Lark Susak

A research tool for measurement of recovery from sedation: The vancouver sedative recovery scale

The need for a research tool to measure recovery from sedation was identified during the design phase of a study investigating sedative protocols following open heart surgery in children. A thorough review of the literature failed to show any scales that measure degree of sedation in children at various times after initial awakening. The Vancouver Sedative Recovery Scale (VSRS) was developed through an iterative process during which we identified numerous indicators of levels of alertness among sedated children, and then determined the applicability and face validity of these indicators. The VSRS evaluated in this study consists of 12 distinct items that encompass three categories of indicators (response; eye appearance and function; and body movement). Total possible VSRS scoring ranges from 0 to 22 (higher score indicating more alert) because some of the 12 items have more than two rating levels. The VSRS was administered to 82 pediatric intensive care unit and postanesthesia recovery patients, with each patient assessed simultaneously by at least two observers. Internal consistency as measured by Cronbachs alpha was excellent: 0.85. Interobserver agreement or reliability as measured by intraclass correlation was also very high: 0.90; and for individual items Cohens kappa ranged from 0.65 to 0.89. We consider the VSRS to be a good beginning in our effort to quantify level of alertness after sedation in the pediatric patient population.

Ingestion of cannabis: a cause of coma in children.

Previous reports of accidental ingestion of cannabis by children are rare. None has reported coma, although one described a stuporous state that required assisted ventilation. Over the past four years, the staff of British Columbias Childrens Hospital has managed six children with cannabis toxicity, three of whom presented in coma, including one with airway obstruction. Recurring diagnostic features included rapid onset of drowsiness, moderate pupil dilation, hypotonia, lid lag, and the presence of small granules or leaves in the mouth. Confirmation was obtained by positive urine screening for cannabinoids. The six cases described emphasize the need for emergency physician awareness of possible diagnostic criteria, the potential severity of intoxication, and the need for prevention through parent education.

The Vancouver sedative recovery scale for children: validation and reliability of scoring based on videotaped instruction

We originally developed and tested the Vancouver Sedative Recovery Scale (VSRS) to measure recovery from sedation following paediatric open heart surgery and reported excellent clinical inter-observer reliability. We now report a new study using videotape instruction of novice raters and videotaped case examples to determine whether the instruction produces adequate skill with the VSRS. Inter-rater reliability was assessed using videotapes of 16 children across a range of ages (six months to six years), and all levels of sedation (unresponsive to fully awake). Variably randomized subsets of six of the 16 test cases were randomly assigned to be rated by each of 16 video-instructed ICU staff volunteers, according to a balanced incomplete block design, such that every pair of raters assessed two children in common. The validity of the ratings from the video-instructed raters was assessed by comparison with “gold standard” scores from two experts who rated all 16 children clinically as the test cases were videotaped. The experts were in agreement themselves (intraclass correlation of 0.976). The correlation between the novice scores (average of six ratings per video) and the live clinical scores (average of two expert ratings) was 0.977 over the 16 test cases. On average, the mean expert rating was slightly higher, but the difference was negligible. (The differences between the mean ratings of the experts and novices for 13 of the 16 videos are very close to zero, while the other three differences, from technically less good videos, are two standard deviations away from zero). The VSRS, video instruction method and incomplete block design may be of use to other clinicians and investigators.RésuméPour mesurer le réveil et la sédation après la chirurgie à coeur ouvert chez l’enfant, nous avons développé et vérifié l’échelle de réveil et de sédation de Vancouver (VSRS) dont nous avons déjà communiqué la fiabilité. Nous pulions maintenant une nouvelle étude au cours de laquelle nous utilisons une vidéocassette pour former les appréciateurs et des exemples sur vidéocassette pour déterminer si cette méthode suffit pour produire une compétence suffisante avec le VSRS. La variabilité entre appréciateurs est évaluée avec des vidéocassettes de 16 enfants d’âges différents (de six mois à six ans) et à tous les degrés de sédation (de l’insensibilité au réveil complet). Des souscatégories variables aléatoires de six des 16 observations expérimentales sont attribuées au hasard pour évaluation à chacun des 16 préposés volontaires déjà initiés à la vidéo à l’unité des soins intensifs, suivant un modèle de bloc équilibré incomplet de sorte que chaque paire d’appréciateurs doit évaluer deux enfants en commun. La validité des évaluations des appréciateurs formés par vidéo est établie par comparaison avec les scores de deux experts qui ont classifé par la clinique les 16 enfants au moment où on les enregistrait sur vidéo. Les experts sont d’accord entre eux (corrélation 0,976). La corrélation entre les appréciateurs novices (en moyenne six évaluationspar vidéo) et les scores de références mesurés sur le vif (moyenne de deux évaluations d’experts) est de 0,977 pour les 16 observations. Les évaluations moyennes des experts sont légèrement plus élevées, mais cette différence est négligeable. Pour 13 des 16 vidéos, la différence entre les évaluations des experts et des novices est très près de zéro, alors que les trois autres différences pour des vidéos de moins bonne qualité technique s’éloignent de deux écarts-types du zéro. Le VSRS, la formation par vidéo et le modèle de bloc équilibré incomplet peuvent être utiles à d’autres cliniciens et chercheurs.

