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 Patients who have survived critical illness are at increased risk for long term morbidity and mortality. Maybe we tend to forget this fact, as we lose sight of these patients when they leave our unit. But this is especially true for ICU patients aged 65 and older! There have been clues that influenza vaccination might reduce morbidity after surviving critical illness and Christiansen et al. have looked exactly into this topic. The investigators examined whether an influenza vaccination (flu shot) affects the 1-year risk of myocardial infarction, stroke, heart failure, pneumonia, and death among ICU survivors aged 65 and older. The investigators Performed a nationwide population-based cohort study They used the Danish Intensive Care Database To evaluate a total 89'818 ICU survivors from 2005 until 2015 It is noteworthy that Influenza vaccinated patients (these were 39% of all) were older, had more chronic diseases and used more prescription medications! Their findings show that 1. Influenza vaccinated patients showed an 8% decreased risk of death and a 16% reduced risk of hospitalisation for stroke within one year 2. Cardiac surgery patients were the subgroup that profited most 3. Unfortunately, no significant association was found for the risk of hospitalisation for myocardial infarction, heart failure or pneumonia.  The flu shot saves lives! This is another strong hint, that the influenza vaccination is clearly of benefit to all adults aged 65 and older. This is especially true for ICU survivors! Christiansen at al. Intensive Care Med 2019 Jul;45(7):957-967. Also worth mentioning: Not only influenza A but also Influenza B infection can pose a risk for severe secondary infection in previously healthy and younger persons. Aebi et al. BMC Infect Dis 2010 Oct 27;10:308.  When the FDA approved dexmedetomidine (DEX) in 1999, intensive care medicine had a novel and highly promising drug at its disposal. Compared to clonidine, dexmedetomidine is an 8 times more selective, central alpha 2 agonist, which binds to all 3 subtypes of the receptor. The properties of this substance were auspicious, among them: sedation, analgesia, neuroprotective effects and a lack of respiratory depression. - Sedation decreases sympathetic activity, aggression and leads to a non-REM-like state, which of all sedatives comes closest to natural sleep. Cognitive functions are maintained, and patients usually remain arousable. - Dexmedetomidine has a particular analgesic effect via modulation in the region of the posterior horn of the spinal cord. This has shown to reduce the use of opiates. - By reducing cerebral catecholamines, dexmedetomidine exerts a neuroprotective effect. - Interestingly, sedation with dexmedetomidine is not associated with significant respiratory depression. These properties pointed to a wide range of applications in the intensive care unit: - Sedation in patients with non-invasive ventilation - Weaning of invasively ventilated patients - Agitated delirium - Treatment of various withdrawal syndromes - Fiberoptic awake intubation in theatre conditions Dexmedetomidine comes with its side effects, though. Most commonly bradycardia and hypotension are observed, making second and third-degree heart block a contraindication. Also, nausea and a dry mouth might be seen. Interestingly, prolonged use might be associated with some extent of discontinuation syndrome similar to clonidine. This involves hypertension, tachycardia, nervousness etc. What Evidence Do We Have So Far? |
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The SPICE III Trial |  |
Precisely this question was now addressed by Shehabi et al., published in the NEJM
They performed an
International (8 countries, 74 ICU's), randomised controlled, unblinded trial
In which they evaluated
4000 ICU patients that were expected to need mechanical ventilation for at least 48 hours and required sedation for safety or comfort
They compared
Patients sedated with propofol, midazolam or other agents as prescribed by the treating physician with patients receiving dexmedetomidine as a continuous infusion
(if DEX alone was insufficient, other agents could be added! In fact, 64% of patients also received propofol, 3% midazolam and 7% received both)
They found
1. No difference in 90-day mortality (primary outcome) and
2. No difference in death after 180 days, institutional dependency at 180 days, mean cognitive decline and assessment of the quality of life. Also no difference in median days free from coma to day 28 and median ventilator-free days at day 28 (all secondary outcomes)
3. Dexmedetomidine was though associated with significantly more events of bradycardia, hypotension (no further info on the use of vasopressors) and asystoles (14 vs 2; 7 required mechanical resuscitation measures)
- DEX is an attractive sedative in certain situations (alcohol withdrawal, other forms of delirium, weaning process etc.), BUT
- DEX doesn't seem to provide any advantage in the sedation of mechanically ventilated patients in the ICU and
- Might be problematic due to adverse cardiovascular effects, especially in this group of patients
Shehabe et al. N Engl J Med 2019; 380:2506-2517
Did you Know?
Apparently, intranasal dexmedetomidine seems used successfully for sedation in adults and children. J Clin Neurophysiol. 2019 May 16.
Acute decompensated heart failure comes in many ways as remains a challenge for optimal treatment since various conditions can cause it, e.g. advanced chronic heart failure, cardiogenic- and septic-shock, cardiac- and non-cardiac surgery, etc. Among many other interventions, the infusion of positive inotropes is often used on one side and vasodilators on the other side to stabilize the situation and improve cardiac function. Despite all these measures, the re-admission rate and mortality remain a significant problem among these patients.
