The spectrum, management and outcome of cellulitis in subtropical South Africa.

BACKGROUND: This study aimed to ascertain the microbiology, severity stratification, and clinical outcomes of cellulitis based on our current management for comparison with international reports. METHODS: A retrospective chart review was conducted of all patients with cellulitis treated by the department of surgery at Ngwelezana Hospital over an 18-month period. Severity of cellulitis was graded, and a comparison was made of the Eron and Modified Dundee classifications. Superficial swabs were taken for culture on patients who had cellulitis with open wounds or blisters. Culture results, antibiotics used, need for surgical intervention, and length of hospital stay were documented and analysed. RESULTS: One hundred and thirty-four patients had cellulitis. Severity grading for classes I-IV in the Eron classification was 3%, 57%, 39% and 1%, respectively, and for the Modified Dundee classification, 47%, 11%, 38%, and 4%, respectively. Co-amoxiclav was the most used antibiotic (73%). Superficial skin swabs were taken from 49 patients and 34 cultured 44 specific organisms. The most common organism identified was Staphylococcus aureus (30%). Several gram-negative and anaerobic organisms were cultured. Fifty-three patients required surgical debridement of the infected area and one patient required an above-knee amputation. Mean hospital stay for patients who did not receive surgical intervention was 6 days (IQR 3) and 7 days (IQR 4) for those who did. There were no deaths. CONCLUSION: The Dundee classification triages fewer patients as class 2 severity than the Eron system and its use has the potentail to reduce the number of patients hospitalised. Gram-positive organisms predominated in those cultured, but gram-negative cultures were frequent compared to other reported series. Co-amoxiclav is effective as first-line antimicrobial therapy in our environment.

Penetrating colon trauma - outcomes related to single versus multiple colonic injuries.

INTRODUCTION: There is no conclusive evidence to guide surgical management in the presence of multiple colonic injuries as opposed to a single colonic injury, and whether multiple colonic suture lines are associated with worse outcomes than single suture lines. AIM: We reviewed the outcomes of penetrating colonic trauma in relation to whether patients had single versus multiple colonic suture lines (primary repair or anastomosis) following laparotomy. METHODS: A retrospective study was conducted at a major trauma centre in South Africa from 2012-2020 for all patients over 18 years who had sustained penetrating colon injury. RESULTS: 541 cases were included: 409 with single suture line and 54 with multiple suture lines. There were no differences between groups in terms of mechanism of injury (gunshot vs stab; p = 0.328), Injury Severity Score (p = 0.071), or Penetrating Abdominal Trauma Index (p = 0.396). Admission lactate was worse for multiple suture line patients (p = 0.049), but no other blood gas parameters were different, and there was no higher incidence of damage control surgery (p = 0.558) or ICU admission (p = 0.156) for this group. There was a higher rate of diversion in the multiple suture line group (p < 0.001). Univariable logistic regression did not show an increased risk of gastro-intestinal complications, suture line leak rate, or mortality for multiple suture lines compared to single. CONCLUSION: It appears that there is no appreciable difference in outcome between patients with a single colonic suture line compared to patients with more than one suture line following trauma laparotomy. In light of this, each injury should be treated on its own merit, in the context of the patient's overall physiological condition, without undue fear of leaving the patient with more than one colonic suture line. However, judicious use of diversion remains advisable.

Penetrating colon trauma-the effect of concomitant small bowel injury on outcome.

INTRODUCTION: There is limited evidence to suggest that patients with penetrating colon injury have higher complication rates when there is concomitant small bowel (SB) injury. AIM: We performed a retrospective study looking at outcomes of penetrating colonic trauma in patients with- and without concomitant SB injury. METHODS: We interrogated our electronic registry over an eight-year period (2012-2020) for all patients over 18 years who had sustained penetrating colon injury and who had survived beyond 72 h. Demographic data, admission physiology, and Injury Severity Score (ISS) were recorded. Two groups of patients were observed: those with colonic injury (no SB injury) and those with combined colon and SB injury. Outcomes observed included leak rates, length of Intensive Care Unit (ICU) stay, length of hospital stay (LOS), morbidity and mortality. RESULTS: A total of 450 patients were eligible for analysis, of which 257 had colon injury without SB injury and 193 had a combination of colon and SB injury. There was no difference in mechanism of injury between groups. Admission physiology was similar between groups but arterial blood gas values were worse in the combined group. Rates of damage control surgery and ICU admission were higher in the combined group. Primary repair was done in equal proportions between groups but anastomosis was more frequently performed in the combined group. There was no difference in complication rates, including gastro-intestinal complications and suture line leaks. Length of ICU stay, LOS, and mortality were similar between groups. Univariable analysis demonstrated that the presence of concomitant small bowel injury was not an independent risk factor for colonic suture line failure or death. CONCLUSION: There is no evidence from this data that the presence of a combined penetrating colon and SB injury should change management priorities. Each injury should be treated on its own merit, in the context of the patient's physiology.

