Anne-Maree Kelly

The minimum clinically significant difference in visual analogue scale pain score does not differ with severity of pain

Objective—To determine whether minimum clinically significant difference in visual analogue scale (VAS) pain score varies according to the severity of pain reported. Method—Prospective descriptive study of adult patients in an urban emergency department (ED). On presentation to the ED, patients marked the level of their pain on a 100 mm, non-hatched VAS scale. At 20 minute intervals thereafter they were asked to give a verbal categorical rating of their pain as “a lot better”, “a little better”, “much the same”, “a little worse” or “much worse” and to mark the level of pain on a VAS scale of the same type as used previously. It was pre-defined that patients with VAS pain scores of 30 mm or less would be categorised as having mild pain, those with scores of 70 mm or more were categorised as having severe pain and those from 31 mm to 69 mm, moderate pain. The minimal clinically significant difference (MCSD) in VAS pain score was defined as the mean difference between current and preceding scores when the subject reported “a little worse” or “a little better” pain. Results—156 patients were enrolled in the study, yielding 88 evaluable comparisons where pain was rated as “a little better” or “a little worse”. The MCSD in VAS score in the group overall was 12 mm (95%CI 9 mm to 15 mm). MCSD in VAS score for the “mild pain” group was 11 mm (95%CI 4 mm to 18 mm), for the “moderate pain” group 14 mm (95%CI 10 mm to 18 mm) and for the severe pain group, 10 mm (95%CI 6 mm to 14 mm). There is no statistical difference between the MCSD in VAS score between the severity groups. Conclusions—The MCSD in VAS pain score does not differ with the severity of pain being experienced.

Induction of Therapeutic Hypothermia by Paramedics After Resuscitation From Out-of-Hospital Ventricular Fibrillation Cardiac Arrest A Randomized Controlled Trial

Background— Therapeutic hypothermia is recommended for the treatment of neurological injury after resuscitation from out-of-hospital cardiac arrest. Laboratory studies have suggested that earlier cooling may be associated with improved neurological outcomes. We hypothesized that induction of therapeutic hypothermia by paramedics before hospital arrival would improve outcome. Methods and Results— In a prospective, randomized controlled trial, we assigned adults who had been resuscitated from out-of-hospital cardiac arrest with an initial cardiac rhythm of ventricular fibrillation to either prehospital cooling with a rapid infusion of 2 L of ice-cold lactated Ringers solution or cooling after hospital admission. The primary outcome measure was functional status at hospital discharge, with a favorable outcome defined as discharge either to home or to a rehabilitation facility. A total of 234 patients were randomly assigned to either paramedic cooling (118 patients) or hospital cooling (116 patients). Patients allocated to paramedic cooling received a median of 1900 mL (first quartile 1000 mL, third quartile 2000 mL) of ice-cold fluid. This resulted in a mean decrease in core temperature of 0.8°C (P=0.01). In the paramedic-cooled group, 47.5% patients had a favorable outcome at hospital discharge compared with 52.6% in the hospital-cooled group (risk ratio 0.90, 95% confidence interval 0.70 to 1.17, P=0.43). Conclusions— In adults who have been resuscitated from out-of-hospital cardiac arrest with an initial cardiac rhythm of ventricular fibrillation, paramedic cooling with a rapid infusion of large-volume, ice-cold intravenous fluid decreased core temperature at hospital arrival but was not shown to improve outcome at hospital discharge compared with cooling commenced in the hospital. Clinical Trial Registration— URL: http://www.anzctr.org.au. Unique identifier: ACTRN12605000179639.

