Recent advances in respiratory monitory in nonoperating room anesthesia.

Purpose Of Review: Sedation for nonoperating room procedures is experiencing a considerable increase in demand. Respiratory compromise is one of the most common adverse events seen in sedation. Capnography is a modality that has been widely adopted in this area, but may not be well suited to the special demands of nonoperating room sedation.

Drug-induced sleep endoscopy: from obscure technique to diagnostic tool for assessment of obstructive sleep apnea for surgical interventions.

Purpose Of Review: Provide a practical update on drug-induced sleep endoscopy (DISE) for anesthesia providers, which can also serve as a reference for those preparing to establish a DISE program.

Recent Findings: New developments in surgical approaches to OSA and the growing global incidence of the condition have stimulated increased interest and demand for drug-induced sleep endoscopy. New techniques include transoral robotic surgery and hypoglossal nerve stimulation.

Anesthesia in the Electrophysiology Laboratory.

The electrophysiology suite is a foreign location to many anesthesiologists. The initial experience was with shorter procedures under conscious sedation, and the value of greater tailoring of the sedation/anesthesia by anesthesiologists was not perceived until practice patterns had already been established. Although better control of ventilation with general anesthesia may be expected, suppression of arrhythmias, blunting of the hemodynamic adaptation to induced arrhythmias, and interference by muscle relaxants with identification of the phrenic nerve may be seen.

Understanding Infusion Pumps.

Infusion systems are complicated electromechanical systems that are used to deliver anesthetic drugs with moderate precision. Four types of systems are described-gravity feed, in-line piston, peristaltic, and syringe. These systems are subject to a number of failure modes-occlusion, disconnection, siphoning, infiltration, and air bubbles.

Hilbert-Huang Transform Yields Improved Minute Volume Estimates from Respiratory Inductance Plethysmography During Transitions to Paradoxical Breathing.

Background: Anesthesia and sedation are associated with paradoxical breathing. Respiratory inductance plethysmography (RIP) permits measurement of respiratory motion in clinical settings not conducive to spirometry, but correlation of RIP volume changes and spirometer flow in the time domain is degraded by the development of paradoxical breathing. The Hilbert-Huang transform (HHT) is a nonlinear signal analysis method that permits the instantaneous magnitude and phase of nonstationary signals to be estimated in the frequency domain.

Provocation of atrial fibrillation triggers during ablation: does the use of general anesthesia affect inducibility?

Introduction: The autonomic nervous system exerts important effects upon atrial fibrillation (AF) initiation. The strategy of anesthesia used during AF ablation may impact the provocation of AF triggers. We hypothesized that the use of general anesthesia (GA) would reduce the incidence of provokable AF triggers in patients undergoing AF ablation compared to patients studied while receiving only conscious sedation (CS).

Safety and efficacy of drug-induced sleep endoscopy using a probability ramp propofol infusion system in patients with severe obstructive sleep apnea.

Background: Drug-induced sleep endoscopy (DISE) uses sedative-hypnotics to induce moderate obstruction in sleep apnea patients, thereby facilitating anatomic assessment of obstructive physiology. Implementation of DISE with propofol requires a dosing strategy that reliably and efficiently produces obstruction while minimizing oxygen desaturation.

Methods: The surgeon in a prospective study of transoral robotic resection of the tongue base enrolled 97 patients with obstructive sleep apnea confirmed by polysomnography who failed continuous positive airway pressure.

Performance of Masimo rainbow acoustic monitoring for tracking changing respiratory rates under laryngeal mask airway general anesthesia for surgical procedures in the operating room: a prospective observational study.

Background: Accurate monitoring of respiratory rate may be useful for the early detection of patient deterioration. Monitoring of respiratory rate in the operating room under general anesthesia by spirometry is technically straightforward and demonstrates high fidelity. Accurate measurement of the respiratory rate of an unattended patient outside the operating room is fraught with challenges.

Considerations for the use of short-acting opioids in general anesthesia.

Anesthesiologists play a critical role in facilitating a positive perioperative experience and early recovery for patients. Depending on the kind of procedure or surgery, a wide variety of agents and techniques are currently available to anesthesiologists to administer safe and efficacious anesthesia. Notably, the fast-track or ambulatory surgery environment requires the use of agents that enable rapid induction, maintenance, and emergence combined with minimal adverse effects.

Time-delay when updating infusion rates in the Graseby 3400 pump results in reduced drug delivery.

Infusion pumps are commonly used for infusion of drugs for physiologic control, and infusion rate has been demonstrated to affect the parameters of pharmacokinetic models. In attempting to develop a model that explained this behavior, we examined the behavior of the Graseby 3400 syringe pump under a range of flow conditions and with variations in syringe characteristics. Two issues were identified: start-up loss (the difference between actual and ideal delivery on initial infusion) and update loss (the difference between actual and ideal delivery when transmitting a command to change infusion rate).

