Testing the Feasibility and Acceptability of Using an Artificial Intelligence Chatbot to Promote HIV Testing and Pre-Exposure Prophylaxis in Malaysia: Mixed Methods Study

BACKGROUND

The HIV epidemic continues to grow fastest among men who have sex with men (MSM) in Malaysia in the presence of stigma and discrimination. Engaging MSM on the internet using chatbots supported through artificial intelligence (AI) can potentially help HIV prevention efforts. We previously identified the benefits, limitations, and preferred features of HIV prevention AI chatbots and developed an AI chatbot prototype that is now tested for feasibility and acceptability.

OBJECTIVE

This study aims to test the feasibility and acceptability of an AI chatbot in promoting the uptake of HIV testing and pre-exposure prophylaxis (PrEP) in MSM.

METHODS

We conducted beta testing with 14 MSM from February to April 2022 using Zoom (Zoom Video Communications, Inc). Beta testing involved 3 steps: a 45-minute human-chatbot interaction using the think-aloud method, a 35-minute semistructured interview, and a 10-minute web-based survey. The first 2 steps were recorded, transcribed verbatim, and analyzed using the Unified Theory of Acceptance and Use of Technology. Emerging themes from the qualitative data were mapped on the 4 domains of the Unified Theory of Acceptance and Use of Technology: performance expectancy, effort expectancy, facilitating conditions, and social influence.

RESULTS

Most participants (13/14, 93%) perceived the chatbot to be useful because it provided comprehensive information on HIV testing and PrEP (performance expectancy). All participants indicated that the chatbot was easy to use because of its simple, straightforward design and quick, friendly responses (effort expectancy). Moreover, 93% (13/14) of the participants rated the overall chatbot quality as high, and all participants perceived the chatbot as a helpful tool and would refer it to others. Approximately 79% (11/14) of the participants agreed they would continue using the chatbot. They suggested adding a local language (ie, Bahasa Malaysia) to customize the chatbot to the Malaysian context (facilitating condition) and suggested that the chatbot should also incorporate more information on mental health, HIV risk assessment, and consequences of HIV. In terms of social influence, all participants perceived the chatbot as helpful in avoiding stigma-inducing interactions and thus could increase the frequency of HIV testing and PrEP uptake among MSM.

CONCLUSIONS

The current AI chatbot is feasible and acceptable to promote the uptake of HIV testing and PrEP. To ensure the successful implementation and dissemination of AI chatbots in Malaysia, they should be customized to communicate in Bahasa Malaysia and upgraded to provide other HIV-related information to improve usability, such as mental health support, risk assessment for sexually transmitted infections, AIDS treatment, and the consequences of contracting HIV.

30-Day Readmission Rate of Patients with COPD and Its Associated Factors: A Retrospective Cohort Study from a Tertiary Care Hospital

Purpose

Readmission of chronic obstructive pulmonary disease (COPD) has been used as a measure of performance for COPD care. This study aimed to determine the rate of readmission of COPD in tertiary care hospital in Malaysia and its associated factors.

Patients and Methods

A retrospective cohort study was conducted at a tertiary care hospital in Malaysia from 1st January to 21st May 2019. Seventy admissions for COPD exacerbation involving 58 patients were analyzed.

Results

The majority of the patients were male (89.8%), had a mean age of 71.95 ± 7.24 years and a median smoking history of 40 (IQR = 25) pack-years, 84.5% were in GOLD group D and 91.4% had a mMRC grading of 2 or greater. Approximately 60.3% had upper or lower respiratory tract infection as the cause of exacerbation; one in five patients had uncompensated hypercapnic respiratory failure at presentation, and 27.6% needed mechanical ventilatory support. Approximately 43.1% of patients had a history of exacerbation that required hospitalisation in the past year. The mean blood eosinophil concentration was 0.38 ± 0.46 x109 cells/L. The 30-day readmission rate was 20.3%, revisit rate to the emergency room within 30 days after discharge was 3.4%, and in-hospital mortality rate was 1.7%. Among all characteristics, a higher baseline mMRC grade (p = 0.038) and history of exacerbation in the past 1 year (p < 0.001) were statistically associated with 30-day readmission.

Conclusion

The 30-day readmission rate for COPD exacerbation in a Malaysian tertiary hospital is similar to the rates in high-income countries. Exacerbation in the previous year and a higher baseline mMRC grading were significant risk factors for 30-day readmission in patients with COPD. Strategies of COPD management should concentrate on improvement of symptoms control by optimisation of pharmacotherapy, and early initiation of pulmonary rehabilitation, and structured integrated care programs to reduce readmission rates.