While Levosimendan is still under investigation in the U.S., it is used worldwide for the short-term treatment of acutely decompensated severe chronic heart failure, especially when other treatment options have failed. Some recommend the usage of this drug in a different setting like sepsis-related heart failure or coronary heart disease.
How does Levosimendan work?
Levosimendan has some remarkable properties, which are mainly caused by three mechanisms:
1. Enhancement of the calcium sensitivity of the myofilament by binding to troponin C.
2. Opening of adenosine triphosphate-sensitive potassium (KATP) channels in vasculature smooth muscle.
3. Opening of mitochondrial KATP channels.
These mechanisms result in a positive inotropy of the heart, an increase in stroke volume (SV) and therefore, cardiac output (CO). Besides, it's vasodilatory properties seems beneficial for coronary perfusion and reduce pulmonary capillary wedge pressure (PCWP).
All these effects do not appear to induce an unfavourable energy balance in the myocardial cell, and also the oxygen demand is not increased.
ScienceDirect.com
So what's the Evidence?
The Small Bits and Pieces
First publications back in the 90ies and early 2000s were indicative for the properties of levosimendan. Three studies were randomized and double-blinded but very low in patient numbers and therefore not powered enough to provide substantial evidence. Their statements were also not concerning patient outcome or mortality, but its results confirmed that levosimendan enhances cardiac output without oxygen wasting, is well tolerated and leads to favorable hemodynamic effects.
Lilleberg et al. Eur Heart J. 1998;19:660–668.
Ukkonen et al. Clin Pharmacol Ther. 2000;68:522–531.
Nieminen et al. J Am Coll Cardiol. 2000;36:1903–1912.
In 2003 Kivikko et al. published further data from another small trial indication that its beneficial effects (decreases in left and right heart filling pressures and in SVR, as well as increases in stroke volume and cardiac index) are maintained for at least 24 hours after discontinuation of a 24-hour infusion. At this point, it is worth mentioning that the author published these findings as a current employee of Orion Pharma, which manufactures levosimendan.
Kivikko et al. Circulation. 2003;107:81–86.
Further data indicated that its effect might be sustained for up to at least a week, although also this study included only 22 patients!
8. Lilleberg et al. Eur J Heart Fail. 2007;9:75–82.
A Lancet publication in 2002 by Follath et al. presented a multicentre, randomized, double-blind trial in which they compared the effect of levosimendan to dobutamine in patients that were admitted to a hospital with low-output heart failure and were judged to require hemodynamic monitoring and treatment with an intravenous inotropic agent. In these 203 patients, levosimendan had a consistently better effect than dobutamine on the individual hemodynamic variables at the end of the 24 h treatment period (cardiac output and pulmonary capillary wedge pressure). The change in clinical symptoms like fatigue and dyspnoea were not significantly different, though.
Interestingly, for the first time, the levosimendan group showed lower mortality than in the dobutamine group for up to 180 days. However, it's important to mention its absence of placebo control and its rather small sample size.
Follath et al. Lancet. 2002;360:196–202.
The Big Lumps
The SURVIVE Study
In the SURVIVE study Mebazaa et al. compared the efficacy and safety of intravenous levosimendan or dobutamine in patients hospitalized with acute decompensated heart failure who required inotropic support.
They performed a
randomized, double-blind trial at 75 centers in 9 countries
in which they evaluated
1327 patients hospitalized with acute decompensated heart failure who required inotropic support
They found that
the addition of levosimendan to standard therapy resulted in fewer deaths compared with dobutamine, especially in the first few weeks after treatment
but
Levosimendan did not significantly reduce all-cause mortality at 180 days or affect any secondary clinical outcomes
randomized, double-blind trial at 75 centers in 9 countries
in which they evaluated
1327 patients hospitalized with acute decompensated heart failure who required inotropic support
They found that
the addition of levosimendan to standard therapy resulted in fewer deaths compared with dobutamine, especially in the first few weeks after treatment
but
Levosimendan did not significantly reduce all-cause mortality at 180 days or affect any secondary clinical outcomes
The REVIVE Studies - Heart Failure
In the Randomized Multicenter Evaluation of Intravenous Levosimendan Efficacy studies (REVIVE I and REVIVE II) the efficacy of levosimendan on symptoms of heart failure during five days after starting a 24h trial drug infusion was assessed.
Each patient's clinical course over 5 days was determined by a composite of the patient's self-assessment of symptoms together with a physician's assessment of the occurrence of clinical deterioration.
The primary endpoint of the study was a new clinical composite endpoint (improvement, unchanged or worse - including death) derived from studies in chronic heart failure and first evaluated in 100 ADHF patients in the REVIVE I pilot study.
