Predictors and outcomes of withholding and withdrawal of life-sustaining treatments in intensive care units in Singapore: a multicentre observational study.

BACKGROUND: Clinical practice guidelines on limitation of life-sustaining treatments (LST) in the intensive care unit (ICU), in the form of withholding or withdrawal of LST, state that there is no ethical difference between the two. Such statements are not uniformly accepted worldwide, and there are few studies on LST limitation in Asia. This study aimed to evaluate the predictors and outcomes of withholding and withdrawal of LST in Singapore, focusing on the similarities and differences between the two approaches. METHODS: This was a multicentre observational study of patients admitted to 21 adult ICUs across 9 public hospitals in Singapore over an average of three months per year from 2014 to 2019. The primary outcome measures were withholding and withdrawal of LST (cardiopulmonary resuscitation, invasive mechanical ventilation, and vasopressors/inotropes). The secondary outcome measure was hospital mortality. Multivariable generalised mixed model analysis was used to identify independent predictors for withdrawal and withholding of LST and if LST limitation predicts hospital mortality. RESULTS: There were 8907 patients and 9723 admissions. Of the former, 80.8% had no limitation of LST, 13.0% had LST withheld, and 6.2% had LST withdrawn. Common independent predictors for withholding and withdrawal were increasing age, absence of chronic kidney dialysis, greater dependence in activities of daily living, cardiopulmonary resuscitation before ICU admission, higher Acute Physiology and Chronic Health Evaluation (APACHE) II score, and higher level of care in the first 24 h of ICU admission. Additional predictors for withholding included being of Chinese race, the religions of Hinduism and Islam, malignancy, and chronic liver failure. The additional predictor for withdrawal was lower hospital paying class (with greater government subsidy for hospital bills). Hospital mortality in patients without LST limitation, with LST withholding, and with LST withdrawal was 10.6%, 82.1%, and 91.8%, respectively (p < 0.001). Withholding (odds ratio 13.822, 95% confidence interval 9.987-19.132) and withdrawal (odds ratio 38.319, 95% confidence interval 24.351-60.298) were both found to be independent predictors of hospital mortality on multivariable analysis. CONCLUSIONS: Differences in the independent predictors of withholding and withdrawal of LST exist. Even after accounting for baseline characteristics, both withholding and withdrawal of LST independently predict hospital mortality. Later mortality in patients who had LST withdrawn compared to withholding suggests that the decision to withdraw may be at the point when medical futility is recognised.

Rostered Routine Testing: A Necessary Evil?

We report our institution's experience of detecting a staff member who was infected with severe acute respiratory syndrome coronavirus 2 while he was asymptomatic, as part of a rostered routine testing program, and how the institution was able to undertake measures to curb the spread, hence reducing the impact on the daily operations of our institution.

Regional citrate anti-coagulation dose titration: impact on dose of continuous renal replacement therapy.

BACKGROUND: Regional citrate anti-coagulation (RCA) is the recommended anti-coagulation for continuous renal replacement therapy (CRRT). Citrated replacement fluids provide convenience but may compromise effluent delivery when adjusted to maintain circuit ionised calcium levels (circuit-iCa). This study aims to evaluate the effect of RCA titration on the delivered CRRT effluent dose. METHODS: This prospective observational study evaluated patients on RCA-CRRT in continuous veno-venous hemodiafiltration mode. Citrated replacement fluid was titrated to target circuit-iCa 0.26-0.40 mmol/L. Patients were then stratified into 'reduced-dose' who required citrate down-titration and 'stable-dose' who did not. RESULTS: Data from 200 RCA-CRRT sessions were collected. The reduced-dose RCA group (n = 114) had higher median initial citrate dose (3.00 vs 2.50; P < 0.001) but lower time-averaged dose (2.49 vs 2.60; P < 0.001). In addition, median prescribed effluent dose was 33.3 mL/kg/h (28.6-39.2) but median delivered effluent dose was significantly lower at 29.9 mL/kg/h (25.4-36.9; P < 0.001). Mortality was higher in the reduced-dose RCA group (39.5% vs 25.6%; P = 0.022) and in patients with delivered-to-prescribed effluent dose ratio of < 0.9 vs ≥ 0.9 (51.3% vs 29.2%; P = 0.014). CONCLUSION: RCA titration can significantly impact delivered CRRT effluent dose. Measures should be taken to address the CRRT dose deficit and prevent poor outcomes due to inadequate dialysis.

The accuracy of healthcare worker versus self collected (2-in-1) Oropharyngeal and Bilateral Mid-Turbinate (OPMT) swabs and saliva samples for SARS-CoV-2.

