The development of a nurse-led preoperative anaesthesia screening tool by Delphi consensus

BACKGROUND

Low- and middle-income countries have a critical shortage of specialist anaesthetists. Most patients arriving for surgery are of low perioperative risk. Without immediate access to preoperative specialist care, an appropriate interim strategy may be to ensure that only high-risk patients are seen preoperatively by a specialist. Matching human resources to the burden of disease with a nurse-administered pre-operative screening tool to identify high-risk patients who might benefit from specialist review prior to the day of surgery may be an effective strategy.

OBJECTIVE

To develop a nurse-administered preoperative anaesthesia screening tool to identify patients who would most likely benefit from a specialist review before the day of surgery, and those patients who could safely be seen by the anaesthetist on the day of surgery. This would ensure adequate time for optimisation of high-risk patients preoperatively and limit avoidable day-of-surgery cancellations.

METHODS

A systematic review was conducted to identify preoperative screening questions for use in a three-round Delphi consensus process. A panel of 16 experienced full-time clinical anaesthetists representing all university-affiliated anaesthesia departments in South Africa participated to define a nurses' screening tool for preoperative assessment.

RESULTS

Ninety-eight studies were identified, which generated 79 questions. An additional 14 items identified by the facilitators were added to create a list of 93 questions for the first round. The final screening tool consisted of 81 questions, of which 37 were deemed critical to identify patients who should be seen by a specialist prior to the day of surgery.

CONCLUSION

A structured nurse-administered preoperative screening tool is proposed to identify high-risk patients who are likely to benefit from a timely preoperative specialist anaesthetist review to avoid cancellation on the day of surgery.

Serum Adiponectin and Leptin Among Ghanaian Migrants in Amsterdam and Their Compatriots in Rural and Urban Ghana: The RODAM Study

Background

The rapidly rising cardiometabolic disease (CMD) burden in urbanizing sub-Saharan African populations and among sub-Saharan African migrants in Europe likely affects serum adiponectin and leptin levels, but this has not yet been quantified.

Objectives

To compare the serum levels of adiponectin and leptin among migrant, and non-migrant (urban and rural) populations of Ghanaian descent.

Methods

Cross-sectional analysis of serum leptin and adiponectin in the multi-centre Research on Obesity and Diabetes among African Migrants (RODAM) study. Logistic-regression models were used to examine the association between these adipocyte-derived hormones after stratification (sex, geographic area) and adjustments for potential confounders.

Results

A total of 2518 Ghanaians were included. Rural participants had the highest serum adiponectin and lowest leptin levels compared to Amsterdam and urban Ghanaians (P < .001). In fully adjusted models, participants living in urban Ghana had significantly higher odds of hyperleptinemia compared to rural participants (women-odds ratio 2.88; 95% CI, 1.12-7.38, P = .028 and men 43.52, 95% CI, 4.84-391.25, P < .001). Urban Ghanaian men also had higher odds of elevated leptin: adiponectin ratio (6.29, 95% CI, 1.43-27.62, P = .015). The odds of hyperleptinemia were only higher in Amsterdam Ghanaian men (10.56; 95% CI, 1.11-100.85, P = .041), but not in women (0.85; 95% CI, 0.30-2.41, P = .759). There was no significant association between hypoadiponectinemia and geographical location in both sexes.

Conclusion

Urbanization is associated with serum adiponectin and leptin levels after adjusting for confounding covariates in sub-Saharan Africans. These findings serve as a backdrop for further research on the role adipokines play in CMD epidemiology among Africans.

Acute kidney injury after major non-cardiac surgery: Incidence and risk factors

BACKGROUND

Acute kidney injury (AKI) is a major post-surgical complication that contributes to morbidity and mortality. AKI is welldocumented after cardiac surgery. However, less is known regarding the incidence and risk factors following major non-cardiac surgery.Globally the incidence of AKI post major surgery has been evaluated; however, there are no data available for South Africa (SA).

OBJECTIVES

To ascertain the incidence of AKI after major non-cardiac surgery at a tertiary academic SA hospital. Secondary outcomes wereto identify perioperative risk factors that are associated with an elevated risk to develop AKI in the postoperative period.

METHODS

The study was conducted at Tygerberg Hospital, a single tertiary centre in Cape Town, SA. Perioperative records of adults whounderwent major non-cardiac surgery were retrospectively collected. Variables pertaining to potential risk factors for AKI were captured,and serum creatinine levels were recorded up to 7 days postoperatively and compared with baseline measurements to determine whetherAKI had developed. Descriptive statistics along with logistic regression analysis were used to interpret results.

RESULTS

The overall incidence of AKI was 11.2% (95% confidence interval (CI) 9.8 - 12.6). Based on surgical discipline, trauma surgery(19%), followed by abdominal (18.5%) and vascular surgery (17%) had the highest incidence. Independent AKI risk factors wereidentified after multivariate analysis. These were: chronic obstructive pulmonary disease (odds ratio (OR) 2.19; 95% CI 1.09 - 4.37;p=0.005), trauma surgery (OR 3.00; 95% CI 1.59 - 5.64; p=0.001), abdominal surgery (OR 2.14; 95% CI 1.33 - 3.45; p=0.002), vascularsurgery (OR 2.42; 95% CI 1.31 - 4.45; p=0.004), urology procedures (OR 2.45; 95% CI 1.31 - 4.45; p=0.005), red blood cell transfusion(OR 1.81; 95% CI 1.21 - 2.70; p=0.004), emergency surgery (OR 1.74; 95% CI 1.15 - 2.65; p=0.009) and inotrope use (OR 2.77; 95% CI1.80 - 4.26; p<0.001).

