ICU and You · Journal Club · Number 98
Twelve experts, a hundred recommendations, and an unusually honest account of how little evidence sits underneath any of it
Singh Y, Urbano Villaescusa J, da Cruz EM, Tibby SM, Bottari G, Saxena R, Guillén M, Lopez Herce J, Di Nardo M, Cecchetti C, Brierley J, de Boode W, Lemson J. Recommendations for hemodynamic monitoring for critically ill children — expert consensus statement issued by the cardiovascular dynamics section of the European Society of Paediatric and Neonatal Intensive Care (ESPNIC). Critical Care 2020;24:620.
Read the paperOpen access under CC BY 4.0, so the full text and the supplementary table of all 94 recommendations are free to anyone. Worth having the supplement open beside the paper — it is the more useful document of the two.
Because they are the news. Not the formal, ceremonial version of reading — the daily kind. The journals are our news pages, our opinion columns, our form guide and our sports results. People who would not dream of going a week without knowing what happened in the world will go a year without knowing what happened in their own specialty, and then wonder why the registrar knows something they do not.
It does not have to be a session. You do not need an hour, a highlighter or a plan. Read the abstracts. Skim the contents page of one journal while the kettle boils. Open the one paper in ten that looks interesting and abandon it at paragraph three if it is not. Nobody is marking this.
What matters is staying curious rather than staying current — nobody is current, and the people who claim to be are reading less than they say. What you are actually maintaining is the habit of noticing: that a question is open, that a practice has shifted, that somebody has published the thing you were arguing about last month.
And then do the part that makes it stick. Mention it on a ward round. Argue about it with somebody who disagrees. Ask what the study could not have shown. A paper read alone is half a paper.
Publish or perish is the line we all know. The quieter one is this: absorb it, or lose your edge.
Twelve clinicians from the ESPNIC cardiovascular dynamics section set out in 2016 to write evidence-based guidelines for haemodynamic monitoring in children, and could not, because the evidence does not exist. What they produced instead is a consensus statement, and they say so on the first page. A hundred draft recommendations across twelve subgroups went to blind electronic voting; those reaching a median of seven to nine with no individual score below seven were labelled strong agreement, the rest were rewritten and voted again.
72
strong agreement, first round
20
weak agreement, after rewriting and a second vote
2
no agreement reached at all
They also drew the age boundaries deliberately and then admitted the boundaries were artificial: term infants beyond four weeks of postnatal age at one end, eighteen years at the other, chosen to avoid overlapping the neonatal and adult guidelines rather than because children change at those two moments. Anyone who has looked after a thirty-day-old will recognise the compromise.
Most of it, and the recurring instruction is the same one whatever the parameter: no number is a target on its own. Blood pressure should not be the sole therapeutic goal. Central venous pressure should never start a fluid bolus. Central venous oxygen saturation is not a surrogate for cardiac index and should not be titrated to. Lactate is read alongside everything else or not at all. The panel returns to this so often that it stops reading as caution and starts reading as the actual finding.
On clinical signs, they are blunter than most guideline writers manage. No single clinical parameter evaluates global haemodynamic status. Trends beat single determinations, combinations beat individual signs, and therapy should not be titrated on clinical signs or urine output alone once you are past initial resuscitation. Then the line that should stop you: there is no good correlation between clinical assessment and invasive haemodynamic parameters, which tells us the two are not measuring the same compartment. Both may be right about different things.
On fluid, the practical recommendation is the useful one. There is no simple, proven bedside method of predicting fluid responsiveness in children; respiratory variation in aortic peak velocity is the best of them and works only in ventilated children meeting several criteria. So: give small boluses, five to ten millilitres per kilogram, over a short interval, and watch what cardiac output, blood pressure and central venous pressure do. If the venous pressure is climbing and neither of the other two has moved, stop. That is a method anyone can follow at three in the morning without a device.
On echocardiography, strongly recommended as an adjunct and for serial assessment, explicitly not recommended as routine monitoring — it is intermittent and observer-dependent. Where it does earn a specific preference: for fluid responsiveness in ventilated children, use the velocity time integral across the aortic valve rather than inferior vena cava collapsibility. And on devices, the pulmonary artery catheter is not recommended in children at all; bioimpedance, bioreactance and pulse contour are not accurate enough for absolute values and may be worth something as trends.
A consensus document tells you most about a field at the points where consensus fails, and this one has three worth knowing.
There is no agreed blood pressure target for a child under twelve. The panel strongly recommends a mean arterial pressure of at least 65 mmHg over twelve years, borrowed from the adult sepsis guidelines. Below twelve, they reached only weak agreement on values at all. That is the entire age range this fortnight is about, and it means the number on the monitor that most of us treat has no consensus threshold behind it.
Near-infrared spectroscopy fared worst. Six of seven recommendations had to be rewritten, and the only one reaching strong agreement was the recommendation against routine use. There is no agreement on whether a cerebral saturation below forty to fifty per cent, or a twenty per cent fall from baseline, means anything you should act on. Readings from different manufacturers are not interchangeable.
Lactate half-collapsed too: five of ten recommendations needed revision, and the panel could not agree on using it as a goal-directed target. What survived is modest and sensible — repeat a capillary value above 3.0 mmol/L from a reliable site, follow it until it falls below that, and remember that a stubbornly high lactate may be catecholamines and aerobic glycolysis rather than a hypoperfused child.
This is expert opinion, and the authors are candid that it is. Panel members were selected for having published on haemodynamic monitoring in the preceding decade, which is the right way to find expertise and also a way to assemble a room with a shared prior about whether monitoring helps. The output is a set of recommendations about monitoring, from people whose work is monitoring, in a field the same document says has almost no outcome evidence. That is not a flaw in the method so much as the reason the paper exists, but it should shape how much weight a single recommendation carries.
The second thing is resource. Transpulmonary dilution is named as the most reliable measurement of cardiac output, and there are exactly two systems usable below forty kilograms, both intricate to set up, one requiring a femoral arterial catheter large enough to worry about in a small child. The panel notes that some recommendations may not suit low-resource settings. A regional Australian unit is not a low-resource setting, but it is a unit where nobody is putting a PiCCO into a toddler at two in the morning, and the honest reading is that the reliable methods are largely unavailable and the available methods are largely unreliable.
None of which makes it a weak paper. It is the first consensus of its kind, it is free to read, and its real contribution is the map of what we do not know — which is why the supplementary table, listing every recommendation with its level of agreement, is the part to keep.
There is no agreed blood pressure target for a child under twelve. So what do you actually use?
Everyone has something — a formula, a chart on the wall, a number a consultant gave you years ago, or a decision not to use a number at all. I would like to know what is really in use, and where it came from. Tap the closest, and tell me the rest.
Each tap opens a reply straight to me with your answer filled in. If your device blocks it, write to icuandyou@icloud.com instead.