Is it Safe for One Surgeon to Oversee Two Operations Concurrently?

In a previous News Blog I advocated a ‘Taylorised’ (i.e. assembly plant) type of approach to bariatric surgery,[1] where a small number of (expensive) surgeons and anaesthetists would oversee a workforce of (less expensive) physician’s assistants / auxiliary medical personnel – figure reproduced below for your convenience. The argument was that bariatric surgery was the only really effective treatment for obesity resulting in greatly improved long-term outcomes, yet surgical resources, as currently deployed, could not meet the demand. No News Blog reader wrote in to ask “but is it safe to operate in this way?” A recent study, based on over half-a-million operations suggest that the answer is “yes it is” – complications were no greater when bariatric operations were concurrent than when they were done strictly in series.[2] CLAHRC WM News Blog reader Tim Jones has recently visited an eye hospital in Hyderabad, India, where a Taylorised approach is taken to cataract surgery with massive efficiency gains and complication rates even lower than those in the UK. I have written before saying that medicine cannot and should not be Taylorised.[3] Real medicine lies in diagnosing, explaining and consoling. But procedures are ripe for massive efficiency gains.

An Operations Director oversees a Surgeon and two Anaesthetists who oversee six technicians operating on six patients

— Richard Lilford, CLAHRC WM Director

References:

  1. Lilford RJ. Bariatric Surgery – Improve Five-Year Outcomes. NIHR CLAHRC West Midlands News Blog. 23 June 2017.
  2. Liu JB, Ban KA, Berian JR, et al. Concurrent bariatric operations and association with perioperative outcomes: registry based cohort study. BMJ. 2017; 358: j4244.
  3. Lilford RJ. The Future of Medicine. NIHR CLAHRC West Midlands News Blog.23 October 2015.
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Deforestation and Diarrhoea

Contaminated water can lead to numerous diseases, including diarrhoea, a leading cause of child mortality. In a previous News Blog we discussed the importance of water contamination, and the many methods by which it can occur.[1] One such route is contaminated surface water, which has been linked to outbreaks of diarrhoea in previous studies.[2] A major factor affecting the quality of surface water is the ‘watershed condition’ – the natural land cover provided by the ecosystem, such as forests and wetlands. This ecosystem filters pollutants and pathogens from surface water supplies, and can stabilise soil, and minimise erosion and sediment loading.

Herrera and colleagues conducted an observational database study of almost 300,000 children aged under 5 from 35 countries, looking at their health, socioeconomic factors (such as mother’s education, household wealth, access to improved sanitation and water sources), climate (temperature and precipitation) and watershed condition.[3] Watershed condition was measured by estimating the percentage of water that was affected by people and livestock or tree cover upstream from the household.

They found that high tree cover upstream of the child’s household was associated with a lower probability of diarrhoea (odds ratio less than 1, but not specified). This was significant only for rural households, however, not urban. In rural communities it is estimated that only 33% of households obtain their water from piped sources (compared to 79% in urban areas), and 93% of people who use surface water as their main water source live in rural areas.

The authors used a model to estimate that increasing tree cover upstream by 30% would have a similar effect to improving sanitation (an estimated 4% reduction in probability of diarrhoea from baseline). It would, however, not have as great an impact as improving the water source (7% reduction), wealth (12% reduction) or education of the households (13% reduction). It seems that, under certain conditions, conservation strategies that ensure that tree cover is high could serve as effective investments in public health.

— Peter Chilton, Research Fellow

References:

  1. Lilford RJ. A Secondary Sanitary Revolution? What About the First One? NIHR CLAHRC West Midlands News Blog. September 1, 2017.
  2. Bessong, P., Odiyo, J., Musekene, J. & Tessema, A. Spatial distribution of diarrhoea and microbial quality of domestic water during an outbreak of diarrhoea in the Tshikuwi community in Venda, South Africa. J Health Popul Nutr 2009; 27: 652-9.
  3. Herrera D, Ellis A, Fisher B, et al. Upstream watershed condition predicts rural children’s health across 35 developing countries. Nature Comm 2017; 8: 811.