BACKGROUND: Self-sampling for SARS-CoV-2 would significantly raise testing capacity and reduce healthcare worker (HCW) exposure to infectious droplets personal, and protective equipment (PPE) use. METHODS: We conducted a diagnostic accuracy study where subjects with a confirmed diagnosis of COVID-19 (n = 401) and healthy volunteers (n = 100) were asked to self-swab from their oropharynx and mid-turbinate (OPMT), and self-collect saliva. The results of these samples were compared to an OPMT performed by a HCW in the same patient at the same session. RESULTS: In subjects confirmed to have COVID-19, the sensitivities of the HCW-swab, self-swab, saliva, and combined self-swab plus saliva samples were 82.8%, 75.1%, 74.3% and 86.5% respectively. All samples obtained from healthy volunteers were tested negative. Compared to HCW-swab, the sensitivities of a self-swab sample and saliva sample were inferior by 8.7% (95%CI: 2.4% to 15.0%, p = 0.006) and 9.5% (95%CI: 3.1% to 15.8%, p = 0.003) respectively. The combined detection rate of self-swab and saliva had a sensitivity of 2.7% (95%CI: -2.6% to 8.0%, p = 0.321). The sensitivity of both the self-collection methods are higher when the Ct value of the HCW swab is less than 30. The specificity of both the self-swab and saliva testing was 100% (95% CI 96.4% to 100%). CONCLUSION: Our study provides evidence that sensitivities of self-collected OPMT swab and saliva samples were inferior to a HCW swab, but they could still be useful testing tools in the appropriate clinical settings.

Innovative use of health informatics to augment contact tracing during the COVID-19 pandemic in an acute hospital.

This case report describes the innovative design and build of an algorithm that integrates available data from separate hospital-based informatics systems, which perform different daily functions to augment the contact-tracing process of COVID-19 patients by identifying exposed neighboring patients and healthcare workers and assessing their risk. Prior to the establishment of the algorithm, contact-tracing teams comprising 6 members would spend up to 10 hours each to complete contact tracing for 5 new COVID-19 patients. With the augmentation by the algorithm, we observed ≥ 60% savings in overall man-hours needed for contact tracing when there were 5 or more daily new cases through a time-motion study and Monte Carlo simulation. This improvement to the hospital's contact-tracing process supported more expeditious and comprehensive downstream contact-tracing activities as well as improved manpower utilization in contact tracing.

Regional Citrate Anticoagulation for Continuous Renal Replacement Therapy - A Safe and Effective Low-Dose Protocol.

AIMS: Regional citrate anticoagulation (RCA) is the preferred mode of anticoagulation for continuous renal replacement therapy (CRRT). Conventional RCA-CRRT citrate dose ranges from 3 to 5 mmol/L of blood. This study explored the effectiveness of an RCA protocol with lower citrate dose and its impact on citrate-related complications. METHODS: This prospective observational study compared two RCA-CRRT protocols in the intensive care unit. RCA Protocol 1 used an initial citrate dose of 3.0 mmol/L while Protocol 2 started with 2.5 mmol/L. The citrate dose was titrated by sliding scale to target circuit-iCa 0.26-0.40 mmol/L. Calcium was re-infused post-dialyzer and titrated by protocol to target systemic-iCa 1.01-1.20 mmol/L. RESULTS: Two hundred RCA-CRRT sessions were performed (81 Protocol 1; 119 Protocol 2). The median age was 65.4 years and median APACHE-II score was 23. Citrate dose for Protocol 1 was significantly higher than Protocol 2 in the first 12 h. The circuit clotting rate was similar in both arms (Protocol 1: 9.9%; Protocol 2: 9.2%; P = 0.881). With Protocol 2, circuit-iCa levels were 2.42 times more likely to be on target (P = 0.003) while the odds of hypocalcaemia was 4.67 times higher with Protocol 1 (P < 0.001). There was a wider anion gap was noted with Protocol 1, which suggests a propensity for citrate accumulation with higher citrate exposure. CONCLUSION: The RCA protocol with a lower initial citrate dose of 2.5 mmol/L blood had less citrate-related complications with no loss of efficacy. A more precise RCA prescription at the start of treatment avoids unnecessary citrate exposure and improves safety.

Impact of microbial Aetiology on mortality in severe community-acquired pneumonia.

