Immunogenicity and safety of heterologous versus homologous prime-boost schedules with inactivated and adenoviral vectored SARS-CoV-2 vaccines - A prospective multi-center study.

Background: During the peak of Coronavirus disease (COVID-19) pandemic in Thailand when the emergence of delta variant reduced the efficacy of inactivated vaccine, Thailand had abundance of inactivated vaccine but mRNA vaccine was not available and the supply of adenoviral-vectored vaccine was limited. The heterologous vaccination using CoronaVac and ChAdOx1-nCoV-19 vaccines was applied. We aim to compare the immunogenicity of immune response of primary vaccination with homologous ChAdOx1 nCoV-19 and heterologous vaccination with CoronaVac and ChAdOx1 nCoV-19. Methods: A total of 430 adults, scheduled to receive ChAdOx1-nCoV-19 as their second dose of primary COVID-19 vaccination, were enrolled. Participants were classified into two groups based on the first dose vaccine as CoronaVac (heterologous group) or ChAdOx1 nCoV-19 (homologous group). The primary outcome was antibodies to the SARS-CoV-2 spike protein receptor binding domain (anti-RBD) titres at 28 days after the second dose of vaccination. Secondary outcomes were anti-RBD titres at 90 days, surrogate viral neutralizing test (sVNT) at 28 and 90 days, and adverse events. Findings: In 358 participants with correct vaccine interval, the anti-RBD geometric mean titre ratio for the heterologous versus homologous group was 0.55 (95%CI; 0.44-0.067); p < 0.001 at day 28, and 0.80 (95%CI; 0.65-1.00); P = 0.05 at day 90. Median sVNT neutralizing activity was not significantly different in the heterologous versus homologous group at 28 days (93.5 vs 92.7 %); p = 0.13, but significantly higher in the heterologous group at day 90 (82.9 vs 76.4 %); p = 0.01. Interpretation: The homologous vaccination resulted in higher anti-RBD titres at 28 days after vaccination, but titres in the homologous group showed more rapid decline at 90 days. In the sVNT assay, median neutralization was similar at 28 days, but was longer-lasting and higher in the heterologous group at 90 days. Funding: This research received funding from the Royal College of Physicians of Thailand special grant 2021 for research initiative during COVID-19 pandemic.

FLUID AND HEMODYNAMIC MANAGEMENT IN SEVERE DENGUE.

In the critical phase of dengue fever, the leakage of intravascular fluid into interstitial space and 3rd space can cause hemoconcentration and severe complications such as dengue shock syndrome (DSS), and it can lead to multiple organ failure, followed by death. Close monitoring, early detection and prompt management are the keys in successful treatment. In a hemodynamically unstable patient, crystalloid is the fluid of choice in initial management. However, if they are not responsive despite adequate resuscitation, a careful search for others causes is mandatory and fluids should be switched from crystalloid to colloid. If the leakage leads to restriction of the use of fluids (pulmonary edema), the addition of a vasopressor such as norepinephrine needs to be considered. After stabilizing the hemodynamics and clinical improvement, the physician has to know when to reduce and discontinue the fluid to avoid congestion and others complications.

Predicting fluid responsiveness in septic shock patients by using 3 dynamic indices: is it all equally effective?

OBJECTIVE: To evaluate the effectiveness and accuracy of three dynamic indices, currently available in intensive care monitoring devices, which are pulse pressure variation (PPV), stroke volume variation (SVV) and pulse oximetry plethysmographic waveform variation (POPV) in septic patients. MATERIAL AND METHOD: This prospective clinical trial was conducted in 20 deeply sedated septic patients 18 years of age and older who had invasive blood pressure monitoring with an intraarterial cannula. PPV, SVV and POPV (%) were calculated using five consecutive snapshots from every patient's monitor. Statistical analysis compared using linear regression, paired t-test or student t-test, and receiver operating characteristic (ROC) curve analysis. RESULTS: The authors found that, strong correlation existed of PPV for the detection of percent cardiac index change (r2 = 0.794, p < 0.001). A respiratory variation in POPV exceeding 14% (sensitivity of 72%, specificity of 90%), SVV exceeding 11% (sensitivity 90%, specificity 92%) allowed detection of PPV exceeding 12% (sensitivity 84%, specificity 96%). CONCLUSION: Comparing of PPV, SVV and POPV, PPV is the most correlate with percent change in cardiac index and the most effective dynamic index for predict fluid responsiveness in adult septic critically ill patients who are on controlled mechanical ventilator, followed by SVV and POPV.

