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Lamb T, Abouyannis M, de Oliveira SS, Shenoy K. R, Geevar T, Zachariah A, Sharma SK, Bhatt N, Mukaka M, Harriss E, Lalloo DG, Ashley EA, Monteiro WM, Smithuis F, Eddleston M. The 20-minute whole blood clotting test (20WBCT) for snakebite coagulopathy-A systematic review and meta-analysis of diagnostic test accuracy. PLoS Negl Trop Dis 2021; 15:e0009657. [PMID: 34375338 PMCID: PMC8405032 DOI: 10.1371/journal.pntd.0009657] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 08/30/2021] [Accepted: 07/16/2021] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND The 20-minute whole blood clotting test (20WBCT) has been used to detect coagulopathy following snakebite for almost 50 years. A systematic review and meta-analysis of the 20WBCT was conducted to evaluate the accuracy of the 20WBCT to detect coagulopathy, indicative of systemic envenoming. METHODS AND FINDINGS Databases were searched from inception up to 09/12/2020 to identify studies that compared the 20WBCT and INR/fibrinogen on five or more subjects. Data was extracted from full-text articles by two reviewers using a predetermined form. Authors of 29 studies that lacked sufficient details in the manuscript were contacted and included if data meeting the inclusion criteria were provided. Included studies were evaluated for bias using a tailored QUADAS-2 checklist. The study protocol was prospectively registered on PROSPERO database (CRD42020168953). The searches identified 3,599 studies, 15 met the inclusion criteria and 12 were included in the meta-analysis. Data was reported from 6 countries and included a total of 2,270 patients. The aggregate weighted sensitivity of the 20WBCT at detecting INR >1.4 was 0.84 (CI 0.61 to 0.94), the specificity was 0.91 (0.76 to 0.97) and the SROC AUC was 0.94 (CI 0.91 to 0.96). The aggregate weighted sensitivity of the 20WBCT at detecting fibrinogen <100 mg/dL was 0.72 (CI 0.58 to 0.83), the specificity was 0.94 (CI 0.88 to 0.98) and the SROC AUC was 0.93 (0.91 to 0.95). Both analyses that used INR and fibrinogen as the reference test displayed considerable heterogeneity. CONCLUSIONS In the absence of laboratory clotting assays, the 20WBCT remains a highly specific and fairly sensitive bedside test at detecting coagulopathy following snakebite. However, clinicians should be aware of the importance of operator training, standardized equipment and the lower sensitivity of the 20WBCT at detecting mild coagulopathy and resolution of coagulopathy following antivenom.
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Affiliation(s)
- Thomas Lamb
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar
- Centre of Tropical Medicine and Global Health Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Michael Abouyannis
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
- KEMRI–Wellcome Research Programme, Kilifi, Kenya
| | - Sâmella Silva de Oliveira
- Dr. Heitor Viera Dourado Tropical Medicine Foundation, Carlos Borborema Clinical Research Unit Manaus, Manaus, Brazil
- College of Health Sciences, University of the State of Amazonas, Manaus, Brazil
| | | | | | | | | | | | - Mavuto Mukaka
- Centre of Tropical Medicine and Global Health Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Faculty of Tropical Medicine, Mahidol-Oxford Tropical Medicine Research Unit, Mahidol University, Bangkok, Thailand
| | - Eli Harriss
- Bodleian Health Care Libraries, University of Oxford, Oxford, United Kingdom
| | - David G. Lalloo
- Centre for Snakebite Research and Interventions, Liverpool School of Tropical Medicine, Liverpool, United Kingdom
| | - Elizabeth A. Ashley
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar
- Centre of Tropical Medicine and Global Health Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
- Lao-Oxford-Mahosot Hospital-Wellcome Trust Research Unit, Vientiane, Lao People’s Democratic Republic
| | - Wuelton Marcelo Monteiro
- Dr. Heitor Viera Dourado Tropical Medicine Foundation, Carlos Borborema Clinical Research Unit Manaus, Manaus, Brazil
- College of Health Sciences, University of the State of Amazonas, Manaus, Brazil
| | - Frank Smithuis
- Myanmar Oxford Clinical Research Unit, Yangon, Myanmar
- Centre of Tropical Medicine and Global Health Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Michael Eddleston
- Pharmacology, Toxicology & Therapeutics, University/BHF Centre for Cardiovascular Science University of Edinburgh, Edinburgh, United Kingdom
- South Asian Clinical Toxicology Research Collaboration Dept of Clinical Medicine, University of Peradeniya, Peradeniya, Sri Lanka
