagnostic tool in the early phase and for continuous monitoring of an initially conservative treatment regime.

Validation of a skills assessment scoring system for transesophageal echocardiographic monitoring of hemodynamics

OBJECTIVE

Transesophageal echocardiography (TEE) is increasingly used in hemodynamic monitoring in the intensive care unit. This paper describes and validates a scoring system for assessing competence in TEE performed by intensivists for this indication.

DESIGN

Prospective study over an 18-month period.

SETTINGS

Two medical intensive care units.

METHODS

The scoring system is used to assess four aspects of TEE: quality of the views (score out of 14); semiquantitative evaluation of respiratory variations in the superior vena cava, valve regurgitation, size of the right ventricle (score out of 10); accuracy of measurement of velocity-time integrals for pulmonary and aortic flow, peak velocity of the E and A waves of mitral flow, left ventricular fractional area change (score out of 8); summary and proposed treatment (score out of 8). The scoring system was validated by using it to assess intensivists after 1 month (M1), 3 months (M3) and 6 months (M6) of training. TEE was done on a mechanically ventilated, hypotensive patient and scored by comparing the intensivist's examination with that of the expert examiner. The intensivists were divided into two groups of theoretical expertise at the start of training.

RESULTS

Nineteen intensivists were evaluated. The scores at M1 for level 0 (no experience in echocardiography) and level 1 (previous experience) were, respectively, 18.5 +/- 4 and 24.7 +/- 5. The scores at M1, M3, and M6 were, respectively, 20.4 +/- 5, 30.4 +/- 5 and 35.7 +/- 3. At M6, the intensivists had performed TEE 29 +/- 10 times.

CONCLUSION

The scoring system was discriminatory and sensitive to change, and could be used as a tool to assess an intensivist's mastery of TEE.

Transesophageal echocardiography for diagnosis of traumatic aortic injury: an appraisal of the evidence

BACKGROUND

An overview of the validity of transesophageal echocardiography (TEE) in patients suspected to have traumatic aortic injury (TAI).

METHODS

Computerized bibliographic search of trials from 1994 to 2002 evaluating the use of TEE to confirm the diagnosis of TAI. Seven relevant studies out of 204 were identified, involving 758 patients. The accuracy of TEE was analyzed by constructing summary receiver-operating characteristic (sROC) curves and computing areas under the sROC curve.

RESULTS

No prospective randomized trial was found. Although accuracy varied greatly, summary ROC curve found that TEE enjoyed a high diagnostic performance. Some study characteristics can affect accuracy.

CONCLUSIONS

Our findings seems to indicate that TEE is a valuable tool for diagnosing TAI, and its use as first-line evaluation of such patients can be supported; however, given the lack of randomized trials, no standard of care can be drawn from the present overview: future studies should look at this problem more carefully, and should be methodologically rigorous.

[Aortic diverticulum: differential diagnosis of traumatic lesions of the thoracic aorta]

We report the case of a 31-year-old patient with a chest trauma after a mountaineering accident. Contrast enhanced spiral computed tomography of the thorax showed a lesion of the aortic isthmus, suspected of being an aortic disruption. As the diagnosis of aortic rupture could not be formally established with computed tomography, a transoesophageal echocardiography and an aortic angiography were performed which showed a ductus diverticulum, representing one of the differential diagnoses of traumatic aortic disruption. A knowledge of this entity and its diagnostic criteria may avoid an unnecessary thoracotomy.