Factors associated with all-cause mortality in tuberculosis patients in a Malaysian tertiary hospital

INTRODUCTION

The all-cause mortality for tuberculosis is 1 in every 10 patients in Malaysia. The currently available national surveillance database does not record patients' variables such as socio-economic factors, existing co-morbidities, and risk behavior for investigation. An electronic medical record system can capture this missing information and use it to determine all-cause mortality factors more accurately. Our study aims to determine the factors associated with all-cause mortality in a cohort of tuberculosis patients in a Malaysian tertiary hospital which is equipped with an electronic medical record system.

METHODOLOGY

Records of patients diagnosed with tuberculosis from 1st January 2018 to 30th September 2019 were retrieved. Sociodemographic and clinical data were extracted. Treatment outcomes and all-cause mortality were recorded at 1 year after diagnosis. Univariate, multivariate, and stepwise regression were used to determine the factors associated with all-cause mortality.

RESULTS

Four-hundred and seventy-one patients were reviewed. The mean age was 46.6 ± 19.7 years. The all-cause mortality rate at one year of diagnosis was 15.3%. Factors identified were age [aOR 1.026 (95% CI: 1.004-1.049)], chronic kidney disease [aOR 3.269 (1.508-7.088)], HIV positive status [aOR 4.743 (1.505-14.953)], active cancer [aOR 5.758 (1.605-20.652)], liver disease [aOR 6.220 (1.028-37.621)], and moderate to advanced chest X-ray findings [aOR 3.851 (1.033-14.354)].

CONCLUSIONS

On average, one in seven patients diagnosed with TB died within a year in a Malaysian tertiary hospital. Identification of this vulnerable group using the associated factors found in this study may help to reduce the risk of mortality through early intervention strategies.

Gut microbiome of helminth-infected indigenous Malaysians is context dependent

BACKGROUND

While microbiomes in industrialized societies are well characterized, indigenous populations with traditional lifestyles have microbiomes that are more akin to those of ancient humans. However, metagenomic data in these populations remains scarce, and the association with soil-transmitted helminth infection status is unclear. Here, we sequenced 650 metagenomes of indigenous Malaysians from five villages with different prevalence of helminth infections.

RESULTS

Individuals from villages with higher prevalences of helminth infections have more unmapped reads and greater microbial diversity. Microbial community diversity and composition were most strongly associated with different villages and the effects of helminth infection status on the microbiome varies by village. Longitudinal changes in the microbiome in response to albendazole anthelmintic treatment were observed in both helminth infected and uninfected individuals. Inference of bacterial population replication rates from origin of replication analysis identified specific replicating taxa associated with helminth infection.

CONCLUSIONS

Our results indicate that helminth effects on the microbiota were highly dependent on context, and effects of albendazole on the microbiota can be confounding for the interpretation of deworming studies. Furthermore, a substantial quantity of the microbiome remains unannotated, and this large dataset from an indigenous population associated with helminth infections is a valuable resource for future studies. Video Abstract.

Efficacy of triple dose albendazole treatment for soil-transmitted helminth infections

In Malaysia, soil-transmitted helminth (STH) infections still persist among indigenous communities. In the past, local studies have focused mostly on epidemiologic aspects of STH infections with a scarcity of information on the efficacy of deworming treatment. The present study consisted of 2 phases: a cross-sectional phase on current epidemiological status and risk factors of STH infections and a longitudinal study over 6 weeks on triple dose albendazole efficacy against STH infections. A total of 253 participants were recruited at baseline and a pre-tested questionnaire was administered to obtain information on socio-demographics, environmental and behavioural risk factors. Stool samples were evaluated using a modified Kato-Katz technique. Cure rate (CR) and egg reduction rate (ERR) were assessed at 3 weeks following a 3-day course of 400mg albendazole treatment and infection status were observed again at 6 weeks. Baseline positivity of trichuriasis, ascariasis and hookworm infections were 56.1%, 11.9% and 20.2%, respectively. Multivariate analysis showed age below 18 years old (P = 0.004), without latrine in house (P = 0.042) and indiscriminate defecation (P = 0.032) were associated with STH infections. In the longitudinal study (N = 89), CR for trichuriasis was 64.6%, while CR of 100% was observed for both ascariasis and hookworm. ERR was above 90% for all three STH species. A rapid increased of Trichuris trichiura egg output was observed at 6 weeks. In conclusion, STH infections are highly prevalent among indigenous communities. Children and teenagers, poor sanitation and hygiene behaviour were determinants for STH infections. Triple dose albendazole is found to be efficacious against Ascaris lumbricoides and hookworm infections but has moderate curative effect with high ERR against T. trichiura. Although triple dose albendazole regimen has logistic challenges and may not be a routine option, consideration of this treatment regime may still be necessary in selective communities to reduce high intensity of T. trichiura infection.