Calling All Men – Screening for Prostate Cancer Probably Does Save a Few Prostate Cancer Deaths

Two large randomised trials with 12 years follow-up.[1] [2] One shows reduction in prostate cancer deaths, the other produced a null result. But science cannot prove a null, and point estimates were favourable in both trials. Moreover, there were many differences in implementation of screening across the two large trials. So the authors of a recent study [3] amalgamated the individual research from each individual study and analysed the consolidated dataset to adjust for differences in screening intensity using a measure of the average time by which diagnosis is advanced by screening compared to not screening. This was calculated in different ways, but the results do suggest a screening effect on prostate cancer deaths of about 8%. Whether this translates into all-cause mortality is uncertain, as per a previous News Blog on this issue.[4] I was attracted to this paper, not only because prostate screening is a controversial and important public health issue, but also because it deals with a common scenario in contemporary clinical research – apparently contradictory trial results where one trial provides a null result and the other provides a positive result.

— Richard Lilford, CLAHRC WM Director

References:

  1. Schröder FH, Hugosson J, Roobol MJ, et al. Screening and prostate cancer mortality: results of the European Randomised Study of Screening for Prostate Cancer (ERSPC) at 13 years of follow-up. Lancet. 2014; 384: 2027-35.
  2. Pinsky PF, Prorok PC, Yu K, et al. Extended mortality results for prostate cancer screening in the PLCO trial with median follow-up of 15 years. Cancer. 2017; 123: 592-9.
  3. Tsodikov A, Gulati R, Heijnsdijk AEM, et al. Reconciling the Effects of Screening on Prostate Cancer Mortality in the ERSPC and PLCO Trials. Ann Intern Med. 2017; 164: 449-55.
  4. Lilford RJ. Thyroid Cancer: Another Indolent Tumour Prone to Massive Over Diagnosis. NIHR CLAHRC West Midlands News Blog. 24 March 2017.

Fair is Fair: Preventing the Misuse of Visiting Hours to Reduce Inequities

The experience of healthcare as a social activity feels very different when viewed from the perspectives of the patient, their relatives, or the healthcare staff. The patient is the centre of attention, but profoundly dependent; the relatives are independent, but unempowered and on foreign ground; and the staff are on home territory and authoritative. These unequal relationships come into sharp focus in the emotionally charged context of critical illness and the Intensive Care Unit. Which of us would not want our family to be near to us and supported by the staff in such a situation? And yet surveys repeatedly show that there is wide variation between countries in national policies, that restrictive visiting is common in practice, and that there is wide variation between ICUs in how those policies are applied.[1-3] Why should this be so?

When patients are asked, they express a strong preference to be visited by their relatives.[4] Involvement of relatives in their loved one’s care has been linked to improved outcomes in a number of conditions, including stroke.[5] [6] However, nursing staff attitudes to visiting [7] reveal concerns about the additional workload involved in caring for and communicating with relatives, and that their presence by the bedside might impede delivery of care, adversely affect infection control, or result in exhaustion of family members. Deeper enquiry might well reveal a lack of empathy and professional confidence: anxiety about being constantly observed by family members, or that lapses in care might result in criticism.

Netzer and Iwashyna take a social justice perspective to argue that this is wrong, and that ICUs should implement current national best practice guidance by making open visiting for families the default,[8] thereby avoiding selection bias in permitting or restricting access. The authors argue that excluding families from their relative’s care can impact negatively on both the patient and relative. The visiting hours offered to relatives may be misaligned with their working hours, creating a further obstacle for those with less flexibility and support from their employer, especially in a society where zero hour contracts are more common.

Moreover, staff discretion to vary these restrictions creates opportunities for conscious or unconscious selection bias. The authors describe a personal experience in which visiting hours reinforced the racial inequalities seen in US healthcare. Such biases might also affect other minorities such as same-sex couples, or transgender communities. Training in equality and diversity organised by NHS Trusts might minimise conscious bias, but the fact remains that while restricted visiting is the default, discretion increases the opportunity for social discrimination.

In considering an open visiting policy, attention must be paid to the potential negatives this may pose. Organisations will be conscious of staff limitations and resources, and the potential for abusive/disruptive family members. Ethnic minority or migrant families bring with them different cultural norms and behaviours which may impact adversely on the family members of indigenous patients. Implementation of open visiting would need to include contingencies to cope with such events as they occur, an example being training staff to have the necessary skills and behaviours to deal with such situations. We are working on this as part of the HS&DR-funded PEARL Project (Patient Experience And Reflective Learning), which also includes interventions designed to maximise empathy.[9] Ultimately, the level of involvement of relatives in their family members’ care should be a decision made by the patient and the family and supported by professionally confident and compassionate staff.

