PURPOSE:

We report a case of unrecognized cardiac tamponade diagnosed pre-induction by focused transthoracic echocardiography (TTE). The value of focused perioperative TTE, the anesthetic implications of Churg-Strauss syndrome, and the diagnosis of cardiac tamponade are discussed. CLINICAL FEATURES: A 58-yr-old man with a history of severe asymptomatic aortic stenosis presented for elective endoscopic sinus surgery for intractable nasal polyps with recurrent sinusitis. His cardiologist and cardiac surgeon had recommended proceeding with surgery, as aortic valve replacement was not indicated because he was asymptomatic. Prior to induction, a focused TTE was performed by anesthesia in order to document the degree of aortic stenosis, baseline ventricular function, and baseline volume status. This provided a baseline for comparison in case the patient's hemodynamic status should deteriorate intraoperatively. Unexpectedly, the TTE examination revealed cardiac tamponade. After confirmation of the diagnosis by cardiology, urgent pericardiocentesis was performed. A diagnosis of Churg-Strauss syndrome was ultimately made, and the patient was treated with high-dose prednisone therapy.

CONCLUSION:

Focused TTE has significant clinical utility for the diagnosis and assessment of hemodynamically significant cardiac conditions, particularly in the complex patient where clinical examination is challenging and echocardiographic findings can have immediate management implications.

PURPOSE:

Management of severe pre-eclamptic patients is a challenge for the staff on obstetrical wards. We demonstrate that ultrasound applied to several organs performed at a patient's bedside gave the information required for the patient's management, without the need to transfer her to the radiology department or to call external consultants. CLINICAL FEATURES: A 29-yr-old severely pre-eclamptic patient with HELLP syndrome (hemolysis, cytolysis, thrombopenia) presented, in the post-partum period, with an occult uterine hemorrhage diagnosed with bedside abdominal/pelvic ultrasound. Ultrasound was also used to insert a central venous catheter. After undergoing a hysterectomy to control hemorrhage and receiving activated factor VII, the patient recovered uneventfully. Hemodynamic management was optimized non-invasively using pulmonary and cardiac ultrasound, when the patient developed hemorrhagic shock followed by pulmonary edema. Volume replacement was guided by cardiac ultrasound findings, and we were able to detect incipient interstitial pulmonary edema and follow its course using pulmonary ultrasound.

CONCLUSION:

Practitioners must be aware of the role of whole-body ultrasound in the diagnosis and treatment of complex, multi-organ conditions such as pre-eclampsia. Moreover, ultrasound helps in the management of global hemodynamics. The training of anesthesiologists in a variety of ultrasound techniques should be encouraged.

PURPOSE:

Cerebral desaturation occurs frequently in patients undergoing one-lung ventilation for thoracic surgery. The mechanism of this desaturation is unclear regarding its etiology. The objective of this study was to investigate whether or not decreases in cerebral oxygen saturation associated with one-lung ventilation were a consequence of decreased cardiac output.

METHODS:

A blinded observational study was conducted in 23 patients undergoing one-lung ventilation with thoracic surgery. Eighteen patients completed the study. Cerebral oxygen saturation was monitored using near-infrared spectroscopy (FORE-SIGHT(®) monitor). Invasive blood pressure was monitored and hemodynamic variables were interrogated using the FloTrac(®) system. Anesthesia was maintained with sevoflurane with a F i O2 of 1.0. Post-hoc analysis involved a comparison between baseline and integrated changes in cerebral saturation, heart rate, stroke index, cardiac index, and stroke volume variability.

RESULTS:

All patients showed cerebral desaturation from a baseline of two-lung ventilation in the lateral decubitus position following institution of one-lung ventilation. The cardiac index was stable at these times, but with one-lung ventilation, the heart rate decreased and the stroke index increased to maintain a stable product. The integral of heart rate × time was inversely correlated with the integral of cerebral desaturation × time (linear regression analysis; P = 0.02; (df) = 16)).

CONCLUSIONS:

Cerebral oxygen desaturation was universal during one-lung ventilation in this study. There was no correlation between cerebral desaturation and cardiac output or other hemodynamic variables.

PURPOSE:

To investigate whether tracheostomy increases the risk of sternal wound infection (SWI) post cardiac surgery.

METHODS:

All patients undergoing cardiac surgery via median sternotomy from September 1997 to October 2010 were included in this retrospective observational study. Primary exposure was tracheostomy performed during admission to the cardiac surgical intensive care unit. The primary outcome was SWI during hospital admission. Multivariable logistic regression was used to determine if tracheostomy was an independent predictor of SWI. Restriction and propensity score analyses were then used to assess if tracheostomy is a causal risk factor for SWI.

RESULTS:

Four hundred and eleven of 18,845 patients (2.2%) were treated with tracheostomy. Incidences of SWI in tracheostomy and non-tracheostomy groups were 19.5% (80/411) and 0.8% (154/18,434), respectively. Using multivariable logistic regression analysis, tracheostomy was found to be an independent predictor of SWI (odds ratio [OR] 2.8; 95% confidence interval [CI] 1.9 to 4.2). In an analysis restricted to respiratory failure patients, tracheostomy was associated with sternal wound infection (OR 3.4; 95% CI 2.4 to 4.9). When the analysis was stratified by the risk of receiving tracheostomy as represented by propensity score (PS), 46 patients (12%) in the intermediate risk category (PS 0.2-0.4) had SWIs (adjusted OR 2.97; 95% CI 1.6 to 5.6), and 52 patients (14%) in the highest risk category (PS > 0.4) had SWIs (OR 1.52; 95% CI 0.85 to 2.87).

DISCUSSION:

Our single-centre observational study of cardiac surgery patients found tracheostomy to be an independent risk factor for SWI. Our analysis showed a robust association when restricted to patients with respiratory failure and after the population was stratified by the propensity to have a tracheostomy.