In non-trauma patients, do you base your decision to intubate patients with decreased conscious level on the GCS? These guys in Scotland describe a series of poisoned patients with GCS range 3-14 managed on an ED observation unit without tracheal intubation, with no demonstrated cases of aspiration. They say: ‘This study suggests that it can be safe to observe poisoned patients with decreased consciousness, even if they have a GCS of 8 or less, in the ED‘. Small numbers, but gets you thinking. This subject would make a great randomised controlled trial.
Decreased Glasgow Coma Scale score does not mandate endotracheal intubation in the emergency department
J Emerg Med. 2009 Nov;37(4):451-5
Category Archives: ICU
Stuff relevant to patients on ICU
Oblique view for IJV cannulation
Simple really. Using the transverse view the needle tip can be hard to visualise. In the longitudinal view you don’t see the carotid artery. Applying an oblique view with an obliquely oriented needle “uses the superiority of the short axis view by visualizing all of the important surrounding structures (artery and vein) in an oblong view while allowing continuous real-time visualization of the long axis of the needle, therefore providing a larger, more easily visible target with a brighter more easily recognized needle.” The ultrasound probe is orientated at approximately 45° so that the medial end of the ultrasound probe aligns with the patient’s contralateral nipple or shoulder.
The oblique view: an alternative approach for ultrasound-guided central line placement
J Emerg Med. 2009 Nov;37(4):403-8
Full Text Article
EGDT sepsis bundle challenged
An article in American Journal of Emergency Medicine by two intensivists challenges the science behind Rivers’ early goal-directed therapy (EGDT) protocol for severe sepsis / septic shock. In a nutshell:
- Rivers’ study was small (n = 263), nonblinded, industry-supported and single-center
- early fluids and antibiotics are a sound idea, but other components of EGDT are flawed
- targeting a CVP is meaningless and could result in hypovolaemia or pulmonary oedema; dynamic markers of preload responsiveness such as pulse pressure variation or IVC diameter variation are better guides to fluid resuscitation
- ScvO2 may be normal or elevated in septic shock patients; the low average ScvO2 in Rivers’ study has not been reproduced in subsequent studies.
- packed cells have significant side effects and their non-deformability, pro-inflammatory and pro-thrombotic effects may impair microvascular perfusion and paradoxically worsen tissue oxygen delivery
- dobutamine can potentially further worsen the haemodynamic status of patients with hypovolaemia, vasodilation, or a hyperdynamic circulation, which cannot be differentiated using CVP and ScvO2
Early goal-directed therapy: on terminal life support?
Am J Emerg Med. 2010 Feb;28(2):243-5
I like this paper, mainly because I have been uncomfortable with the chasing of arbitrary targets for some time. My own practice is to try to improve markers of organ hypoperfusion (such as lactate, urine output, mental status, and skin perfusion as well as blood pressure) by early antibiotics, fluid resuscitation guided by clinical and sonographic (IVC) signs, and vasoactive drugs guided by clinical and sonographic (basic echo) findings. I place a central venous catheter for access for the vasoactive drugs, rather than to get a CVP reading. I do measure ScvO2 with a central venous blood gas, but have rarely seen one below 70% even in severely shocked patients – I’m far more interested in clearing the lactate, as are these guys.
Preventing AKI on the ICU
A multinational European working group produced the following evidence-based recommendations for preventing acute kidney injury (AKI). Read the full guideline before criticising – some are just suggestions, some recommendations; I have not included the strength of recommendation or grade of evidence in my summary below.
Volume expansion
Diuretics
- Do not use loop diuretics to prevent or ameliorate AKI
Vasopressors and inotropes
- Maintain mean arterial pressure (MAP) at least 60–65 mmHg, however, target pressure should be individualized where possible, especially if knowledge of the premorbid blood pressure is available.
- In case of vasoplegic hypotension as a result of sepsis or SIRS use either norepinephrine or dopamine (along with fluid resuscitation) as the first-choice vasopressor agent to correct hypotension.
- Do not use low-dose dopamine for protection against AKI.
Vasodilators
- Use vasodilators for renal protection when volume status is corrected and the patient is closely hemodynamically monitored with particular regard to the development of hypotension.
- Prophylactic use of fenoldopam, if available, in cardiovascular surgery patients at risk of AKI. Do not use fenoldopam for prophylaxis of contrast nephropathy.
- Use theophylline to minimize risk of contrast nephropathy, especially in acute interventions when hydration is not feasible.
- Do not use natriuretic peptides as protective agents against AKI in critically ill patients, while its use may be considered during cardiovascular surgery.
