Seminars in anesthesia最新文献

This report describes a complication from the use of a mechanical ultrasound transducer and needle guide to perform internal jugular cannulation. Misalignment of the probe led to an inability to visualize the needle and accidental carotid puncture. Placement of the central line was successful with landmark technique, and there were no sequelae. The transducer design explains how such misalignment may occur if the crystal oscillation is not symmetric. The manufacturer recommends periodic testing for probe alignment, and awareness of this potential problem may help other users avoid patient injury with this type of ultrasound transducer.

This review deals with time-domain acoustic reflectometry, which is a dynamic, real-time imaging modality that can be used to generate an easily interpretable area-distance profile of a cavity, such as the breathing tube/lower airway system or the esophagus. Without resorting to capnography, the acoustic reflectometry profile allows for instant diagnosis of the site of placement of the breathing tube: tracheal, bronchial, or esophageal. Additional applications include: evaluation of sleep apnea, septal disorders, plus the site and the severity of breathing tube obstruction (kinks, mucus plugs) and of lower airway abnormalities (bronchospasm, pulmonary edema). Other applications of the acoustic reflectometer are discussed.

We reviewed the current state of knowledge regarding pediatric sedation mainly for nonpainful procedures, such as MRI studies. The increasing number of requests for pediatric sedation has triggered intense research for finding various solutions that would enable the safe administration of sedation by nonanesthesiologist physicians, supervised trained nursing personnel (CRNAs and/or RNs), or sedation teams combining different provider types. We also reviewed the current data on the use of dexmedetomidine in children, as a sedative agent in the MRI suite. Dexmedetomidine is an excellent sedative, has analgesic properties, and appears to be clinically safe from a respiratory point of view even at high doses, although instances of bradycardia and hypotension have been reported. Dexmedetomidine appears to be a promising option for sedation in the pediatric population in the MRI setting.

High-resolution ultrasound imaging is being progressively used in the perioperative period by anesthesiologists. Current applications include diagnostic echocardiography, vascular access, and peripheral/neuraxial neural blockade. In central and peripheral vessel cannulation, ultrasound guidance is used both as a primary technique and as a rescue method when conventional techniques fail. For many nerve block techniques, ultrasound imaging has resulted in better procedural success rates and improved safety. This review discusses the use of ultrasound guidance for vascular access procedures and nerve blocks.

Ultrasonography has provided anesthesiologists with the opportunity to visualize anatomy and guide needle insertion to peripheral nerves, as well as ensuring deposition of local anesthetic solutions accurately. Potential benefits include improved efficiency of nerve blockade, reduced patient discomfort, improved block efficacy, and avoidance of undesirable needle trauma or injection trauma to nerves or surrounding structures. Methods of blocking the brachial plexus using ultrasound guidance are reviewed and the existing literature summarized.

Intraoperative transesophageal echocardiography (TEE) is an invaluable tool for the management of cardiac surgical procedures. It allows evaluation of myocardial function, valvular pathology, atheromatous disease, dissection of the aorta, and estimation of pulmonary artery pressure. Despite its relative safety, TEE has a reported estimated risk of 0.18%. Esophageal injury is the major risk associated with TEE placement. This is a case report of a patient who sustained a contained esophageal dissection during insertion of a TEE probe prior to minimally invasive mitral valve repair. It is also a demonstration of use of the multi-imaging modalities used to evaluate and manage patients until full recovery.

Use of ultrasound guidance for regional anesthesia has grown in popularity recently. Advocates claim many benefits, including higher success rates, a decrease in block performance time, a decrease in onset time, a higher quality block, the ability to use less local anesthetic, and a longer duration of block. Many also believe that the ability to visualize critical structures decreases the rate of complications. This article reviews the current evidence for these claimed benefits. In addition, discussion of how clinical practice patterns are affected and how ultrasound can add to the knowledge base of regional anesthesia practice is presented.

Much has been written in the medical and human factors literature in recent years about the similarities between aviation and medicine (especially anesthesiology). In this discussion, we ask whether medicine really can learn lessons from aviation and what those lessons are. In particular we will focus on error management, the root causes of adverse events, including fatigue, barriers for safety, and the personality traits that may contribute to adverse outcomes (for which we have coined the term “Shiva factor”—named for the Hindu god who can be both the preserver of life and the destroyer).

The concept of situational awareness (SA) is well known in the field of aviation, human factors and psychology. Understanding of its importance in the daily practice of anesthesiology is beginning to appear. All perioperative team members have a responsibility to identify both the presence and absence of SA to protect our patients as we attempt to deliver the highest quality and safest care. This article introduces the reader to some of the fundamental concepts of SA and its application to anesthesiology.