Feasibility study of a smartphone pupillometer and evaluation of its accuracy.

Measurement of pupillary characteristics, such as pupillary unrest in ambient light, and reflex dilation have been shown to be useful in a variety of clinical situations. Dedicated pupillometers typically capture images in the near-infrared to allow imaging in both light and darkness. However, because a subset of pupillary measurements can be acquired with levels of visible light suitable for conventional cameras, it is theoretically possible to capture data using general purpose cameras and computing devices such as those found on smartphones. Here we describe the development of a smartphone-based pupillometer and compare its performance with a commercial pupillometer. Smartphone pupillometry software was developed and then compared with a commercial pupillometer by performing simultaneous scans in both eyes, using the smartphone pupillometer and a commercial pupillometer. The raw scans were compared, as well as a selected pupillary index: pupillary unrest in ambient light. In 77% of the scans the software was able to successfully identify the pupil and iris. The raw data as well as calculated values of pupillary unrest in ambient light were in clinically acceptable levels of agreement; Bland-Altman analysis of raw pupil measurements yielded a 95% confidence interval of 0.26 mm. In certain situations a smartphone pupillometer may be an appropriate alternative to a commercial pupillometer.

100% Nitrous Oxide in the Oxygen Line: How Could This Happen in a Modern Anesthesia Machine?

The inadvertent crossover between O2 and N2O pipelines has become extremely rare in practice. We describe a case where it was possible to ventilate with 100% N2O instead of the intended 100% O2 on a modern anesthesia delivery system (Dräger Apollo; Drägerwerk AG & Co KgaA, Lübeck, Germany). This was the result of the incorrect assembly of diameter index safety system (DISS) components during preventative maintenance that defeated the DISS failsafe system. To make incorrect assembly easier to avoid, DISS component labeling could be more prominent and color-coded, or the internal construction of the gas manifold could incorporate DISS.

An Anesthesia Attempt to Be Green: How Do You Waste Your Carbon Dioxide Absorbers?

Operating room waste is categorized as noncontaminated solid waste (SW) and regulated medical waste (RMW). RMW is treated by autoclaving at an increased economic and environmental cost. We evaluated these costs with a focus on the disposable carbon dioxide (CO2) absorbers. At our institution, exhausted CO2 absorbers were discarded as RMW. We collaborated with product representatives, anesthesia and perioperative staff, and waste management personnel to identify opportunities and barriers for recycling and waste reduction. Ultimately, we agreed to discard CO2 absorbers as SW instead of RMW, a strategy that is practical, less expensive, and more environmentally appropriate.

Capnoperitoneum During Peroral Endoscopic Myotomy-Recognition and Management: A Case Report.

Peroral endoscopic myotomy (POEM) is a minimally invasive procedure for treating esophageal achalasia. During POEM, carbon dioxide is insufflated under pressure into the esophagus and stomach, which can cause clinically significant capnoperitoneum, capnomediastinum, or capnothorax. We present a case in which gas accumulation in the abdomen during POEM had adverse effects on ventilation. Once the cause was recognized, needle decompression of the abdomen led to immediate improvement in ventilation.

A Case Illustrating the Costs of Quality Improvement: Nine Months to Move Needles and Syringes on the Anesthesia Cart.

Powerful entities are pushing physicians to become more involved with quality improvement (QI). We report a QI project to standardize and improve the ergonomics of the anesthesia medication and supply cart. Simply obtaining approval to make minor changes to the cart involved 54 phone calls, 164 e-mails, 4 presentations, 2 forms, 9 meetings, and 4 months of time. Confusion over fiscal matters further delayed the project by an additional 3 months. A combination of competing regulations, administrative overprocessing, and the lack of dedicated QI financial resources made simple improvements a challenge. The costs of participating in QI deserve attention.

Delayed emergence after anesthesia.

In most instances, delayed emergence from anesthesia is attributed to residual anesthetic or analgesic medications. However, delayed emergence can be secondary to unusual causes and present diagnostic dilemmas. Data from clinical studies is scarce and most available published material is comprised of case reports. In this review, we summarize and discuss less common and difficult to diagnose reasons for delayed emergence and present cases from our own experience or reference published case reports/case series. The goal is to draw attention to less common reasons for delayed emergence, identify patient populations that are potentially at risk and to help anesthesiologists identifying a possible cause why their patient is slow to wake up.

Risk factors for respiratory depression in patients undergoing retrobulbar block for vitreoretinal surgery.

BACKGROUND AND OBJECTIVE: To determine the risk factors for respiratory depression during retrobulbar block administration before vitreoretinal surgery. PATIENTS AND METHODS: Prospective, observational case series of 113 patients undergoing monitored anesthesia care and retrobulbar block before vitreoretinal surgery at a tertiary medical center. RESULTS: Chin lift, jaw thrust, and bag mask ventilation were performed in eight (7.1%), nine (8%), and six (5.3%) patients, respectively. No patients required intubation. Age, sex, body mass index, history of obstructive sleep apnea, American Society of Anesthesiologists physical status level, and baseline oxygen saturation were not predictive of airway intervention. Of the four anesthetic agents utilized (midazolam, fentanyl, alfentanil, and propofol), only propofol and fentanyl were associated with an increased risk for clinically significant apnea. Use of three medications for sedation was associated with a 5.4-fold increase in the relative risk of requiring a respiratory rescue intervention. CONCLUSION: During preoperative sedation for retrobulbar block administration, the use of propofol, fentanyl, or a combination of three anesthetics is associated with a statistically significant increase in the risk for respiratory depression requiring resuscitation.