Agreement between arterial and central venous values for pH, bicarbonate, base excess, and lactate

Objective: This study aimed to determine the extent of agreement between central venous and arterial values for pH, bicarbonate, base excess, and lactate in a group of intensive care unit (ICU) patients. Methods: A prospective study of a convenience sample of patients deemed by their treating doctor to require blood gas analysis as part of their clinical care in ICU. It compared pH, bicarbonate, base excess and lactate on arterial and central venous samples taken within five minutes of each other. Data were analysed using bias (Bland–Altman) methods. Results: A total of 168 matched sample pairs from 110 patients were entered into the study. All variables showed close agreement. The mean difference between arterial and venous values of pH was 0.03 pH units, for bicarbonate 0.52 mmol/l, for lactate 0.08 mmol/l, and for base excess 0.19 mmol/l. All showed acceptably narrow 95% limits of agreement. Conclusion: Central venous pH, bicarbonate, base excess, and lactate values showed a high level of agreement with the respective arterial values, with narrow 95% limits of agreement. These results suggest that venous values may be an acceptable substitute for arterial measurement in this clinical setting.

Induction of prehospital therapeutic hypothermia after resuscitation from nonventricular fibrillation cardiac arrest

Objective:To evaluate the effects on temperature and outcome at hospital discharge of a pre-hospital rapid infusion of large volume, ice-cold intravenous Hartmanns solution in patients with out-of-hospital cardiac arrest and an initial cardiac rhythm of asystole or pulseless electrical activity. Design:Prospective, randomized, controlled clinical trial. Setting:Pre-hospital emergency medical service and 12 critical care units in Melbourne, Australia. Patients:One hundred and sixty three patients who had been resuscitated from cardiac arrest with an initial cardiac rhythm of asystole or pulseless electrical activity. Interventions:Patients were randomized to either pre-hospital cooling using a rapid infusion of up to two litres ice-cold Hartmanns solution (82 patients) or cooling after hospital admission (81 patients). The planned duration of therapeutic hypothermia (32°C–34°C) in both groups was 24 hrs. Measurements and Main Results:Patients allocated to pre-hospital cooling received a median of 1500 ml of ice-cold fluid. This resulted in a mean decrease in core temperature of 1.4°C compared with 0.2°C in hospital cooled patients (p < .001). The time to therapeutic hypothermia (<34°C) was 3.2 hrs in the pre-hospital cooled group compared with 4.8 hrs in the hospital cooled group (p = .0328). Both groups received a mean of 15 hrs cooling in the hospital and only 7 patients in each group were cooled for 24 hrs. Overall, there was no difference in outcomes at hospital discharge with favorable outcome (discharge from hospital to home or rehabilitation) in 10 of 82 (12%) in the pre-hospital cooled patients, compared with 7 of 81 (9%) in the hospital cooled patients (p = .50). In the patients with a cardiac cause of the arrest, 8 of 47 patients (17%) who received pre-hospital cooling had a favorable outcome at hospital discharge compared with 3 of 43 (7%) in the hospital cooled group (p = .146). Conclusions:In adults who have been resuscitated from out-of-hospital cardiac arrest with an initial cardiac rhythm of asystole or pulseless electrical activity, pre-hospital cooling using a rapid infusion of large-volume, ice cold intravenous Hartmanns solution decreases core temperature at hospital arrival and decreases the time to therapeutic hypothermia. In patients with a cardiac cause of the arrest, this treatment may increase the rate of favorable outcome at hospital discharge. Further larger studies should evaluate the effects of pre-hospital cooling when the initial cardiac rhythm is asystole or pulseless electrical activity, particularly in patients with a cardiac cause of the arrest.

Height and surfacing as risk factors for injury in falls from playground equipment: a case-control study.