BACKGROUND: The impact of different classes of microbial pathogens on mortality in severe community-acquired pneumonia is not well elucidated. Previous studies have shown significant variation in the incidence of viral, bacterial and mixed infections, with conflicting risk associations for mortality. We aimed to determine the risk association of microbial aetiologies with hospital mortality in severe CAP, utilising a diagnostic strategy incorporating molecular testing. Our primary hypothesis was that respiratory viruses were important causative pathogens in severe CAP and was associated with increased mortality when present with bacterial pathogens in mixed viral-bacterial co-infections. METHODS: A retrospective cohort study from January 2014 to July 2015 was conducted in a tertiary hospital medical intensive care unit in eastern Singapore, which has a tropical climate. All patients diagnosed with severe community-acquired pneumonia were included. RESULTS: A total of 117 patients were in the study. Microbial pathogens were identified in 84 (71.8%) patients. Mixed viral-bacterial co-infections occurred in 18 (15.4%) of patients. Isolated viral infections were present in 32 patients (27.4%); isolated bacterial infections were detected in 34 patients (29.1%). Hospital mortality occurred in 16 (13.7%) patients. The most common bacteria isolated was Streptococcus pneumoniae and the most common virus isolated was Influenza A. Univariate and multivariate logistic regression showed that serum procalcitonin, APACHE II severity score and mixed viral-bacterial infection were associated with increased risk of hospital mortality. Mixed viral-bacterial co-infections were associated with an adjusted odds ratio of 13.99 (95% CI 1.30-151.05, p = 0.03) for hospital mortality. CONCLUSIONS: Respiratory viruses are common organisms isolated in severe community-acquired pneumonia. Mixed viral-bacterial infections may be associated with an increased risk of mortality.

ValuedCare program: a population health model for the delivery of evidence-based care across care continuum for hip fracture patients in Eastern Singapore.

BACKGROUND: To test a population health program which could, through the application of process redesign, implement multiple evidence-based practices across the continuum of care in a functionally integrated health delivery system and deliver highly reliable and consistent evidence-based surgical care for patients with fragility hip fractures in an acute tertiary general hospital. METHODS: The ValuedCare (VC) program was developed in three distinct phases as an ongoing collaboration between the Geisinger Health System (GHS), USA, and Changi General Hospital (CGH), Singapore, modelled after the GHS ProvenCare® Fragile Hip Fracture Program. Clinical outcome data on consecutive hip fracture patients seen in 12 months pre-intervention were then compared with the post-intervention group. Both pre- and post-intervention groups were followed up across the continuum of care for a period of 12 months. RESULTS: VC patients showed significant improvement in median time to surgery (97 to 50.5 h), as well as proportion of patients operated within 48 h from hospital admission (48% from 18.8%) as compared to baseline pre-intervention data. These patients also had significant reduction (p value < 0.001) of acute inpatient complications such as delirium, pneumonia, urinary tract infections, and pressure sores. VC program has shown significant reduction in median length of stay for acute hospital (13 to 9 days) as well as median combined length of stay for acute and sub-acute rehabilitation hospital (46 to 39 days), thus reducing the total duration of hospitalization and saving total hospital bed days. Operative and inpatient mortality, together with readmission rates, remained low and comparable to international Geriatric Fracture Centers (GFCs). CONCLUSION: The implementation of VC methodology has enabled consistent delivery of high-quality, reliable and comprehensive evidence-based care for hip fracture patients at Changi General Hospital. This has also reflected successful change management and interdisciplinary collaboration within the organization through the program. There is potential for testing this methodology as a quality improvement framework replicable to other disease groups in a functionally integrated healthcare system.

Region of Interest-Based Tamper Detection and Lossless Recovery Watermarking Scheme (ROI-DR) on Ultrasound Medical Images.

Tampering on medical image will lead to wrong diagnosis and treatment, which is life-threatening; therefore, digital watermarking on medical image was introduced to protect medical image from tampering. Medical images are divided into region of interest (ROI) and region of non-interest (RONI). ROI is an area that has a significant impact on diagnosis, whereas RONI has less or no significance in diagnosis. This paper has proposed ROI-based tamper detection and recovery watermarking scheme (ROI-DR) that embeds ROI bit information into RONI least significant bits, which will be extracted later for authentication and recovery process. The experiment result has shown that the ROI-DR has achieved a good result in imperceptibility with peak signal-to-noise ratio (PSNR) values approximately 48 dB, it is robust against various kinds of tampering, and the tampered ROI was able to recover to its original form. Lastly, a comparative table with the previous research (TALLOR and TALLOR-RS watermarking schemes) has been derived, where these three watermarking schemes were tested under the same testing conditions and environment. The experiment result has shown that ROI-DR has achieved speed-up factors of 22.55 and 26.65 in relative to TALLOR and TALLOR-RS watermarking schemes, respectively.

