Biomedical subjects

Kevin Chu

Publications and source records attributed to Kevin Chu.

5 recordsLinked to original sources

PubMed2006

CPR training and CPR performance: do CPR-trained bystanders perform CPR?

OBJECTIVES: To determine factors associated with cardiopulmonary resuscitation (CPR) provision by CPR-trained bystanders and to determine factors associated with CPR performance by trained bystanders. METHODS: The authors performed a prospective, observational study (January 1997 to May 2003) of individuals who called 911 (bystanders) at the time of an out-of-hospital cardiac arrest. A structured telephone interview of adult cardiac-arrest bystanders was performed beginning two weeks after the incident. Elements gathered during interviews included bystander and patient demographics, identifying whether the bystander was CPR trained, when and by whom the CPR was performed, and describing the circumstances of the event. If CPR was not performed, we asked the bystanders why CPR was not performed. Logistic regression was used to calculate odds ratios and 95% confidence intervals (95% CI) for factors associated with CPR performance. RESULTS: Of 868 cardiac arrests, 684 (78.1%) bystander interviews were completed. Of all bystanders interviewed, 69.6% were family members of the victims, 36.8% of the bystanders had more than a high-school education, and 54.1% had been taught CPR at some time. In 21.2% of patients, the bystander immediately started CPR, and in 33.6% of cases, someone started CPR before the arrival of emergency medical services (EMS). Important overall predictors of CPR performance were the following: witnessed arrest (OR = 2.3; 95% CI = 1.4 to 3.8); bystander was CPR trained (OR = 6.6; 95% CI = 3.5 to 12.5); bystander had more than a high-school education (OR = 2.0; 95% CI = 1.2 to 3.1), or arrest occurred in a public location (OR = 3.1; 95% CI = 1.7 to 5.8). These variables were significant predictors of CPR performance among CPR-trained bystanders, as was CPR training within five years (OR = 4.5; 95% CI = 2.8 to 7.3). Common reasons that the CPR-trained bystanders cited for not performing CPR were the following: 37.5% stated that they panicked, 9.1% perceived that they would not be able to do CPR correctly, and 1.1% thought that they would hurt the patient. Surprisingly, only 1.1% objected to performing mouth-to-mouth resuscitation. CONCLUSIONS: A minority of CPR-trained bystanders performed CPR. CPR provision was more common in CPR-trained bystanders with more than a high-school education and when CPR training had been within five years. Previously espoused reasons for not doing CPR (mouth-to-mouth, infectious-disease risk) were not the reasons that bystanders cited for not doing CPR. Further work is needed to maximize CPR provision after CPR training.

Adult↗

PubMed2005

Likelihood ratios increase diagnostic certainty in pulmonary embolism.

Pulmonary embolism (PE) is a difficult diagnosis to confirm. The choice of tests has led to a myriad of algorithms. Diagnostic uncertainty can be quantified by the application of the tests' likelihood ratios (LR). Positive and negative LR enable the conversion of a pretest to a post-test probability, given a positive and negative test result, respectively. Thus, a pretest probability of <17% and a negative D-dimer with a negative LR of 0.05 (sensitivity 98%, specificity 40%) lead to a post-test probability of PE of <1%. Ventilation perfusion (V/Q) scans with a normal, very low, low, intermediate and high probability result have an LR of 0, 0.125, 0.25, 1 and 17, respectively. Also, patients with a V/Q scan result other than normal or high probability still have a post-test probability of PE from 3 to 65%. Positive and negative computed tomography pulmonary angiograms (CTPA) have an LR of 8.6 and 0.06, respectively (sensitivity 95%, specificity 89%). Patients with a high pretest probability and negative CTPA again still have a post-test probability of more than 10%. However, as the post-test probability after one test becomes the pretest probability for the next, test results used cumulatively progressively narrow the gap to a final diagnosis. The post-test probability after a D-dimer, V/Q scan, CTPA, leg ultrasound or pulmonary angiography, alone or in any combination or in any order, can be calculated using their LR. Use of LR thus assists in the precise interpretation of test results, such as in complex algorithms for PE.

Angiography↗

PubMed2004

Nebulized lidocaine decreases the discomfort of nasogastric tube insertion: a randomized, double-blind trial.