CONCLUSION

The results of our study are in keeping with international literature regarding the incidence of AKI after major non-cardiacsurgery. The risk factor profile, however, is in several regards different from what has been found elsewhere.

Following Evidence-Based Recommendations for Perioperative Pain Management after Cesarean Section Is Associated with Better Pain-Related Outcomes: Analysis of Registry Data

Women who have had a Cesarean Section (CS) frequently report severe pain and pain-related interference. One reason for insufficient pain treatment might be inconsistent implementation of evidence-based guidelines. We assessed the association between implementing three elements of care recommended by guidelines for postoperative pain management and pain-related patient-reported outcomes (PROs) in women after CS. The analysis relied on an anonymized dataset of women undergoing CS, retrieved from PAIN OUT. PAIN OUT, an international perioperative pain registry, provides clinicians with treatment assessment methodology and tools for patients to assess multi-dimensional pain-related PROs on the first postoperative day. We examined whether the care included [i] regional anesthesia with a neuraxial opioid OR general anesthesia with wound infiltration or a Transvesus Abdominis Plane block; [ii] at least one non-opioid analgesic at the full daily dose; and [iii] pain assessment and recording. Credit for care was given only if all three elements were administered (= “full”); otherwise, it was “incomplete”. A “Pain Composite Score-total” (PCStotal), evaluating outcomes of pain intensity, pain-related interference with function, and side-effects, was the primary endpoint in the total cohort (women receiving GA and/or RA) or a sub-group of women with RA only. Data from 5182 women was analyzed. “Full” care was administered to 20% of women in the total cohort and to 21% in the RA sub-group. In both groups, the PCStotal was significantly lower compared to “incomplete” care (p < 0.001); this was a small-to-moderate effect size. Administering all three elements of care was associated with better pain-related outcomes after CS. These should be straightforward and inexpensive for integration into routine care after CS. However, even in this group, a high proportion of women reported poor outcomes, indicating that additional work needs to be carried out to close the evidence-practice gap so that women who have undergone CS can be comfortable when caring for themselves and their newborn.

Post-traumatic Lemierres Syndrome: A rare presentation secondary to mandibular fracture

Lemierre’s Syndrome is a rare phenomenon with a low prevalence and is characteristically seen in patients with an oropharyngeal infection that is complicated by thrombophlebitis of the internal jugular vein and secondary septic emboli. We present the case of a 16 year old previously well male who was diagnosed with a rare case of Lemierre’s syndrome secondary to a mandibular fracture. Blood tests and radiological imaging confirmed the diagnosis, with CT scan of the patients head and neck revealing a right mandibular fracture with abscess formation, bilateral parapharyngeal abscesses, bilateral internal jugular vein thromboses, left sigmoid sinus thrombosis, cavernous sinus thrombosis, post septal orbital cellulitis with enhancing infraorbital collections and a subdural empyema overlying the left tentorium cerebelli. The treatment is usually non-operative with antibiotics and in some instances surgical drainage. In this case a combination of surgical drainage for source control and antibiotics were used. Unfortunately, despite an initial improvement in the patient’s clinical status the patient died. This is the first case of Lemierre’s syndrome secondary to blunt facial trauma reported in the scientific literature. This case highlights the importance of clinicians having a high degree of suspicion of Lemierre’s syndrome when a patient presents with typical clinical features following facial trauma.

System-level policies on appropriate opioid use, a multi-stakeholder consensus

BACKGROUND

This consensus statement was developed because there are concerns about the appropriate use of opioids for acute pain management, with opposing views in the literature. Consensus statement on policies for system-level interventions may help inform organisations such as management structures, government agencies and funding bodies.

METHODS

We conducted a multi-stakeholder survey using a modified Delphi methodology focusing on policies, at the system level, rather than at the prescriber or patient level. We aimed to provide consensus statements for current developments and priorities for future developments.

RESULTS

Twenty-five experts from a variety of fields with experience in acute pain management were invited to join a review panel, of whom 23 completed a modified Delphi survey of policies designed to improve the safety and quality of opioids prescribing for acute pain in the secondary care setting. Strong agreement, defined as consistent among> 75% of panellists, was observed for ten statements.

CONCLUSIONS

Using a modified Delphi study, we found agreement among a multidisciplinary panel, including patient representation, on prioritisation of policies for system-level interventions, to improve governance, pain management, patient/consumers care, safety and engagement.