Cadaver testing to validate design criteria of an adult intraosseous infusion system.

INTRODUCTION The FAST 1 intraosseous (IO) infusion system was designed to deliver fluids and medications into the adult sternum in the prehospital and battlefield environments. OBJECTIVE To test the prototype in 106 cadavers and excised sterna and compare it with other IO devices. RESULTS The insertion force was similar to that of other IO devices (mean, 8.5 kg; range, 2.3-19.6 kg). In 39 of 39 trials, the depth-control mechanism inserted the portal within 1.0 mm of a predetermined distance below the anterior surface of the cortical bone. If misplaced, underpenetration was more likely than overpenetration (mean displacement, -0.3 mm; SD, 0.5 mm). After release, the portal could not be advanced further into the manubrium. Marrow was accessed in 75 of 77 trials. Mean flow rates were 109 mL/min for normal saline solution and 102 mL/min for hypertonic saline/dextran, similar to the Cook Sur-Fast device. CONCLUSION The cadaver and bench tests demonstrated the reliability and safety of the FAST 1 system at the design/prototype stage.

The cost-benefit of pulse-oximeter use in the prehospital environment.

INTRODUCTION Pulse-oximetry has proven clinical value in Emergency Departments and Intensive Care Units. In the prehospital environment, oxygen is given routinely in many situations. It was hypothesized that the use of pulse oximeters in the prehospital setting would provide a measurable cost-benefit by reducing the amount of oxygen used. METHODS This was a prospective study conducted at 12 ambulance stations (average transport times > 20 minutes). Standard care protocols and paramedic assessments were used to determine which patients received oxygen and the initial flow rate used. Pulse-oximetry measurements (SpO2) were then taken. If SpO2 fell below 92% or rose above 96% (except in patients with chest pain), oxygen (O2) flow rates were adjusted. Costs of oxygen use were calculated: volume that would have been used based on initial flow rate; and volume actually used based on actual flow rates and transport time. RESULTS A total of 1,907 patients were recruited. Oximetry and complete data were obtained on 1,787 (94%). Of these, 1,329 (74%) received O2 by standard protocol: 389 (27.5%) had the O2 flow decreased; 52 had it discontinued. Eighty-seven patients (6%) not requiring O2 standard protocol were hypoxemic (SpO2 < 92%) by oximetry, and 71 patients (5%) receiving oxygen required flow rate increases. Overall, O2 consumption was reduced by 26% resulting in a cost-savings of

Midazolam following open heart surgery in children: haemodynamic effects of a loading dose.

0.20/patient. Prehospital pulse-oximetry allows unnecessary or excessive oxygen therapy to be avoided in up to 55% of patients transported by ambulance and can help to identify suboptimally oxygenated patients (11%). CONCLUSIONS Rationalizing the O2 administration using pulse-oximetry reduced O2 consumption. Other health care savings likely would result from a reduced incidence of suboptimal oxygenation. Oxygen cost-saving justifies oximeter purchase for each ambulance annually where patient volume exceeds 1,750, less frequently for lower call volumes, or in those services where the mean transport time is less than the 23 minute average noted in this study.

Paramedic Evaluation of Adult Intraosseous Infusion System

Our objective was to establish the safety and effectiveness of a loading dose of midazolam for postoperative sedation of children recovering from open heart surgery; a prospective randomized placebo‐controlled double‐blind study was done with subjects randomized to three groups according to loading dose. I=0.08 mg·kg−1; II=0.04 mg·kg−1; and III=0.00 mg·kg−1 (placebo). An open label continuous midazolam infusion protocol followed. Haemodynamic parameters were monitored. The study was discontinued following an adverse event involving the 23rd subject. When data for all 23 subjects were combined, there was a mean decrease of 10% in blood pressure (BP) 30 min after the loading dose (P<0.001). Heart rate change was less significant. Clinicians identified four hypotensive episodes as temporally associated with the midazolam load, two each in Groups I (0.08 mg·kg−1) and III (placebo). One subject in Group I (the 23rd) became hypotensive within five min of receiving the loading dose, had a difficult clinical course and died four weeks postoperatively. We cannot conclude that the loading dose of midazolam had any systematic haemodynamic effect in our study population. Although the clinical course of the 23rd subject suggests a subset of more susceptible children (those who receive opioid analgesia with midazolam, are volume‐restricted, and/or undergo more complex forms of surgical correction), many critical care patients are inherently physiologically unstable, and concluding clinically that blood pressure fluctuation is drug related may be erroneous.