COVID-19 depression and its risk factors in Asia Pacific - A systematic review and meta-analysis

BACKGROUND

This systematic review and meta-analysis aim to synthesize the extant literature reporting the effects of COVID-19 pandemic based on the pooled prevalence of depression among affected populations in Asia Pacific, as well as its risk factors.

METHOD

A systematic review and meta-analysis approach was adopted as per the PRISMA guidelines, targeting articles published in PubMed, Google Scholar and Scopus from January 2021 to March 30, 2021. The screening resulted in 82 papers.

RESULTS

The overall pooled depression prevalence among 201,953 respondents was 34% (95%CI, 29-38, 99.7%), with no significant differences observed between the cohorts, timelines, and regions (p > 0.05). Dominant risk factors found were fear of COVID-19 infection (13%), gender (i.e., females; 12%) and deterioration of underlying medical conditions (8.3%), regardless of the sub-groups. Specifically, fear of COVID-19 infection was the most reported risk factor among general population (k = 14) and healthcare workers (k = 8). Gender (k = 7) and increased workload (k = 7) were reported among healthcare workers whereas education disruption among students (k = 7).

LIMITATION

The review is limited to articles published in three electronic databases. Conclusion The pandemic has caused depression among the populations across Asia Pacific, specifically among the general population, healthcare workers and students. Immediate attention and interventions from the concerned authorities are needed in addressing this issue.

COVID-19 mental health prevalence and its risk factors in South East Asia

With the record surge of positive cases in Southeast Asia, there is a need to examine the adverse mental effects of COVID-19 among the under-researched countries. This study aims to synthesize the extant literature reporting the effects of COVID-19 pandemic on the psychological outcomes of people in Southeast Asia, and its risk factors. A scoping review was adopted targeting articles published in PubMed, Google Scholar and Scopus from January 2020 to March 30, 2021. Articles were screened using predetermined eligibility criteria, resulting in 26 papers. Elevated prevalence of adverse mental effects was noted in most of the countries as the pandemic progressed over time, with Malaysia and Philippines reporting higher prevalence rates. Mental decline was found to be more profound among the general population compared to healthcare workers and students. Dominant risk factors reported were age (younger), sex (females), education (higher), low coping skill and social/family support, and poor reliability in COVID-19 related information. Adverse mental effects were noted among population, healthcare workers and students in most of the Southeast Asian countries. Intervention and prevention efforts should be based at community-level and prioritize young adults, females, and individuals with dire financial constraints.

Observational study investigating the prevalence of asymptomatic stage B heart failure in patients with type 2 diabetes who are not known to have coronary artery disease

OBJECTIVE

To identify the prevalence of stage B heart failure (SBHF) in patients with type 2 diabetes mellitus (T2DM) with no history of cardiovascular disease (CVD).

DESIGN

Observational study.

SETTING

A single-centre study in which eligible patients were recruited from T2DM clinic. Following consent, patients completed a questionnaire and underwent physical examinations. Patients had blood drawn for laboratory investigations and had a transthoracic echocardiography.

PARTICIPANTS

A total of 305 patients who were not known to have CVD were recruited. Patients with deranged liver function tests and end stage renal failure were excluded.

MAIN OUTCOME MEASURES

Echocardiographic parameters such as left ventricular ejection fraction, left ventricular mass index (LVMI), left ventricular hypertrophy, left atrial enlargement and diastolic function were examined.

RESULTS

A total of 305 patients predominantly females (65%), with mean body mass index of 27.5 kg/m² participated in this study. None of them had either a history or signs and symptoms of CVD. Seventy-seven percent of patients had a history of hypertension and 83% of this study population had T2DM for more than 10 years. Mean HbA1c of 8.3% was recorded. Almost all patients were taking metformin. Approximately, 40% of patients were on newer anti-T2DM agents such as sodium-glucose cotransporter-2 and dipeptidyl peptidase 4 inhibitors. Fifty-seven percent (n=174) of the study population had SBHF at the time of study: diastolic dysfunction, increased LVMI and increased left atrial volume index (LAVI) were noted in 51 patients (17%), 128 patients (42%) and 98 patients (32%), respectively. Thirty-seven patients (12%) had both increase LVMI and LAVI.