Identifying knowledge needed to improve surgical care in Southern Africa using a theory of change approach

Surgical healthcare has been prioritised in the Southern African Development Community (SADC), a regional intergovernmental entity promoting equitable and sustainable economic growth and socioeconomic development. However, challenges remain in translating political prioritisation into effective and equitable surgical healthcare. The AfroSurg Collaborative (AfroSurg) includes clinicians, public health professionals and social scientists from six SADC countries; it was created to identify context-specific, critical areas where research is needed to inform evidence-grounded policy and implementation. In January 2020, 38 AfroSurg members participated in a theory of change (ToC) workshop to agree on a vision: ‘An African-led, regional network to enable evidence-based, context-specific, safe surgical care, which is accessible, timely, and affordable for all, capturing the spirit of Ubuntu[1]’ and to identify necessary policy and service-delivery knowledge needs to achieve this vision. A unified ToC map was created, and a Delphi survey was conducted to rank the top five priority knowledge needs. In total, 45 knowledge needs were identified; the top five priority areas included (1) mapping of available surgical services, resources and providers; (2) quantifying the burden of surgical disease; (3) identifying the appropriate number of trainees; (4) identifying the type of information that should be collected to inform service planning; and (5) identifying effective strategies that encourage geographical retention of practitioners. Of the top five knowledge needs, four were policy-related, suggesting a dearth of much-needed information to develop regional, evidenced-based surgical policies. The findings from this workshop provide a roadmap to drive locally led research and create a collaborative network for implementing research and interventions. This process could inform discussions in other low-resource settings and enable more evidenced-based surgical policy and service delivery across the SADC countries and beyond.

Almost 1 in 5 South African adults have chronic pain: a prevalence study conducted in a large nationally representative sample

Limited information on the prevalence and risk factors for chronic pain is available for developing countries. Therefore, we investigated the prevalence of chronic pain and the association between this pain and various personal and sociodemographic factors by including questions in the South Africa Demographic and Household Survey 2016. The survey was conducted by face-to-face interviews with a nationally representative sample of the adult population (ages 15 and older, n = 10,336). Chronic pain was defined as pain or discomfort that had been experienced all the time or on and off for 3 months or more. The prevalence of chronic pain was 18.3% (95% confidence interval [CI]: 17.0-19.7). Women were more likely than were men to have chronic pain (men = 15.8% [95% CI: 13.9-17.8]; woman = 20.1% [95% CI: 18.4-21.8]), and the prevalence of chronic pain increased from 11.3% (95% CI: 9.6-13.3) for the age range 15 to 24 years to 34.4% (95% CI: 30.6-38.4) for the age range over 65 years. The body sites affected most frequently were the limbs (43.6% [95% CI: 40.4-46.9]), followed by the back (30.5% [95% CI: 27.7-33.6]). This article presents the prevalence of chronic pain in the general population of a middle-income African country. These data give much needed insights into the burden of, and risk factors for, chronic pain in low-resource settings, and identify priority groups for intervention.

Caregiver anxiety and the association with acute postoperative pain in children undergoing elective ambulatory surgery in a lower-middle-income country setting

BACKGROUND AND AIMS

Moderate to severe postoperative pain complicates surgeries performed on children in upper-income countries. The successful management of postoperative pain in children requires a biopsychosocial approach. Situational anxiety and anxiety disorders among caregivers influence a child's perioperative experience. This study aims to determine whether there is an association between caregiver's preoperative anxiety and children's postoperative pain in a lower-middle-income country (LMIC) setting.

METHODS

In this cross-sectional, descriptive study, we recruited 76 children aged 4-12 years, undergoing elective ambulatory tonsillectomy or adenotonsillectomy. Primary caregivers completed validated measures of anxiety (the Beck Anxiety Inventory [BAI] and the Kessler Psychological Distress Scale [K10]) prior to the children undergoing surgery. Postoperative pain was measured using the Wong-Baker Faces Pain Rating Scale 4 hours after surgery.

RESULTS

Caregiver anxiety was found in 31.7% of participants using the K10 and in 42.1% using the BAI. Moderate to severe postoperative pain was reported by 51% of children. There was a statistically significant correlation of moderate strength between anxiety scores of caregivers and children's self-reported postoperative pain scores (r = .47 for K10, r = .44 for BAI, P < .001 for both). Two median quantile regression models confirmed that K10 was positively associated with caregiver anxiety (WBFS) with slope = 0.16 and pseudo R²  = 0.25 (P = .002, 95CI: 0.06-0.26) as was BAI with slope = 0.12 and pseudo R²  = 0.22 (P = .013 95CI: 0.03-0.22).

CONCLUSIONS

This study showed that preoperative caregiver anxiety is significantly associated with postoperative pain in children undergoing elective, ambulatory surgery in a LMIC setting (correlation of moderate strength). Interventions aimed at reducing caregiver anxiety should become an important component of the biopsychosocial management of postoperative pain in children.

Accelerated surgery versus standard care in hip fracture (HIP ATTACK): an international, randomised, controlled trial

BACKGROUND

Observational studies have suggested that accelerated surgery is associated with improved outcomes in patients with a hip fracture. The HIP ATTACK trial assessed whether accelerated surgery could reduce mortality and major complications.

METHODS

HIP ATTACK was an international, randomised, controlled trial done at 69 hospitals in 17 countries. Patients with a hip fracture that required surgery and were aged 45 years or older were eligible. Research personnel randomly assigned patients (1:1) through a central computerised randomisation system using randomly varying block sizes to either accelerated surgery (goal of surgery within 6 h of diagnosis) or standard care. The coprimary outcomes were mortality and a composite of major complications (ie, mortality and non-fatal myocardial infarction, stroke, venous thromboembolism, sepsis, pneumonia, life-threatening bleeding, and major bleeding) at 90 days after randomisation. Patients, health-care providers, and study staff were aware of treatment assignment, but outcome adjudicators were masked to treatment allocation. Patients were analysed according to the intention-to-treat principle. This study is registered at ClinicalTrials.gov (NCT02027896).