Nintendo® Wii Fit based sleepiness tester detects impairment of postural steadiness due to 24 h of wakefulness.

A field-usable sleepiness tester could reduce sleepiness related accidents. 15 subjects' postural steadiness was measured with a Nintendo(®) Wii Fit balance board every hour for 24 h. Body sway was quantified with complexity index, CI, and the correlation between CI and alertness predicted by a three-process model of sleepiness was calculated.

Abdominal relaxation during emergence from general anesthesia with propofol and remifentanil.

Study Objective: To characterize respiratory dynamics during emergence from propofol-remifentanil anesthesia using noninvasive respiratory inductance plethysmography (RIP).

Design: Observational pilot study.

Setting: Operating room in a university-affiliated teaching hospital.

Efforts to enhance catheter stability improve atrial fibrillation ablation outcome.

Background: Contemporary techniques to enhance anatomical detail and catheter contact during atrial fibrillation (AF) ablation include (1) the integration of preacquired tomographic reconstructions with electroanatomical mapping (3-dimensional image integration [I-EAM]), (2) the use of steerable introducers (SIs), and (3) high-frequency jet ventilation (HFJV).

Objective: To prove that using these stabilizing techniques during AF ablation improves 1-year procedural outcome.

Methods: We studied 300 patients undergoing AF ablation at our institution.

Quantitative airway analysis during drug-induced sleep endoscopy for evaluation of sleep apnea.

Objectives/hypothesis: To quantitatively measure changes in airway caliber at multiple anatomical levels during drug-induced sleep endoscopy (DISE) for evaluation of sleep apnea. We hypothesize that patients undergoing DISE will show: 1) collapse at multiple upper airway regions (retropalatal, retroglossal, and retroepiglottic), with greater collapse in the retropalatal region; and 2) greater anterior-posterior dimensional narrowing than the lateral.

Study Design: Case series.

The use of high-frequency jet ventilation for out of operating room anesthesia.

Purpose Of Review: High-frequency jet ventilation is a novel technique for providing mechanical ventilation in the out of operating room (OOR) setting. Case reports and a small series of patients have shown it to be useful in patients undergoing cardiac arrhythmia ablations, interventional radiology procedures, and extracorporeal shock wave lithotripsy. Recently, interest in the technique has grown tremendously as the ability to provide superior surgical conditions may lead to improved efficiency and less side-effects in a variety of procedures.

The variability of response to propofol is reduced when a clinical observation is incorporated in the control: a simulation study.

Background: When using a target-controlled infusion of propofol to produce sedation, the operator assumes that the individual patient's pharmacokinetic parameters match those in the control system so that the specified effect-site target is achieved, and that the specified target is appropriate for the individual patient's sensitivity. These inaccuracies cascade, and this produces error in the desired level of sedation, termed "target error." To address this issue, we designed a control system that incorporates the operator's observation of loss of responsiveness to determine patient sensitivity.

Laser ablation of a large tongue hemangioma with remifentanil analgosedation in the ORL endoscopy suite.

We present a unique, practical, and safe approach to the clinical management of a young male with a large tongue hemangioma who presented for serial surgical treatment of the lesion. Laser ablation was undertaken in the operating room under topical anesthesia with remifentanil analgosedation without the use of supplemental oxygen. Significant involution of the hemangioma was achieved without complication while the patient was awake, cooperative, and able to protect his airway.

Medical intelligence article: novel uses of high frequency ventilation outside the operating room.

High frequency jet ventilation (HFJV) is a technique that is most frequently used in the intensive care unit and during tracheal and otorhinolaryngologic surgery. The utility of HFJV for procedures performed outside of the intensive care unit and operating room is currently being explored. The ability of HFJV to provide mechanical ventilation, yet achieve near static conditions of the chest and abdomen, makes it a very appealing technique for procedures such as pulmonary vein isolation and ablation for atrial fibrillation, targeted radiation therapy for lung and liver tumors, and certain diagnostic imaging techniques.

Sudden Tracheal Collapse during EGD and Subsequent Anesthetic Management with Dexmedetomidine-Ketamine in a Patient with Achalasia and Tracheomalacia.

We present a patient who experienced airway obstruction during an elective esophagogastroduodenoscopy (EGD) under anesthesia secondary to previously undiagnosed tracheomalacia. Physiology of airway obstruction with forced breathing maneuvers is discussed along with the potential advantages of dexmedetomidine-ketamine sedation for management of patients with achalasia undergoing outpatient endoscopic procedures.