Browsing by Author "Calligaro, Gregory"

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    Development of a simple reliable radiographic scoring system to aid the diagnosis of pulmonary tuberculosis
    (Public Library of Science, 2013) Pinto, Lancelot M; Dheda, Keertan; Theron, Grant; Allwood, Brian; Calligaro, Gregory; van Zyl-Smit, Richard; Peter, Jonathan; Schwartzman, Kevin; Menzies, Dick; Bateman, Eric; Pai, Madhukar; Dawson, Rodney
    Rationale: Chest radiography is sometimes the only method available for investigating patients with possible pulmonary tuberculosis (PTB) with negative sputum smears. However, interpretation of chest radiographs in this context lacks specificity for PTB, is subjective and is neither standardized nor reproducible. Efforts to improve the interpretation of chest radiography are warranted. Objectives To develop a scoring system to aid the diagnosis of PTB, using features recorded with the Chest Radiograph Reading and Recording System (CRRS). METHODS: Chest radiographs of outpatients with possible PTB, recruited over 3 years at clinics in South Africa were read by two independent readers using the CRRS method. Multivariate analysis was used to identify features significantly associated with culture-positive PTB. These were weighted and used to generate a score. RESULTS: 473 patients were included in the analysis. Large upper lobe opacities, cavities, unilateral pleural effusion and adenopathy were significantly associated with PTB, had high inter-reader reliability, and received 2, 2, 1 and 2 points, respectively in the final score. Using a cut-off of 2, scores below this threshold had a high negative predictive value (91.5%, 95%CI 87.1,94.7), but low positive predictive value (49.4%, 95%CI 42.9,55.9). Among the 382 TB suspects with negative sputum smears, 229 patients had scores <2; the score correctly ruled out active PTB in 214 of these patients (NPV 93.4%; 95%CI 89.4,96.3). The score had a suboptimal negative predictive value in HIV-infected patients (NPV 86.4, 95% CI 75,94). CONCLUSIONS: The proposed scoring system is simple, and reliably ruled out active PTB in smear-negative HIV-uninfected patients, thus potentially reducing the need for further tests in high burden settings. Validation studies are now required.
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    High flow nasal oxygen in resource constrained, non-intensive care high care wards for COVID-19 acute hypoxaemic respiratory failure: comparing outcomes of first versus third waves
    (2024) Audley, Gordon George; Calligaro, Gregory
    Background: High flow nasal oxygen (HFNO) is an accepted treatment for severe COVID-19 related acute hypoxaemic respiratory failure (AHRF) especially where limited access to intensive care unit (ICU) resources exists, and approximately halves the need for invasive mechanical ventilation. Objectives: To determine if treatment outcomes would be better in the third COVID wave (irrespective of differences in variant virulence; ancestral vs delta) due to increased institutional experience and capacity for HNFO and more restrictive admission criteria for respiratory high care wards and ICU dictated by the higher case load in the third wave. Methods: We included consecutive patients with COVID-19-related AHRF treated with HFNO during the first (7 May to 25 August 2020) and third COVID waves (4 July to 4 September 2021) at Groote Schuur Hospital. The primary endpoint was comparison of HFNO failure between the first and third waves of the COVID-19 pandemic. Findings: A total of 744 patients were included: 343 in the first, and 401 in the third COVIDwave. Patients treated with HFNO in the first wave had an older median (IQR) age (53 (46-61) vs 47 (40-56) years, p<0.001), and a higher prevalence of diabetes (46.9 vs. 36.9%, p=0.006), hypertension (51.0% vs 35.2%, p<0.001), obesity (33.5% vs 26.2%, p=0.029) and HIV infection (12.5% vs 5.5%, p<0.001). Median (IQR) arterial oxygen partial pressure to fraction inspired oxygen ratio (PaO2/FiO2) at HFNO initiation and the ratio of oxygen saturation/FiO2 to respiratory rate within 6 hours (ROX-6 score) after HFNO commencement were lower in the first wave compared with the third: 57.9 (47.3-74.3) vs 64.3 (51.2-79.0), p=0.005 and 3.19 (2.37-3.77) vs 3.43 (2.93-4.00), p<0.001, respectively. Despite these differences in comorbidities and baseline measures of oxygenation, the likelihood of HFNO failure (57.1% versus 59.6.1%, p=0.498) and mortality (52.1% vs 46.9%, p=0.159) did not differ between first and third waves the first and third COVID waves. Conclusion: Despite differences in overall case load, baseline patient characteristics, virulence of the circulating wave variant and institutional experience with HFNO, treatment outcomes were very similar in the first and third COVID waves. We conclude that once severe respiratory failure is established in COVID pneumonia, comorbidities and HFNO provider experience make little difference to outcome.
