Hong Kong Journal of Emergency Medicine

Personal protective equipment used for protection of healthcare workers in the combat against Severe Acute Respiratory Syndrome Coronavirus 2 pandemic is in limited supply worldwide at present – 2020. Use of barrier enclosure during endotracheal intubation can potentially act as a cost-effective adjunct to minimize risks of transmitting the infection to healthcare workers. However, there is concern that the enclosure itself will act as a barrier to the intubation procedure in the emergency settings.

To evaluate the negative effect of barrier enclosure (an aerosol box) on the performance of video-assisted intubation in a manikin

A total of 41 Emergency Department doctors from a local hospital were recruited to perform intubation in a manikin simulating normal and more difficult airways (Cormack-Lehane grades I and IIb) with and without the box. The primary outcome was time of successful intubation. The secondary outcomes were first-attempt success rate, number of successful attempts, need of adjuncts, dental injury and ease of intubation as perceived by the participants.

The aerosol box had no significant negative effect on the time of successful intubation (p = 0.630 (Grade I airway) and p = 0.436 (Grade IIb airway)), first-attempt success rate, number of successful attempts, need of adjuncts or dental injury. Participants subjectively reported extra yet minor challenges during intubation in the presence of the box.

Within limits of the pilot study, the aerosol box had no statistical significant difference but an increasing trend of prolonged endotracheal intubation interval in the Grade IIb airway and negative impact on first-pass success, and could potentially be used to protect healthcare workers during the aerosol-generating intubation procedure.

An outbreak of coronavirus disease 2019 (COVID-19) took place in Wuhan, China, by the end of 2019, and the disease continues to spread all over the world. The number of patients is increasing rapidly, a large number of infected patients is critically ill, and the mortality is high. However, information on COVID-19 patients is limited, and its clinical characteristics have not been fully studied.

To compare the performances of point-of-care lung ultrasound (LUS) and bedside chest X-ray in assessing the condition of COVID-19 patients with acute respiratory distress syndrome (ARDS).

This observational study enrolled 42 COVID-19 patients with ARDS who were admitted to the Department of Critical Care Medicine of the Wuhan Union Hospital from February to April 2020. The point-of-care LUS characteristics of the COVID-19 patients with ARDS were summarized, and the performances of LUS and bedside chest X-ray in assessing the patient’s condition were compared.

Most of the 42 patients were elderly individuals with chronic clinical diseases. The proportion of patients older than 60 years old was 85.7%. All patients were given invasive mechanical ventilation; eight (19.0%) of them received venovenous extracorporeal membrane oxygenation support. LUS has evident advantages in detecting lung consolidation, patchy shadows, and pleural thickening, and pleural line changes in particular. The receiver operating characteristic analysis indicated that the sensitivity, Youden index, and kappa value for detecting COVID-19 patients with ARDS were higher for LUS than the chest X-ray.

LUS has better diagnostic accuracy and sensitivity in COVID-19 patients with ARDS than the chest X-ray.

Effective triage and early detection are very important for the control and treatment of coronavirus disease 2019. For this purpose, reverse transcription polymerase chain reaction and chest computed tomography are used in emergency departments.

The aim of the study was to examine the diagnostic performance of computed tomography and to compare the inter-observer agreement among radiologists and between clinicians, in a coronavirus disease 2019 pneumonia high-prevalence area.

After exclusions, 534 patients were retrospectively included in this study. Reverse transcription polymerase chain reaction was considered as gold standard for diagnosis. All computed tomography images were independently reviewed by two radiologists who were blinded to reverse transcription polymerase chain reaction results and other clinical information. Each computed tomography scan was scored in four categories as typical, intermediate, atypical, and negative, regarding coronavirus disease 2019 pneumonia according to Radiological Society of North America guideline. As for the evaluation of the diagnostic performance, typical and intermediate appearances were accepted as positive for coronavirus disease 2019. In addition, the computed tomography scans were scored by two clinicians as coronavirus disease 2019 positive and negative.

The study group included 534 patients after the exclusion criteria. As a result of the repeated reverse transcription polymerase chain reaction tests, 396 (74%) patients were diagnosed with coronavirus disease 2019, 138 (26%) patients had a negative result and were evaluated as a control group. When the reverse transcription polymerase chain reaction results were referenced as the gold standard; the accuracy rates of radiologists and clinicians (R1, R2, C1, and C2) in the diagnosis of coronavirus disease 2019 were 78%, 79%, 73%, and 71%, their sensitivity rates were 83%, 83%, 74%, and 75%, and the negative predictive values were 57%, 58%, 49%, and 46%, respectively. Inter-observer agreements among the reviewers ranged from good to excellent.