Hormonal manipulation and activated protein C
- Avoid routine use of tight glycemic control in the general ICU population. Use “Normal for age’’ glycemic control with intravenous (IV) insulin therapy to prevent AKI in surgical ICU patients, on condition that it can be done adequately and safely applying a local protocol which has proven efficacy in minimizing rate of hypoglycemia.
- Do not use thyroxine, erythropoietin, activated protein C or steroids routinely to prevent AKI.
Metabolic interventions
- All patients at risk of AKI should have adequate nutritional support, preferably through the enteral route
- Do not use N-acetylcysteine as prophylaxis against contrast induced nephropathy or other forms AKI in critically ill patients because of conflicting results, possible adverse reactions, and better alternatives.
- Do not routinely use selenium to protect against renal injury.
Extracorporeal therapies
- Use periprocedural continuous veno-venous hemofiltration (CVVH) in an ICU environment to limit contrast nephropathy after coronary interventions in high-risk patients with advanced chronic renal insufficiency
Prevention of acute kidney injury and protection of renal function in the intensive care unit
Expert opinion of the working group for nephrology, ESICM
Intensive Care Med. 2010 Mar;36(3):392-411
Bad news for etomidate from CORTICUS
In an a priori substudy of the CORTICUS multi-centre, randomised, double-blind, placebo-controlled trial of hydrocortisone in septic shock, the use and timing of etomidate administration was examined in relation to outcome.
Of 499 analysable patients, 96 (19.2%) received etomidate within the 72 h prior to inclusion. The proportion of non-responders to ACTH was significantly higher in patients who were given etomidate than in other patients (61.0 vs. 44.6%, P = 0.004). Etomidate therapy was associated with a higher 28-day mortality in univariate analysis (P = 0.02) and after correction for severity of illness (42.7 vs. 30.5%; P=0.06 and P=0.03) in two multi-variant models. Hydrocortisone administration did not change the mortality of patients receiving etomidate (45 vs. 40%).
Some of the previous attacks on etomidate have not been founded on the most rigorous evidence. However this study adds further to the difficulty in justifying etomidate’s use when a perfectly acceptable alternative (ketamine) exists for rapid sequence induction in the haemodynamically unstable septic patient.
The effects of etomidate on adrenal responsiveness and mortality in patients with septic shock.
Intensive Care Med. 2009 Nov;35(11):1868-76
Low PPV can still be fluid responsive
Pulse pressure variation with respiration (PPV) predicts fluid responsiveness in mechanically ventilated patients. Because this is due to transmission of airway pressures to the vasculature, it is hypothesised that low tidal volume ventilation (or non compliant lungs, or both) results in less PPV even in fluid-responsive patients. This was confirmed in a study looking at the effect of airway driving pressure (Pplat – PEEP) on PPV. The study confirmed the positive predictive value of a high PPV, but some of those patients with a ‘low’ PPV (below a commonly accepted cut-off of 13%) were still fluid responsive, which was defined as a 15% or more increase in stroke index after a fluid challenge. In fluid responders with a low PPV, (Pplat – PEEP) was less than or equal to 20 cmH20.
Take home message: In mechanically ventilated patients, PPV values <13% do not rule out fluid responsiveness, especially when (Pplat – PEEP) was less than or equal to 20
The influence of the airway driving pressure on pulsed pressure variation as a predictor of fluid responsiveness
Intensive Care Med. 2010 Mar;36(3):496-503
No sedation for patients receiving mechanical ventilation
Danish intensivists demonstrate that just bolusing morphine without sedatives results in fewer days on a ventilator and a shortened ICU and hospital stay. Obviously not appropriate for some patients (therapeutic hypothermia, head injury with raised ICP, etc.) and some patients randomised to the no sedation group eventually required sedation. Delirium was three times more common in the no sedation group (20% vs 7%).
A protocol of no sedation for critically ill patients receiving mechanical ventilation: a randomised trial
Lancet. 2010 Feb 6;375(9713):475-80
Procalcitonin reduced antibiotic use
In a multicentre study in France, adult patients expected to stay in the intensive care unit for more than 3 days who had suspected bacterial infections were randomised to have antibiotics started or stopped based on predefined cut-off ranges of procalcitonin concentrations (n=307 patients) or to receive antibiotics according to present guidelines (control, n=314). Patients in the procalcitonin group had significantly more days without antibiotics than did those in the control group (14∙3 days [SD 9·1] vs 11∙6 days [SD 8∙2]; absolute difference 2∙7 days, 95% CI 1∙4 to 4∙1, p<0∙0001) without a difference in 28-day or 60-day mortality or ICU length of stay. An editorial points out that as an open-label trial, a treatment bias might have occurred because physicians were aware that their patients had had procalcitonin measurements taken, raising the question as to whether the procalcitonin concentrations themselves or simply the act of measuring procalcitonin led to the recorded reduction in antibiotic use.