FINDINGS

Between March 14, 2014, and May 24, 2019, 27 701 patients were screened, of whom 7780 were eligible. 2970 of these were enrolled and randomly assigned to receive accelerated surgery (n=1487) or standard care (n=1483). The median time from hip fracture diagnosis to surgery was 6 h (IQR 4-9) in the accelerated-surgery group and 24 h (10-42) in the standard-care group (p<0·0001). 140 (9%) patients assigned to accelerated surgery and 154 (10%) assigned to standard care died, with a hazard ratio (HR) of 0·91 (95% CI 0·72 to 1·14) and absolute risk reduction (ARR) of 1% (-1 to 3; p=0·40). Major complications occurred in 321 (22%) patients assigned to accelerated surgery and 331 (22%) assigned to standard care, with an HR of 0·97 (0·83 to 1·13) and an ARR of 1% (-2 to 4; p=0·71).

INTERPRETATION

Among patients with a hip fracture, accelerated surgery did not significantly lower the risk of mortality or a composite of major complications compared with standard care.

FUNDING

Canadian Institutes of Health Research.

The Critical Care Society of Southern Africa Consensus Guideline on ICU Triage and Rationing (ConICTri)

Background

In South Africa (SA), administrators and intensive care practitioners are faced with the challenge of resource scarcity as well as an increasing demand for intensive care unit (ICU) services. ICU services are expensive, and practitioners in low- to middle-income countries experience the consequences of limited resources daily. Critically limited resources necessitate that rationing and triage (prioritisation) decisions are routinely necessary in SA, particularly in the publicly funded health sector.

Purpose

The purpose of this guideline is to utilise the relevant recommendations of the associated consensus meeting document and other internationally accepted principles to develop a guideline to inform frontline triage policy and ensure the best utilisation of adult intensive care in SA, while maintaining the fair distribution of available resources.

Recommendations

An overall conceptual framework for the triage process was developed. The components of the framework were developed on the basis that patients should be admitted preferentially when the likely incremental medical benefit derived from ICU admission justifies admission. An estimate of likely resource use should also form part of the triage decision, with those patients requiring relatively less resources to achieve substantial benefit receiving priority for admission. Thus, the triage system should maximise the benefits obtained from ICU resources available for the community. Where possible, practical examples of what the consensus group agreed would be considered appropriate practice under specified South African circumstances were provided, to assist clinicians with practical decision-making. It must be stressed that this guideline is not intended to be prescriptive for individual hospital or regional practice, and hospitals and regions are encouraged to develop specified local guidelines with locally relevant examples. The guideline should be reviewed and revised if appropriate within 5 years.

Conclusion

In recognition of the absolute need to limit patient access to ICU because of the lack of sufficient intensive care resources in public hospitals, this guideline has been developed to guide policy-making and assist frontline triage decision-making in SA. This document is not a complete plan for quality practice, but rather a template to support frontline clinicians, guide administrators and inform the public regarding appropriate triage decision-making.

The Critical Care Society of Southern Africa Consensus Statement on ICU Triage and Rationing (ConICTri)

Background

In South Africa (SA), intensive care is faced with the challenge of resource scarcity as well as an increasing demand for intensive care unit (ICU) services. ICU services are expensive, and practitioners in low- to middle-income countries experience daily the consequences of limited resources. Critically limited resources necessitate that rationing and triage (prioritisation) decisions are frequently necessary in SA, particularly in the publicly funded health sector.

Purpose

The purpose of this consensus statement is to examine key questions that arise when considering the status of ICU resources in SA, and more specifically ICU admission, rationing and triage decisions. The accompanying guideline in this issue is intended to guide frontline triage policy and ensure the best utilisation of intensive care in SA, while maintaining a fair distribution of available resources. Fair and efficient triage is important to ensure the ongoing provision of high-quality care to adult patients referred for intensive care.

Recommendations

In response to 14 key questions developed using a modified Delphi technique, 29 recommendations were formulated and graded using an adapted GRADE score. The 14 key questions addressed the status of the provision of ICU services in SA, the degree of resource restriction, the efficiency of resource management, the need for triage, and how triage could be most justly implemented. Important recommendations included the need to formally recognise and accurately quantify the provision of ICU services in SA by national audit; actively seek additional resources from governmental bodies; consider methods to maximise the efficiency of ICU care; evaluate lower level of care alternatives; develop a triage guideline to assist policy-makers and frontline practitioners to implement triage decisions in an efficient and fair way; measure and audit the consequence of triage; and promote research to improve the accuracy and consistency of triage decisions. The consensus document and guideline should be reviewed and revised appropriately within 5 years.