In REVIVE II the investigators performed one of the
first large, prospective, randomized, double-blind, controlled trials
in which they evaluated
600 patients admitted at 103 sites in the United States, Australia, and Israel
with
worsening heart failure and dyspnea at rest despite treatment with intravenous diuretics, and left ventricular ejection fraction of < 35% measured within the last year
whereas
patients were randomized to either receive levosimendan for 24h or standard treatment alone
They found that after 5 days
- more patients receiving levosimendan experienced improvement compared with those who were on placebo (19.4% vs 14.6%, respectively, a 33% relative increase; P = .015)
- fewer patients receiving levosimendan worsened compared with patients who were on placebo (19.4% vs 27.2%, respectively), a 29% relative decrease, and
- fewer patients receiving levosimendan required rescue therapy (15.1%) vs placebo (26.2%), a 42% relative decrease.
Among other secondary endpoints, levosimendan improved
B-type natriuretic peptide (BNP) levels, length of hospital stay and dyspnoea at 6 hours
But
mortality at 90 days did not differ significantly between treatment arms (a secondary endpoint) and
the most common treatment-emergent cardiovascular adverse events were more frequent with levosimendan, including hypotension (50% vs 36%), ventricular tachycardia (25% vs 17%), and atrial fibrillation (8% vs 2%).
first large, prospective, randomized, double-blind, controlled trials
in which they evaluated
600 patients admitted at 103 sites in the United States, Australia, and Israel
with
worsening heart failure and dyspnea at rest despite treatment with intravenous diuretics, and left ventricular ejection fraction of < 35% measured within the last year
whereas
patients were randomized to either receive levosimendan for 24h or standard treatment alone
They found that after 5 days
- more patients receiving levosimendan experienced improvement compared with those who were on placebo (19.4% vs 14.6%, respectively, a 33% relative increase; P = .015)
- fewer patients receiving levosimendan worsened compared with patients who were on placebo (19.4% vs 27.2%, respectively), a 29% relative decrease, and
- fewer patients receiving levosimendan required rescue therapy (15.1%) vs placebo (26.2%), a 42% relative decrease.
Among other secondary endpoints, levosimendan improved
B-type natriuretic peptide (BNP) levels, length of hospital stay and dyspnoea at 6 hours
But
mortality at 90 days did not differ significantly between treatment arms (a secondary endpoint) and
the most common treatment-emergent cardiovascular adverse events were more frequent with levosimendan, including hypotension (50% vs 36%), ventricular tachycardia (25% vs 17%), and atrial fibrillation (8% vs 2%).
The LeoPARDS-Trial - Sepsis
In this study investigators wanted to know whether in adult patients who have sepsis the application of levosimendan reduces the incidence and severity of acute organ dysfunction compared with placebo.
In this study investigators wanted to know whether in adult patients who have sepsis the application of levosimendan reduces the incidence and severity of acute organ dysfunction compared with placebo.
They performed a
Randomised, double-blind, placebo-controlled multi-centre trial in 34 general ICUs in the UK
in which they evaluated
516 patients with suspected or confirmed infection and 2 or more SIRS criteria who were dependent on vasopressors for at least four hours to maintain their blood pressure.
They compared
the intravenous infusion of levosimendan or placebo for 24 hours in addition to standard care
and found:
- No significant difference in the daily Sequential Organ Failure Assessment (SOFA) score up to day 28 (primary outcome)
- No statistical difference on death at 28 days, at ICU discharge and hospital discharge (secondary outcome)
- And: The use of levosimendan was associated with more hemodynamic instability, lower mean arterial pressures, therefore more need for noradrenalin at 24h and significantly more supraventricular tachyarrhythmias (all secondary outcomes).
Randomised, double-blind, placebo-controlled multi-centre trial in 34 general ICUs in the UK
in which they evaluated
516 patients with suspected or confirmed infection and 2 or more SIRS criteria who were dependent on vasopressors for at least four hours to maintain their blood pressure.
They compared
the intravenous infusion of levosimendan or placebo for 24 hours in addition to standard care
and found:
- No significant difference in the daily Sequential Organ Failure Assessment (SOFA) score up to day 28 (primary outcome)
- No statistical difference on death at 28 days, at ICU discharge and hospital discharge (secondary outcome)
- And: The use of levosimendan was associated with more hemodynamic instability, lower mean arterial pressures, therefore more need for noradrenalin at 24h and significantly more supraventricular tachyarrhythmias (all secondary outcomes).
The CHEETAH Trial - Cardiac Surgery
The question in CHEETAH was if levosimendan compared to placebo reduces mortality in patients undergoing cardiac surgery with left ventricular dysfunktion.
This time Landoni et al. performed a
Multi-centre, randomised, placebo-controlledand parallel group designed trial
in which they evaluated
506 patients scheduled for cardiac surgery with peri-operative cardiovascular dysfunction
defined as
pre-operative left ventricular ejection fraction (LVEF) < 25%, pre-operative intra-aortic balloon pump (IABP), intra- or post-operative (within 24 hours) IABP or significant inotropic requirement
They compared
Levosimendan infusion continued for up to 48 hours (or until ICU discharge) or placebo
and found
No difference in mortality at thirty 30 days (primary outcome)
And no difference in survival over time, renal replacement therapy, the median duration of mechanical ventilation, the median hospital stay and interruptions due to adverse events (all secondary outcomes).