Parallel Digital Watermarking Process on Ultrasound Medical Images in Multicores Environment.

With the advancement of technology in communication network, it facilitated digital medical images transmitted to healthcare professionals via internal network or public network (e.g., Internet), but it also exposes the transmitted digital medical images to the security threats, such as images tampering or inserting false data in the images, which may cause an inaccurate diagnosis and treatment. Medical image distortion is not to be tolerated for diagnosis purposes; thus a digital watermarking on medical image is introduced. So far most of the watermarking research has been done on single frame medical image which is impractical in the real environment. In this paper, a digital watermarking on multiframes medical images is proposed. In order to speed up multiframes watermarking processing time, a parallel watermarking processing on medical images processing by utilizing multicores technology is introduced. An experiment result has shown that elapsed time on parallel watermarking processing is much shorter than sequential watermarking processing.

Watermarking of ultrasound medical images in teleradiology using compressed watermark.

The open accessibility of Internet-based medical images in teleradialogy face security threats due to the nonsecured communication media. This paper discusses the spatial domain watermarking of ultrasound medical images for content authentication, tamper detection, and lossless recovery. For this purpose, the image is divided into two main parts, the region of interest (ROI) and region of noninterest (RONI). The defined ROI and its hash value are combined as watermark, lossless compressed, and embedded into the RONI part of images at pixel's least significant bits (LSBs). The watermark lossless compression and embedding at pixel's LSBs preserve image diagnostic and perceptual qualities. Different lossless compression techniques including Lempel-Ziv-Welch (LZW) were tested for watermark compression. The performances of these techniques were compared based on more bit reduction and compression ratio. LZW was found better than others and used in tamper detection and recovery watermarking of medical images (TDARWMI) scheme development to be used for ROI authentication, tamper detection, localization, and lossless recovery. TDARWMI performance was compared and found to be better than other watermarking schemes.

Watermark Compression in Medical Image Watermarking Using Lempel-Ziv-Welch (LZW) Lossless Compression Technique.

In teleradiology, image contents may be altered due to noisy communication channels and hacker manipulation. Medical image data is very sensitive and can not tolerate any illegal change. Illegally changed image-based analysis could result in wrong medical decision. Digital watermarking technique can be used to authenticate images and detect as well as recover illegal changes made to teleradiology images. Watermarking of medical images with heavy payload watermarks causes image perceptual degradation. The image perceptual degradation directly affects medical diagnosis. To maintain the image perceptual and diagnostic qualities standard during watermarking, the watermark should be lossless compressed. This paper focuses on watermarking of ultrasound medical images with Lempel-Ziv-Welch (LZW) lossless-compressed watermarks. The watermark lossless compression reduces watermark payload without data loss. In this research work, watermark is the combination of defined region of interest (ROI) and image watermarking secret key. The performance of the LZW compression technique was compared with other conventional compression methods based on compression ratio. LZW was found better and used for watermark lossless compression in ultrasound medical images watermarking. Tabulated results show the watermark bits reduction, image watermarking with effective tamper detection and lossless recovery.

Cardiac ischemia in patients with septic shock randomized to vasopressin or norepinephrine.

INTRODUCTION: Cardiac troponins are sensitive and specific biomarkers of myocardial necrosis. We evaluated troponin, CK, and ECG abnormalities in patients with septic shock and compared the effect of vasopressin (VP) versus norepinephrine (NE) on troponin, CK, and ECGs. METHODS: This was a prospective substudy of a randomized trial. Adults with septic shock randomly received, blinded, a low-dose infusion of VP (0.01 to 0.03 U/min) or NE (5 to 15 µg/min) in addition to open-label vasopressors, titrated to maintain a mean blood pressure of 65 to 75 mm Hg. Troponin I/T, CK, and CK-MB were measured, and 12-lead ECGs were recorded before study drug, and 6 hours, 2 days, and 4 days after study-drug initiation. Two physician readers, blinded to patient data and drug, independently interpreted ECGs. RESULTS: We enrolled 121 patients (median age, 63.9 years (interquartile range (IQR), 51.1 to 75.3), mean APACHE II 28.6 (SD 7.7)): 65 in the VP group and 56 in the NE group. At the four time points, 26%, 36%, 32%, and 21% of patients had troponin elevations, respectively. Baseline characteristics and outcomes were similar between patients with positive versus negative troponin levels. Troponin and CK levels and rates of ischemic ECG changes were similar in the VP and the NE groups. In multivariable analysis, only APACHE II was associated with 28-day mortality (OR, 1.07; 95% CI, 1.01 to 1.14; P=0.033). CONCLUSIONS: Troponin elevation is common in adults with septic shock. We observed no significant differences in troponin, CK, and ECGs in patients treated with vasopressin and norepinephrine. Troponin elevation was not an independent predictor of mortality. TRIAL REGISTRATION: Controlled-trials.com ISRCTN94845869.