Conclusion

In recognition of the absolute need to limit patient access to ICU because of the lack of sufficient intensive care resources in public hospitals, recommendations and a guideline have been developed to guide policy-making and assist frontline triage decision-making in SA. These documents are not a complete plan for quality practice but rather the beginning of a long-term initiative to engage clinicians, the public and administrators in appropriate triage decision-making, and promote systems that will ultimately maximise the efficient and fair use of available ICU resources.

Screening for acute HIV infection in South Africa: finding acute and chronic disease

BACKGROUND

The yield of screening for acute HIV infection among general medical patients in resource-scarce settings remains unclear. Our objective was to evaluate the strategy of using pooled HIV plasma RNA to diagnose acute HIV infection in patients with negative or discordant rapid HIV antibody tests in Durban, South Africa.

METHODS

We prospectively enrolled patients with negative or discordant rapid HIV antibody tests from a routine HIV screening programme in an out-patient department in Durban with an HIV prevalence of 48%. Study participants underwent venipuncture for pooled qualitative HIV RNA, and, if this was positive, quantitative RNA, enzyme immunoassay and Western blot (WB). Patients with negative or indeterminate WB and positive quantitative HIV RNA were considered acutely infected. Those with chronic infection (positive RNA and WB) despite negative or discordant rapid HIV tests were considered to have had false negative rapid antibody tests.

RESULTS

Nine hundred and ninety-four participants were enrolled with either negative (n=976) or discordant (n=18) rapid test results. Eleven [1.1%; 95% confidence interval (CI) 0.6-2.0%] had acute HIV infection, and an additional 20 (2.0%; 95% CI 1.3-3.1%) had chronic HIV infection (false negative rapid test).

CONCLUSIONS

One per cent of out-patients with negative or discordant rapid HIV tests in Durban, South Africa had acute HIV infection readily detectable through pooled serum HIV RNA screening. Pooled RNA testing also identified an additional 2% of patients with chronic HIV infection. HIV RNA screening has the potential to identify both acute and chronic HIV infections that are otherwise missed by standard HIV testing algorithms.

PCBs in air, soil and milk in industrialized and urban areas of KwaZulu-Natal, South Africa

Information regarding polychlorinated biphenyls (PCBs) in environmental media in Africa is limited. This paper presents results of a monitoring program conducted in KwaZulu-Natal Province, South Africa designed to characterize levels, trends and sources of airborne PCBs. Particulate and vapor samples were sampled over the 2004-2005 period at three sites. The total PCB concentration averaged 128+/-47 pgm(-3), and levels were highest in winter. Tri- through hexa-congeners predominated, and the vapor fraction was predominant. Several tetra- through hexa-chlorinated congeners had levels comparable to those at urban sites in the northern hemisphere, but hepta- through deca-congeners resembled levels at background sites. PCB source areas, deduced using spatial and temporal patterns, compositional information and trajectory analyses, likely included local, regional and global sources. Soils at three rural sites showed high PCB concentrations, and milk from a local dairy showed PCB concentrations comparable to USA levels in year 2000.

11C-PIB PET imaging in Alzheimer disease and frontotemporal lobar degeneration

BACKGROUND

The PET tracer (11)C-labeled Pittsburgh Compound-B ((11)C-PIB) specifically binds fibrillar amyloid-beta (Abeta) plaques and can be detected in Alzheimer disease (AD). We hypothesized that PET imaging with (11)C-PIB would discriminate AD from frontotemporal lobar degeneration (FTLD), a non-Abeta dementia.

METHODS

Patients meeting research criteria for AD (n = 7) or FTLD (n = 12) and cognitively normal controls (n = 8) underwent PET imaging with (11)C-PIB (patients and controls) and (18)F-fluorodeoxyglucose ((18)F-FDG) (patients only). (11)C-PIB whole brain and region of interest (ROI) distribution volume ratios (DVR) were calculated using Logan graphical analysis with cerebellum as a reference region. DVR images were visually rated by a blinded investigator as positive or negative for cortical (11)C-PIB, and summed (18)F-FDG images were rated as consistent with AD or FTLD.

RESULTS

All patients with AD (7/7) had positive (11)C-PIB scans by visual inspection, while 8/12 patients with FTLD and 7/8 controls had negative scans. Of the four PIB-positive patients with FTLD, two had (18)F-FDG scans that suggested AD, and two had (18)F-FDG scans suggestive of FTLD. Mean DVRs were higher in AD than in FTLD in whole brain, lateral frontal, precuneus, and lateral temporal cortex (p < 0.05), while DVRs in FTLD did not significantly differ from controls.

CONCLUSIONS

PET imaging with (11)C-labeled Pittsburgh Compound-B ((11)C-PIB) helps discriminate Alzheimer disease (AD) from frontotemporal lobar degeneration (FTLD). Pathologic correlation is needed to determine whether patients with PIB-positive FTLD represent false positives, comorbid FTLD/AD pathology, or AD pathology mimicking an FTLD clinical syndrome.