Any Other Clues?
In contrast to these clinically somewhat discouraging results Shang et al. have published a meta-analysis in 2017 of randomized controlled trials looking at the usage of levosimendan in patients with heart failure, cardiogenic shock and acute coronary syndrome.
They ended up looking at a total of nine studies, most of them low in patient numbers and comparing levosimendan to either placebo or other drugs (dobutamine and enoximone).
In contrast to these clinically somewhat discouraging results Shang et al. have published a meta-analysis in 2017 of randomized controlled trials looking at the usage of levosimendan in patients with heart failure, cardiogenic shock and acute coronary syndrome.
They ended up looking at a total of nine studies, most of them low in patient numbers and comparing levosimendan to either placebo or other drugs (dobutamine and enoximone).
According to these data the authors conclude that levosimendan is associated with reduced total mortality, decreased incidence of worsening HF, and improved hemodynamic outcomes and does not increase the risk of adverse events except for hypotension in patients with HF (including CS) complicating ACS. Thus, levosimendan should be recommended for routine clinical application in these patients.
Am J Cardiovasc Drugs 2017 Dec;17(6):453-463.
According to current evidence
- Levosimendan has interesting mechanisms of action and successfully seems to enhance cardiac output without additional oxygen wasting. This includes decreased right and left ventricular filling pressures, decreased SVR, as well as increases in stroke volume and cardiac index. Also, PCWP is decreased.
- In terms of various patient groups, patients with acute heart failure or acute on chronic heart failure appear to benefit in terms of clinical symptoms, if at all.
- Unfortunately, there is no convincing clinical evidence that levosimendan has any benefit in long term outcomes in terms of mortality.
- And, levosimendan seems to be associated with some potential treatment-emergent cardiovascular adverse events like hypotension, supraventricular and ventricular arrhythmia.
Acute myocardial infarction - It's pain radiating to the right arm we have to worry about!
15/3/2019
It was only back in in 1987 when William Heberdeen (not to confound with William Heberdeen, a London doctor who described the Heberdeen nodes back in the 18th century) published the first description of ischemic chest pain. It was the birth of the classical image of strangling chest pain that occasionally radiates to the left arm, associated with exertion and relieved by rest.
A recent publication in the BMJ shows, that positive troponin levels are found frequently in patients with non-cardiac problems. This finding underlines the importance of good history taking, including the assessment of chest pain (CP) characteristics.
A recent publication in the BMJ shows, that positive troponin levels are found frequently in patients with non-cardiac problems. This finding underlines the importance of good history taking, including the assessment of chest pain (CP) characteristics.
Circulation. 2018;138:e618–e651. (Click image for link to article)
The TRAPID-AMI Study
McCord J et al. have taken a closer look at chest pain and associated symptoms and their association with the diagnosis of acute myocardial infarction. They also analysed these symptoms in relation to the size of the AMI.
They performed an
international, multicenter diagnostic study
in which they evaluated
1282 patients admitted for possible AMI to emergency departments in Europe, the US and Australia
The outcome was
the correlation of symptoms with the diagnosis of AMI and its relation to myocardial infarction size
They found that
1. only 4 symptoms were independently predictive of AMI
- Radiation to the right arm/ shoulder (OR 3.0, CI 1.8-5.0)
- Chest pressure (OR 2.5, CI 1.3-4.6)
- CP worsened by physical activity (OR 1.7, CI 1.2-2.5)
- Radiation to left arm/ shoulder (OR 1.7, CI 1.1-2.4)
2. Patients with more than 1 of the 4 symptoms were more likely to have AMI
- For patients who had all 4 symptoms, 55% had a diagnosis of AMI
3. Patients with larger AMI's were more likely to have
- pulling CP
- pain in the right upper chest (right supramammillary area)
- and right arm/shoulder radiation
They performed an
international, multicenter diagnostic study
in which they evaluated
1282 patients admitted for possible AMI to emergency departments in Europe, the US and Australia
The outcome was
the correlation of symptoms with the diagnosis of AMI and its relation to myocardial infarction size
They found that
1. only 4 symptoms were independently predictive of AMI
- Radiation to the right arm/ shoulder (OR 3.0, CI 1.8-5.0)
- Chest pressure (OR 2.5, CI 1.3-4.6)
- CP worsened by physical activity (OR 1.7, CI 1.2-2.5)
- Radiation to left arm/ shoulder (OR 1.7, CI 1.1-2.4)
2. Patients with more than 1 of the 4 symptoms were more likely to have AMI
- For patients who had all 4 symptoms, 55% had a diagnosis of AMI
3. Patients with larger AMI's were more likely to have
- pulling CP
- pain in the right upper chest (right supramammillary area)
- and right arm/shoulder radiation
- It's time to get rid of the classical image of CP radiating only into the left arm. While this might still be the predominant complaint at presentation, it's the right sided shoulder/ arm pain we should keep a close eye on!