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Thanasut A, Silkosessak O, Subbalekha K. Platelet-rich fibrin did not affect autologous bone graft in repairing alveolar clefts. JOURNAL OF ORAL AND MAXILLOFACIAL SURGERY, MEDICINE, AND PATHOLOGY 2021. [DOI: 10.1016/j.ajoms.2021.01.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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Costa TND, Silva AMD, Souza RMD, Monteiro WM, Bernarde PS. Efficacy of the 20-minute whole blood clotting test (WBCT20) in the diagnosis of coagulation alteration related to snakebites in a Western Brazilian Amazon hospital. Rev Soc Bras Med Trop 2021; 54:e00912021. [PMID: 34105627 PMCID: PMC8186896 DOI: 10.1590/0037-8682-0091-2021] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 04/30/2021] [Indexed: 11/24/2022] Open
Abstract
Introduction: The efficacy of 20-minute whole blood clotting (WBCT20) and the Lee-White clotting time (LWCT) tests in diagnosing coagulation alterations from snakebites were compared. Methods: We evaluated 89 snakebite cases treated at the Hospital Regional do Juruá em Cruzeiro do Sul, Acre, Brazil. Results: WBCT20 results were normal in 33.7% and unclottable in 66.3% of cases, while LWCT results were normal in 23.6% and altered (prolonged or unclottable) in 76.4% of cases, with no significant differences. Conclusions: The WBCT20 is important for rapidly diagnosing coagulation alterations from snakebites. Furthermore, it is efficient, inexpensive, and can be deployed in isolated hospitals.
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Affiliation(s)
- Tamires Nascimento da Costa
- Universidade Federal do Acre, Campus Floresta, Laboratório de Herpetologia, Cruzeiro do Sul, AC, Brasil.,Universidade Federal do Acre, Programa de Pós-Graduação Stricto Sensu em Ciências da Saúde na Amazônia Ocidental, Rio Branco, AC, Brasil
| | - Ageane Mota da Silva
- Instituto Federal do Acre, Campus de Cruzeiro do Sul, Cruzeiro do Sul, Acre, Brasil
| | - Rodrigo Medeiros de Souza
- Universidade Federal do Acre, Campus Floresta, Laboratório de Microbiologia, Imunologia e Parasitologia, Cruzeiro do Sul, AC, Brasil
| | - Wuelton Marcelo Monteiro
- Universidade do Estado do Amazonas, Manaus, AM, Brasil.,Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, AM, Brasil
| | - Paulo Sérgio Bernarde
- Universidade Federal do Acre, Campus Floresta, Laboratório de Herpetologia, Cruzeiro do Sul, AC, Brasil.,Universidade Federal do Acre, Programa de Pós-Graduação Stricto Sensu em Ciências da Saúde na Amazônia Ocidental, Rio Branco, AC, Brasil
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Williams HF, Layfield HJ, Vallance T, Patel K, Bicknell AB, Trim SA, Vaiyapuri S. The Urgent Need to Develop Novel Strategies for the Diagnosis and Treatment of Snakebites. Toxins (Basel) 2019; 11:E363. [PMID: 31226842 PMCID: PMC6628419 DOI: 10.3390/toxins11060363] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 06/18/2019] [Accepted: 06/18/2019] [Indexed: 01/09/2023] Open
Abstract
Snakebite envenoming (SBE) is a priority neglected tropical disease, which kills in excess of 100,000 people per year. Additionally, many millions of survivors also suffer through disabilities and long-term health consequences. The only treatment for SBE, antivenom, has a number of major associated problems, not least, adverse reactions and limited availability. This emphasises the necessity for urgent improvements to the management of this disease. Administration of antivenom is too frequently based on symptomatology, which results in wasting crucial time. The majority of SBE-affected regions rely on broad-spectrum polyvalent antivenoms that have a low content of case-specific efficacious immunoglobulins. Research into small molecular therapeutics such as varespladib/methyl-varespladib (PLA2 inhibitors) and batimastat/marimastat (metalloprotease inhibitors) suggest that such adjunctive treatments could be hugely beneficial to victims. Progress into toxin-specific monoclonal antibodies as well as alternative binding scaffolds such as aptamers hold much promise for future treatment strategies. SBE is not implicit during snakebite, due to venom metering. Thus, the delay between bite and symptom presentation is critical and when symptoms appear it may often already be too late to effectively treat SBE. The development of reliable diagnostical tools could therefore initiate a paradigm shift in the treatment of SBE. While the complete eradication of SBE is an impossibility, mitigation is in the pipeline, with new treatments and diagnostics rapidly emerging. Here we critically review the urgent necessity for the development of diagnostic tools and improved therapeutics to mitigate the deaths and disabilities caused by SBE.