Regulation of renal alpha 2-adrenoceptor activity in Dahl salt-sensitive rats by dietary sodium changes

The objective of the study was to evaluate the concept that genetically predisposed salt-sensitivity contributes to an increased adrenergic susceptibility and renal alpha 2-adrenoceptor (A2) abnormality in Dahl salt-sensitive hypertensive rats. The results showed: i) After 2 months of Na-loading (8% NaCl) Dahl salt-sensitive (DSS) rats expressed increased sodium and water retention which paralleled gradual development of diastolic hypertension. Low Na diet (0.5% NaCl) does not prevent hypertension but delays its development. ii) The increased activity of the sympathetic nervous system (SNS), in DSS rats corresponded to the development of hypertension and was stimulated by Na-loading. It was assessed by plasma catecholamine levels and heart rate changes. iii) The increased density of renal A2 by 29% was upregulated by high sodium diet, and coupled with increased norepinephrine level by 53%, only in DSS but not in DSR rats. iv) No strain renal A2 and epinephrine differences between DSS and DSR were found in weanling, prehypertensive rats, or in the adult DSS and DSR on low Na diet. By mediating an enhanced receptor-coupled response, such as increased proximal tubular sodium reabsorption during sodium loading, a genetic abnormality of renal alpha 2-adrenoceptors may contribute to some of the pathophysiologic derangements leading to hypertension in Dahl salt-sensitive rats.

Sympathetic and platelet adrenergic activity and salt sensitivity: an experimental study

The objective of the study was to evaluate the advanced hypothesis that genetically predisposed salt-sensitivity contributes to an increased adrenergic susceptibility and platelet activity and both these factors play a role in the pathogenesis of hypertension in a Dahl rat model. The results showed: i) Dahl salt-sensitive rats (DS) gradually develop a diastolic hypertension by the end of 3 months of age, in spite of the diet they are fed. Low-Na diet (0.5% NaCl) does not prevent hypertension but delays its development. High-Na diet (8%) exacerbates their hypertension. ii) After 2 months of Na-loading, DS rats expressed significantly increased sodium and water retention and increased plasma volume by 15%, compared with 2.8% in Dahl salt-resistant (DR) rats on high-Na diet. iii) The increased activity of the sympathetic nervous system (SNS) in DS rats paralleled the development of hypertension and was stimulated by Na-loading. It was assessed by their catecholamines status and heart rate changes. iv) Platelet activity of DS rats was increased as reflected in collagen-induced nonstimulated and adrenaline-stimulated aggregation, and an increased plasma T x B2/6-keto PGF1 alpha ratio. Na-loading further increased platelet activity. v) Both DR and DS rat platelets displayed alpha 2-adrenoceptors (A2) of low binding capacity (Bmax 25 and 35 fmol/mg protein, respectively) and low affinity (KD 5.6 nM for both groups), suggesting that platelet alpha 2 adrenoceptors in this strain of rats might not play a significant biological role in their increased platelet activity. The fact that platelet alpha 2-adrenoceptors do not define the stimulation of SNS in DS rat do not exclude their participation in development of salt-dependent hypertension, since a genetic defect(s) of these ubiquitous receptors (brain, kidney, blood vessels) could still contribute to the pathogenesis of the disease.

Cyclin D1 and retinoblastoma protein expression in oesophageal squamous cell carcinoma

AIMS

To assess the immunoexpression of cyclin D1 and retinoblastoma in a cohort of oesophageal squamous cell carcinoma cases from South Africa to see whether there is a relation between these two proteins. In addition, protein expression was correlated with clinicopathological features.

METHODS

Fifty biopsies and 30 oesophagectomy specimens were immunostained with commercially available antibodies to cyclin D1 and retinoblastoma proteins, following microwave antigen retrieval.

RESULTS

Twenty three of the 80 cases (29%) showed cyclin D1 protein expression. However, only five cases had > 50% of the tumour cells displaying immunopositivity. Three of the four cases with lymph node spread were cyclin D1 positive in the primary tumour and the metastasis. Fifty three cases were immunoreactive with the antiretinoblastoma antibody; 29 of these cases showing > 50% of cells with immunolabelling. Of the 23 cyclin D1 positive cases, 18 were also retinoblastoma positive. No correlation was observed between cyclin D1 and retinoblastoma protein expression and age, sex, race, or histological grade.

CONCLUSIONS

Cyclin D1 is expressed in a minority of cases of oesophageal squamous carcinomas from South Africa. However, three of four cases with lymph node spread were cyclin D1 positive, thus indicating that cyclin D1 positive tumours may have a greater propensity for spread. In addition, 18 of 23 cyclin D1 positive cases also expressed retinoblastoma protein. These findings suggest a possible relation between cyclin D1 and retinoblastoma proteins in a proportion of cases of oesophageal squamous.

Balloon mitral valvotomy with a single catheter: a comparison between bifoil/trefoil and the Inoue balloon