CONCLUSION

Our study has revealed a high prevalence of SBHF in T2DM patients without overt cardiac disease in Malaysia that has one of the highest prevalence of TDM in the world.

Cardiac arrhythmia triggered by diuretic-induced hyponatremia

Diuretics have a long and distinguished history in the treatment of hypertension and heart failure. Clinical practice guidelines recommend that diuretics should be considered to be as suitable as other antihypertensive agents for the initiation and maintenance of antihypertensive treatment. However, diuretics may potentially cause electrolyte disturbances and metabolic side effects. Diuretic-induced hyponatremia is probably more prevalent than generally acknowledged. We present an unusual case of indapamide-induced hyponatremia and hypokalemia complicated by cardiac arrhythmia. The adverse drug reaction was reversible and non-life-threatening, but this case serves as a reminder that careful evaluation and constant monitoring are necessary when prescribing diuretics.

A rare case of multiple bronchial artery aneurysms associated with a double aortic arch

Bronchial artery aneurysm is uncommon, and the occurrence of multiple aneurysms arising from a bronchial artery is even rarer. To date, there has been only one published case report describing double bronchial artery aneurysms. We herein describe a case of three aneurysms arising from a left bronchial artery, accompanied by multiple bilateral hypertrophied bronchial and intercostobronchial arteries, as well as a double aortic arch. Bronchial artery aneurysm is potentially life-threatening, and immediate treatment is recommended to minimise the potential risk of rupture. The aneurysms in our case were successfully treated via transcatheter arterial embolisation using coils.

A review of dengue research in malaysia

Dengue infection is a major cause of morbidity and mortality in Malaysia. To date, much research on dengue infection conducted in Malaysia have been published. One hundred and sixty six articles related to dengue in Malaysia were found from a search through a database dedicated to indexing all original data relevant to medicine published between the years 2000-2013. Ninety articles with clinical relevance and future research implications were selected and reviewed. These papers showed evidence of an exponential increase in the disease epidemic and a varying pattern of prevalent dengue serotypes at different times. The early febrile phase of dengue infection consist of an undifferentiated fever. Clinical suspicion and ability to identify patients at risk of severe dengue infection is important. Treatment of dengue infection involves judicious use of volume expander and supportive care. Potential future research areas are discussed to narrow our current knowledge gaps on dengue infection.

Frequency-dependent cell death by optical tweezers manipulation

Optical tweezers were used to scan individual Chronic Myelogenous Leukemia cells to determine if the cell death depends on the scanning conditions. Although increasing the scanning frequency or amplitude means greater force applied to the cells, their effects on cell death are not a simple increasing trend, as observed in the optical microscopy. Indeed, cell death sharply increased at particular screening frequencies and amplitudes, whereas other frequencies or amplitudes were less detrimental. These results suggest that cell damage was more sensitive to certain scanning conditions, rather than simply high-applied forces.

Randomised clinical trial: pregabalin attenuates the development of acid-induced oesophageal hypersensitivity in healthy volunteers - a placebo-controlled study

BACKGROUND

Acid infusion in humans induces primary and secondary oesophageal hypersensitivity. The effects of pregabalin, a centrally-acting modulator of voltage-sensitive calcium channels, on development of acid-induced oesophageal hypersensitivity remain unknown.

AIM

To study the effects of pregabalin on development of secondary oesophageal hypersensitivity in healthy humans.

METHODS

Placebo-controlled, double-blind, randomised, cross-over study of 15 healthy volunteers (six women, age 21-56 years). After oesophageal manometry, baseline pain thresholds (PTs) to proximal oesophageal electrical stimulation were determined using bipolar ring electrodes. A 30-min infusion of HCl was performed in the distal oesophagus followed by PT measurements at 30 and 90 min. This protocol was repeated after administration of pregabalin (dosing schedule: 75 mg twice daily for 3 days then 150 mg twice daily for 1 day and then 150 mg on the morning of study) or placebo.