Penetrating Colon Trauma-the Effect of Injury Location on Outcomes.

BACKGROUND: There is limited evidence to suggest that the more distal a penetrating colonic injury, the poorer its expected outcome, prompting consideration of diversion rather than anastomosis when faced with left colonic injury. The clinical outcomes of penetrating colonic trauma in relation to their anatomical location within the colon were reviewed. METHODS: A review was performed over eight years (2012-2020) of all patients over 18 years who had sustained penetrating colon injury and presented to our trauma centre in South Africa. Direct comparison was made between right colon vs left colon injuries. RESULTS: A total of 450 patients were included; right colon: 260, left colon: 190. Gunshots predominated in the right colon, and the PATI was higher in this group. There were minimal differences in admission physiology and blood gas parameters between groups, but higher damage control surgery and ICU admission rates for the right colon group. There were similar rates of primary repair, anastomosis, and stoma between groups. Leak rates were no different between the two groups, and although overall complication rates were higher for the right colon, there was no difference with regard to gastro-intestinal and other complications, nor for mortality. While regression analysis did identify PATI to be a risk factor for overall complications and mortality, it failed to do so for anastomotic leak. CONCLUSION: Our study did not demonstrate any difference in anastomotic leak rates or mortality between right vs left colonic injury. We recommend that all colonic injuries should be treated on their own merit, balanced against the patient's condition, regardless of anatomical location within the colon.

Refeeding syndrome in surgical patients post initiation of artificial feeding, a prospective cohort study in a low-income country.

BACKGROUND & AIMS: South Africa's inequitable history has contributed to a malnourished population, further aggravated by high levels of violence and economic uncertainty culminating in a population suffering the sequelae of poverty. The perceived notion is that malnutrition places the South African population at greater risk for development of refeeding syndrome. This study aimed to identify the incidence of refeeding syndrome in the South African population. METHODS: All patients admitted into the surgical intensive care unit from 1 November 2019 to 30 September 2020, were screened using the National Institute for Health and Care Excellence (NICE) refeeding risk criteria. Patients started on artificial feeds with one or more risk factors were included in the study. The syndrome was confirmed using the King's College criteria and compared with the American Society for Parenteral and Enteral Nutrition (ASPEN) criteria for refeeding syndrome. RESULTS: 200 Patients were included in this study. The median age of the sample population was 41 years (IQR 30-58) with a male predominance (63%). All patients included had one or more risk factors and 62 (31%) of patients fulfilled the NICE criteria. The sensitivity of the NICE criteria was 33% and specificity was 70%. The most common risk factors identified were little or no nutritional intake for >5 days (55%) followed by a history of alcohol abuse, drugs including insulin, chemotherapy, diuretics or antacids (18%). Specificity values for all risk factors were >80% apart from little or no nutritional intake for >5 days which had a specificity of 64.2%. Sensitivity values for all risk factors were low. 84.5% of patients received artificial nutritional support in the form of enteral feeds, 9% parenteral and 6.5% both enteral and parenteral feeds. A total of 146 patients required electrolyte supplementation. Three patients fulfilled the King's College criteria and one subsequently died. In comparison, 25 patients fulfilled the ASPEN criteria and 3 demised. CONCLUSION: Due to the low sensitivity and specificity of the NICE criteria, we advise that it be used merely as a guideline to identify patients at risk of refeeding syndrome and one should remain vigilant in patients with any risk factors present. Due to the small number of patients who fulfilled the King's College criteria and significant difference in incidence when compared to the ASPEN definition, a conclusion regarding the accuracy of both diagnostic criteria could not be made. We recommend a review of the current definition and a global adoption of an agreed criteria for the estimation of the true prevalence.

An analysis of paediatric snakebites in north-eastern South Africa.

BACKGROUND: Snakebites are an underappreciated health concern in middle- and lower-income countries. The lack of national data vastly impacts funding for this health crisis, as well as strategies for treatment and prevention. Children are particularly vulnerable to snakebite and data in this group is limited. METHODS: This study included paediatric patients, aged 13 years old or younger, admitted to Ngwelezana Tertiary Hospital, Department of Surgery with a snakebite or snakebite related complication, from 1 September 2008 to 31 December 2013. Data captured included demographics, time of presentation, syndromic symptoms, blood results and patient management. RESULTS: A total of 274 patients were included in this study. The median age at presentation was 8 years, with approximately 70% of the patients aged between 6 and 13 years, with a male predominance (56%). The median time of presentation after sustaining a snakebite was 7 hours (interquartile range 4-13 hours). The majority of patients (71%) presented with cytotoxic manifestations. A total of 53 patients received antivenom of whom 25% suffered adverse reactions. Fifty-six patients underwent one or more procedures on their affected limbs. Three patients required admission to the intensive care unit; all were part of the cytotoxic group and received antivenom. There were no recorded mortalities. CONCLUSION: The majority of snakebites are cytotoxic in nature. One-fifth of the paediatric population require antivenom and one-fifth require a surgical procedure post envenomation. Adverse effects post antivenom use are common but manageable. Prevention programmes are needed to help reduce this burden of disease and a nationwide snakebite registry is long overdue.