STUDY OBJECTIVE: Nasogastric tube insertion is a common emergency department (ED) procedure that is associated with considerable patient discomfort. The safety and efficacy of nebulized lidocaine for upper airway anesthesia have previously been demonstrated. We determine whether nebulized lidocaine administered before nasogastric tube insertion significantly reduces patient discomfort. METHODS: A double-blind, placebo-controlled, randomized clinical trial of adult patients was conducted in the EDs of 2 university hospitals. Twenty-nine participants were administered nebulized lidocaine (4 mL 10%), and 21 participants received nebulized normal saline solution. Patient discomfort was measured using a 100-mm visual analog scale. The difficulty of nasogastric tube insertion was evaluated using a 5-point Likert scale. RESULTS: There was a clinical and statistical significant difference in patient discomfort associated with the passage of the nasogastric tube between nebulized lidocaine and placebo groups (mean visual analog scale score 37.7 versus 59.3 mm, respectively; difference between group means 21.6 mm; 95% confidence interval [CI] 5.3 to 38.0 mm). There was not a detectable difference in difficulty with the passage of the nasogastric tube between the 2 groups (median 2 versus 2; median difference 0; 95% CI -1 to 1). Epistaxis occurred more frequently in the lidocaine group (17% versus 0%; difference 17%; 95% CI 3.5% to 31%). CONCLUSION: Nebulized lidocaine decreases the discomfort of nasogastric tube insertion and should be considered before passing a nasogastric tube. An increased frequency of epistaxis, however, may be associated with its use.

Aged↗

PubMed2004

The application of North American CT scan criteria to an Australian population with minor head injury.

OBJECTIVE: To determine potential changes in the number of CT head scans performed if the New Orleans Criteria (NOC) or Canadian CT Head Rule (CCTR) was applied to an Australian emergency department population of minor head injured (MHI) patients. METHODS: A retrospective chart review was conducted in an adult metropolitan teaching hospital in Brisbane. All patients presenting over a 3-month period with a GCS Score of 15 following an MHI and had a CT head scan performed were selected for analysis. Using clinically significant CT abnormalities and neurological intervention as the outcome measures, the NOC and CCTR were applied to determine if CT scanning was considered necessary. RESULTS: Of the 240 patients reviewed, 230 had a normal CT scan and 10 had clinically significant CT abnormalities. One patient with CT abnormality required neurosurgical intervention. Application of the NOC would have resulted in a 3.8% (95% CI 1.7-7.0%) reduction in CT scans performed without missing any patients with CT abnormalities or requiring neurological intervention. Application of the CCTR using both high and low risk factors would have resulted in a 46.7% (95% CI 40.2-53.2%) reduction in CT scans performed without missing the patient requiring neurological intervention, but would not have detected two patients with clinically significant CT abnormalities. CONCLUSION: Neither the NOC nor the CCRT appear suitable for significantly reducing the number of normal CT head scans performed without missing clinically significant CT abnormalities when applied to our current clinical practice.

Adolescent↗

PubMedDate not supplied

Radiological imaging to improve the emergency department diagnosis of acute appendicitis.

OBJECTIVES: To determine the institution's current non-therapeutic (negative) appendicectomy rate; the frequency of clinical predictors for appendicitis in patients who underwent appendicectomy; and the utilization and accuracy of ultrasound scans (USS) and computed tomography (CT) in the diagnosis of appendicitis. METHODS: A retrospective chart review was conducted in an adult, metropolitan teaching hospital. Patients who presented to the ED and underwent an appendicectomy over a 12-month period were analysed. Symptoms and signs predictive of appendicitis, results of USS and CT scans if performed, and histopathology findings were abstracted from patient records. RESULTS: Two hundred and forty patients had appendicectomies, 147 (61%) were male and the median age was 25 years (range 14-78 years). The negative appendicectomy rate was 14.3% (95% CI 9.1-21.0%) and 18.3% (95% CI 11.0-26.7%) in males and females, respectively. Abdominal pain shifting to the right iliac fossa (RIF), anorexia and RIF rebound tenderness were found more frequently in patients with positive than negative appendicectomies (P < 0.05). USS and CT scans were performed in 68 (28%) and 15 (9.5%) patients, respectively. The likelihood ratio for appendicitis in patients with a normal USS or a normal CT scan was 0.83 (95% CI 0.56-1.24) and 0.08 (95% CI 0.01-0.60), respectively. There were no false positive CT scan results. CONCLUSION: Computed tomoraphy scanning should play an increasing role in the ED management of suspected appendicitis. Our negative appendicectomy rate could potentially be halved by the introduction of CT scans in the diagnostic work up of these patients.

Adolescent↗