Use of high flow nasal cannula oxygen therapy for patients infected with SARS-CoV-2 outside intensive care setting

BACKGROUND

In early 2022, there was a sudden surge of patients infected by the Omicron variant of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in Hong Kong (HK), resulting in 9,163 deaths as of 29 May 2022. Many of the local population had not been vaccinated before this wave. The number of patients who developed coronavirus disease 2019 (COVID-19) related respiratory failure outnumbered the capacity of intensive care unit (ICU) beds. Some of these patients had to be supported with high flow nasal cannula (HFNC) therapy outside ICU setting. HK was in crisis situation. The primary objective of this study is to assess the 28-day mortality of this group of patients. The secondary objective is to explore any predictors of non-survivors to help clinical decision-making in future crisis.

METHODS

This is a retrospective observational study of patients suffering from COVID-19 related respiratory failure who received HFNC therapy in general medical wards of two hospitals during the period of 17 Mar to 30 Apr 2022. Survival and risk factors were reviewed.

RESULTS

Forty-nine patients were recruited. Twenty-six patients (53%) survived at 28-day after initiation of HFNC support. Three clinical parameters were found to be significantly associated with mortality at 28-day: (I) SpO2/FiO2 (SF) ratio <160 at 48 hours; (II) SF ratio <191 at 72 hours; (III) serial SF ratio at 48 or 72 hours showing no improvement over that at the time of initiation of HFNC therapy.

CONCLUSIONS

Use of HFNC outside ICU setting showed benefit to patients suffering from COVID-19 related acute hypoxemic respiratory failure (AHRF). Serial SF ratio monitoring at 48 and 72 hours after therapy initiation might serve as predictors of outcome and thus guide clinical decision-making for medical resource allocation in outbreak situation.

Effect of CYP2D6 and CYP3A4 Genotypes on the Efficacy of Cholinesterase Inhibitors in Southern Chinese Patients With Alzheimer's Disease

Alzheimer's disease (AD) is the most prevalent form of dementia, and age is strongly associated with the incidence of AD. This study aimed to investigate the association between the genotypes of CYP2D6, CYP3A4, and CYP2C9 genes to the clinical efficacy and tolerability of cholinesterase inhibitors (ChEIs) in Chinese patients with AD. One hundred seventy-nine patients with AD with newly prescribed with ChEIs were recruited. The clinical response and tolerability were evaluated at baseline, 3rd-, 6th-, and 12th-month follow-ups and were compared according to their genotypes of CYP2D6, CYP3A4, and CYP2C9. Among patients prescribed with donepezil/galantamine, CYP2D6*10 carriers showed significantly less side effects (P = .009). CYP2D6*10 carriers responded better to ChEIs and resulted in better improvement in Alzheimer's Disease Assessment Scale-Cognitive subscale (P = .027) and Mini-Mental State Examination (P = .012). Further study is required to replicate the finding, and it might be useful for clinicians to decide the medication based on the patients' CYP genotypes.

Coexisting Cerebral Infarction in Alzheimer's Disease Is Associated with Fast Dementia Progression: Applying the National Institute for Neurological Disorders and Stroke/Association Internationale pour la Recherche et l'Enseignement en Neurosciences Neuro

OBJECTIVES

To determine whether patients with Alzheimer's disease (AD) and coexisting cerebral infarction (CI) that satisfy the National Institute for Neurological Disorders and Stroke/Association Internationale pour la Recherche et l'Enseignement en Neurosciences (NINDS-AIREN) neuroimaging criteria for vascular dementia (VaD) progress faster than those who do not satisfy the neuroimaging criteria.

DESIGN

Retrospective cohort study.

SETTING

Multidisciplinary memory clinic in a tertiary hospital.

PARTICIPANTS

One hundred thirty consecutive patients with AD, with or without CI, followed up regularly for more than 1 year.

MEASUREMENTS

The patients were classified according to the distribution and severity of CI as defined according to the NINDS-AIREN neuroimaging criteria into those with AD and no CI (AD-N), those with AD and CI not fulfilling neuroimaging criteria (AD-I), and those with AD and CI fulfilling neuroimaging criteria (AD-V), and their differences in dementia progression were tested. The loss of independence, indicated by institution admission or a clinical dementia rating (CDR) score of 3, was defined as the endpoint for a poor outcome.