The study used the following guidelines for starting, continuing, or stopping of antibiotics according to procalcitonin concentrations:
Guidelines for starting of antibiotics – Excludes situations requiring immediate antibiotic treatment (eg, septic shock, purulent meningitis)
- Concentration <0·25 μg/L – Antibiotics strongly discouraged
- Concentration ≥0·25 and <0·5 μg/L – Antibiotics discouraged
- Concentration ≥0·5 and <1 μg/L – Antibiotics encouraged
- Concentration ≥1 μg/L – Antibiotics strongly encouraged
If blood sample taken for calculation of procalcitonin concentration at early stage of episode, obtain a second procalcitonin concentration 6–12 h later
Guidelines for continuing or stopping of antibiotics
- Concentration <0·25 μg/L – Stopping of antibiotics strongly encouraged
- Decrease by ≥80% from peak concentration, or concentration ≥0·25 and <0·5 μg/L – Stopping of antibiotics encouraged
- Decrease by <80% from peak concentration, and concentration ≥0·5 μg/L – Continuing of antibiotics encouraged
- Increase of concentration compared with peak concentration and concentration ≥0·5 μg/L – Changing of antibiotics strongly encouraged
Use of procalcitonin to reduce patients’ exposure to antibiotics in intensive care units (PRORATA trial): a multicentre randomised controlled trial
Lancet. 2010 Feb 6;375(9713):463-74
Prone Ventilation for ARDS
A multicentre randomised controlled trial of 342 adult patients with moderate to severe ARDS assessed the effect of prone ventilation on mortality, and showed no benefit (6-month mortality was 52.7% and 63.2%, respectively (RR, 0.78; 95% CI, 0.53-1.14; P = .19).
Complications were higher in the prone group.
Prone positioning in patients with moderate and severe acute respiratory distress syndrome: a randomized controlled trial
JAMA. 2009 Nov 11;302(18):1977-84
Higher PEEP in ARDS
The current mortality of 35% associated with acute lung injury (ALI) is roughly three times higher than that associated with ST-segment elevation myocardial infarction. Protective ventilation strategies limiting tidal volumes and plateau pressures improve outcome, but the optimial level of PEEP is debated. In patients with ALI and its more severe form acute respiratory distress syndrome (ARDS), higher levels of PEEP may prevent atelectasis, recruit already collapsed alveolar units, and reduce pulmonary damage by avoiding the cyclical opening and collapse of alveoli.
In a systematic review and meta-analysis of individual-patient data, researchers investigated the association between higher vs lower PEEP levels and patient-important outcomes among adults with acute lung injury or ARDS who receive ventilation with low tidal volumes.
Randomized trials eligible for this review compared higher with lower levels of PEEP (mean difference of at least 3 cm H2O between groups) in critically ill adults with ALI or ARDS. Eligible trials incorporated a target tidal volume of less than 8 mL/kg of predicted body weight in both the experimental and the control ventilation strategies and provided patient follow-up to death or for at least 20 days.
Three trials, including 2299 patients, met the eligibility criteria: the Assessment of Low Tidal Volume and Elevated End-Expiratory Pressure to Obviate Lung Injury (ALVEOLI) trial, the Lung Open Ventilation to Decrease Mortality in the Acute Respiratory Distress Syndrome (LOVS) study, and the Expiratory Pressure Study (EXPRESS).
There were 374 hospital deaths in 1136 patients (32.9%) assigned to treatment with higher PEEP and 409 hospital deaths in 1163 patients (35.2%) assigned to lower PEEP (adjusted relative risk [RR], 0.94; 95% confidence interval [CI], 0.86-1.04; P = .25). Treatment effects varied with the presence or absence of ARDS (as opposed to ALI). In patients with ARDS (n = 1892), there were 324 hospital deaths (34.1%) in the higher PEEP group and 368 (39.1%) in the lower PEEP group (adjusted RR, 0.90; 95% CI, 0.81-1.00; P = .049). Rates of pneumothorax and vasopressor use were similar.
The authors conclude that treatment with higher vs lower levels of PEEP was not associated with improved hospital survival overall when ALI/ARDS were considered together, but higher levels were associated with improved survival among the pre-defined subgroup of patients with ARDS.
Higher vs lower positive end-expiratory pressure in patients with acute lung injury and acute respiratory distress syndrome: systematic review and meta-analysis
JAMA. 2010 Mar 3;303(9):865-73