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Affiliation(s)
| | | | - Thomas Vallance
- School of Pharmacy, University of Reading, Reading RG6 6AH, UK.
| | - Ketan Patel
- School of Biological Sciences, University of Reading, Reading RG6 6AH, UK.
| | - Andrew B Bicknell
- School of Biological Sciences, University of Reading, Reading RG6 6AH, UK.
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Benjamin JM, Chippaux JP, Sambo BT, Massougbodji A. Delayed double reading of whole blood clotting test (WBCT) results at 20 and 30 minutes enhances diagnosis and treatment of viper envenomation. J Venom Anim Toxins Incl Trop Dis 2018; 24:14. [PMID: 29796013 PMCID: PMC5956810 DOI: 10.1186/s40409-018-0151-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 04/27/2018] [Indexed: 12/28/2022] Open
Abstract
Background The whole blood clotting test (WBCT) is a simple test of coagulation that is often used in the assessment, diagnosis, and therapeutic monitoring of snakebite patients in sub-Saharan Africa. WBCT requires only a clean glass tube and several milliliters of venous blood and is ideal for use in poorly equipped health centers throughout the rural areas where 95% of snakebites occur. However, questions surrounding the accuracy and reliability of the test remain unanswered due to variations in testing conditions and a lack of comparative research with which to validate them. This is the first study to evaluate WBCT results at both 20-min (WBCT20) and 30-min (WBCT30) reading times in the same group of snakebite patients. Methods In order to define the best reading time, the authors compared the results of serial WBCT evaluation at both 20 and 30 min after collection in 23 patients treated for snake envenomation in Bembèrèkè, northern Benin. Results WBCT results were identical at both reading times in patients without coagulopathy or when coagulation was restored permanently following a single dose of antivenom. Out of 17 patients with coagulopathy, 14 showed discrepancies between WBCT20 and WBCT30 results in at least one pair of serial evaluations. These could be completely contradictory results (e.g. normal clot at WBCT20 and no clot at WBCT30) or a marked difference in the quality of the clot (e.g. no clotting activity at WBCT20 and an unstable partial clot at WBCT30). WBCT discrepancies were encountered most frequently in three situations: initial normalization of hemostasis following antivenom therapy, detection of a secondary resumption of coagulopathy, or final restoration of hemostasis after a secondary resumption had occurred. Conclusions This study suggests that the WBCT is robust and that a sequential reading should improve the diagnosis and monitoring of venom-induced coagulopathies. It also indicates the possibility of discrepancies in the sensitivity of WBCT20 and WBCT30 for detecting the resolution or reoccurrence of coagulopathy and identifies how these findings, if confirmed, may be used to increase the efficacy and efficiency of antivenom treatment in the field.
