Know your phases and master fluid management

ADQIThe ADQI renal authority turns its attention to fluid strategy in ADQI III’s BJA article.

 

 

 

 

 

Choose the right fluid balance target for the stage of critical illness:

  1. Rescue – first few minutes; generous fluid boluses to treat shock. Obviously, not all patients require this phase.
  2. Optimization – few hours; assessment of tissue perfusion, use of fluid responsiveness markers, working towards stability
  3. Stabilization – next few days; cover losses but otherwise minimize fluids and keep balance neutral-ish.
  4. De-escalation – mobilize fluid; allow or encourage it out; negative balance.

Different measurements and vital signs are valid (or used) at different stages. The utility of ScvO2, cardiac output monitoring, echo and fluid responsiveness markers for assessing volume status are largely confined to the ‘optimization’ period.

Lack of attention in the optimization and stabilization stage is common. Fluid in drugs and electrolyte replacement adds up and often passes relatively unchecked.

In addition a current article in Crit Care involved 492  patients in a prospective registry-collected observational study. Multivariate LR was used to assess whether fluid balance and hypotension (on RRT) was related to death or prolonged renal support. Positive fluid balance, or hypotension, in the first seven days of renal support was associated with greater mortality, but not long term renal support.

It’s difficult to draw any firm conclusions from this observational study. Although many variables were adjusted for, some can never be. Immortal time bias is a particular potential problem in this instance. However it as least adds more weight to ADQI’s assertions.

Immortal bias

 

More on ‘shaping’ fluid balance on the OXICM site.

 

 

 

Towards global consensus on end of life care principles in the ICU

End of life care 2The  WELPICUS study group have used an interesting approach (using the Likert scale to assess a number of statements) to try to gain international consensus (from more than 30 countries) on what matters in end of life care in the ICU.

 

 

 

Autonomy and decision making

There was considerable support for respecting advanced directives (AD), but not necessarily for doctors to encourage patients to write them. There is little current use AND low medical adherence. Patients with capacity may change their mind. Don’t break the law to follow an AD! So, know the law.

Decision making and capacity key elements reaffirmed.

  • Possession of necessary values,
  • ability to communicate and understand,
  • ability to reason.

Strong support for 3-tier model:

  1. Autonomous decision making where possible;
  2. Acknowledge previously communicated views when capacity is lost;
  3. Elsewhere, act in best interests.

Capacity is felt to be conditional – ICU collects complex cases and complex decisions for which a basic level capacity may be insufficient. (America/Europe historical disparity on this is lessening). Patients known preferences trump relatives preferences.

Gain consent for invasive procedures when possible.

Use shared decision making

Large international variation in involvement of surrogates in decisions about EOL. Europe very keen on shared decision making.

Life-sustaining treatments

Consensus gained on withdrawal of treatment when chances of surviving are very low or patient’s wishes against it are known. Includes CPR!

Not yet complete consensus on details of withdrawal/withhold/palliative issues due to legal issues in various countries. Again, know the law!

Decisions regarding end of life care should be made in by the multi-disciplinary ICU/home team AND in discussion with patient/family.

The intent must never be to shorten life, even if this is allowed by law.

Brain death

Near consensus on discontinuation of all therapy after BD. If the family does not accept brain death then most countries allow discontinuation anyway, but if their wishes are honoured then the patient is NOT required to remain on the ICU.

Palliative care

Physical, social, spiritual and emotional needs attended to – in order to facilitate as much autonomy as possible.

end of life consensus

Inadvisable actions

Non-beneficial treatments and investigations should be avoided. Difficulty with what ‘beneficial means’.

Documentation

Document decisions and their rationale.

Education

Everyone needs educating and teaching should be culture/law/religion specific.

Clinical ethics committees

These committees can be useful for advice where opinions differ.

Uncontested statements

Keep families included, informed and happy

Maximise life-saving but bear in mind long-term QOL

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The global mind-set on end of life principles appears to be converging but some interesting differences remain.

Emphasis on shared-decision making is evident.

