Tag Archives: critical care

All Updates, ICU

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

All Updates, ICU

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

All Updates, ICU, Resus

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

All Updates, Kids, Resus

Difficult mask ventilation

A comprehensive review of difficult mask ventilation (DMV) reports that the incidence of DMV varies widely (from 0.08% to 15%) depending on the criteria used for its definition. It reminds us that the independent predictors of DMV are:

  • Obesity
  • Age older than 55 yr
  • History of snoring
  • Lack of teeth
  • The presence of a beard
  • Mallampati Class III or IV
  • Abnormal mandibular protrusion test

The review also points out that DMV does not automatically mean difficult laryngoscopy, although it does increase its likelihood.
In addition to positioning, oral and nasal adjuncts, two person technique, and jaw thrust, the application of 10 cmH20 CPAP may help splint open the airway and reduce the difficulty of mask ventilation in some patients.
Difficult mask ventilation
Anesth Analg. 2009 Dec;109(6):1870-80
Causes of DMV:
1) Technique-related

1. Operator: Lack of experience

2. Equipment

a. Improper mask size
b. Difficult mask fit: e.g., beard, facial anomalies, retrognathia
c. Leakage from the circuit
d. Faulty valve
e. Improper oral/nasal airway size
3. Position: Suboptimal head and neck position
4. Incorrectly applied cricoid pressure
5. Drug related
a. Opioid-induced vocal cord closure
b. Succinylcholine-induced masseter rigidity
c. Inadequate depth of anesthesia
d. Lack of relaxation?

2) Airway-related

1. Upper airway obstruction

a. Tongue or epiglottis
b. Redundant soft tissue in morbid obesity and sleep
apnea patients
c. Tonsillar hyperplasia
d. Oral, maxillary, pharyngeal, or laryngeal tumor
e. Airway edema e.g., repeated intubation attempts,
trauma, angioedema
f. Laryngeal spasm
g. External compression e.g., large neck masses and
neck hematoma

2. Lower airway obstruction

a. Severe bronchospasm
b. Tracheal or bronchial tumor
c. Anterior mediastinal mass
d. Stiff lung
e. Foreign body
f. Pneumothorax
g. Bronchopleural fistula

3) Severe chest wall deformity or kyphoscoliosis restricting chest expansion

Acute Med, All Updates, ICU, Resus

Lactate clearance goal in sepsis

Previous work in severe sepsis/septic shock patients has shown that a decrease in lactate concentration by at least 10% during emergency department resuscitation predicts survival. Since this is a potential alternative resuscitation goal to a central venous oxygen saturation (ScvO2) of 70% (as per surviving sepsis campaign guidelines), lactate clearance was compared with ScvO2 in a randomised non-inferiority trial of 300 patients.
All patients were managed in the ED and received fluids, antibiotics, and vasopressors as needed. Then lactate clearance or ScvO2 were measured, and if the respective goals of 10% or 70% were not met, packed cells or dobutamine were given depending on haematocrit. Lactate clearance was the percentage decrease in lactate between two venous specimens taken two hours apart.
Interestingly only 29 patients received either packed cells or dobutamine. Each group was similar in terms of time to antibiotic therapy and amount of fluid given. Patients in the group resuscitated to a lactate clearance of 10% or higher had 6% lower in-hospital mortality than those resuscitated to an ScvO2 of at least 70% (95% CI for this difference, –3% to 15%) exceeding the –10% predefined noninferiority threshold.
The authors conclude ‘these data support the substitution of lactate measurements in peripheral venous blood as a safe and efficacious alternative to a computerized spectrophotometric catheter in the resuscitation of sepsis.’
Lactate clearance vs central venous oxygen saturation as goals of early sepsis therapy: a randomized clinical trial
JAMA. 2010 Feb 24;303(8):739-46

All Updates, ICU, Resus

Noradrenaline vs Dopamine in Shock

Another nail in dopamine’s coffin? In a blinded randomised controlled trial in shocked patients1, there was no difference in mortality when dopamine was compared with noradrenaline as the initial vasopressor. However the dopamine group had a significantly higher incidence of dysrythmia. In addition, mortality was higher in the predefined subgroup of 280 patients with cardiogenic shock. The results of this European study of 1679 patients are very similar to those of a similar but open-label American trial in 252 patients published recently2.
1. Comparison of Dopamine and Norepinephrine in the Treatment of Shock
NEJM 2010;362(9):779-89
2. Efficacy and Safety of Dopamine versus Norepinephrine in the Management of Septic Shock
Shock. 2009 Oct 21. [Epub ahead of print]

All Updates, PHARM, Resus

Etomidate versus ketamine for rapid sequence intubation

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Finally a well designed blinded randomised controlled trial on this subject. 0.3 mg/kg etomidate was compared with 2mg/kg ketamine for RSI in 655 patients requiring emergency intubation in the pre-hospital, emergency department, or intensive care unit environments. No difference was observed in intubation conditions or the primary endpoint of maximum SOFA score in the first three days, although the etomidate group had a higher rate of adrenal insufficiency as defined by response to an ACTH test.
Etomidate versus ketamine for rapid sequence intubation in acutely ill patients: a multicentre randomised controlled trial.
Lancet. 2009 Jul 25;374(9686):293-300

Acute Med, All Updates, ICU, Kids, PHARM, Resus, Trauma

Ad hoc resus teams less effective

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During simulated cardiac arrest resuscitations, a comparision was made between those run by teams that had had time to form before the arrest, and those that had to be assembled ad hoc after the arrest occurred. 99 teams of three doctors, including GPs and hospital physicians were studied. ACLS algorithms were less closely followed in the ad hoc formed teams, with more delays to therapies such as defibrillation. Analysis of voice recordings revealed the ad hoc teams to make fewer leadership utterances (eg. ‘we should defibrillate’ or ‘the next countershock will be 360J’) and more reflective utterances (eg. ‘what should we do next?’). The authors suggest that team building is therefore to be regarded as an additional task imposed on teams formed ad hoc during CPR that may substantially impact on outcome. No surprise to those of us who banned ‘cardiac arrest teams’ from our emergency department resuscitation rooms many years ago!
 
Hands-on time during cardiopulmonary resuscitation is affected by the process of teambuilding: a prospective randomised simulator-based trial
BMC Emerg Med. 2009 Feb 14;9:3
http://www.ncbi.nlm.nih.gov/pubmed/19216796
Full text at http://www.biomedcentral.com/1471-227X/9/3

Acute Med, All Updates, ICU

NIV for weaning

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Use of non-invasive ventilation to wean critically ill adults off invasive ventilation: meta-analysis and systematic review
The growing evidence base in support of liberating patients from invasive mechanical ventilation by means of non-invasive weaning is summarised in this systematic review of 12 randomised trials. Non-invasive weaning was associated with decreased mortality, ventilator associated pneumonia, length of stay in intensive care and hospital, total duration of mechanical ventilation, and duration of invasive ventilation. It should be noted that most of the trials exclusively enrolled patients with exacerbation of chronic obstructive pulmonary disease; benefits in other types of ventilated patients remain to be firmly proven.
BMJ. 2009 May 21;338:b157
http://www.ncbi.nlm.nih.gov/pubmed/19460803