RESULTS

T0 PTs were similar in patients after receiving placebo or pregabalin [mean (s.d.) 32.9 mA (20.5) vs. 34.1 (15.7), P = 0.42]. Pregabalin reduced development of acid-induced hypersensitivity in the proximal oesophagus at 30 min [mean change in PT (C.I.) placebo -6.2 mA (-11.3 to +1.3) vs. pregabalin +0.20 mA (-2.7 to +3.3)] and 90 min [placebo -3.7 mA (-10.0 to +2.0) vs. pregabalin +0.7 mA (-4.7 to 7.3)] overall P = 0.001. Pregabalin reduced median visual analogue scale score for acid-induced pain (1/10 vs. placebo 3/10, P = 0.027).

CONCLUSIONS

Pregabalin attenuates development of secondary hypersensitivity in the proximal oesophagus after distal oesophageal acidification; it may thus have a role in treatment of patients with proven oesophageal pain hypersensitivity.

Relapse of amoebic infection 10 years after the infection

A 52-year-old man with schizophrenia, who had a history of amoebic liver abscess treated with combination antimicrobial agents, presented 10 years later with severe rectal bleeding. Diagnosis of amoebic colitis was confirmed by histological examination of endoscopic biopsy. Doctors treating patients with amoebic infection should be aware of the risk of eradication failure. Post-treatment stool testing, preferably by antigen testing or polymerase chain reaction, should be performed after antimicrobial treatment.

Electrocardiographical case. Narrow complex tachycardia provoked by the Valsalva manoeuvre

A 19-year-old Chinese man presented with tachyarrhythmia during a human centrifuge session while performing a Valsalva manoeuvre at near normal (+1.4 Gz) centripetal forces. It was likely that the hydrostatic effects of sustained centrifugal forces, the distortion of the heart's shape, as well as swings in the autonomic dominance pre- and post-Valsalva manoeuvre, contributed to the tachyarrhythmia. The 12-lead ECG showed a narrow complex tachycardia with visible P-waves after the QRS complexes consistent with a long R-P' tachycardia. The intracardiac electrogram demonstrated a concentric retrograde atrial activation during narrow complex tachycardia. The V-A interval was 150 ms which was much longer than in typical atrioventricular nodal reentry tachycardia, which is usually less than 70 ms. The A-H interval was short and the H-A interval was long, indicating that antegrade activation was over the fast pathway and retrograde activation was over the slow pathway. The diagnosis was atypical atrioventricular nodal reentry tachycardia, and radiofrequency ablation was successfully applied to the slow AV nodal pathway.

Application of immersed MF (IMF) followed by reverse osmosis (RO) membrane for wastewater reclamation: A case study in Malaysia

A pilot scale membrane plant was constructed and monitored in Shah Alam, Malaysia for municipal wastewater reclamation for industrial application purposes. The aim of this study was to verify its suitability under the local conditions and environmental constraints for secondary wastewater reclamation. Immersed-type crossflow microfiltration (IMF) was selected as the pretreatment step before reverse osmosis filtration. Secondary wastewater after chlorine contact tank was selected as feed water. The results indicated that the membrane system is capable of producing a filtrate meeting the requirements of both WHO drinking water standards and Malaysian Effluent Standard A. With the application of an automatic backwash process, IMF performed well in hydraulic performance with low fouling rate being achieved. The investigations showed also that chemical cleaning is still needed because of some irreversible fouling by microorganisms always remains. RO treatment with IMF pretreatment process was significantly applicable for wastewater reuse purposes and promised good hydraulic performance.

Electrocardiographical case. A case of wide complex tachycardia

A 43-year-old Chinese woman complained of a one week history of irregular rapid palpitations associated with chest discomfort and dyspnoea. Her heart rate was more than 160 beats per minute and blood pressure was 154/95 mmHg. 12-lead electrocardiogram (ECG) showed a wide complex tachycardia with a slightly irregular rhythm. Delta waves were also present. She was treated appropriately with intravenous procainamide but developed torsades de pointes secondary to prolonged QT interval. Electrophysiology study revealed atrial tachycardia with a left-sided accessory pathway which was successfully ablated.

Thyrotoxic periodic paralysis complicated by near-fatal ventricular arrhythmias

A 35-year-old Chinese man presented with acute thyrotoxic periodic paralysis complicated by near-fatal cardiac arrhythmias due to persistent hypokalaemia, despite maximum potassium supplementation. He was eventually resuscitated with external cadioversion. In this unusual case of severe refractory hypokalaemia leading to ventricular fibrillation in a patient with underlying thyrotoxicosis, the potential dangers concerning the use of dextrose infusion and beta-adrenergic agent for resuscitation are highlighted.