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Personally, I find the comments about ‘very low chance of surviving’ unhelpful. On the whole we can make death on the ICU humane and largely dignified. But, in many cases we don’t have reliable markers of long-term outcome for individuals. We know that it almost always ends badly but to aim for the improbably tiny ‘bulls-eye’ of a good outcome you risk hitting the far larger surrounding zone of drawn-out death or unacceptable quality of life.

Consequently I often find, in discussions with patients and families regarding withdrawing, withholding or limiting treatment that the following elements need to be explained:

  • Death is most probable whatever we do.
  • There may be a tiny chance of survival, but…
  • what is much more likely, if we continue aggressive treatment, is that death will be protracted and potentially unpleasant or the quality of long-term health will be (unacceptably?) low.

Any advice on handling these discussions?

Be wiser, do less to be better.

Choose wiselyOver the last couple of years, 4 US critical care societies put together a literature-scouring taskforce as part of the Choosing Wisely campaign. After a lengthy process they came up with 5 cost-effective, tradition-questioning recommendations:

 

 

 

 

 

1. Do not order diagnostic tests at regular intervals (such as every day), but rather in response to specific clinical questions;

Avoid anaemia (and so transfusions). Avoid ultimately inconsequential incidental findings demand further work-up.

 

2. Do not transfuse red blood cells in hemodynamically stable, non-bleeding ICU patients with an Hb concentration greater than 7 g/dl;

A threshold of 7 mg/dl results in better survival, fewer complications, and reduced costs. And preserves a precious resource. But unelucidated subgroups may exist.

 

3. Do not use parenteral nutrition in adequately nourished critically ill patients within the first 7 days of an ICU stay;

If not malnourished prior to admission, early PN (even in those not tolerating EN) is possibly harmful and costs more.

 

4. Do not deeply sedate mechanically ventilated patients without a specific indication and without daily attempts to lighten sedation;

Protocol-based approaches can safely limit unnecessary deep sedation – eg lightest effective dose; analgesic before sedative; daily sedation holds.

 

5. Do not continue life support for patients at high risk for death or severely impaired functional recovery without offering patients and their families the alternative of care focused entirely on comfort

Routinely engage high-risk patients and their next of kin or advocate in discussions about limiting the level of aggression of treatment. Promotes patient’s/family’s values, improves the quality of death, and reduces family distress. Initiating palliative care pathways/team may be beneficial even where death is not necessarily expected.

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Whether or not these would be your top five the ambition is laudable and these 5 recommendations, originally published in January, have generally withstood criticism over the last 9 months, and ‘savings’ are being made.

 

EN or PN for getting the calories in?

Everyone knows early enteral nutrition’s a good thing, don’t they?Calories outcomes

A large (2400) pragmatic (real-life!), randomised, unblinded trial in non-elective admissions to 33 UK ICUs, CALORIES looked at the difference in early feeding enterally ‘v’ parenterally, powered for a 20% difference (RRR, or 6% ARR) in mortality at 30 days. Feeding was started within 36 hours of admission, aiming to achieve 25 kcal/kg/day by 72hr, and continued for 5 days. A different focus to EPaNIC and Doig 2013 in that the patients were able to receive either EN or PN.

Most patients in each group didn’t achieve their target, and caloric intake was about the same in each. The parenteral group had less hypoglycaemia (4 ‘v’ 6%), smaller gastric residuals (~100 v ~1000ml) and less vomiting.

But 90 day mortality was no different (around 33%), nor was the length of stay or rate of infective complications, liver dysfunction, GI ischaemia, abdominal distension, aspiration or electrolyte disturbance.

About 7% of the parenteral group (ie to enteral) and 1.5% in the other direction – of uncertain significance.

PN might be expected to be more likely to deliver target calories but in the real world there are logistical barriers to this. Based on this study route doesn’t matter, so long as the patient group is similar to yours (15% post-op, APACHE 20, mean age 65, mortality 30% etc)!

Early ‘v’ late PN’s not beneficial but early EN and PN have the same outcomes? Depends on how you feel about EpANIC‘s shortcomings perhaps. Better feed formulation and less CRBSI may have changed the risk/benefit balance.

Is this a myth busted? Cost, technical aspects and patient specific factors will continue to inform our choice, but maybe we can we be freer with our early PN. And will the guideline compilers act on this?

