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Three Part Question

In [non-pregnant patients with obesity] does [left lateral position] improve the likelihood of [minimising inferior vena cava syndrome or supine hypotension]?

Clinical Scenario

You are the emergency department duty doctor for resus, and a known epileptic with a BMI of 34 is now-post ictal and you have decided to place him in the recovery position. A colleague (who has recently been on an obstetric resuscitation course) asks which side you wish to roll him over on to, and whether the non-pregnant patient is at risk of supine hypotensive syndrome?

Search Strategy

EMBASE, PubMed and CINAHL were searched, with no limitation on date or language, via the NICE Healthcare Databases Advanced Search portal.
CINAHL:
14 combined results for: ~"(obes*).ti AND (aortocaval OR compression OR Inferior vena cava syndrome OR IVCS OR (supine AND hypoten*)).ti"

Medline:
25 combined results for: ~"(aortocaval OR compression OR Inferior vena cava syndrome OR IVCS OR (supine AND hypoten*)).ti AND (obes*).ti"

EMBASE:
36 combined results for: ~"(aortocaval OR compression OR Inferior vena cava syndrome OR IVCS OR (supine AND hypoten*)).ti AND (obes*).ti"

Search Outcome

Total: 73 results, with 38 duplicated. After removal of these, 35 articles screened, using the Rayyan platform (1), based on title or abstract with regard to the three part question, with 33 excluded:
- 2 specifically related to the obese pregnant patient

2 papers directly relevant to the clinical question posed. Search of references from both papers yielded no positive papers relevant to the three part question. Only full text available for one paper.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Linicus Y et al 2016 Germany	29 adult patients referred for evaluation of signs and symptoms of heart failure to a University Hospital, mean BMI 32.7.	Case Series (3)	Assessment of pressure gradient between thoracic and abdominal vena cava by Swan-Ganz catheter	Mean pressure difference of 4.3mmHg +/- 4.3 (SD) with a range of 0 to 20mmHg. r = 0.66 with , p-value of 0.0008 in BMI >30. Some patients with raised BMI without any elevated pressure difference	Position of patient during catheterisation not clearly detailed. No comparison with non-obese patients matched for comorbidities, but other causes of pressure gradients such as heart failure evaluated for by TAPSE and pulmonary artery pressure measurement. No imaging performed
Meinhardt et al 2008 Brazil	Single patient having preoperative insertion of a IVC filter, BMI >70	Case Report (3)	Retrospective opportunistic report	Confirmation of IVCS by femoral venography and celiac trunk arteriography, not quantified in abstract.	Abstract only retrievable. No values given in abstract detailing degree of compression

Comment(s)

There is paucity of information regarding supine hypotensive syndrome (or its causes such as aortocaval compression and inferior vena cava syndrome) in the higher BMI population, however there is an established clinical approach to patients with a gravid uterus involving either manual uterine displacement or left lateral positioning. The weight associated with obesity differs from pregnancy in range, distribution and shape which may explain the biomechanics observed(2). Given the increasing trend of high BMI patients, consideration should be made in opting for a left sided recovery position (left lateral position) in the teaching of the recovery position, where the option is available, with emphasis being correct positioning rather than side. This could be considered more relevant in those with a BMI over 30 (Grade D recommendation). This has implications in the training and delivery of first aid, care provided at events (football stadia etc.) and major incidents involving triage of a large number of patients; in addition to emergency medical care.

Clinical Bottom Line

In patients with significant obesity, where there are no over-riding health and safety or manual handling considerations, preference should be given to a left lateral position. This is the recommended position(4) for women over 20 weeks gestation not requiring manual uterine displacement, and in the absence of any articles to the contrary, would be a suitable for position for larger habitus patients, pregnant or otherwise (Grade D Recommendation) References 1. Ouzzani M, Hammady H, Fedorowicz Z, Elmagarmid A. Rayyan-a web and mobile app for systematic reviews. Syst Rev [Internet]. 2016;5(1):1–10. Available from: http://dx.doi.org/10.1186/s13643-016-0384-4 2. Linicus Y, Kindermann I, Cremers B, Maack C, Schirmer S, Böhm M. Vena cava compression syndrome in patients with obesity presenting with edema and thrombosis. Obesity. 2016;24(8):1648–52. 3. Meinhardt N, Souto K, Vasiluk Knebel A, Stein A. Inferior Vena Cava Syndrome and Morbid Obesity. Obes Surg. 2008;18:1649–52. 4. Bedson R, Riccoboni A. Physiology of pregnancy: Clinical anaesthetic implications. Contin Educ Anaesthesia, Crit Care Pain. 2014;14(2):69–72.

References

1. Linicus Y, Kindermann I, Cremers B, Maack C, Schirmer S, Böhm M. Vena cava compression syndrome in patients with obesity presenting with edema and thrombosis Obesity 17 June 2016
2. Meinhardt N, Souto K, Vasiluk Knebel A, Stein A. Inferior Vena Cava Syndrome and Morbid Obesity Obesity Surgery 2008;18:1649–52.