Pilot study using technetium-99m pertechnetate sequential radionuclide-sialography to assess salivary gland function in nasopharyngeal cancer patients on radiation therapy

INTRODUCTION

Nasopharyngeal carcinoma (NPC) is mainly treated by radiation therapy. A common complication of radiotherapy is xerostomia. Direct measurements of the amount of saliva produced using suction cups and volumetric assessments are cumbersome and time-consuming. Sequential radionuclide sialography is a reproducible and convenient method of measuring salivary function.

MATERIALS AND METHODS

Patients with newly diagnosed NPC underwent a pilot study using technetium-99m pertechnetate sequential radionuclide sialography to assess their salivary function before and at 3 months post radiation therapy. From the sialography, time activity curves were obtained for analysis of salivary function. The shape of the time activity curve with citric acid stimulation was classified into 4 types according to the degree of radiation-induced dysfunction.

RESULTS

All 14 patients had worse (P < 0.005) time activity curves for both parotids and submandibular glands after radiation therapy. All patients with abnormal curves before radiation therapy presented type IV (non-functioning) curve after radiation therapy. A ratio of pre- and post-stimulation counts allowed for quantification of the degree of stimulatory response. We found a significant decrease in Rc before and after radiation therapy for all salivary glands (P < 0.001). The salivary gland to background ratio, which is a reflection of the degree of salivary gland functional uptake, also had a significant reduction after radiation.

CONCLUSION

It is feasible to use technetium-99m pertechnetate in the measurement of salivary gland function in nasopharyngeal cancer patients treated with radiation therapy.

Fatal pulmonary haemorrhage with the combined use of abciximab and fibrinolytic agent

The increased bleeding risk associated with the use of abciximab has been well reported. The risk appears to be amplified when abciximab is administered concurrently with a fibrinolytic agent. We report and review the literature on the occurrence of a case of fatal pulmonary haemorrhage, a rare bleeding complication, in a patient who received both these drugs.

A preliminary study of the utility of combined cardiac markers in the evaluation of patients presenting early with suspected acute coronary syndrome

OBJECTIVE

The aim of the study was to investigate and compare the usefulness and accuracy of various cardiac markers [troponin I, creatine kinase MB (CKMB) mass, creatine kinase (CK), CKMB activity] to aid early diagnosis of myocardial infarction. We also examined the ability of the various cardiac markers to prognosticate future adverse cardiac events.

MATERIALS AND METHODS

Patients admitted within 8 hours of maximal chest pain suggestive of acute coronary syndrome with non-diagnostic electrocardiograms were recruited. Blood samples were obtained on admission to the wards and repeated 4 hours later. These results were later correlated to the final hospital discharge diagnosis.

RESULTS

The 37 patients in the study were a high-risk population with over 50% presenting with a Thrombolysis in Myocardial Infarction (TIMI) risk score of greater or equal to 3. Myoglobin was the most sensitive marker (100% sensitivity) in early prediction of patients who were subsequently diagnosed to have a myocardial infarction. Patients with an elevated troponin I level but normal CK and myoglobin levels had a significantly higher risk of developing a major adverse clinical event (MACE) within 3 months of the initial presentation.

CONCLUSION

Myoglobin is the most sensitive marker when compared to CK, CKMB and troponin I for diagnosing patients presenting early with chest pain and a non-diagnostic electrocardiogram and who subsequently develop either a ST-elevation myocardial infarction or non-ST elevation myocardial infarction. Patients with an elevated troponin I level but normal CK and myoglobin levels are at higher risk of an adverse clinical event.

Dual-site atrial pacing for atrial fibrillation in patients without bradycardia

Atrial pacing has been shown to delay the onset of atrial fibrillation (AF) when compared with ventricular pacing in patients with sick sinus syndrome. The role for pacing in the control of AF in patients without bradycardia is uncertain. We performed a randomized, crossover, single-blinded study in 22 patients (14 women, aged 63 +/- 10 years) with paroxysmal AF refractory to treatment with oral sotalol (202 +/- 68 mg/day) and no bradycardic indication for pacing. All patients received a dual-chamber pacemaker with 2 atrial pacing leads positioned at the high right atrium and coronary sinus ostium, respectively. Patients were randomized in a crossover fashion to be paced for 12 weeks, either with high right atrial (RA) pacing at 30 beats/min ("Off") or dual-site RA pacing with an overdrive algorithm that maintained atrial pacing at a rate slightly above the sinus rate ("On"). Treatment on resulted in a significantly higher percentage of atrial pacing and a reduction in atrial ectopic frequency than the treatment off period. The time to the first clinical AF recurrence was prolonged (15 +/- 17 to 50 +/- 35 days, p = 0.006), and total AF burden was reduced (45 +/- 34% vs 22 +/- 29%, p = 0.04) in the on-treatment phase. However, there was no difference in AF checklist symptom scores or overall quality-of-life measures. Dual-site RA pacing with continued sinus overdrive prolonged the time to AF recurrence and decreased AF burden in patients with paroxysmal AF. The absence of a major impact on symptom control suggests that pacing should be used as an adjunctive therapy with other treatment modalities for AF.