- Chest pain radiating to the right shoulder/ arm is more predicitive of myocardial infarction than left sided chest pain
- And remember: a positive Troponin alone does not fullfill the diagnostic criteria of AMI!
Crit Pathw Cardiol. 2019 Mar;18(1):10-15.
Top Ten Websites in Critical Care Medicine Education
The Journal of Intensive Care Medicine has recently published a review of websites providing educational content that is part of the Free Open Access Meducation (FOAMed) movement. The authors have searched the web for critical care medicine education websites and have identified 97 sites they consider relevant for critical care.
These websites were then reviewed and evaluated using the Critical Care Medical Education Website Quality Evaluation Tool (CCMEWQET). They were then split up into three tertiles according to their score.
Congratulations to the Top Ten websites that indeed provide excellent educational information freely accessible.
Oh, and by the way we might mention that our small site Crit.Cloud has been considered among 96 other as relavant in this field and has ended up in the middle tertile with its ranking. 🙃
A big thank you to the authors of this paper for their excellent work and for providing us with an updated list of websites worth taking a closer look! We are delighted to follow their wish by sharing the table of these websites.
Wolbrink TA et al. J Intensive Care Med. 2018 Jan;34(1):3-16
Full List of all Website Reviewed (Click on a table enlarge)
Central venous lines a commonly used in critical care and normally don't cause too many problems. They are though associated with potentially severe complications like infection, thrombosis, occlusion, bleed and of course pneumothorax on insertion. Although the usage of ultrasound guidance minimises the risk of the latter, there remains a restriction risk of this happening, giving you the challenge to solve this problem professionally.
The Case
A 67-year old lady needed the insertion of a central venous catheter during surgery, which the anaesthetist performed with the aid of ultrasound but of course under aggravated conditions. When brought into the critical care unit postoperatively she presented with no audible breathing sound on the right side of her chest. An ultrasound (US) of the right lung showed no visible pleural gliding, and in M-mode only 'sea' but no 'beach' or 'sand'.
Left lung: Beach, Sea and Sky: No pneumothorax!
Right lung: No Beach (no sand): Suggests pneumothorax!
To estimate the extent of the pneumothorax, we performed a pa chest x-ray (CR), which confirmed the diagnosis. The image showed an apical interpleural distance of 3cm and laterally of 2-3cm.
To estimate the extent of the pneumothorax, we performed a pa chest x-ray (CR), which confirmed the diagnosis. The image showed an apical interpleural distance of 3cm and laterally of 2-3cm.
How often does this happen? Could I have prevented this complication? What would you do in this situation? To answer these and some other questions we performed a quick review of current literature and provide a short review.
Are iatrogenic pneumothoraces common?
It's a fact: Iatrogenic injuries are an inevitable part of medicine. Emergent procedures performed in the emergency department (ED) present a higher risk for iatrogenic injury than in more controlled settings (Swain et al., 2005; Mort, 2004). This fact implies that you should NEVER perform a procedure if you cannot handle the potential complications. A procedural error followed by mismanagement increases the likelihood of morbidity and mortality immensely.
The incidence in the literature varies from 0 to 6% (numbers are higher in emergencies), bearing in mind, that depending on the control method used (US, CR or none), some are just not diagnosed. Subclavian vein insertion has been reported to have a higher incidence of pneumothorax than internal jugular vein insertion.
The incidence in the literature varies from 0 to 6% (numbers are higher in emergencies), bearing in mind, that depending on the control method used (US, CR or none), some are just not diagnosed. Subclavian vein insertion has been reported to have a higher incidence of pneumothorax than internal jugular vein insertion.
What can I do to prevent iatrogenic pneumothoraces?
- Make sure that there is an indication for central venous access (e.g. vasopressors in low to moderate doses are no absolute indication, PulmCC: Are central lines really needed for vasopressor infusions?)
- Use a standardized method of CVC insertion in your unit or institution
- Insertion by experienced physician (performing more than 50 CVC insertion a year) or at least his assistance has proved to lower the risk of pneumothorax
- The use of ultrasound during CVC catheterization reduces the time required for insertion and the rate of mechanical complications
- Use a standardized method of CVC insertion in your unit or institution
- Insertion by experienced physician (performing more than 50 CVC insertion a year) or at least his assistance has proved to lower the risk of pneumothorax
- The use of ultrasound during CVC catheterization reduces the time required for insertion and the rate of mechanical complications
How do I diagnose a pneumothorax
Iatrogenic pneumothorax might not cause any clinical symptoms, especially in the young and otherwise healthy patient. Symptoms might include chest pain (sometimes radiating to the ipsilateral shoulder), shortness of breath (to life-threatening respiratory distress) and less commonly cough, anxiety or malaise.
On examination, you might find tachypnoea, asymmetrical lung expansion, unilaterally decreased breath sounds. Cardiovascular findings might include tachycardia, hypotension, pulsus paradoxus and jugular venous distension (often present in tension pneumothorax). Subcutaneous emphysema and tracheal deviation might occur occasionally.