OBJECTIVES: Despite the widespread promotion of safety standards no epidemiological studies have adequately evaluated their effectiveness in preventing injury in falls from playground equipment. This study evaluated the effectiveness of the height and surfacing requirements of the New Zealand standard for playgrounds and playground equipment. SETTING: Early childhood education centres and schools in two major cities in the South Island of New Zealand. METHODS: Data were collected on 300 children aged 14 years or less who had fallen from playground equipment. Of these, 110 (cases) had sustained injury and received medical attention, while 190 (controls) had not sustained injury requiring medical attention. RESULTS: Logistic regression models fitted to the data indicated that the risk of injury being sustained in a fall was increased if the equipment failed to comply with the maximum fall height (odds ratio (OR) = 3.0; 95% confidence interval (CI) 0.7 to 13.1), surfacing (OR = 2.3; 95% CI 1.0 to 5.0), or safe fall height (OR = 2.1; 95% CI 1.1 to 4.0) requirements. Falls from heights in excess of 1.5 metres increased the risk of injury 4.1 times that of falls from 1.5 metres or less and it was estimated that a 45% reduction in children attending emergency departments could be achieved if the maximum fall height was lowered to 1.5 metres. CONCLUSIONS: Although the height and surfacing requirements of the New Zealand standard are effective in preventing injury in falls from playground equipment, consideration should be given to lowering the maximum permissible fall height to 1.5 metres.

Randomized controlled trial comparing the effectiveness and safety of intranasal and intramuscular naloxone for the treatment of suspected heroin overdose

AIMS Traditionally, the opiate antagonist naloxone has been administered parenterally; however, intranasal (i.n.) administration has the potential to reduce the risk of needlestick injury. This is important when working with populations known to have a high prevalence of blood-borne viruses. Preliminary research suggests that i.n. administration might be effective, but suboptimal naloxone solutions were used. This study compared the effectiveness of concentrated (2 mg/ml) i.n. naloxone to intramuscular (i.m.) naloxone for suspected opiate overdose. METHODS This randomized controlled trial included patients treated for suspected opiate overdose in the pre-hospital setting. Patients received 2 mg of either i.n. or i.m. naloxone. The primary outcome was the proportion of patients who responded within 10 minutes of naloxone treatment. Secondary outcomes included time to adequate response and requirement for supplementary naloxone. Data were analysed using multivariate statistical techniques. RESULTS A total of 172 patients were enrolled into the study. Median age was 29 years and 74% were male. Rates of response within 10 minutes were similar: i.n. naloxone (60/83, 72.3%) compared with i.m. naloxone (69/89, 77.5%) [difference: -5.2%, 95% confidence interval (CI) -18.2 to 7.7]. No difference was observed in mean response time (i.n.: 8.0, i.m.: 7.9 minutes; difference 0.1, 95% CI -1.3 to 1.5). Supplementary naloxone was administered to fewer patients who received i.m. naloxone (i.n.: 18.1%; i.m.: 4.5%) (difference: 13.6%, 95% CI 4.2-22.9). CONCLUSIONS Concentrated intranasal naloxone reversed heroin overdose successfully in 82% of patients. Time to adequate response was the same for both routes, suggesting that the i.n. route of administration is of similar effectiveness to the i.m. route as a first-line treatment for heroin overdose.

Parent visual analogue scale ratings of children's pain do not reliably reflect pain reported by child

Objectives To determine whether parent and child visual analogue scale (VAS) scores for the pain associated with acute conditions in the child agree sufficiently for these methods of measurement to be considered interchangeable in pain and analgesia research. Design This was a prospective, two-group, repeated measures, blinded study in an urban pediatric emergency department. Children aged 8 to 15 years seeking treatment for painful conditions and the parents of these children were asked to rate the child’s pain independently using a VAS on as many as four occasions at 20-minute intervals. Both participants were blinded to their previous rating and the rating of the other participant. The main outcome measure was the correlation of child and parent VAS pain scores by Pearson correlation and bias plot (Bland-Altman) analysis of agreement between tests. Results Seventy-eight child-parent sets participated, yielding 289 VAS pain score comparison pairs for evaluation. The correlation between child and parent VAS pain scores was 0.63 (95% CI, 0.56–0.70). Bias plot analysis revealed a bias of 5% and 95% limits of agreement from −38 to +47 mm. The degree of difference between child and parent scores was variable, but there was an increasing tendency for parents to underestimate the child’s pain when the child recorded VAS pain scores at the higher end of the scale. Conclusions Parents’ VAS score ratings of their children’s pain correlate only moderately with the children’s VAS pain scores and show poor levels of agreement. The difference between the measures is variable and appears to be more marked when the child reports a higher VAS score. This research raises doubt about whether parental rating of a child’s pain is an appropriate surrogate marker in pediatric pain and analgesia research.