Radiological Society of North America guideline related to coronavirus disease 2019 has excellent inter-observer agreement among chest radiologists. In this study, radiologists and clinicians have presented similar and good diagnostic performances in the evaluation of coronavirus disease 2019–suspected patients with chest computed tomography in high-epidemic area.

Similar to many Asian cities, there is no statutory provision for the determination of the duty borne by bystander first aiders when assisting victims in Hong Kong.

The aim of this study was to explore the views of a Good Samaritan Law by first-aid learners in Hong Kong.

A cross-sectional survey was conducted among first-aid course participants from the two largest training providers in Hong Kong using a self-administered questionnaire.

In total, 1223 questionnaires were completed and returned. Only 12.1% (147/1211) of participants have ever heard of Good Samaritan Law. After a short description of Good Samaritan Law was provided, 71.4% (848/1188) agreed or strongly agreed on a Likert-type scale that a Good Samaritan Law is necessary; 95.2% (1148/1223) support the enactment of a Good Samaritan Law in Hong Kong.

The majority of first-aid learners in Hong Kong supported the enactment of Good Samaritan Law. Overcoming the fear of litigation and improving bystander cardiopulmonary resuscitation rate is a priority for improving survival rates from sudden cardiac arrest in Hong Kong.

Hong Kong rates of bystander cardiopulmonary resuscitation are very low by international standards. Several Hong Kong secondary schools have begun incorporating cardiopulmonary resuscitation training into their curriculums for teachers and students.

This study aimed to explore secondary school cardiopulmonary resuscitation programs and better understand school principals’ attitudes toward cardiopulmonary resuscitation training.

A cross-sectional survey was sent to all Hong Kong secondary school principals (public and private, except for special education schools) between December 2017 and March 2018. A self-administered questionnaire of 20 items focusing on school characteristics, details of any in-school cardiopulmonary resuscitation materials or training, attitudes toward teaching cardiopulmonary resuscitation, and any barriers or ways to promote school cardiopulmonary resuscitation training was given to all school principals in the territory. This study was approved by the Survey and Behavioural Research Ethics committee of the Chinese University of Hong Kong on September 13, 2017.

Out of the 506 schools contacted, 110 completed surveys were returned (21.7%). Cardiopulmonary resuscitation training was offered in 33.6% (37/110), while 92.7% (102/110) had an automatic external defibrillator. A majority (69.1% (76/110)) agreed or strongly agreed that cardiopulmonary resuscitation training should be compulsory for secondary school students. In schools where cardiopulmonary resuscitation was taught, most cardiopulmonary resuscitation students were aged 15–17 years, and most courses ran for < 5 h. Increased funding could encourage more schools to offer cardiopulmonary resuscitation training to students in the future.

One-third (33.6%) of Hong Kong secondary schools offer cardiopulmonary resuscitation training. Increased funding may support school-based cardiopulmonary resuscitation instruction and improve rates of bystander cardiopulmonary resuscitation in the future.

Bystander cardiopulmonary resuscitation is a key component of life-saving after an out-of-hospital cardiac arrest. In the pre-arrival instructions for out-of-hospital cardiac arrest, it is recommended that the patient be laid on a flat floor. However, the most common reason for not performing cardiopulmonary resuscitation is that the bystander could not move the patient.

This study aim to investigate the effects of using a home-bed mattress on the quality of chest compression.

In this prospective, randomized study, chest compression without ventilation was performed for 4 min on a Resusci Anne manikin placed on a flat floor or on three types of home-bed mattresses (hard, medium and soft). Chest compression depth, chest compression rate and chest recoil were measured from the manikin with the Laerdal PC Skill Reporting System, and changes in chest compression quality using the four different surfaces were compared.

Thirty participants were enrolled to perform chest compression. There was no significant difference in chest compression depth and depth accuracy between the four surfaces. The median chest compression rates were 108.1 ± 8.5, 107.0 ± 8.3, 103.3 ± 8.9 and 98.3 ± 7.9 compressions/min (p < 0.001) for the flat floor, hard-, medium-, and soft-firmness mattresses, respectively. Moreover, there was no a significant difference in chest recoil accuracy.