A definite diagnosis is made by performing chest radiography (CR), CT-scan or bedside ultrasonography (US). Supine chest radiographs are unreliable in making the diagnosis of pneumothorax, with a sensitivity value of 36%. US is more sensitive than supine CR and as sensitive as CT in the detection of pneumothoraces. Performance of US for the detection of pneumothorax is excellent and is superior to supine CR. Considering the ease of access and the outstanding clinical performance of US (numerous studies have described near 100% sensitivity and 90% to 95% specificity if a thorough examination is performed), current studies support the routine use of US for the detection of pneumothorax.
- Clinical signs are unspecific and might not be present
- Ultrasonography is the first choice for the detection of pneumothorax
- For a general evaluation of the size of a pneumothorax, an erect chest x-ray in inspiration is recommended
- CT scans are only recommended for uncertain or complex cases
On examination, you might find tachypnoea, asymmetrical lung expansion, unilaterally decreased breath sounds. Cardiovascular findings might include tachycardia, hypotension, pulsus paradoxus and jugular venous distension (often present in tension pneumothorax). Subcutaneous emphysema and tracheal deviation might occur occasionally.
A definite diagnosis is made by performing chest radiography (CR), CT-scan or bedside ultrasonography (US). Supine chest radiographs are unreliable in making the diagnosis of pneumothorax, with a sensitivity value of 36%. US is more sensitive than supine CR and as sensitive as CT in the detection of pneumothoraces. Performance of US for the detection of pneumothorax is excellent and is superior to supine CR. Considering the ease of access and the outstanding clinical performance of US (numerous studies have described near 100% sensitivity and 90% to 95% specificity if a thorough examination is performed), current studies support the routine use of US for the detection of pneumothorax.
- Clinical signs are unspecific and might not be present
- Ultrasonography is the first choice for the detection of pneumothorax
- For a general evaluation of the size of a pneumothorax, an erect chest x-ray in inspiration is recommended
- CT scans are only recommended for uncertain or complex cases
Does every central line need a chest x-ray after insertion?
CR of supine patients is not sensitive enough to identify hidden pneumothorax because the air initially dissipates within the nondependent and medial parts of the chest and therefore can be invisible on supine radiographs. Even upright CR can be challenging and unreliable. Also, CR is often performed immediately after CVC insertion and it is therefore possible that there is not enough time for the development of a pneumothorax large enough to be identified.
- Routine CR after central line insertion is unreliable and not necessary: It's an inefficient screening tool!
- Current evidence supports the use of US to exclude iatrogenic pneumothorax
- Routine CR after central line insertion is unreliable and not necessary: It's an inefficient screening tool!
- Current evidence supports the use of US to exclude iatrogenic pneumothorax
How do I treat an iatrogenic pneumothorax?
If a pneumothorax occurs during the insertion of a central line urgent action might not be necessary. If asymptomatic, you might proceed with the central line insertion when the patient is in urgent need.
- If signs of a tension pneumothorax arise, a simple needle decompression or urgent chest drain is life-saving and allows for a continued controlled attempt of the central line on the same side (you can’t cause a pneumothorax twice).
- Never attempt a central line insertion on the opposite side to avoid bilateral iatrogenic complications!
- In the setting of iatrogenic pneumothorax the BTS guidelines on the management of spontaneous pneumothorax can be applied:
- If signs of a tension pneumothorax arise, a simple needle decompression or urgent chest drain is life-saving and allows for a continued controlled attempt of the central line on the same side (you can’t cause a pneumothorax twice).
- Never attempt a central line insertion on the opposite side to avoid bilateral iatrogenic complications!
- In the setting of iatrogenic pneumothorax the BTS guidelines on the management of spontaneous pneumothorax can be applied:
- Remember: If the inter-pleural space on CR is less than 2cm (some allow 3cm as an upper limit) and the patient remains asymptomatic, conservative treatment is appropriate!
- Apply nasal oxygen 3-5L/min (see below)
- A follow up chest x-rax after 12-24 hours is advisable.
Did you know?
When no supplemental oxygen is applied air is reabsorbed spontaneously by 1.25% of pneumothorax size per day. Oxygen administration at 3 L/min nasal canula or higher flow treats possible hypoxemia and is associated with a fourfold increase in the rate of pleural air absorption compared with room air alone.
Got interested? Get more info here:
Pneumothorax as a complication of central venous catheter insertion, N. Tsotsolis et al. Ann Transl Med. 2015 Mar; 3(3): 40. OPEN ACCESS
Management of spontaneous pneumothorax: British Thoracic Society pleural disease guideline 2010, A. MacDuff et al. Thorax. 2010 Aug. OPEN ACCESS
Ding W. et al. Diagnosis of pneumothorax by radiography and ultrasonography: a meta-analysis. Chest. 2011 Oct;140(4):859-866.
Contou D et al. Small-bore catheter versus chest tube drainage for pneumothorax. Am J Emerg Med. 2012 Oct. 30 (8):1407-13.