Effect of different endotracheal suctioning systems on cardiorespiratory parameters of ventilated patients

INTRODUCTION

We conducted this prospective randomised cross-over study to evaluate the effect of closed system (CS) versus open system (OS) endotracheal suctioning on heart rate (HR), mean arterial pressure (MAP), respiratory rate (RR), oxygen saturation (SpO2) and electrocardiogram (ECG) rhythm of patients on mechanical ventilation.

MATERIALS AND METHODS

Fourteen adult patients were randomly allocated to receive either CS or OS suctioning in the first instance. For the subsequent suctioning, they were crossed over to the alternate suctioning system. The various cardiorespiratory parameters were recorded at BL1 (baseline 1), S1 (first suction pass), BL2 (baseline 2, i.e. immediately post first suction pass), S2 (second suction pass), T2 (2 minutes post suction) and T5 (5 minutes post suction).

RESULTS

Compared to CS, OS suctioning was found to result in higher HR at S1 (P < or = 0.05) and S2 (P < or = 0.05); higher MAP at BL2 (P < or = 0.05); lower SpO2 at BL2 (P < or = 0.01) and S2 (P < or = 0.01). There was no significant difference in RR between the two suctioning systems. OS suctioning was also noted to result in a significantly higher incidence of arrhythmia (P < = or 0.05).

CONCLUSION

Our study shows that OS suctioning results in more adverse changes in cardiorespiratory parameters compared to CS suctioning.

Initial experience of radiofrequency catheter ablation of supraventricular tachycardia in paediatric patients

INTRODUCTION

The management of supraventricular tachycardia (SVT) in paediatric patients until recently has frequently been pharmacologic therapy, but this approach suffers from the drawbacks of treatment failure, development of drug intolerance and/or side-effects.

AIM

In keeping with recent advances in paediatric cardiology, we share our experience with radiofrequency catheter ablation as an alternative and definitive modality of therapy.

MATERIALS AND METHOD

4 young patients with recurrent SVT underwent electrophysiologic study followed by radiofrequency ablation of the accessory pathways.

RESULTS

Resolution of symptoms was achieved in all patients and no major complication was encountered.

CONCLUSIONS

The ability to ablate permanently the reentrant circuit responsible for SVT has now permitted cure by non-surgical means, and is an important alternative to drug therapy in the management of SVT in children.

Dissemination of respiratory secretions during tracheal tube suctioning in an intensive care unit

Most intensive care patients require frequent tracheal toilet, a procedure usually performed by suctioning the tracheal tube. Such procedures often result in the production and dissemination of droplets. We measured the distance visible droplets disseminated during tracheal tube suctioning of patients in an adult surgical intensive care unit. Fifty consecutive suction procedures in 14 patients intubated with a cuffed tracheal tube were investigated. Visible droplets were scattered over a mean distance of 60 +/- 39 cm (range 25 to 168 cm) from the tracheal tube. Blood agar culture plates were placed at three fixed points from the tracheal tube to identify organisms resulting from environmental contamination (control plates). This was repeated during suctioning procedures (study plates) to look into the occurrence of bacteriological cultures that differ from the control plates. Nine of the 14 patients had tracheal tube aspirate cultures done as part of their work-up for sepsis. In more than 30% of the suctioning procedures on these 9 patients, study plates grew bacteria that were similar to those present in their tracheal tube aspirates. In view of these observations, greater care should be taken to avoid contamination of the patient's immediate environment during tracheal tube suctioning and in the design of the intensive care unit.

The athlete's heart: is this an entity in paediatrics?

A case report of a boy who demonstrates features of an athlete's heart, associated with dilatation of the coronary artery, is presented. The importance of distinguishing this benign condition from pathologic causes such as cardiomyopathy, and risk of sudden death in these athletes is discussed.