Acute heart failure – NICE guideline

NICE AHFThe new NICE guideline for acute heart failure in adults is out. Leaves quite a lot of room for interpretation; few hard and fast recommendations. Sizeable section on further research.

 

 

 

 

In a nutshell:

Have a heart failure team

  • Cardiology ward and outreach

Diagnosis

  • Rule out heart failure if BNP <100 or NT-proBNP <300.
  • Echo those with elevated BNP.

Therapy

No routine opiates and don’t use PA catheters.

1. Stop the beta blocker if shocked, bradycardic on in 3rd degree block

2. Diuresis:

  • start or augment
  • consider ultrafiltration if diuretic resistant.

3. Nitrates:

  • not routinely
  • give for concomitant myocardial ischaemia, severe hypertension or regurgitant aortic or mitral valve disease. NOT nitroprusside.

4. Inotropes

  • not routinely
  • use if the cause is reversible – not clear what this means.

5. NIV:

  • straight away for cardiogenic pulmonary oedema with  dyspnoea AND acidosis.
  • consider if respiratory failure not settling, or patient is tiring.

6. Specialist centre involvement

  • Discuss early if reversible severe acute heart failure or potential heart transplant recipient.
  • Get their valve sorted if that’s the problem!

Once stable

  1. Beta blocker – watch rate
  2. ACE – watch renal function
  3. Aldosterone antagonist

Research recommended

1. Fluid removal

  • Dopamine
  • Thiazides
  • Ultrfiltration

2. Balloon pumps

 

 

Comment:

St.Emlyns blog and their recommended reading

 

Refining, not consigning, EGDT?

ARISE protocolPROCESS has been backed up by ARISE in goal-directed therapy for sepsis. PROMISE is awaited (finished recruiting in July).

A large (1600), international, randomised, un-blinded, intention-to-treat trial with sensible exclusion criteria, conducted 2008-2014 of excellent quality. ARISE showed no benefit in using a protocolised 6 hour package for septic shock which involved continuous ScvO2 and CVP targetting

 

 

 

Their protocol included:

1. Supplemental oxygen if saturations <93 (No PaO2 limit)

2. Targets – using pressor (or dilator), red cells, dobutamine, mechanical ventilation to acheive:

  • CVP >8 (or 12 in ventilated)
  • MAP  target range of 65 to 90 mmHg.
  • Continuous ScvO2 >70%

The control group had conventional local management (usually guideline-driven) and weren’t aloud to peak at ScvO2. Both groups received around 2 litres over the 6 hours. Enrolment meant antibiotics had already been given (mean time around 70 mins for both groups).

This surely doesn’t damn EGDT but suggests that the ‘goals’ are now more (or less) clearly:

  • Definitely
    • early antimicrobials – within the first hour?
  • Probably
    • fluid repletion – at least some, but likely to vary with pathology?
    • blood pressure control – 65 as a minimum, but maybe previous BP has an impact?
    • cardiac output improvement when necessary, but not supra-normalising, and not using dopamine?
    • hope to see some lactate reduction!

None of this detracts form sepsis being a ‘thing’ to take seriously and jump on (like MI & CVA). The surviving sepsis campaign quickly issued an update suggesting that ScvO2 and CVP may not be necessary targets. They also point out that whatever the weaknesses of individual elements of the SSC guidelines, if you adhere to them you can expect to do better than institutions that don’t, as demonstrated by their metrics published earlier in the month. Some have commented that a hospital that adheres to a guideline is more likely to be a hospital that has systems for recognition of critical illness, is introspective with its processes, educates internally, collects data and audits well – a better hospital.

It might be argued that perhaps there wasn’t comprehensive equipoise prior to these studies. EGDT has largely been embraced by a specialty short of breakthroughs. Perhaps a worldwide Hawthorne effect plays some part in these ‘non-positive’ studies.

Maybe more of our pre-conceptions about managing sepsis will be stripped away. Maybe in a few years we’ll be practising glycocalyx-protective bolus-less resuscitation, with permissive hypotension and permissive hypoxia. But we will still stay alert for the diagnosis, start the clock and give antimicrobials early. And for now, Rivers EGDT remains as good as any other!