Rami A. et al. Iatrogenic emergency medicine procedure complications and associated trouble-shooting strategies: A narrative review: https://doi.org/10.1108/IJHCQA-08-2017-0157 OPEN ACCESS
Just recently a 75-year-old gentleman was admitted to our unit as he remained unresponsive after short procedural sedation with Propofol. Although he was hemodynamically stable and showed proper spontaneous breathing at any time, the intervention team was concerned about his condition.
On arrival to our ICU, the patient was noted to be still unresponsive. He showed no reaction to painful stimulation. The Pupils were rather wide, but symmetrical in size and showed a prompt response to light. Brain stem reflexes were present and peripheral reflexes were triggerable. His breathing pattern was regular, and saturation levels were above 96% on room air. A blood gas analysis showed a normal pH and normal CO2-levels.
As usual, the common reflexes started to kick in, and some suggested to go for a CT-scan of his head to out-rule some significant complications. Luckily enough, close observation revealed some slow improvement of his alertness, and we considered the possible diagnosis of a central anticholinergic syndrome (CAS).
After the application of 1mg of physostigmine (2x0.5mg) intravenously the patient almost promptly awoke and had an uneventful stay on our unit.
This case just reminded me of these many patients in anaesthesia that inexplicably show delayed awakening after sedation or a general anaesthetic.
In fact, it is estimated that the incidence of central anticholinergic syndrome is around 8- 12 % following general anaesthetic and lesser with regional anaesthesia.
On arrival to our ICU, the patient was noted to be still unresponsive. He showed no reaction to painful stimulation. The Pupils were rather wide, but symmetrical in size and showed a prompt response to light. Brain stem reflexes were present and peripheral reflexes were triggerable. His breathing pattern was regular, and saturation levels were above 96% on room air. A blood gas analysis showed a normal pH and normal CO2-levels.
As usual, the common reflexes started to kick in, and some suggested to go for a CT-scan of his head to out-rule some significant complications. Luckily enough, close observation revealed some slow improvement of his alertness, and we considered the possible diagnosis of a central anticholinergic syndrome (CAS).
After the application of 1mg of physostigmine (2x0.5mg) intravenously the patient almost promptly awoke and had an uneventful stay on our unit.
This case just reminded me of these many patients in anaesthesia that inexplicably show delayed awakening after sedation or a general anaesthetic.
In fact, it is estimated that the incidence of central anticholinergic syndrome is around 8- 12 % following general anaesthetic and lesser with regional anaesthesia.
What is a Central Anticholinergic Syndrome?
Classically the central anticholinergic syndrome (CAS) describes a condition where a substance causes a competitive antagonism of acetylcholine (ACh) at peripheral and central muscarinic receptors. Initially, these were plants containing atropine, hyoscyamine and scopolamine.
There are four muscarinic receptors:
- M1 mainly in the central nervous system (responsible for delirium when antagonised)
- M2 in the brain and heart
- M3 in the salivary glands and
- M4 in the brain and lungs
The PERIPHERAL SYNDROME presents with:
- Dry mouth
- Difficulty swallowing (lack of saliva)
- Photophobia and blurred vision (due to dilated pupils)
- Dry skin, fever
- Reduced bowel sounds and urinary retention
The CENTRAL SYNDROME presents with:
- Agitation, agitated delirium, visual and auditory hallucinations
- Hypoactive delirium may also occur, this seems to be more common though in the postoperative setting
The clinical diagnosis of a CAS is more straightforward when typical peripheral symptoms accompany central signs.
The Problem with the "Silent" Postoperative CAS
The clinical diagnosis of a CAS is often straight forward when typical central symptoms accompany peripheral symptoms. The problems are patients in the postoperative setting, in which the patient often presents with somewhat atypical central symptoms and often minimal or even no peripheral symptoms at all.
Especially in this setting, the anticholinergic syndrome may be accompanied by sedation or coma. The mechanisms causative for this phenomenon are not well understood but might include greater tolerance at peripheral receptors, longer persistence at central receptors or greater CNS susceptibility due to age or disease.
Postoperative CAS is often associated with atypical central symptoms and minimal or even no peripheral signs at all! Sedation and coma are often observed in this setting.
What Drugs Cause CAS?
Common anticholinergics agents should be more accurately referred to as antimuscarinics, as these agents do not generally block nicotinic receptors.
A. H. Dawson, Br J Clin Pharmacol, Nov 2015
The Problem is that many currently used drugs in anaesthesia and critical care are also known to cause this syndrome.
This includes:
Benzodiazepines, opioids, phenothiazines, butyrophenones, ketamine, etomidate, propofol, nitrous oxide, and volatile inhaled anaesthetics!
How Can I Diagnose a "Silent" Postoperative CAS?
The fact that postoperative CAS often lacks the presence of peripheral symptoms makes the diagnosis challenging. The different presentation of the syndrome ranging from somnolence, confusion, amnesia, delayed recovery, stupor, coma to agitation, hallucinations, dysarthria, ataxia, delirium makes it difficult to diagnose accurately.
It is, therefore, a diagnosis of exclusion! The most helpful tool you have is physostigmine!