Comparative study of patients in correct usage of and preference for the Swinghaler and Turbuhaler multidose inhalers.

OBJECTIVE: Current dry powder inhalers (DPIs), introduced to overcome problems associated with pressurized metered dose inhalers (pMDIs), possess not only difficulties originating from their designs but also other barriers that prevent their correct usage. The authors of this study investigated the ease and correctness of use of Swinghaler, a new device in the form of multidose DPI, as well as the preference of the study participants for either a Swinghaler or a Turbuhaler. METHODS: A total of 260 patients from Korea, China, Indonesia, the Philippines, Taiwan, and Thailand were prospectively recruited. Patients who had stable asthma, were more than 12 years old, had no experience with DPIs, and provided informed consents were included, whereas those with limited physical or intellectual ability and prior experience with any DPIs were excluded. RESULTS: There were no group or time effects between the patients who were assigned to use a Swinghaler or a Turbuhaler first. Forty-one (16.1%) participants correctly performed the inhalation maneuver with a Swinghaler, whereas 28 (10.9%) did so with a Turbuhaler; the difference was not statistically significant. The overall assessment on the precise use of the devices indicated that there were no differences between Swinghaler and Turbuhaler usage. Comparing the preference scales between the two devices, the participants gave higher scores to the Swinghaler for all assessment items and were more satisfied with the Swinghaler compared with the Turbuhaler (78.5% vs. 55.0%, p < .001). CONCLUSIONS: The participants showed no difference in their ability to correctly use a Swinghaler when compared with a Turbuhaler and preferred the Swinghaler. These results suggest that the Swinghaler may be an effective and valuable tool for the management of airway diseases.

Empyema thoracis due to nocardiosis and Mycobacterium tuberculosis mixed infections in an AIDS patient.

A 26-year-old Thai man presented with progressive dyspnea for four months and right pleuritic chest pain two days before admission. The chest radiograph showed massive right pleural effusion. Thoracentesis was done, and the culture grew Nocardia spp as well as positive strain for acid-fast bacilli. An anti-HIV test was reactive, with a CD4 count of 12 cells/mm3. The patient was treated with inter-costal tube drainage (ICD) inserted for empyema thoracis. The antimicrobials used trimethoprim-sulfamethoxazole and anti-TB drugs CAT-1 orally. One month later, anti-retroviral therapy with HAART was initiated. At follow-up after 6 months, he was healthy appearing, with a nearly normal chest radiograph.

Exertional heatstroke: early recognition and outcome with aggressive combined cooling--a 12-year experience.

OBJECTIVE: To determine the clinical outcomes of an aggressive combined cooling technique for exertional heatstroke in Thailand. METHODS: We analyzed patients who were diagnosed with exertional heatstroke between 1995 and 2007. Outcomes were assessed both in hospital and at 3 months follow-up. RESULTS: Twenty-eight cases of exertional heatstroke presented to Phramongkutklao Army Hospital over 12 years. All patients developed multiorgan dysfunction and encephalopathy. Twenty-four cases had acute renal failure, 7 of whom required dialysis. Disseminated intravascular coagulation (DIC) was detected in 9 patients (32.1%). In-hospital mortality was 7.1%. Most survivors recovered with nearly normal organ function. However, 9 exhibited prolonged neurologic dysfunction and 2 had chronic renal dysfunction requiring hemodialysis. At 3-month follow-up, neurologic and renal dysfunction in those patients persisted. Higher serum prothrombin time and DIC correlated to fatality. The patients whose core body temperature achieved 38 degrees C within 3 hours revealed a significantly lower DIC and twice as low in the frequency of poor outcome than the patients cooled longer than 3 hours to reduce core body temperature to 38 degrees C. CONCLUSIONS: Despite early recognition and aggressive combined cooling, exertional heatstroke remains associated with multiorgan dysfunction. However, our 7.1% in-hospital mortality rate was low compared to previous studies. Early diagnosis and prompt treatment are critical.