Stay mean with the red stuff in septic shock

TRISS

Narrowing down the TRICC concept to septic shock patients, the TRISS trial looked at a transfusion trigger of 7 g/dl or 9 g/dl, using leuco-depleted blood, for the first 90 days of admission. Multi-centre, parallel-grouped and sensibly powered (over 1000 patients), they achieved good separation of Hb values.

No mortality difference at 90 days. No greater ischaemic events in the lower group and no increased use of life-support elements. But also no deleterious effects of giving blood were noticed – was this because leuco-depleted blood was used (unlike TRICC)?

Strikingly 36% of the higher threshold group were transfused, 2% of the lower.

Possible issues: not blinded, high baseline mortality rate (45% – cf ARISE, although illness severity measured with SOFA/SAPS v APACHE), difficulty picking up ischaemic events (non-protocolised diagnosis), actively infarcting patients were excluded. In the lower threshold group the patient could be transfused if ischaemic and the doctor felt it was wise but it’s not clear whether this happened.

Aside from the clinical lesson, does the very low need for blood in the ‘lower’ group suggest that there is a concerted physiological resetting of the haemoglobin target by the body itself (7ish), and we meddle with that in our correct-the-numbers tendency?

Subgroup analyses to come no doubt.

Awareness of awareness – NAP5 ICU section

aware clipThe recent National Audit Project looked at accidental awareness during general anaesthesia (AAGA). There was a (small) section on ICU/ED.

On the whole clear-headed awareness in the ICU is to be encouraged but hypnosis and sedation need to be taken seriously when required.

Almost all our sedative/induction drugs have some negative effects on the circulation. The balance of physiological upset ‘v’ risk of awareness more acute in ICU.

Principles

Induction:

  • Standard doses often dangerous and compounded by mechanical effect of ventilation.
  • Patient may be obtunded to start with.
  • Difficult airway relatively more common.

Recent study of 472 ICU intubations – almost all used propofol, mean dose was approx 100mg

Procedures:

  • Usually intravenous sedation.
  • Often no anaesthetic machines.
  • Difficult end-points where the patient was already obtunded.

Transfers:

  • Sedation maybe sufficient in calm environment but motion/noise can be stimulating.
  • Monitoring may suffer from movement artefact

 

NAP5 findings

10 cases related to ICU. 3 were patients during transfer post-operatively. 7 cases were on ICU or in ED (2.3%). 5 were morbidly obese.

Induction: 3 cases, all had muscle relaxant – in one case this was the only drug used (collapse and apparent unconsciousness). Low doses of propofol. One difficult intubation.

Maintenance: 2 were shortly after induction. 2 were during invterventions. All had muscle relaxants and iv infusion sedation. All had overall short time on vent and reported awareness pretty soon after waking. Possible effect of pre-morbid tolerance of opiate and benzos.

Transfers: 3 patients transferred from theatre on infusions. All with muscle relaxant.

Patient experience: 2 had paralysis and distress but no pain. 5 reported paralysis and distress and pain.

Summary points

The numbers and proportions in this section of NAP 5 are probably not of value (presumably often awareness is ‘forgotten’ in prolonged illness), but there are some core messages:

  • In critical illness low GCS does not always equate to low likelihood of awareness
  • Sedation end-points are often not available or reliable.
  • Neuromuscular blockade is a risk.
  • Cardiovascular instability should be solved first where possible. Consider induction/sedation agents that cause less hypotension.
  • All reports involved distress (cf anaesthesia) – so expect longer term psych sequelae and support these patients. The critically ill are already a group prone to this.
  • Don’t delay starting infusions post-intubation. Consider TCI infusions. Use intubation checklists that include post-procedure sedation elements.

Research suggestions: DOA monitoring in ICU, TCI use in ICU, preferential use of sedatives with sympathomimetic properties (e.g. Ketamine).

AAGA in ICU/ED may not be completely avoidable. Apparent level of consciousness may be misleading – e.g. in the exhausted, neurologically injured or psychologically impaired.

Addressing each of analgesia/sedation/hypnosis/paralysis/hypotension in appropriate proportion and avoid both the potentially deleterious pressor response and potentially psychologically disabling awareness, while limiting circulatory upset.

 

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