Using a home-bed mattress did not decrease the chest compression quality, except chest compression rate of soft-firmness mattress. Thus, it may be effective to initiate chest compression on a home-bed mattress if the bystander cannot move the patient to the floor.

Therapeutic hypothermia can improve neurological status in cardiac arrest survivors.

We investigated the association between the timing of inducing therapeutic hypothermia and neurological outcomes in patients who experienced out-of-hospital cardiac arrest.

We evaluated data from 116 patients who were comatose after return of spontaneous circulation and those who received therapeutic hypothermia between January 2013 and April 2017. The primary endpoint was good neurological outcomes during index hospitalization, defined as a cerebral performance category score of 1 or 2. Therapeutic hypothermia timing was defined as the duration from the return of spontaneous circulation to hypothermia initiation. We analyzed the effect of early hypothermia induction on neurological results.

In total, 112 patients were enrolled. The median duration to hypothermia initiation was 284 min (25th–75th percentile, 171–418 min). Eighty-two (69.5%) patients underwent hypothermia within 6 h, and 30 (25.4%) had good neurological outcomes. The rates of good neurological outcomes by hypothermia initiation time quartile (shortest to longest) were 28.3%, 34.5%, 14.8%, and 28.6% (p = 0.401). The good neurologic outcomes did not differ between hypothermia patients within 6 h or after (26.5% vs 26.7%, p = 0.986). Short low-flow time and bystander resuscitation were associated with good neurological outcomes (p = 0.044, confidence interval: 0.027–0.955), but the timing of hypothermia initiation was not (p = 0.602, confidence interval: 0.622–1.317).

A shorter low-flow time was associated with good neurological outcomes in out-of-hospital cardiac arrest patients who experienced hypothermia. However, inducing hypothermia sooner, even within 6 h, did not improve the neurological outcomes. Thus, as current guidelines recommend, initiating hypothermia within 6 h of recovery of spontaneous circulation is reasonable.

Accurate prognostic prediction of out-of-hospital cardiac arrest is challenging but important for the emergency team and patient’s family members. A number of prognostic prediction models specifically designed for out-of-hospital cardiac arrest are developed and validated worldwide.

This narrative review provides an overview of the prognostic prediction models out-of-hospital cardiac arrest patients for use in the emergency department.

Out-of-hospital cardiac arrest prognostic prediction models are potentially useful in clinical, administrative and research settings. Development and validation of such models require prehospital and hospital predictor and outcome variables which are best in the standardised Utstein Style. Logistic regression analysis is traditionally employed for model development but machine learning is emerging as the new tool. Examples of such models available for use in the emergency department include ROSC After Cardiac Arrest, CaRdiac Arrest Survival Score, Utstein-Based Return of Spontaneous Circulation, Out-of-Hospital Cardiac Arrest, Cardiac Arrest Hospital Prognosis and Cardiac Arrest Survival Score. The usefulness of these models awaits future studies.

Stridor is one of the common presentations of children admitting to emergency department with respiratory distress. The most common etiology of stridor in pediatric age group is infective pathology or ingestion of foreign body. The presentation of dissecting aneurysm causing stridor in pediatric population is very rare and has never been reported in the literature.

A 14-year-old boy presented to the Emergency Department with sub-acute onset of stridor after fall from height on an uneven surface. A suspicion of foreign body or an infective pathology was made and the child was shifted to the operating room. After performing a successful intubation under general anesthesia, diagnostic rigid bronchoscopy and esophagoscopy were done which revealed a pulsating external compression of trachea. The child was further evaluated and managed for dissecting aneurysm of the aorta.

Among the various causes for stridor in pediatric-trauma population, dissecting aortic aneurysm is a rare cause. The association of elevated renal parameters to dissecting aortic aneurysm has been documented in various studies. Wheezing, shortness of breath, and stridor indicate a tracheal obstruction in a patient with aortic aneurysm. Computed tomography angiography is the investigation of choice. The defect needs to be repaired by a vascular graft under cardiopulmonary bypass.

Stridor in pediatric population with etiology as dissecting aneurysm is unusual. A rare presentation like this deserves to be kept in mind while evaluating stridor in pediatric trauma patients by an emergency physician.