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    High flow nasal oxygen versus mechanical ventilation as initial respirator support in severe COVID-19 ARDS at Groote Schuur Hospital : a propensity score analysis
    (2024) Van Den Berg, Robert William; Calligaro, Gregory
    OBJECTIVE: The Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) pandemic placed an unprecendented burden on global health care resources, and on intensive care unit (ICU) resources in particular. Due to ICU resource limitations, high flow nasal oxygen (HFNO), a novel ventilation strategy, was implemented as an alternative to mechanical ventilation (MV) at Groote Schuur Hospital in Cape Town, South Africa, during the first COVID wave. Patient received MV if HFNO failed. The purpose of this study was to compare outcomes of this “HFNO first” strategy to a “MV first” strategy. METHODS: This was a secondary analysis of two propsective cohort studies conducted during the COVID first wave at Groote Schuur Hospital. Propensity score matching was used to compare outcomes between HFNO as initial ventilation strategy and MV as first-line therapy. Eligible patients were adults (> 18 years) with severe respiratory failure and confirmed COVID-19 pneumonia. The primary endpoint was survival to hospital discharge and secondary analysis assessed duration of respiratory support. RESULTS: After propensity score matching, 110 patients (55 in each group) were included in the final analysis. Survival to hospital discharge was significantly higher in patients treated with HFNO first compared to MV first; 31/55 (56%) versus 17/55 (31%), p=0.007. After adjustment for other covariates, the “HFNO first” group had a 71% increased chance of survival to hospital discharge when compared to the “MV first” group; OR=0.28, 95% CI [0.13 – 0.63], p=0.0018. There was a non-significant trend in patients treated with HFNO group requiring less time on respiratory support (p= 0.06). CONCLUSION: This study supports the evidence for the use of HFNO as an initial ventilation strategy for patients with COVID-19-related acute respiratory distress syndrome (ARDS). Survival rates in the “HFNO first” cohort were significantly higher, even in those that subsequently required ventilation, compared to the “MV first” strategy. This study adds important evidence to the debate on the potential benefits and harms of HFNO as well as highlighting its advantages in a resource-constrained setting. The efficacy and implementation of HFNO as an initial ventilation strategy require further investigation. The “HFNO first” strategy employed at Groote Schuur Hospital in the first wave of the COVID-19 pandemic demonstrated a markedly higher survival rates. This suggests that HFNO is highly effective as an initial ventilation strategy in COVID-19 ARDS in a resource-limited setting
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    Pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension in Cape Town, South Africa
    (2023) Davies-Van, Es Sophie; Calligaro, Gregory; Symons Gregory
    Introduction: Pulmonary endarterectomy (PEA) is the only definitive and potentially curative therapy for chronic thromboembolic pulmonary hypertension (CTEPH), associated with impressive improvements in symptoms and haemodynamics. However, it is only offered at a few centres in South Africa. The characteristics and outcomes of patients undergoing PEA in Cape Town have not been previously reported. Methods and objectives: We interrogated the Adult Cardiothoracic Surgery database at the University of Cape Town (UCT) between December 2005 and April 2021 for patients undergoing PEA at Groote Schuur Hospital and Netcare UCT Private Academic Hospital. The primary outcome was the difference in World Health Organisation (WHO) functional class (WHO-FC) before and at least 6 weeks after surgery. Results: A total of 32 patients underwent PEA: 8 patients were excluded from the final analysis due to incomplete data or a histological diagnosis other than CTEPH. The workup of these patients for surgery was variable: all had CT pulmonary angiograms, 7 (29%) had ventilation: perfusion scans, 5 (21%) underwent right heart catheterisation, and none had pulmonary angiograms. The perioperative mortality was 4/24 (17%): 1 patient (4%) had a cardiac arrest on induction of anaesthesia, 2 patients (8%) died of postoperative pulmonary haemorrhage, and 1 patient (4%) died of septic complications in the intensive care unit. In survivors, the median (IQR) improvement in WHO-FC was 2 classes (1-3, p=0.0004); 10/16 patients (63%) returned to a normal baseline (WHO-FC I).
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    Pulmonary endarterectomy for chronic thromboembolic pulmonary hypertension in Cape Town, South Africa
    (2023) Davies-Van, Es Sophie; Calligaro, Gregory; Symons Gregory
    Introduction: Pulmonary endarterectomy (PEA) is the only definitive and potentially curative therapy for chronic thromboembolic pulmonary hypertension (CTEPH), associated with impressive improvements in symptoms and haemodynamics. However, it is only offered at a few centres in South Africa. The characteristics and outcomes of patients undergoing PEA in Cape Town have not been previously reported. Methods and objectives: We interrogated the Adult Cardiothoracic Surgery database at the University of Cape Town (UCT) between December 2005 and April 2021 for patients undergoing PEA at Groote Schuur Hospital and Netcare UCT Private Academic Hospital. The primary outcome was the difference in World Health Organisation (WHO) functional class (WHO-FC) before and at least 6 weeks after surgery. Results: A total of 32 patients underwent PEA: 8 patients were excluded from the final analysis due to incomplete data or a histological diagnosis other than CTEPH. The workup of these patients for surgery was variable: all had CT pulmonary angiograms, 7 (29%) had ventilation: perfusion scans, 5 (21%) underwent right heart catheterisation, and none had pulmonary angiograms. The perioperative mortality was 4/24 (17%): 1 patient (4%) had a cardiac arrest on induction of anaesthesia, 2 patients (8%) died of postoperative pulmonary haemorrhage, and 1 patient (4%) died of septic complications in the intensive care unit. In survivors, the median (IQR) improvement in WHO-FC was 2 classes (1-3, p=0.0004); 10/16 patients (63%) returned to a normal baseline (WHO-FC I). Conclusion: PEA – even in a low volume centre – is associated with significant improvements in WHO-FC and a return to normal baseline in survivors. Abstract word count: 255 KEYWORDS Chronic thromboembolic pulmonary hypertension (CTEPH), pulmonary endarterectomy (PEA), pulmonary emboli (PE), pulmonary hypertension (PH).