Venous bicarbonate and creatine kinase as diagnostic and prognostic tools in the setting of acute traumatic rhabdomyolysis.

BACKGROUND: Myorenal or crush syndrome often develops following soft-tissue traumatic injury. It is a spectrum of disease that may result in severe renal dysfunction and kidney injury requiring renal replacement therapy. OBJECTIVES: To review a large cohort of patients with so-called myorenal or crush syndrome and assess the biochemical markers of venous bicarbonate and creatine kinase as predictors for the development of acute kidney injury (AKI). METHODS: All patients with myorenal syndrome who presented to Khayelitsha District Hospital, Cape Town, South Africa (SA), and Ngwelezana Hospital, Empangeni, KwaZulu-Natal, SA, between January and December 2017 were identified and reviewed. RESULTS: A total of 212 patients were included in the study. At both hospitals, 94% of the patients were male. Using the Pearson correlation coefficient, we compared creatinine kinase (CK) against serum creatinine. The mean CK level was 5 311.8 U/L and the mean creatinine level 133.457 µmol/L. The r-value was 0.2533. Although this is a technically positive correlation, the relationship between the variables is weak. Using the Pearson R Calculator, we inserted the r-value to calculate the p-value. The p-value was 0.000208. When comparing venous bicarbonate (HCO3) against creatinine, the mean HCO3 level was 22.296 mmol/L and the mean creatinine level 162.053 µmol/L. The r-value was -0.3468. Although this is a technically negative correlation, the relationship between the variables is weak. Using the Pearson R Calculator, we inserted the r-value to calculate the p-value. The p-value was 0.000013. The inverse ratio shown with HCO3 v. creatinine, although still a weak correlation, is significantly better in predicting an increase in creatinine compared with the weak positive correlation of CK v. creatinine. CONCLUSIONS: Although both venous HCO3 and CK showed a weak correlation with creatinine, the former performed significantly better in predicting AKI. In a resource-constrained system, we recommend that HCO3 be measured to assess patients with crush injury and that CK be regarded as a complementary modality.

Using fresh frozen plasma as an emergency treatment modality for hypertriglyceridaemic acute pancreatitis in a resource-constrained environment: A case report and review of literature.

Hypertriglyceridaemia is associated with severe disease such as coronary disease, cerebral vascular accidents and acute pancreatitis. Severe hypertriglyceridaemia is defined as a serum triglyceride value of >55 mmol/L. Hypertriglyceridaemic acute pancreatitis, often found in pregnancy, has a higher mortality rate than the other causes of acute pancreatitis. The cornerstone of treatment is to lower the triglyceride level as quickly as possible. In a resource-constrained environment, plasma exchange is not a viable option. Therefore, exploring the possible efficacity of directly infusing fresh frozen plasma is applicable to rural emergency medicine and may lead to more definitive research. In our case study, we used fresh frozen plasma to enhance the removal of triglyceride because it contains lipoprotein lipase.

Symptomatic hepatothorax presenting 25 years after penetrating thoracoabdominal injury.

Hepatic herniation through the diaphragm is a rare finding. It generally occurs due to a congenital diaphragmatic abnormality or blunt trauma resulting in a diaphragmatic defect. Making the diagnosis is difficult, as there are few definitive clinical signs and chest radiograph (CXR) findings may be non-specific. To our knowledge, only a single case report exists of penetrating right diaphragm injury leading to hepatic herniation. A 42-year-old man presented to the emergency department of a regional hospital with hyperglycaemia and exertional dyspnoea. He was diagnosed with diabetes mellitus type 2. He gave a history of smoking for 15 pack-years, was negative for retroviral disease and had no history of pulmonary tuberculosis. He had no significant surgical history but reported being stabbed with a knife in 1995. The point of entry was below the level of the nipple in the right anterior axillary line. At the time, he was treated with an intercostal drain and discharged home. CXR showed a right-sided chest mass. We considered a differential diagnosis of pulmonary consolidation, diaphragm eventration or hepatothorax. Computerized tomography of the chest and abdomen demonstrated apparent intrathoracic extension of the right liver lobe and partial attenuation of the superior vena cava and right atrium due to a mass effect. The upper border of the liver abutted the aortic arch. Surgical treatment options were discussed. The patient declined surgery and will be followed up as an outpatient.