Cardiac dysrrhthmia in systemic disease

This is an ECG of a 6-year-old girl. She presented to us for management of epilepsy. Magnetic resonance imaging (MRI) of the brain showed multiple lesions consistent with cortical and subcortical tubers. There were also achromic spots on her skin and echocardiography demonstrated a rhabdomyoma near the right ventricular outflow tract. A diagnosis of tuberous sclerosis, an autosomal-dominantly inherited condition, was made. What is abnormal about the ECG?

Endogenous source of bacteria in tracheal tube and proximal ventilator breathing system in intensive care patients

Although bacteria from both the ventilator breathing system and the gastrointestinal tract have been implicated in the pathogenesis of ventilator-associated pneumonia, an endogenous source of bacteria in the proximal respiratory breathing system has yet to be demonstrated conclusively. We investigated a potential route of bacterial colonization from the stomach contents to the efferent limb of the ventilator breathing system by bacterial culture of daily specimens from six sites in 20 surgical intensive care patients. Gram-negative bacilli were isolated in a progressively increasing proportion of samples at successive sampling points, consistent with an endogenous-to-external route of spread (patients, chi-square = 14.12, P < 0.02; samples, chi-square = 106.15, P < 0.001). Identical strains of gram-negative bacilli, confirmed by REPS typing, were found at two or more sites in seven patients. In all seven, gram-negative bacilli were first isolated from a site in the patient. In none of the 20 patients was there evidence of a sequence of colonization from the ventilator tubing or Y-piece connector towards the patient. Probable colonization sequences plotted from the time of first isolation supported the proposed sequence in six patients, and in five began with the stomach contents. Isolation sequences contrary to the proposed direction of colonization involved four bacterial species and two patients, and did not extend beyond two sample sites. These findings imply that the retrograde route of bacterial colonization of the ventilated lung extends into the proximal respiratory breathing system and may help to identify additional targets for preventive intervention.

Malposition of a long central venous catheter in the right inferior thyroid vein--a case report

This case report hopes to bring to attention the possibility of malposition and ligation of a long central venous catheter in a central venous tributary in the course of major neck surgery. A 49-year-old gentleman underwent total laryngectomy and right radical neck dissection for laryngeal carcinoma. A long central venous catheter was inserted via the right basilic vein. This was subsequently found to have malpositioned into the right inferior thyroid vein and ligated. It required an exploration of the neck wound to remove the ligated catheter.

Correlation of P-wave polarity with underlying electrophysiologic mechanisms of long RP' tachycardia

Analysis of surface electrocardiograms from patients with long RP' tachycardia due to either atypical atrioventricular node reentrant tachycardia, permanent junctional reciprocating tachycardia, or low atrial tachycardia was performed. Although a negative P wave in the inferior leads is common to all 3 mechanisms, the results suggest that a positive or isoelectric P wave in electrocardiographic lead I strongly supports a diagnosis of atypical atrioventricular node reentrant tachycardia, whereas a negative or biphasic P wave in lead I argues against this mechanism.

Paediatric pacemaker implant using the transvenous endocardial approach

The advent of the pacemaker has opened a whole new dimension to management in cardiology. Although its use has been well described in adults, its role in paediatric cardiology has proven to be equally exciting and challenging. We describe a case of a child with complex cyanotic heart disease who had an insertion of a cardiac pacemaker via the transvenous route, one of the youngest to be performed locally. This article also highlights the pertinent features of paediatric pacemaker therapy, including its indications and implantation technique.

A comparative study of the efficacy of postoperative analgesia with intraoperative epidural lidocaine with or without morphine

We compared postoperative analgesia in 15 patients (group A) who were given intraoperative epidural morphine 3 mg and lidocaine 150 mg after laminectomy/discectomy with that of 15 patients (group B) who were given only epidural lidocaine 150 mg. Epidural administration was accomplished by direct placement of the epidural catheter into the epidural space under direct vision during surgery. Eight patients (53%) in group A and 15 patients (100%) in group B required supplementary narcotics during the first 24 h postoperatively (P<0.05). The amount of supplementary narcotics given to group A patients was significantly less than that for group B (P<0.05), and the pain scores for group A patients were also significantly lower at 1, 2, and 6 h postoperatively (P<0.05). There was no difference in the observed side effects in the two groups. We conclude that postoperative pain relief following laminectomy/discectomy is superior when epidural morphine is added to lidocaine than when lidocaine is being used alone.