Efficiency of oxygen delivery through different oxygen entrainment devices during sedation under low oxygen flow rate: a bench study.

Sedative anesthetic procedures outside the operating room may depend on cylinders as oxygen source. Cylinders have limited storage capacity and a low oxygen flow rate improves the durability. We conducted the bench study to evaluate the fraction of inspired oxygen (FiO) in different oxygen entrainment devices under low oxygen flow rate.

A desflurane and fentanyl dosing regimen for wake-up testing during scoliosis surgery: Implications for the time-course of emergence from anesthesia.

Background/purpose: The Stagnara wake-up test assesses neurological deficits during scoliosis surgery, and response surface interaction models for opioids and inhaled agents predicts anesthetic drug effects. We hypothesized that there is an optimal desflurane-fentanyl dosing regimen that can provide a faster and more predictable wake-up time, while also ensuring adequate analgesia during wake-up testing.

Methods: Twenty-three American Society of Anesthesiologists Class I-II scoliosis patients who received desflurane-fentanyl anesthetic regimens were enrolled in this posthoc study, and their intraoperative drug administration data were collected retrospectively.

Accuracy of CO₂ monitoring via nasal cannulas and oral bite blocks during sedation for esophagogastroduodenoscopy.

Esophagogastroduodenoscopy procedures are typically performed under conscious sedation. Drug-induced respiratory depression is a major cause of serious adverse effects during sedation. Capnographic monitoring of respiratory activity improves patient safety during procedural sedation.

Response surface model predictions of wake-up time during scoliosis surgery.

Background: With the use of previously published data, new sevoflurane-remifentanil interaction models of various degrees of sedation were created and adapted to desflurane-fentanyl by using minimal alveolar concentration and opioid equivalencies. These models were used to predict return of responsiveness in patients undergoing scoliosis surgery during a wake-up test. Our hypothesis was that one of the interaction models would accurately predict return of responsiveness during a wake-up test.

Using the entropy of tracheal sounds to detect apnea during sedation in healthy nonobese volunteers.

Background: Undetected apnea can lead to severe hypoxia, bradycardia, and cardiac arrest. Tracheal sounds entropy has been proved to be a robust method for estimating respiratory flow, thus maybe a more reliable way to detect obstructive and central apnea during sedation.

Methods: A secondary analysis of a previous pharmacodynamics study was conducted.

Evaluation of the effect of information integration in displays for ICU nurses on situation awareness and task completion time: A prospective randomized controlled study.

Objective: The study measured whether nurses' situation awareness would increase and task completion time decrease when they used an integrated information display compared to traditional displays for medication management, patient awareness and team communication.

Setting: The Burn Trauma Intensive Care Unit (BTICU) at the University Hospital, University of Utah Health Science Center, Salt Lake City, Utah, USA.

Participants: 12 experienced BTICU nurses.

Graphical user interface simplifies infusion pump programming and enhances the ability to detect pump-related faults.

Background: Drug administration errors are frequent and are often associated with the misuse of IV infusion pumps. One source of these errors may be the infusion pump's user interface.

Methods: We used failure modes-and-effects analyses to identify programming errors and to guide the design of a new syringe pump user interface.

ICU nurses' evaluations of integrated information displays on user satisfaction and perceived mental workload.

Consolidated information from multiple sources (patient monitors, electronic medical records, infusion pumps, ventilators, medication references) may improve nurses' work and patient safety. Objective. Two hypotheses were tested, that integrated information displays (a) improve nurses' satisfaction and (b) lower perceived mental workload.

Evaluation of an integrated intensive care unit monitoring display by critical care fellow physicians.

In the past two far-view displays, which showed vital signs, trends, alarms, infusion pump status, and therapy support indicators, were developed and assessed by critical care nurses (Görges et al. in Dimens Crit Care Nurs. 30(4):206-17, 2011).

Intensive care unit nurses' information needs and recommendations for integrated displays to improve nurses' situation awareness.

Objective: Fatal errors can occur in intensive care units (ICUs). Researchers claim that information integration at the bedside may improve nurses' situation awareness (SA) of patients and decrease errors. However, it is unclear which information should be integrated and in what form.

A far-view intensive care unit monitoring display enables faster triage.

Although nurses perform the majority of the clinical tasks in an intensive care unit, current patient monitors were not designed to support a nurse's workflow. Nurses constantly triage patients, deciding which patient is currently in the most need of care. To make this decision, nurses must observe the patient's vital signs and therapeutic device information from multiple sources.

Activated charcoal effectively removes inhaled anesthetics from modern anesthesia machines.

Introduction: If a malignant hyperthermia-susceptible patient is to receive an anesthetic, an anesthesia machine that has been used previously to deliver volatile anesthetics should be flushed with a high fresh gas flow. Conflicting results from previous studies recommend flush times that vary from 10 to 104 minutes. In a previously proposed alternative decontamination technique, other investigators placed an activated charcoal filter in the inspired limb of the breathing circuit.