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Affiliation(s)
- Jordan Max Benjamin
- Center for the Study and Research of Malaria Associated with Pregnancy and Childhood (CERPAGE), 08 BP 841 Cotonou, Bénin.,2Whitman College, Department of Biology, Walla Walla, WA 99362 USA
| | - Jean-Philippe Chippaux
- 2Whitman College, Department of Biology, Walla Walla, WA 99362 USA.,3IRD UMR216, Mère et enfant face aux infections tropicales, 75006 Paris, France.,4PRES Sorbonne Paris Cité, Université Paris Descartes, Faculté de Pharmacie, 75270 Paris, France
| | - Bio Tamou Sambo
- 5Département de chirurgie et spécialités, Faculté de Médecine, Université Parakou, Parakou, Bénin
| | - Achille Massougbodji
- Center for the Study and Research of Malaria Associated with Pregnancy and Childhood (CERPAGE), 08 BP 841 Cotonou, Bénin
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de Brito Sousa JD, Sachett JAG, de Oliveira SS, Mendonça-da-Silva I, Marques HO, de Lacerda MVG, Fan HW, Monteiro WM. Accuracy of the Lee-White Clotting Time Performed in the Hospital Routine to Detect Coagulopathy in Bothrops atrox Envenomation. Am J Trop Med Hyg 2018; 98:1547-1551. [PMID: 29611503 DOI: 10.4269/ajtmh.17-0992] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Snake envenomation is a major public health problem in Brazil. Systemic complications that may arise from snakebites are mainly related to coagulopathy. The Lee-White clotting time (LWCT) is a simple and inexpensive test and available even in remote health facilities. However, the diagnostic value of such test needs to be evaluated to accurately diagnose coagulopathy in the clinical practice. This study aimed to assess the reliability of the LWCT performed in hospital routine to diagnose venom-induced coagulopathy. We studied 186 patients admitted at the Tropical Medicine Foundation Dr. Heitor Vieira Dourado in Manaus, Amazonas, Brazil, with Bothrops envenomation diagnosis. At admission, blood samples were collected for performing LWCT and the concentration of fibrinogen. Sensitivity, specificity, positive predictive value, negative predictive value, likelihood ratios, diagnostic odds ratio, and accuracy were calculated with 95% confidence intervals. From the total, 85.5% had hypofibrinogenemia. The sensitivity of the LWCT to the diagnosis of hypofibrinogenemia was 78.0% and the specificity 40.7%. The accuracy of the test was 72.6%, and patients with a prolonged LWCT had 2.4 higher odds of developing hypofibrinogenemia. In addition, the LWCT was also compared with venom antigen levels and systemic hemorrhage. The LWCT showed moderate sensitivity to detect consumption coagulopathy and constitutes a valuable tool for the diagnosis of Bothrops snake envenomation and indication of antivenom therapy.
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Affiliation(s)
- Jose Diego de Brito Sousa
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil.,Instituto de Pesquisa Clinica Carlos Borborema, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Jacqueline Almeida Gonçalves Sachett
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil.,Instituto de Pesquisa Clinica Carlos Borborema, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Sâmella Silva de Oliveira
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil.,Instituto de Pesquisa Clinica Carlos Borborema, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | - Iran Mendonça-da-Silva
- Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil.,Instituto de Pesquisa Clinica Carlos Borborema, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | | | - Marcus Vinicius Guimarães de Lacerda
- Instituto de Pesquisas Leônidas e Maria Deane, Fundação Oswaldo Cruz, Manaus, Brazil.,Instituto de Pesquisa Clinica Carlos Borborema, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil
| | | | - Wuelton Marcelo Monteiro
- Instituto de Pesquisa Clinica Carlos Borborema, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.,Programa de Pós-graduação em Medicina Tropical, Universidade do Estado do Amazonas, Manaus, Brazil
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Little M. Treatment of snakebite in Australia: gathering the evidence. Med J Aust 2013; 199:723-4. [DOI: 10.5694/mja13.11111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Accepted: 11/11/2013] [Indexed: 11/17/2022]
Affiliation(s)
- Mark Little
- School of Public Health, Tropical Medicine & Rehabilitation Sciences, James Cook University, Cairns, QLD
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Perry DL, Bollinger L, L.White G. The Baboon (Papio spp.) as a model of human Ebola virus infection. Viruses 2012; 4:2400-16. [PMID: 23202470 PMCID: PMC3497058 DOI: 10.3390/v4102400] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2012] [Revised: 10/17/2012] [Accepted: 10/17/2012] [Indexed: 01/09/2023] Open
Abstract
Baboons are susceptible to natural Ebola virus (EBOV) infection and share 96% genetic homology with humans. Despite these characteristics, baboons have rarely been utilized as experimental models of human EBOV infection to evaluate the efficacy of prophylactics and therapeutics in the United States. This review will summarize what is known about the pathogenesis of EBOV infection in baboons compared to EBOV infection in humans and other Old World nonhuman primates. In addition, we will discuss how closely the baboon model recapitulates human EBOV infection. We will also review some of the housing requirements and behavioral attributes of baboons compared to other Old World nonhuman primates. Due to the lack of data available on the pathogenesis of Marburg virus (MARV) infection in baboons, discussion of the pathogenesis of MARV infection in baboons will be limited.