— Olivia Brookes, PEARL Project Manager;
— Prof Julian Bion, PEARL Chief Investigator, Professor of Intensive Care Medicine

References:

  1. Liu V, Read JL, Scruth E, Cheng E. Visitation policies and practices in US ICUs. Crit Care. 2013; 17(2):R71.
  2. Giannini A, Miccinesi G, Leoncino S. Visiting policies in Italian intensive care units: a nationwide survey. Intensive Care Med. 2008; 34(7):1256-62.
  3. Greisen G, Mirante N, Haumont D, Pierrat V, Pallás-Alonso CR, Warren I, Smit BJ, Westrup B, Sizun J, Maraschini A, Cuttini M; ESF Network. Parents, siblings and grandparents in the Neonatal Intensive Care Unit. A survey of policies in eight European countries. Acta Paediatr. 2009 Nov;98(11):1744-50.
  4. Wu C, Melnikow J, Dinh T, Holmes JF, Gaona SD, Bottyan T, Paterniti D, Nishijima DK. Patient Admission Preferences and Perceptions. West J Emerg Med. 2015; 16(5):707-14.
  5. Inouye SK, Bogardus ST, Jr., Charpentier PA, et al. A multicomponent intervention to prevent delirium in hospitalized older patients. New Engl J Med. 1999; 340(9):669-76.
  6. Tsouna-Hadjis E, Vemmos KN, Zakopoulos N, Stamatelopoulos S. First-stroke recovery process: the role of family social support. Arch Phys Med Rehabil. 2000; 81(7): 881-7.
  7. Berti D, Ferdinande P, Moons P. Beliefs and attitudes of intensive care nurses toward visits and open visiting policy. Intensive Care Med. 2007; 33(6): 1060-5.
  8. Netzer G, Iwashyna TJ. Fair is Fair: Preventing the Misuse of Visiting Hours to Reduce Inequities. Ann Am Thorac Soc. 2017.
  9. Teding van Berkhout E, Malouff JM. The efficacy of empathy training: A meta-analysis of randomized controlled trials. J Couns Psychol. 2016; 63(1):32-41.

How Many Mutations for Cancer?

During our lifetime our somatic cells (non-reproductive cells) constantly accumulate mutations – in some cases these mutations lead to uncontrolled proliferation and allow the cells to invade other tissues and spread to other organs – i.e. become cancerous. Most of the mutations in cancerous cells are unimportant – it is only a few that are ‘drivers’ of cancer and dictate the way the cell behaves. However, we do not know how many mutations are actually required to cause cancer, or whether this number varies across cancer types.

Researchers working for the Wellcome Trust looked at over 7,500 tumours of 29 cancer types using methods adapted from molecular evolution to see which mutations were more common in cancerous than in non-cancerous cells.[1] They found that, on average, cancerous cells have around four coding substitutions (where a DNA nucleobase is exchanged for another, such as switching from adenine to guanine) that are ‘driver mutations’. This ranged from around one mutation per tumour in thyroid and testicular cancer, four in breast and liver cancer, to more than ten in endometrial and colorectal cancer. Of these ‘driver mutations’ around half occur in cancer genes that have yet to be discovered.

In the long-term these findings could help advance the development of precision cancer treatment, allowing drugs to be specifically targeted at the appropriate mutation(s).

— Peter Chilton, Research Fellow

Reference:

  1. Matrincorena I, Raine KM, Gerstung M, Dawson KJ, Haase K, Van Loo P, Davies H, Stratton MR, Campbell PJ. Universal Patterns of Selection in Cancer and Somatic Tissues. Cell. 2017.

Raising Blood Pressure in Sepsis Patients

I never cease to be amazed at the number of treatments that were received wisdom, but which have been shown to be harmful – sometimes thoroughly harmful.

I well remember my professor of surgery extolling the virtues of completely restoring blood pressure in patients who were bleeding heavily. It turns out that this sensible sounding treatment is plain wrong. One should raise the blood pressure sufficiently to keep the patient awake and the kidneys perfused, but no more. Likewise, I was always taught that in cases of septic shock, fluid replacement should be sufficient to restore blood volume. The latter idea was critically questioned after a randomised trial of a bolus of fluid for critically ill children [1] (which we featured in the quiz in our last News Blog). Here, the fluid bolus was associated with a striking increase in the risk of death.

