Technical failure of the EZ-blocker™ causing serious adverse events during one lung ventilation: a case series.

We present a case series of intra-operative adverse events while using a specific type of bronchial blocker, designed to facilitate device positioning and minimise the risk of dislocation. The Rüsch® EZ-blocker™ (Teleflex Life Sciences Ltd., Athlone, Ireland) is a Y-shaped catheter equipped with two separately inflatable cuffs at the tip - one for each bronchial lumen. In this report, we describe four cases where the use of the EZ-blocker was associated with the development of high airway pressures, hypoxaemia and expansion of the non-dependent lung. Bronchoscopic evaluation showed spontaneous inflation of the cuff within the dependent (i.e. ventilated) bronchus, causing bronchial obstruction, and volume loss of the cuff within the non-dependent (i.e. unventilated) bronchus, causing unintended expansion of the non-dependent lung. After removal of the bronchial blocker, the catheter showed no visible defect, but a bench test revealed a functional connection inside the catheter which allowed air to pass slowly from one bronchial cuff to the other. This technical defect relates to the unique design of the EZ-blocker as it is the only bronchial blocker equipped with two bronchial cuffs. Clinicians should be aware of this inherent risk since complications may develop insidiously and affect both lungs simultaneously. Early recognition and prompt intervention can prevent life-threatening intra-operative deterioration.

Assessment of Spinal Cord Ischemia With Near-Infrared Spectroscopy: Myth or Reality?

Non-invasive near-infrared spectroscopy is gaining popularity in the detection of spinal cord ischemia following aortic aneurysm repair. However, practical recommendations are lacking. This review focuses on the physiological and anatomical background, as well as on the clinical implementations of near-infrared spectroscopy as a tool for monitoring ischemia of the spinal cord. Clinical recommendations based on the currently available evidence are rendered.

Changes in a surgical stress index in response to standardized pain stimuli during propofol-remifentanil infusion.

BACKGROUND: The surgical stress index (SSI) is based on a sum of the normalized pulse beat interval (PBI) and the pulse wave amplitude (PPGA) time series of the photoplethysmography. As a measure of the nociception-anti-nociception balance in response to a standardized pain stimulus, SSI was compared with EEG changes in state and response entropy (SE and RE), PPGA, and heart rate (HR) during various targeted pseudo-steady-state concentrations of propofol and remifentanil. METHODS: Forty ASA I patients were allocated to one of the four groups to receive a remifentanil step-up/-down effect-compartment target-controlled infusion (Ce(remi)) of 0, 2, 6, 2, 0 ng ml(-1), or 6, 2, 0, 2, 6 ng ml(-1), and an effect-compartment target-controlled propofol infusion (Ce(prop)) to keep the SE between 30 and 50 or 15 and 30, respectively. At each steady-state Ce(remi), maximum change in SSI, SE, RE, PPGA, and HR after a noxious stimulus was compared with the baseline value. A correlation and prediction probability (P(K)) with Ce(prop) and Ce(remi) was measured. RESULTS: Static and dynamic values of SSI correlated to Ce(remi) better than SE, RE, HR, and PPGA. SSI was independent of Ce(prop), in contrast to SE and RE. The P(K) for Ce(remi) both before and during a noxious stimulus was better with SSI. CONCLUSIONS: SSI appeared to be a better measure of nociception-anti-nociception balance than SE, RE, HR, or PPGA.