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Affiliation(s)
- Donna L. Perry
- Integrated Research Facility, Division of Clinical Research, NIAID, NIH, Frederick, MD, USA;
| | - Laura Bollinger
- Integrated Research Facility, Division of Clinical Research, NIAID, NIH, Frederick, MD, USA;
| | - Gary L.White
- Department of Pathology, University of Oklahoma Baboon Research Resource, University of Oklahoma, Ft. Reno Science Park, OK, USA;
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Ogunfowokan O. Bite-to-hospital time and morbidity in victims of viper bite in a rural hospital in Nigeria. Afr J Prim Health Care Fam Med 2012. [PMCID: PMC4565144 DOI: 10.4102/phcfm.v4i1.371] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Background: Mortality amongst in-hospital patients bitten by carpet viper in northern Nigeria has reduced, related to use of a monospecific ovine Fab snake antivenom. However, many victims survive with temporary or permanent morbidity. Objectives: Study objectives were to: (1) determine and score the morbidity caused by carpet viper bite; and (2) find the relationship between bite-to-hospital time and morbidity amongst victims of carpet viper bite.Method: A prospective study was conducted in a rural hospital in north-central Nigeria. The morbidities scored were oedema, tenderness, prolonged whole-blood clotting time, blister, ulcer, need for blood transfusion, coma, hypotension, convulsion, length of hospital stay, need for disarticulation, and need for skin graft. A score of one was given to each objective sign. The bite-to-hospital time of 233 subjects was obtained. Descriptive and inferential statistical analysis was done.Results: Most of the subjects (150 or 64%) came to the hospital within 6 hours of the snake bite, with 2 (1%) arriving within 1 hour. The median bite-to-hospital time was 5 hours, with a range of 0.5–216 hours. Major morbidities were oedema, seen in 212 (91.0%; 95% CI 86.6–94.3%); incoagulable blood, seen in 205 (88%; 95% CI 83.1–91.9%), and tenderness, seen in 201 (86.3%; 95% CI 81.2–90.4%). The mean morbidity score was 8 ± 4. For every unit increase in logged bite-to-hospital time, the morbidity score increased by 1.85 (p < 0.001).Conclusion: Morbidity caused by carpet viper bite is high in Zamko, north-central Nigeria, and correlates with increasing bite-to-hospital time.
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Affiliation(s)
- Oluwagbenga Ogunfowokan
- Jos University Teaching Hospital, Jos, Nigeria
- Department of Family Medicine, National Hospital, Abuja, Nigeria
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Simpson ID. The "worldwide shortage" of antisnake venom: is the only right answer "produce more" or is it also "use it smarter?". Wilderness Environ Med 2008; 19:99-107. [PMID: 18513107 DOI: 10.1580/07-weme-con-1591.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
A frequent tenet of snakebite literature is what has been described as the "worldwide shortage of antisnake venom" (ASV) and the demand for greater production. Antisnake venom is the mainstay of snakebite management, and thus this principle of "shortage" can impact the view of policy makers when it comes to framing solutions to the problem. This paper presents a model to enable policy makers to assess the amount and utilization of ASV in their areas. The model assesses ASV usage according to 2 criteria: risk and wastage. The actual usage of ASV is segmented in the model into the following main areas: (1) victims who receive too little ASV (high risk/low wastage); (2) victims who receive ASV either unnecessarily or in too great a quantity (low risk/high wastage); (3) victims who receive ASV that is not effective (high risk/high wastage); (4) victims who receive ASV according to effective local protocols (low risk/low wastage). The current proposition about the "shortage" of ASV and the proposal to simply produce more addresses only a small part of the high-risk/low-wastage group and does not address the 2 high-wastage groups. Until the high-wastage groups are recognized and resolved with training and local protocols and moved into the low-risk/low-wastage group, the true requirement for ASV worldwide cannot be assessed.
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Affiliation(s)
- Ian D Simpson
- Pakistan Medical Research Council, Islamabad, Pakistan.
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