Now a somewhat similar trial has been carried out among critically-ill adults.[2] The study was carried out in Zambia among patients with septicaemia. Over 200 patients were randomised to receive fluids (and sometimes drugs) to restore blood volume and raise the blood pressure versus less intensive therapy. The results of this trial among adults with sepsis are striking; there was a considerable increase in death rates among those in the intervention group. The difference was considerable at 15 percentage points. Patients in the intervention group received a mean of 3.5 litres of intravenous fluid compared with only 2 litres among controls. Further, 14% received a medicine to support blood pressure in the intervention group compared to only 2% in the control group.

Not surprisingly most of the patients in the study were HIV positive, but there is little reason to think that these results cannot be generalised more widely. A picture is starting to emerge in the literature in favour of not trying to completely restore blood volume in critically-ill patients, at least in African settings. There is a single RCT in North America that produced contradictory findings.[3] It is hard to explain why treatment should produce such different findings across African and North American settings.

— Richard Lilford, CLAHRC WM Director

Reference:

  1. Maitlan K, Kiguli S, Opoka RO, et al. Mortality after Fluid Bolus in African Children with Severe Infection. N Engl J Med. 2011; 364: 2483-95.
  2. Andrews B, Semler MW, Muchemwa L, et al. Effect of an Early Resuscitation Protocol on In-hospital Mortality Among Adults With Sepsis and Hypotension. A Randomized Clinical Trial. JAMA. 2017; 318(13):1233-40.
  3. Rivers E, Nguyen  B, Havstad  S,  et al.  Early goal-directed therapy in the treatment of severe sepsis and septic shockN Engl J Med. 2001; 345(19): 1368-77.

Autism and Allergies

The prevalence of autism spectrum disorder (ASD) is increasing, with the US Centers for Disease Control and Prevention estimating that 1 in 68 people have the disorder. While there is no single known cause of ASD, research has suggested that the immune system may have a role, and that activation of the maternal immune response during pregnancy may increase the risk of ASD developing in the unborn child. A recent paper in Nature investigated associations between the maternal immune activation (MIA) and the severity of ASD symptoms in their child.[1]

The authors analysed an existing cohort of 220 children diagnosed with autism spectrum disorder (ASD) and found that the children whose mothers had a history of allergies and/or asthma had significantly higher scores on the social responsiveness scale (SRS) (p=0.016), compared to those whose mothers did not. The SRS measures social interaction, language, and repetitive/restricted behaviours and interests in the child; a higher score is suggestive of a greater degree of social impairment symptoms. The association was not seen when looking at autoimmune conditions, but many of the mothers were diagnosed with autoimmune problems post-pregnancy, which may have affected the findings.

Although no causal relationship was shown, the study does suggest that the immune system may have a role in ASD.

— Peter Chilton, Research Fellow

Reference:

  1. Patel S, Masi A, Dale RC, Whitehouse AJO, Pokorski I, Alvares GA, Hickie IB, Breen E, Guastella AJ. Social impairments in autism spectrum disorder are related to maternal immune history profile. Mol Psychiatry. 2017.

Oxygen Supplementation After Stroke

A drop in blood oxygen levels is common in the first few days after an acute stroke. One imagines that this oxygen deficit would be harmful in someone whose brain cells were already under attack. It is known that the area where cells have died in a stroke is surrounded by an area (penumbra) where cells are damaged, but may recover.

But plausible hypotheses are often not confirmed when put to a scientific test. So a randomised trial was conducted in over 8000 stroke patients to get better information on this point.[1] The resulting paper, published in JAMA, showed almost identical results when patients were treated with or without prophylactic oxygen supplementation. The primary outcome was a score of disability assessed at 90 days after the original insult.

Outcomes were measured within narrow confidence limits and the therapy was unhelpful across various subgroups and irrespective of baseline oxygen levels.  So here is another example of a superficially appealing treatment, which confers no benefit when put to the test. Administering supplemental oxygen is intrusive and I do not recommend this therapy.

— Richard Lilford, CLAHRC WM Director

Reference:

  1. Roffe C, Nevatte T, Sim J, et al. Effect of Routine Low-Dose Oxygen Supplementation on Death and Disability in Adults With Acute Stroke The Stroke Oxygen Study Randomized Clinical Trial. JAMA. 2017; 318(12):1125-35.