RESULTS

The mean age was 75.8, and 68.5% were women. The initial Mini-Mental State Examination (MMSE) score was 15.3+/-0.4, and the average duration of follow up was 30.4 months. Fifty-four patients had reached study endpoint at the time of analysis. AD-V (hazard ratio (HR)=3.1, 95% confidence interval (CI)=1.2-8.2), use of psychotropic drugs (HR=2.7, 95% CI=1.1-6.4), and initial MMSE score (HR=0.9, 95% CI=0.8-1.0) were independent predictors of poor outcome in the Cox regression model.

CONCLUSION

In AD, co-occurrence of CI with distribution and severity as defined in the NINDS-AIREN neuroimaging criteria for VaD is associated with faster dementia progression.

Low-molecular-weight heparin for the treatment of acute ischemic stroke

BACKGROUND

Despite doubts about their efficacy and concern about their safety, antithrombotic agents are often used to treat acute ischemic stroke. Recent experience in patients with other thromboembolic disorders suggests that low-molecular-weight heparin, which requires only subcutaneous administration once or twice daily, may be more effective and safer than standard (unfractionated) heparin.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial comparing two dosages of low-molecular-weight heparin with placebo in the treatment of ischemic stroke. Patients were randomly assigned within 48 hours of the onset of symptoms to receive high-dose nadroparin (4100 anti-factor Xa IU twice daily), low-dose nadroparin (4100 IU once daily), or placebo subcutaneously for 10 days. The primary measure of outcome was death or dependency regarding activities of daily living six months after randomization. Secondary outcomes were death, hemorrhagic transformation of the infarction, and other complications at 10 days, and death or dependency at 3 months.

RESULTS

A total of 2750 patients were screened for the study. Among 312 patients randomized, 306 had outcomes that were analyzed at six months. Forty-five patients (45 percent) in the high-dose group, 53 patients (52 percent) in the low-dose group, and 68 patients (65 percent) in the placebo group died or became dependent. There was a significant dose-dependent effect among the three study groups in favor of low-molecular-weight heparin (P = 0.005 by the chi-square test for trend). No significant differences among the groups in the occurrence of secondary outcomes were observed at 10 days.

CONCLUSIONS

For patients with ischemic stroke treated within 48 hours of the onset of symptoms, low-molecular-weight heparin was effective in improving outcomes at six months.

Once weekly versus twice weekly subcutaneous administration of recombinant human erythropoietin in patients on continuous ambulatory peritoneal dialysis

Twice weekly subcutaneous (s.c.) administration of recombinant human erythropoietin (rHuEPO) is effective in reversing renal anemia in CAPD patients. However the optimal frequency of administration has not been established. It would be more convenient to give rHuEPO by once weekly rather than twice weekly injection. We have therefore compared the effect of twice weekly versus once weekly s.c. administration of rHuEPO. Two groups of 10 CAPD patients were given the same starting dose of s.c. rHuEPO (100 U/kg body wt/week) either as a single weekly dose or twice weekly in divided doses. The rHuEPO dosage was then adjusted according to the hematologic response. The aim was to increase hemoglobin levels by about 1 g/dl per month. The target hemoglobin was 10 g/dl. After 16 weeks of treatment with rHuEPO, the hemoglobin levels rose from 6.6 +/- 1.2 (mean +/- SD) to 10.1 +/- 1.1 g/dl in the once weekly group and from 6.4 +/- 0.8 to 10.2 +/- 1.1 g/dl in the twice weekly group. The average doses of rHuEPO used during the study were 84 +/- 16 and 88 +/- 15 U/kg body wt/wk for the once weekly and twice weekly groups respectively. Subcutaneous administration of low dose rHuEPO is effective in reversing renal anemia. Similar responses were obtained with once weekly and twice weekly regimens. It is therefore acceptable and convenient for patients to receive one weekly s.c. injection of rHuEPO for the treatment of renal anemia.