Parental weight estimation of their child's weight is more accurate than other weight estimation methods for determining children's weight in an emergency department?

Objective: To compare the various paediatric weight estimation methods (Advanced Pediatric Life Support, Broselow Tape, Argall, and Best Guess) and parental estimate to measured weight. Patients and method: A convenience sample of children aged 1–11 years who presented to the emergency department over a 6 month period were eligible for inclusion. Data collected included height, age, ethnicity, parent estimate of weight and measured weight. Body mass index (BMI) was calculated. The outcome of interest was agreement between estimated weight and measured weight for each method. Data were analysed by descriptive statistics and performance of each weight estimation method was compared using mean difference (MD), root mean square error (RMSE) and agreement within 10%. Results: 410 cases were included in this study. The median age was 4 years, there were more boys (54.4%), and the majority of cases were of Caucasian ethnicity (74.9%). The mean BMI of the sample was 17 kg/m2 and mean actual weight was 21.2 kg. Parent estimate was the most accurate method with 78% of parent estimates within 10% of measured weight and the lowest mean difference (−0.6 kg) and RMSE (3.1 kg). The Broselow tape was the most accurate of the other methods, with 61% of estimations within 10% of measured weight. Conclusion: Parental estimation of weight is more accurate than the other weight estimation methods studied. When this is not available, the Broselow tape is the most accurate alternative method.

Venous pCO2 and pH can be used to screen for significant hypercarbia in emergency patients with acute respiratory disease

This prospective study of patients with acute respiratory illness or potential ventilatory compromise compared pCO(2) and pH on an arterial and a venous blood sample with the aims of determining whether venous pH and pCO(2) can replace arterial values in the management of patients with acute respiratory disease and to determine whether there is a cut-off level of venous pCO(2) that can accurately screen for significant hypercarbia (pCO(2) > 50 mm Hg). Data were analyzed using bias plot and receiver operator characteristic (ROC) curve methods. There were 196 sample-pairs analyzed; 56 (29%) had significant hypercarbia. For pH, there was very good agreement with venous samples being an average of 0.034 pH units lower than arterial samples. With respect to pCO(2), there was only fair agreement, with the pCO(2) on average 5.8 mm Hg higher in venous samples and 95% limits of agreement -8.8 to +20.5 mm Hg. The ROC curve analysis showed that a venous pCO(2) level of 45 mm Hg was a potential screening cutoff (sensitivity for the detection of hypercarbia of 100%, specificity 57%). This study shows that venous pH is an acceptable substitute for arterial measurement but there is not sufficient agreement for venous pCO(2) to be able to replace arterial pCO(2) in the clinical evaluation of ventilatory function. Venous pCO(2) may be able to be used as a screening test for hypercarbia using a screening cut-off of 45 mm Hg.

A process approach to improving pain management in the emergency department: development and evaluation

Aim—(1) To describe a process approach to the improvement of pain management in emergency departments. (2) To compare analgesia ordering and administration practices for patients with acute fractures before and after implementation of a nurse managed, titrated intravenous narcotic policy. Method—Retrospective chart review of patients with long bone fractures for the years 1993 and 1997. Results—There was a dramatic change in analgesia administration practices away from the intramuscular route in favour of the intravenous route (p<0.001). For long bone fractures, in 1993, 53% of patients received intramuscular narcotic analgesia compared with 5% in 1997. In contrast, in 1993, 6% of the patients received intravenous narcotic analgesia compared with 54% in 1997. Conclusion—This study demonstrates that a process approach to improving pain management that resulted in both changes in drug administration and pain assessment and management processes made a significant and sustained change to analgesia ordering and administration practices for patients with long bone fractures in an emergency department.