Critical care delivery across health care systems in low-income and low-middle-income country settings: A systematic review

Background

Prior research has demonstrated that low- and low-middle-income countries (LLMICs) bear a higher burden of critical illness and have a higher rate of mortality from critical illness than high-income countries (HICs). There is a pressing need for improved critical care delivery in LLMICs to reduce this inequity. This systematic review aimed to characterise the range of critical care interventions and services delivered within LLMIC health care systems as reported in the literature.

Methods

A search strategy using terms related to critical care in LLMICs was implemented in multiple databases. We included English language articles with human subjects describing at least one critical care intervention or service in an LLMIC setting published between 1 January 2008 and 1 January 2020.

Results

A total of 1620 studies met the inclusion criteria. Among the included studies, 45% of studies reported on pediatric patients, 43% on adults, 23% on infants, 8.9% on geriatric patients and 4.2% on maternal patients. Most of the care described (94%) was delivered in-hospital, with the remainder (6.2%) taking place in out-of-hospital care settings. Overall, 49% of critical care described was delivered outside of a designated intensive care unit. Specialist physicians delivered critical care in 60% of the included studies. Additional critical care was delivered by general physicians (40%), as well as specialist physician trainees (22%), pharmacists (16%), advanced nursing or midlevel practitioners (8.9%), ambulance providers (3.3%) and respiratory therapists (3.1%).

Conclusions

This review represents a comprehensive synthesis of critical care delivery in LLMIC settings. Approximately 50% of critical care interventions and services were delivered outside of a designated intensive care unit. Specialist physicians were the most common health care professionals involved in care delivery in the included studies, however generalist physicians were commonly reported to provide critical care interventions and services. This study additionally characterised the quality of the published evidence guiding critical care practice in LLMICs, demonstrating a paucity of interventional and cost-effectiveness studies. Future research is needed to understand better how to optimise critical care interventions, services, care delivery and costs in these settings.

Registration

PROSPERO CRD42019146802.

Public knowledge of cardiovascular disease and response to acute cardiac events in three municipalities in Brazil

Objective

To conduct a landscape assessment of public knowledge of cardiovascular disease risk factors and acute myocardial infarction symptoms, cardiopulmonary resuscitation (CPR) and automated external defibrillator (AED) awareness and training in three underserved communities in Brazil.

Methods

A cross-sectional, population-based survey of non-institutionalised adults age 30 or greater was conducted in three municipalities in Eastern Brazil. Data were analysed as survey-weighted percentages of the sampled populations.

Results

3035 surveys were completed. Overall, one-third of respondents was unable to identify at least one cardiovascular disease risk factor and 25% unable to identify at least one myocardial infarction symptom. A minority of respondents had received training in CPR or were able to identify an AED. Low levels of education and low socioeconomic status were consistent predictors of lower knowledge levels of cardiovascular disease risk factors, acute coronary syndrome symptoms and CPR and AED use.

Conclusions

In three municipalities in Eastern Brazil, overall public knowledge of cardiovascular disease risk factors and symptoms, as well as knowledge of appropriate CPR and AED use was low. Our findings indicate the need for interventions to improve public knowledge and response to acute cardiovascular events in Brazil as a first step towards improving health outcomes in this population. Significant heterogeneity in knowledge seen across sites and socioeconomic strata indicates a need to appropriately target such interventions.

Systematic review and meta-analysis of intravascular temperature management vs. surface cooling in comatose patients resuscitated from cardiac arrest

OBJECTIVE

To systematically review the effectiveness and safety of intravascular temperature management (IVTM) vs. surface cooling methods (SCM) for induced hypothermia (IH).

METHODS

Systematic review and meta-analysis. English-language PubMed, Embase and the Cochrane Database of Systematic Reviews were searched on May 27, 2019. The quality of included observational studies was graded using the Newcastle-Ottawa Quality Assessment tool. The quality of included randomized trials was evaluated using the Cochrane Collaboration's risk of bias tool. Random effects modeling was used to calculate risk differences for each outcome. Statistical heterogeneity and publication bias were assessed using standard methods.

ELIGIBILITY

Observational or randomized studies comparing survival and/or neurologic outcomes in adults aged 18 years or greater resuscitated from out-of-hospital cardiac arrest receiving IH via IVTM vs. SCM were eligible for inclusion.