Towards a Unifying Theory for the Development of Health and Social Services as the Economy Develops in Countries

In a previous news blog I proposed grassroots solutions to the transportation of critically ill patients to hospital.[1] Other work has demonstrated the effectiveness of community action groups in many contexts, such as maternity care.[2] More recently I have read that the Kenyan government is proposing a combination of local authority and community action (Water Sector Trust Fund) to improve water and sewage in urban settlements.[3] The idea is for the local authority to provide the basic pipe infrastructure and then for local communities to establish linkages to bring water and sewage into homes. The government does not merely lay pipes, but also stimulates local involvement, including local subsidies and micro-enterprises. This epitomises collaboration between authorities and community groups.

In an extremely poor, post-conflict country, such as South Sudan, it is hard to find activities where the authorities and local people work together to improve health and wellbeing. On the other hand, in extremely rich countries like Norway and Switzerland, the government provides almost all that is required; all the citizen has to do is walk into the bathroom and turn on the tap.

The idea that is provoked by these many observations is that different solutions suit different countries at different points in their development. So much so obvious. Elaboration of the idea would go something like this. When a country is at the bottom end of the distribution for wealth, there is very little to be done other than put the basics of governance and law and order into place and try to reduce corruption. Once the country becomes more organised and slightly better off, a mixture of bottom-up and top-down solutions should be implemented. At this point, the tax base is simply too small for totally top-down, Norwegian style, solutions. In effect the bottom-up contribution makes good the tax deficit – it is a type of local and voluntary taxation. As the economy grows and as the middle class expands, the tax base increases and the government can take a larger role in funding and procuring (or providing) comprehensive services for its citizens.

This might seem anodyne written down as above. However, it is important to bear in mind that harm can be done by making the excellent the enemy of the good. Even before a substantial middle-class evolves in society, wealth is being generated. I recently visited a number of urban settlements (slums) in Nigeria, Pakistan and Kenya. All of these places were a hive of economic activity. This activity was mostly in the informal sector, generating small surpluses. Such wealth is invisible to the tax person, but it is there, and can be used. Using it requires organisation: “grit in the oyster”. The science base on how best to provide this ‘grit’ is gradually maturing. In order for it to do so, studies must be carried out across various types of community engagement and support. I expect this to be a maturing field of inquiry to which the global expansion of the CLAHRC message can contribute. Members of our CLAHRC WM team are engaging in such work through NIHR-funded programmes on health services and global surgery, and we hope to do so with regard to water and sanitation in the future.

— Richard Lilford, CLAHRC WM Director

References:

  1. Lilford RJ. Transport to Place of Care. NIHR CLAHRC West Midlands News Blog. 29 September 2017.
  2. Lilford RJ. Lay Community Health Workers. NIHR CLAHRC West Midlands News Blog. 10 April 2015.
  3. Water Sector Trust Fund, GIZ. Up-scaling Basic Sanitation for the Urban Poor (UBSUP) in Kenya. 2017.

So What About Oxygen for Heart Attacks Then?

A heart attack is caused by blockage of one of the arteries that supplies oxygen to the heart muscle. When this happens some of the heart muscle dies quickly and, as with stroke, this area of necrosis is surrounded by a penumbra where the heart muscle cells are damaged but not dead. Oxygen administered through a face-mask results in an increase in the amount of oxygen dissolved in the blood. Surely then, oxygen makes sense in people who are having a heart attack? Such therapy has been standard since my days as a medical student.

Well, it turns out that while oxygen therapy does no harm in heart attack victims, it also does no good whatsoever. This is the result of a randomised trial of over 6600 patients.[1] Death rates, a test for heart cell damage, and re-hospitalisation rates were almost identical across the two groups. The null result was consistent across all pre-specified subgroups of patients.

A picture is starting to emerge: oxygen therapy does not limit tissue loss in patients with acute ischemic injury.

It is quite difficult to improve on the bodies evolutionary adaptations to injury as the following report will further reinforce.

— Richard Lilford, CLAHRC WM Director

Reference:

  1. Hoffman R, James SK, Jernberg T, et al. Oxygen Therapy in Suspected Acute Myocardial Infarction. New Engl J Med. 2017; 337: 1240-9.