Scatter correction for large non-human primate brain imaging using microPET.

The baboon is well suited to pre-clinical evaluation of novel radioligands for positron emission tomography (PET). We have previously demonstrated the feasibility of using a high resolution animal PET scanner for this application in the baboon brain. However, the non-homogenous distribution of tissue density within the head may give rise to photon scattering effects that reduce contrast and compromise quantitative accuracy. In this study, we investigated the magnitude and distribution of scatter contributing to the final reconstructed image and its variability throughout the baboon brain using phantoms and Monte Carlo simulated data. The scatter fraction is measured up to 36% at the centre of the brain for a wide energy window (350-650 keV) and 19% for a narrow (450-650 keV) window. We observed less than 3% variation in the scatter fraction throughout the brain and found that scattered events arising from radioactivity outside the field of view contribute less than 1% of measured coincidences. In a contrast phantom, scatter and attenuation correction improved contrast recovery compared with attenuation correction on its own and reduced bias to less than 10% at the expense of the reduced signal-to-noise ratio. We conclude that scatter correction is a necessary step for ensuring high quality measurements of the radiotracer distribution in the baboon brain with a microPET scanner, while it is not necessary to model out of field of view scatter or a spatially variant scatter function.

Attenuation correction for the large non-human primate brain imaging using microPET.

Assessment of the biodistribution and pharmacokinetics of radiopharmaceuticals in vivo is often performed on animal models of human disease prior to their use in humans. The baboon brain is physiologically and neuro-anatomically similar to the human brain and is therefore a suitable model for evaluating novel CNS radioligands. We previously demonstrated the feasibility of performing baboon brain imaging on a dedicated small animal PET scanner provided that the data are accurately corrected for degrading physical effects such as photon attenuation in the body. In this study, we investigated factors affecting the accuracy and reliability of alternative attenuation correction strategies when imaging the brain of a large non-human primate (papio hamadryas) using the microPET Focus 220 animal scanner. For measured attenuation correction, the best bias versus noise performance was achieved using a (57)Co transmission point source with a 4% energy window. The optimal energy window for a (68)Ge transmission source operating in singles acquisition mode was 20%, independent of the source strength, providing bias-noise performance almost as good as for (57)Co. For both transmission sources, doubling the acquisition time had minimal impact on the bias-noise trade-off for corrected emission images, despite observable improvements in reconstructed attenuation values. In a [(18)F]FDG brain scan of a female baboon, both measured attenuation correction strategies achieved good results and similar SNR, while segmented attenuation correction (based on uncorrected emission images) resulted in appreciable regional bias in deep grey matter structures and the skull. We conclude that measured attenuation correction using a single pass (57)Co (4% energy window) or (68)Ge (20% window) transmission scan achieves an excellent trade-off between bias and propagation of noise when imaging the large non-human primate brain with a microPET scanner.

High-resolution imaging of the large non-human primate brain using microPET: a feasibility study.

The neuroanatomy and physiology of the baboon brain closely resembles that of the human brain and is well suited for evaluating promising new radioligands in non-human primates by PET and SPECT prior to their use in humans. These studies are commonly performed on clinical scanners with 5 mm spatial resolution at best, resulting in sub-optimal images for quantitative analysis. This study assessed the feasibility of using a microPET animal scanner to image the brains of large non-human primates, i.e. papio hamadryas (baboon) at high resolution. Factors affecting image accuracy, including scatter, attenuation and spatial resolution, were measured under conditions approximating a baboon brain and using different reconstruction strategies. Scatter fraction measured 32% at the centre of a 10 cm diameter phantom. Scatter correction increased image contrast by up to 21% but reduced the signal-to-noise ratio. Volume resolution was superior and more uniform using maximum a posteriori (MAP) reconstructed images (3.2-3.6 mm(3) FWHM from centre to 4 cm offset) compared to both 3D ordered subsets expectation maximization (OSEM) (5.6-8.3 mm(3)) and 3D reprojection (3DRP) (5.9-9.1 mm(3)). A pilot (18)F-2-fluoro-2-deoxy-d-glucose ([(18)F]FDG) scan was performed on a healthy female adult baboon. The pilot study demonstrated the ability to adequately resolve cortical and sub-cortical grey matter structures in the baboon brain and improved contrast when images were corrected for attenuation and scatter and reconstructed by MAP. We conclude that high resolution imaging of the baboon brain with microPET is feasible with appropriate choices of reconstruction strategy and corrections for degrading physical effects. Further work to develop suitable correction algorithms for high-resolution large primate imaging is warranted.