RESULTS

In total, 12 studies met inclusion criteria. These enrolled 1573 patients who received IVTM; and 4008 who received SCM. Survival was 55.0% in the IVTM group and 51.2% in the SCM group [pooled risk difference 2% (95% CI -1%, 5%)]. Good neurological outcome was achieved in 40.9% in the IVTM and 29.5% in the surface group [pooled risk difference 5% (95% CI 2%, 8%)]. There was a 6% (95% CI 11%, 2%) lower risk of arrhythmia with use of IVTM and 15% (95% CI 22%, 7%) decreased risk of overcooling with use of IVTM vs. SCM. There was no significant difference in other evaluated adverse events between groups.

CONCLUSIONS

IVTM was associated with improved neurological outcomes vs. SCM among survivors resuscitated following cardiac arrest. These results may have implications for care of patients in the emergency department and intensive care settings after resuscitation from cardiac arrest.

Economic impacts of environmentally attributable childhood health outcomes in the European Union

BACKGROUND

There is increasing evidence of the role that exposure to industrial chemicals plays in the development of childhood disease. The USA and the European Union (EU) have taken divergent policy approaches to managing this issue, and economic estimates of disease costs attributable to environmental exposures in children are available in the USA but not the EU. We undertook the first economic evaluation of the impacts of childhood environmental chemical exposures in the EU.

METHODS

We used a cost-of-illness approach to estimate health care system costs, and used environmentally attributable fraction modelling to estimate the proportion of childhood disease due to environmental exposures. We analysed data on exposures, disease prevalence and costs at a country level, and then aggregated costs across EU member states to estimate overall economic impacts within the EU.

RESULTS

We found the combined environmentally attributable costs of lead exposure, methylmercury exposure, developmental disabilities, asthma and cancer to be $70.9 billion in 2008 (range: $58.9-$90.6 billion). These costs amounted to ~0.480% of the gross domestic product of the EU in 2008.

CONCLUSIONS

Childhood chemical exposures present a significant economic burden to the EU. Our study offers an important baseline of disease costs before the implementation of Registration, Evaluation and Authorization of Chemicals, which is important for studying the impacts of this policy regime.

Classification of carotid stenosis by millimeter CT angiography measures: effects of prevalence and gender

BACKGROUND AND PURPOSE

Previous studies quantifying moderate and severe carotid stenosis by direct millimeter measures on CT angiography (CTA) did not consider how prevalence and gender may influence classification cutoff values.

MATERIALS AND METHODS

Three hundred nineteen carotid arteries were evaluated in consecutive patients with known or suspected carotid artery disease. Millimeter measures were obtained of the stenotic carotid bulb lumen and distal internal carotid artery (ICA). Interclass correlation coefficients (ICC) defined interobserver and intraobserver agreement. North American Symptomatic Carotid Endarterectomy Trial (NASCET)-style percent stenosis ratios were calculated per carotid artery and used in linear regression and receiver operating characteristic (ROC) curve analysis to define equivalent millimeter quantification and classification values. Likelihood ratios and prevalence-specific positive/negative predictive values (PPV/NPV) were calculated to determine the most appropriate millimeter cutoff values to classify stenosis.

RESULTS

Interobserver agreement was excellent for stenosis measures (0.90) and good for distal ICA measures (0.79). Gender-specific regression curves and ROC curves indicated that millimeter stenosis is an excellent tool to quantify and classify carotid stenosis. Assuming a 10% prevalence of severe stenosis, we found that the cutoff value maximizing NPV and PPV was 1.1 mm for both genders (female: PPV = 86.2, NPV = 97.7; male: PPV = 83.2, NPV = 95.9). Assuming a 40% prevalence of moderate stenosis, we found that the cutoff values differed between genders: female = 2.0 mm (PPV = 91.3, NPV = 91.5), male = 2.1 mm (PPV = 91.6, NPV = 92.4). Specific millimeter cutoffs will vary depending upon the clinical scenario, prevalence, and gender.

CONCLUSIONS

Direct millimeter stenosis measures are an excellent tool to classify moderate and severe carotid artery stenosis. Millimeter classification cutoff values that best approximate NASCET classifications vary depending on prevalence and gender.