Results of percutaneous mitral valvotomy were compared in two groups undergoing the procedure at our institution. Group I: 100 patients having had percutaneous valvotomy with the Schneider-Medintag bifoil (2 x 19 mm) or trefoil (3 x 15 mm or 3 x 12 mm) catheters, and group II; 150 patients in whom the procedure was performed with the Inoue balloon (24-30 mm). Baseline clinical (age, gender, NYHA class and echo score) and haemodynamic variables were similar in both groups. Haemodynamic improvement occurred in both groups. Although the reduction in left atrial pressure did not differ significantly between the two groups, the increase in mitral valve area was significantly (P < 0.001) higher for group I (0.8 +/- 0.2 to 1.9 +/- 0.7 and 0.8 +/- 0.3 to 1.6 +/- 0.3 cm2 respectively for mitral area, and 22 +/- 6 to 13 +/- 5 and 21 +/- 6 to 13 +/- 5 mmHg respectively for mean left atrial pressure). The increase in cardiac output was statistically significant in group I (3.2 +/- 0.7 to 4.0 +/- 0.9 l.min-1, P < 0.05) but not in group II (3.5 +/- 2.0 to 3.7 +/- 0.9 l.min-1, ns). Inter-atrial shunting immediately after valvotomy was recorded in 19% of group I patients compared with 6% in group II (P < 0.001). The overall incidence of significant mitral regurgitation (3+ or 4+) was similar in both groups (5% and 4% respectively). However, when the stepwise dilatation technique was employed in group II, the incidence had dropped to 2.1%.(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous balloon mitral valvotomy in pregnant patients with tight pliable mitral stenosis

Percutaneous balloon mitral valvotomy was attempted in severely symptomatic (New York Heart Association class III or IV) pregnant patients (mean age 30 years) with tight mitral stenosis. Nineteen patients were pregnant (mean gestation 30 weeks, range 26 to 34) and one patient was in the immediate postpartum period. All patients had undergone a trial of diuretic therapy and 16 were also taking atenolol. Percutaneous valvotomy was performed with the Inoue catheter (18 patients) or the Schneider-Medintag bifoil (2 x 19 mm) balloon catheter (2 patients). The fluoroscopy time was 9.2 +/- 3.4 minutes. After percutaneous valvotomy the mean mitral gradient decreased from 17.9 +/- 6.2 to 5.9 +/- 2.4 mm Hg (p < 0.001). The mitral valve area (pressure half time) increased from 0.8 +/- 0.2 to 1.7 +/- 0.2 cm2 (p < 0.001). These hemodynamic changes were accompanied by immediate symptomatic improvement by at least one New York Heart Association functional grade in all patients. Moderate (3+) mitral regurgitation developed in one patient. Eighteen patients had normal infants delivered vaginally at term without assistance, and one patient had a normal infant delivered by cesarean section at 35 weeks' gestation. We conclude that percutaneous balloon mitral valvotomy for pliable mitral stenosis in pregnancy is safe for both the mother and fetus. We recommend that it be performed in symptomatic patients with tight mitral stenosis so as to avoid hemodynamic complications in the latter stages of pregnancy.

Abnormal insulin receptor binding in cultured monocytes in myotonic muscular dystrophy

Even though one of the characteristic features of myotonic dystrophy (MyD) is the high level of circulating insulin, 125I-insulin-binding data in MyD have been controversial. In the present study we utilized cultured monocytes to avoid problems of reproducibility and variability in age, and examined the affinity and binding characteristics of 125I-insulin binding in MyD patients and controls. The Bmax and mean affinity constant, Ka, were significantly lower, while the number of receptors per cell had increased in the patient group as compared to the controls. The data confirm our earlier findings that there is no primary defect in insulin receptors in MyD, and the disturbed insulin response may be due to an abnormality in the membrane environment. Since the insulin receptor is an integral membrane protein, abnormal plasma membrane lipid composition may lead to impaired lipid-protein interactions, and hence affect the binding characteristics in MyD.

Balloon valvuloplasty versus closed commissurotomy for pliable mitral stenosis: a prospective hemodynamic study

Closed surgical mitral valvotomy is the procedure of choice in most patients with symptomatic pliable mitral stenosis in developing countries. The procedure is efficacious and safe. Mitral valvotomy performed with a balloon has shown similar good results, with infrequent complications in selected subjects. Because there is a paucity of studies comparing the two techniques, this study was undertaken to compare the results of percutaneous balloon mitral valvuloplasty with those of closed commissurotomy as determined by catheterization studies. Forty-five patients with tight pliable mitral stenosis were randomly assigned to one of two groups: 23 patients had balloon valvuloplasty by the single catheter technique (group I) and 22 underwent closed surgical valvotomy (group II). The two groups were similar with regard to clinical and hemodynamic findings before intervention. Mitral valve area increased from 0.8 +/- 0.3 to 2.1 +/- 0.7 cm2 in group I (p less than 0.001) and from 0.7 +/- 0.2 to 1.3 +/- 0.3 cm2 in group II (p less than 0.001). Pulmonary artery pressure and pulmonary vascular resistance decreased in both groups, but these changes did not reach statistical significance in group II. Treadmill exercise time increased from 3.8 +/- 2.3 to 7.3 +/- 2.6 min in group I (p less than 0.001) and from 4 +/- 2.6 to 5.6 +/- 2.6 min in group II (p less than 0.001). There were no deaths. One patient in each group developed moderate (3+) mitral regurgitation. A small interatrial shunt (less than 1.5:1) was detected in three patients in group I immediately after the procedure.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulmonary hypertension in aortic regurgitation: early surgical outcome