An outbreak of botulism in Thailand: clinical manifestations and management of severe respiratory failure.

BACKGROUND: Northern Thailand's biggest botulism outbreak to date occurred on 14 March 2006 and affected 209 people. Of these, 42 developed respiratory failure, and 25 of those who developed respiratory failure were referred to 9 high facility hospitals for treatment of severe respiratory failure and autonomic nervous system involvement. Among these patients, we aimed to assess the relationship between the rate of ventilator dependence and the occurrence of treatment by day 4 versus day 6 after exposure to bamboo shoots (the source of the botulism outbreak), as well as the relationship between ventilator dependence and negative inspiratory pressure. METHODS: We reviewed the circumstances and timing of symptoms following exposure. Mobile teams treated patients with botulinum antitoxin on day 4 or day 6 after exposure in Nan Hospital (Nan, Thailand). Eighteen patients (in 7 high facility hospitals) with severe respiratory failure received a low- and high-rate repetitive nerve stimulation test, and negative inspiratory pressure was measured. RESULTS: Within 1-65 h after exposure, 18 of the patients with severe respiratory failure had become ill. The typical clinical sequence was abdominal pain, nausea and/or vomiting, diarrhea, dysphagia and/or dysarthria, ptosis, diplopia, generalized weakness, urinary retention, and respiratory failure. Most patients exhibited fluctuating pulse and blood pressure. Repetitive nerve stimulation test showed no response in the most severe stage. In the moderately severe stage, there was a low-amplitude compound muscle action potential with a low-rate incremented/high-rate decremented response. In the early recovery phase, there was a low-amplitude compound muscle action potential with low- and high-rate incremented response. In the ventilator-weaning stage, there was a normal-amplitude compound muscle action potential. Negative inspiratory pressure variation among 14 patients undergoing weaning from mechanical ventilation was observed. Kaplan-Meier survival analysis identified a shorter period of ventilator dependency among patients receiving botulinum antitoxin on day 4 (P=.02). CONCLUSIONS: Patients receiving botulinum antitoxin on day 4 had decreased ventilator dependency. In addition, for patients with foodborne botulism, an effective referral system and team of specialists are needed.

Clinical, laboratory findings and microbiologic characterization of bronchiectasis in Thai patients.

OBJECTIVE: The aim of the present study was to characterize the clinical features, underlying disease states, laboratory findings and microbiological characterization of bronchiectasis in Thai patients. METHODOLOGY: For a 2-year period all consecutive patients diagnosed with bronchiectasis at Phramongkutklao Hospital, Bangkok, Thailand, were recruited. Data including history, physical examination, underlying disease and laboratory studies were carefully reviewed and recorded. RESULTS: Fifty patients diagnosed with bronchiectasis were enrolled. Their mean age was 58 years. The most common background aetiology was tuberculosis. Six per cent of the patients were diagnosed as having diffuse panbronchiolitis. Normal chest radiographs were found in 10%. The common organisms isolated were Pseudomonas aeruginosa (20%), Haemophilus influenzae (14%), Klebsiella pneumoniae (14%) and Streptococcus pneumoniae (6%). Non-tuberculous mycobacteria which included Mycobacterium kansasii and Mycobacterium chelonae were found in 6%. CONCLUSION: We report the characteristics of bronchiectasis in Thai patients. The most common identifiable aetiology was tuberculosis.