A tool predicting future mean arterial blood pressure values improves the titration of vasoactive drugs.

Background: Vasoactive drug infusion rates are titrated to achieve a desired effect, e.g., mean arterial blood pressure (MAP), rather than using infusion rates based on body weight.

An evaluation of remifentanil-sevoflurane response surface models in patients emerging from anesthesia: model improvement using effect-site sevoflurane concentrations.

Introduction: We previously reported models that characterized the synergistic interaction between remifentanil and sevoflurane in blunting responses to verbal and painful stimuli. This preliminary study evaluated the ability of these models to predict a return of responsiveness during emergence from anesthesia and a response to tibial pressure when patients required analgesics in the recovery room. We hypothesized that model predictions would be consistent with observed responses.

Improving alarm performance in the medical intensive care unit using delays and clinical context.

Introduction: In an intensive care unit, alarms are used to call attention to a patient, to alert a change in the patient's physiology, or to warn of a failure in a medical device; however, up to 94% of the alarms are false. Our purpose in this study was to identify a means of reducing the number of false alarms.

Methods: An observer recorded time-stamped information of alarms and the presence of health care team members in the patient room; each alarm response was classified as effective (action taken within 5 min), ineffective (no response to the alarm), and ignored (alarm consciously ignored or actively silenced).

Flow-through versus sidestream capnometry for detection of end tidal carbon dioxide in the sedated patient.

Background: End tidal carbon dioxide (ETCO(2)) in non-intubated patients can be monitored using either sidestream or flow-through capnometry [Yamamori et al., J Clin Monit Comput 22(3):209-220, 2008]. The hypothesis of this validation study is that, flow-through capnometry will yield a more accurate estimate of ETCO(2) than sidestream capnometry when evaluated in a bench study during low tidal volumes and high oxygen administration via nasal cannula.

Part Task and variable priority training in first-year anesthesia resident education: a combined didactic and simulation-based approach to improve management of adverse airway and respiratory events.

Background: Part task training (PTT) focuses on dividing complex tasks into components followed by intensive concentrated training on individual components. Variable priority training (VPT) focuses on optimal distribution of attention when performing multiple tasks simultaneously with the goal of flexible allocation of attention. This study explored how principles of PTT and VPT adapted to anesthesia training would improve first-year anesthesiology residents' management of simulated adverse airway and respiratory events.

An evaluation of remifentanil propofol response surfaces for loss of responsiveness, loss of response to surrogates of painful stimuli and laryngoscopy in patients undergoing elective surgery.

Introduction: In this study, we explored how a set of remifentanil-propofol response surface interaction models developed from data collected in volunteers would predict responses to events in patients undergoing elective surgery. Our hypotheses were that these models would predict a patient population's loss and return of responsiveness and the presence or absence of a response to laryngoscopy and the response to pain after surgery.

Methods: Twenty-one patients were enrolled.

A simulation-based evaluation of a graphic cardiovascular display.

Introduction: A graphic presentation of complex information can facilitate early detection and management of adverse events. Prior work found that graphical presentation of selected cardiovascular variables led to earlier detection of a simulated ischemic event. Based on these findings, a second evaluation explored the utility of a graphical cardiovascular display (GCD) in a variety of simulated adverse cardiopulmonary events for two different display configurations.

Rapid recovery from sevoflurane and desflurane with hypercapnia and hyperventilation.

Background: Hypercapnia with hyperventilation shortens the time between turning off the vaporizer (1 MAC) and when patients open their eyes after isoflurane anesthesia by 62%.

Methods: In the present study we tested whether a proportional shortening occurs with sevoflurane and desflurane.

Results: Consistent with a proportional shortening, we found that hypercapnia with hyperventilation decreased recovery times by 52% for sevoflurane and 64% for desflurane (when compared with normal ventilation with normocapnia).

Development and evaluation of a just-in-time support system.

Objective: To lay the foundation for a framework of just-in-time support (JITS) for novices dealing with urgent, unfamiliar tasks, and to evaluate a JITS system.

Background: More than 350,000 people die annually of cardiac arrest in the United States. In response, automated defibrillators are advocated that, unfortunately, do not provide important respiratory support.

Hypercapnia shortens emergence time from inhaled anesthesia in pigs.

Background: Anesthetic clearance from the lungs and the circle rebreathing system can be maximized using hyperventilation and high fresh gas flows. However, the concomitant clearance of CO2 decreases PAco2, thereby decreasing cerebral blood flow and slowing the clearance of anesthetic from the brain. This study shows that in addition to hyperventilation, hypercapnia (CO2 infusion or rebreathing) is a significant factor in decreasing emergence time from inhaled anesthesia.