A review of the haemodynamic data of 139 patients with isolated, severe, chronic aortic regurgitation revealed severe pulmonary hypertension (pulmonary artery systolic pressure of greater than or equal to 60 mmHg) in 34 (24 per cent). The left ventricular end-diastolic pressure was high in all patients, suggesting that pulmonary hypertension was a consequence of severe long-standing regurgitation with ventricular dysfunction. Aortic valve replacement was performed in 69 patients, 33 of whom had normal or mildly elevated pulmonary artery systolic pressure (less than 39 mmHg; group I) and 36 of whom had moderate or markedly elevated pulmonary artery systolic pressures (less than 40 mmHg; group II). There was no difference in mortality or prevalence of post-operative complications between these two groups of patients. Furthermore, New York Heart Association (NYHA) functional class and cardiothoracic ratio were similar in both groups at the six-month assessment. The pulmonary vascular resistance fell from 4.7 +/- 3.5 to 1.5 +/- 0.8 units x m2 in 13 of 17 patients who had repeat catheterization after surgery. Pulmonary artery systolic pressure reverted to normal in 10 of these 13 patients. It is concluded that pulmonary hypertension consequent upon raised left ventricular end-diastolic pressure is common in severe aortic regurgitation, is largely reversible, and does not influence the early outcome after aortic valve replacement.

Arrhythmias in idiopathic dilated cardiomyopathy. A preliminary study

Idiopathic dilated cardiomyopathy is second to valvular heart disease as a cause of congestive heart failure in blacks in southern Africa. The disease has a deteriorating clinical course with high mortality. More than half these deaths are sudden and have been related to arrhythmias. In a preliminary study of 20 black patients in congestive heart failure caused by dilated cardiomyopathy, 24-hour ambulatory ECG monitoring was used to assess the prevalence, type and clinical significance of arrhythmias. Eighteen of the 20 patients (90%) had arrhythmias. Supraventricular arrhythmias were detected in 17 (85% of the total), and 18 (90%) had complex ventricular arrhythmias. Eleven (55%) had non-sustained ventricular tachycardia (VT). There was no correlation between complex ventricular arrhythmia and clinical features, resting ECG, chest radiograph or echocardiographic data. Over a 3-year period 13 patients died (65%), half these deaths being unexpected. All 13 had complex ventricular arrhythmias, and those who died suddenly had non-sustained VT. This small prospective study shows that ventricular arrhythmias are common in dilated cardiomyopathy in blacks and are frequently complex and dangerous. Sudden death is common and is more than likely to be related to VT in the presence of an already poorly functioning left ventricle.

High-dose oral amoxycillin in the treatment of infective endocarditis

Oral antibiotic therapy for infective endocarditis is not yet widely accepted. A study was undertaken to assess the efficacy of oral amoxycillin in this condition. Fifteen patients were treated with high-dose oral amoxycillin for 6 weeks. Twelve responded to treatment and remain well at 3 years. There were 3 deaths--1 at day 7 due to sudden aortic cusp rupture, and 2 late deaths due to pulmonary and cerebral embolism respectively. There was 1 relapse of streptococcal prosthetic valve endocarditis 8 weeks after oral treatment, but this responded to conventional intravenous therapy. Oral amoxycillin is effective in uncomplicated streptococcal endocarditis, and should not be used with prosthetic valve infections.

Arrhythmia in hypertrophic cardiomyopathy: exercise and 48 hour ambulatory electrocardiographic assessment with and without beta adrenergic blocking therapy

Submaximal treadmill exercise electrocardiography and 48 hour ambulatory electrocardiographic monitoring were performed in 30 patients with hypertrophic cardiomyopathy both with and without beta adrenergic blocking therapy. During ambulatory electrocardiographic monitoring 1 patient (3 percent) had no arrhythmia, 14 patients (46 percent) had supraventricular tachycardia or paroxysmal atrial fibrillation, 13 (43 percent) had multiform or paired ventricular extrasystoles and 8 (26 percent) had ventricular tachycardia. The frequency of these ventricular arrhythmias was almost identical with and without beta adrenergic blocking drugs (mean dose in "propranolol equivalents" 280 mg daily). With beta blocking therapy fewer patients had supraventricular tachycardia; however, the difference was not significant. During exercise testing 18 patients (60 percent) had ventricular extrasystoles and 3 patients (10 percent) had paired ventricular extrasystoles and the frequency was almost identical with and without beta adrenergic blocking therapy. No routine echocardiographic or hemodynamic measurement predicted the serious ventricular arrhythmias. It is concluded that asymptomatic ventricular arrhythmia is a common occurrence in patients with hypertrophic cardiomyopathy and its frequency is not reduced with beta adrenergic blocking therapy. Because occult arrhythmia may be the cause of sudden death it is important to detect it in these patients so that an effort can be made to improve prognosis with specific antiarrhythmic treatment.

Bilateral renal cortical necrosis: a report of 2 cases

Two cases of renal cortical necrosis, one of which occurred after an obstetric complication (abruptio placentae) and the other after postpartum haemorrhage, are described. The diagnosis was made by percutaneous renal biopsy, intravenous pyelography and selective nephro-angiography. Immunofluorescence studies of the kidney showed no abnormality in one patient, but showed the presence of IgM in the glomerular basement membrane in the second patient. Hypotension was not observed when anuria occurred. Both patients survived. The importance of prolonged haemodialysis is stressed, since one patient was oliguric for 57 days and required intermittent haemodialysis for 5 months, while the second patient was oliguric for 17 days, required haemodialysis for 5 months and now has established hypertension.