Activation of the Escherichia coli marA/soxS/rob regulon in response to transcriptional activator concentration

The paralogous transcriptional activators MarA, SoxS, and Rob activate a common set of promoters, the marA/soxS/rob regulon of Escherichia coli, by binding a cognate site (marbox) upstream of each promoter. The extent of activation varies from one promoter to another and is only poorly correlated with the in vitro affinity of the activator for the specific marbox. Here, we examine the dependence of promoter activation on the level of activator in vivo by manipulating the steady-state concentrations of MarA and SoxS in Lon protease mutants and by measuring promoter activation using lacZ transcriptional fusions. We found that: (i) the MarA concentrations needed for half-maximal stimulation varied by at least 19-fold among the 10 promoters tested; (ii) most marboxes were not saturated when there were 24,000 molecules of MarA per cell; (iii) the correlation between the MarA concentration needed for half-maximal promoter activity in vivo and marbox binding affinity in vitro was poor; and (iv) the two activators differed in their promoter activation profiles. The marRAB and sodA promoters could both be saturated by MarA and SoxS in vivo. However, saturation by MarA resulted in greater marRAB and lesser sodA transcription than did saturation by SoxS, implying that the two activators interact with RNA polymerase in different ways at the different promoters. Thus, the concentration and nature of activator determine which regulon promoters are activated, as well as the extent of their activation.

Correlation of carotid stenosis diameter and cross-sectional areas with CT angiography

PURPOSE

Carotid stenosis quantification traditionally uses measurements of narrowest stenosis diameter. The stenotic carotid lumen, however, is often irregularly shaped. New PACS workstation tools allow for more precise calculation of carotid geometry. We compare the narrowest stenosis diameter with 2D area stenosis measurements, with the hypothesis that the narrowest diameter is a good predictor of the more precise area measurement.

METHODS

Two neuroradiologists evaluated 178 stenosed carotids in a blinded protocol. Carotid artery bulb stenosis was identified on axial CT angiography and measured in millimeters at its narrowest diameter. An AGFA Impax 4.5 Volume Tool (VT) using Hounsfield units was used to estimate the cross-sectional area of the contrast luminogram. Pearson correlation coefficients were calculated between the millimeter stenosis and the VT area, as well as between the VT area and the calculated area (radius based on narrowest diameter). Regression analysis was performed with the VT area and narrowest diameter datasets.

RESULTS

Excellent interobserver correlation (correlation coefficients, 0.71-0.85; 2-tailed significance = .01) permitted averaging of measurement data. There is excellent correlation between the VT area and the narrowest diameter (correlation coefficient, 0.88; n = 176). The VT area was generally greater than the calculated area by an average of 2.77 mm2. There was excellent correlation between the VT area and the calculated area (correlation coefficient, 0.87; n = 176). Regression analysis shows the ability of the diameter measurements to predict corresponding area stenosis.

CONCLUSION

Although some carotid stenoses are irregularly shaped and noncircular, measurement of the narrowest stenosis is a reasonably reliable predictor of the cross-sectional area.

Diagnosing carotid stenosis near-occlusion by using CT angiography

BACKGROUND/PURPOSE

Identification of carotid near-occlusion is essential before calculation of percent stenosis because stroke risk is lower than other severe stenosis and the treatment benefit is less. Calculations with reduced distal diameters are fallacious. CT angiography (CTA) is convenient and accurately quantifies internal carotid artery (ICA) stenosis.

METHODS

In a blinded protocol, 268 carotid artery CTAs for known or suspected carotid disease were independently evaluated by 2 neuroradiologists. All carotid arteries were measured in millimeters at the narrowest diameter of the stenotic bulb, distal ICA well beyond the tapering bulb, and distal external carotid artery (ECA). Near-occlusions were independently identified, with disagreements settled by consensus meeting. Receiver operating characteristic (ROC) curve analysis defined the threshold values that best predicted near-occlusion according to (1) ICA stenosis, (2) distal ICA, (3) distal ICA: contralateral distal ICA, and (4) distal ICA: ECA. Paired permutations of variables were evaluated.

RESULTS

Forty-two near-occlusion distal ICAs were identified. The ROC-derived threshold values determined near-occlusion carotid stenosis with a sensitivity range, 90.2-97.3; specificity, 84.1-89.9; positive predictive value (PPV), 61.3-66.7; and negative predictive value (NPV), 96.7-99.4. Ranges for paired permutations were also determined: sensitivity, 82.9-91.9; specificity, 95.4-96.8; PPV, 78.6-85.7; and NPV, 96.3-98.4.