A rare but potentially lethal complication of dengue.

Severe rhabdomyolysis is an uncommon but potentially fatal complication of dengue fever that is not well characterised and may be underreported. With the resurgence and continued rise of dengue cases worldwide, physicians must be aware of the less common but serious complications of dengue. Here, we report a patient who presented with severe rhabdomyolysis secondary to dengue fever with a serum creatine kinase of 742 900 U/L.

Tamper localization and lossless recovery watermarking scheme with ROI segmentation and multilevel authentication.

Tamper localization and recovery watermarking scheme can be used to detect manipulation and recover tampered images. In this paper, a tamper localization and lossless recovery scheme that used region of interest (ROI) segmentation and multilevel authentication was proposed. The watermarked images had a high average peak signal-to-noise ratio of 48.7 dB and the results showed that tampering was successfully localized and tampered area was exactly recovered. The usage of ROI segmentation and multilevel authentication had significantly reduced the time taken by approximately 50 % for the tamper localization and recovery processing.

Agreement in electrocardiogram interpretation in patients with septic shock.

OBJECTIVE: The reliability of electrocardiogram interpretation to diagnose myocardial ischemia in critically ill patients is unclear. In adults with septic shock, we assessed intra- and inter-rater agreement of electrocardiogram interpretation, and the effect of knowledge of troponin values on these interpretations. DESIGN: Prospective substudy of a randomized trial of vasopressin vs. norepinephrine in septic shock. SETTING: Nine Canadian intensive care units. PATIENTS: Adults with septic shock requiring at least 5 µg/min of norepinephrine for 6 hrs. INTERVENTIONS: Twelve-lead electrocardiograms were recorded before study drug, and 6 hrs, 2 days, and 4 days after study drug initiation. MEASUREMENTS: Two physician readers, blinded to patient data and group, independently interpreted electrocardiograms on three occasions (first two readings were blinded to patient data; third reading was unblinded to troponin). To calibrate and refine definitions, both readers initially reviewed 25 trial electrocardiograms representing normal to abnormal. Cohen's Kappa and the φ statistic were used to analyze intra- and inter-rater agreement. RESULTS: One hundred twenty-one patients (62.2 ± 16.5 yrs, Acute Physiology and Chronic Health Evaluation II 28.6 ± 7.7) had 373 electrocardiograms. Blinded to troponin, readers 1 and 2 interpreted 46.4% and 30.0% of electrocardiograms as normal, and 15.3% and 12.3% as ischemic, respectively. Intrarater agreement was moderate for overall ischemia (κ 0.54 and 0.58), moderate/good for "normal" (κ 0.69 and 0.55), fair to good for specific signs of ischemia (ST elevation, T inversion, and Q waves, reader 1 κ 0.40 to 0.69; reader 2 κ 0.56 to 0.70); and good/very good for atrial arrhythmias (κ 0.84 and 0.79) and bundle branch block (κ 0.88 and 0.79). Inter-rater agreement was fair for ischemia (κ 0.29), moderate for ST elevation (κ 0.48), T inversion (κ 0.52), and Q waves (κ 0.44), good for bundle branch block (κ 0.78), and very good for atrial arrhythmias (κ 0.83). Inter-rater agreement for ischemia improved from fair to moderate (κ 0.52, p = .028) when unblinded to troponin. CONCLUSIONS: In patients with septic shock, inter-rater agreement of electrocardiogram interpretation for myocardial ischemia was fair, and improved with troponin knowledge.

Current role of high frequency oscillatory ventilation and airway pressure release ventilation in acute lung injury and acute respiratory distress syndrome.

Lung protective ventilatory strategies using conventional ventilators have resulted in decreased mortality in adult patients who have acute lung injury and acute respiratory distress syndrome. Conceptually, high frequency oscillatory ventilation and airway pressure release ventilation appear not only able to fulfill the goals of lung protection, but also to offer some additional advantages over conventional ventilation. Although early data for each of these modes in adults have been encouraging, their widespread use--particularly outside of a rescue situation--cannot be recommended without further evidence.