CONCLUSIONS

Threshold values provide guidelines for CTA interpretation when assessing carotid artery disease and the presence of near-occlusion. Ultimate identification of near-occlusion requires the interpreter's judgment, with attention to the following criteria: (1) notable stenosis of the ICA bulb and (2) distal ICA caliber reduction compared with (A) expected size, (B) contralateral ICA, and (C) ipsilateral ECA. Near-occlusion distal ICAs can be reliably identified on CTA.

Quantification of carotid stenosis on CT angiography

PURPOSE

Carotid artery stenosis quantification uses percent diameter ratios from conventional angiography. Multidetector high-speed CT angiography (CTA) allows direct millimeter measurement of carotid stenosis. We hypothesize a linear relationship between millimeter stenosis measurements and derived percent, alleviating cumbersome ratio calculations.

METHODS

Two neuroradiologists separately reviewed CTAs of 268 carotid arteries, blinded to other information. The narrowest portion of each carotid stenosis was measured in millimeters from axial source images. Distal internal carotid arteries (ICAs) were measured beyond the bulb, where walls are parallel. North American Symptomatic Carotid Endarterectomy Trial (NASCET)-style ratios were calculated for each ICA, except for suspected near-occlusions. Interobserver agreement was calculated for all measurements. Correlation coefficients were calculated comparing millimeter and derived percent stenosis, followed by regression analysis. Sensitivity and specificity values tested validity.

RESULTS

Interobserver agreement correlations were excellent, from 0.78 to 0.89 (2-tailed P </= .01). Excellent reader correlation permitted averaging of millimeter stenosis and distal ICA measurements, which were then used to calculate mean percent stenosis. Stenosis assessment was confidently performed from source images even with calcification. Regression analysis of mean percent as a function of mean millimeter stenosis shows a linear relationship, correlating 1.3 mm to 70% and 2.2 mm to 50% NASCET-style stenosis (Pearson's correlation of -0.95; n = 136). Direct millimeter measurement defining severe stenosis (70% or greater) has sensitivity of 88.2%, specificity of 92.4%, and negative predicted value of 98.2%.

CONCLUSION

There is a linear relationship between millimeter carotid stenosis diameter and derived percent stenosis. This allows prediction of NASCET-type percent from millimeter stenosis.

Studying non-Hodgkin's lymphoma in two Oklahoma counties: a call for centralized cancer data management

Anecdotal evidence for an increased incidence of non-Hodgkin's lymphoma (NHL) had been informally discussed within several clinical practices in north central Oklahoma. This study was conducted to determine the incidence rates of NHL in Garfield and Kingfisher counties and to evaluate whether these counties represented unique cancer clusters. Data were collected from medical records and tumor registries in 22 area hospitals between 1990-1994. The annual incidence rate per 100,000 persons for Garfield county was 15.51 (95% CI: 10.9-20.1), and for Kingfisher county, 24.22 (95% CI: 12.4-36.1). Both of these rates are increased from the national incidence rate of 13.7 cases of NHL per 100,000 persons, suggesting a significant clinical impact. However, a statistical significance was not detected given the conservative methodology and the small populations involved. The difficulties of performing community-based research, the need for epidemiological studies to reduce clinical experience bias, and the need for centralized cancer data management are discussed.

Penile erection: a reflection of sexual arousal and arousability in male chimpanzees

A study was conducted to determine if sexual motivation in male chimpanzees, defined by the two components, sexual arousal and arousability, could be quantified by measuring penile erection during laboratory pair-tests of sexual behavior. Sexual arousal, the momentary level of sexual excitation, was quantified by single measurements on a scale of penile erection. Sexual arousability, the propensity for arousal, was quantified by the rate of approach to full erection and by mean erection scores. Sexual arousability, as defined, was related to the frequency of male courtship displays, copulations, and ejaculations, which were highest at midcycle and positively correlated with a quantitative measure of female anogenital swelling. Sexual arousal was negatively correlated with continued exposure to the female and least variable during midcycle. These operational definitions of sexual motivation in the male chimpanzee facilitate comparative research in which analogous indexes of sexual motivation are required such as when extrapolating from animal to human.