The prompt arousal of a patient after the application of intravenous physostigmine is highly suggestive of a postoperative central anticholinergic syndrome.
How to Use Physostigmine
When dealing with prolonged somnolence or unexplained agitation following any form of anaesthesia, make sure to check and monitor vital signs and provide basic or advanced life support if necessary.
Exclude common causes first (e.g. overhang of sedatives or opioids, persistent muscular paralysis, hypoxemia, hypercapnia, hypoglycemia and other).
If common causes can be excluded and CAS is a probable diagnosis, you should consider the application of intravenous physostigmine.
Physostigmine in recommended doses is considered safe! Possible adverse effects are considered unlikely. Studies found cholinergic symptoms sometimes to be mild, and these adverse effects are more an indication of probable excessive doses rather than an established safety concern.
For postoperative CAS a dose of 1mg of physostigmine i/v is recommended.
This dose can be divided into two doses of 0.5mg i/v if required.
The maximum dose recommended in this setting is 2mg i/v.
Updated 28/01/2019
While this website concentrates on finding relevant publications from the world of Critical Care, there are always papers from other fields that attract our attention.
Recently, a remarkable detail from a publication of an even more noteworthy journal has been brought to our notice. I admit I rarely read articles on 'Nature', but this article is worth a very close look after all.
Chiou L. et al. have published an article about a noninvasive genomic sequencing of populations from faeces in this years January issue of Scientific Reports of 'Nature'. In this article, they deal with the problem that it is difficult to obtain high-quality samples for genomic studies from wild animals. They, therefore, describe a cost-effective method for enriching host DNA from noninvasive faecal samples.
And in fact, it is worthwhile to have a closer look at the faeces sample in this article as Nature has placed a portrait of Mr Trump in a rather delicate position.
While this website concentrates on finding relevant publications from the world of Critical Care, there are always papers from other fields that attract our attention.
Recently, a remarkable detail from a publication of an even more noteworthy journal has been brought to our notice. I admit I rarely read articles on 'Nature', but this article is worth a very close look after all.
Chiou L. et al. have published an article about a noninvasive genomic sequencing of populations from faeces in this years January issue of Scientific Reports of 'Nature'. In this article, they deal with the problem that it is difficult to obtain high-quality samples for genomic studies from wild animals. They, therefore, describe a cost-effective method for enriching host DNA from noninvasive faecal samples.
And in fact, it is worthwhile to have a closer look at the faeces sample in this article as Nature has placed a portrait of Mr Trump in a rather delicate position.
Finding the hidden Trump-Portrait, here's how:
Update 28/01/2019: The authors have reacted and changed the resolution of the image so that a closer zoom is no longer possible. Following instructions refers to the previous publication.
1. Open the article in pubmed (just to proof, it's no fake news):
Chiou KL et al. Scientific Reports, 2018 January 31: Methylation-based enrichement facilitates low-cost, noninvasive genomic scale sequencing of populations from feces
2. It's OPEN ACCESS! Open the article via the full text links on the top right.
3. Download the pdf version of the article.
4. Go to page 3, figure 1. Spot the heap of feces right behind the pavian?
5. Zoom in on that heap of feces... zoom in closer... even closer!
This publication impressively demonstrates the interdependence of science and politics.
Remember, sometimes the unexpected lies in the detail.
Did the editors of Nature actually realise this?
Update 28/01/2019: Well, obviously they now have!
OPEN ACCESS: Chiou KL et al. Scientific Reports 2018 January 31: Methylation-based enrichement facilitates low-cost, noninvasive genomic scale sequencing of populations from feces
Anticoagulated patients are common, and the amount of available oral anticoagulants is becoming more diverse and confusing. Anticoagulation is the cornerstone in the treatment of thrombosis and thromboembolic complications in a variety of diseases. Lixiana, Pradaxa, Eliquis and Xarelto are some of these pretty-sounding drugs that many doctors know but find it difficult to keep up.
So if you work in an emergency room, anaesthesia or intensive care, there's a good chance you will be facing an anticoagulant patient with potentially critical bleeding that could require urgent treatment... And this leaves you with the following questions:
- What is a critical bleed (apart from obvious massive bleeding)? Does this bleeding need imminent reversal?
- Do I need any laboratory testing before?
- What treatment should I actually give the patient?
If you do not have a guideline in your institution, it may be time to create one, and the following publication is indeed very useful for this purpose!
The 2017 ACC Expert Consensus Decision Pathway on Management of Bleeding in Patients on Oral Anticoagulants very nicely summarises current evidence and expert opinion on these issues. But the very best are their excellent figures, providing all the answers you need: simple and very understandable!
So if you work in an emergency room, anaesthesia or intensive care, there's a good chance you will be facing an anticoagulant patient with potentially critical bleeding that could require urgent treatment... And this leaves you with the following questions:
- What is a critical bleed (apart from obvious massive bleeding)? Does this bleeding need imminent reversal?
- Do I need any laboratory testing before?
- What treatment should I actually give the patient?
If you do not have a guideline in your institution, it may be time to create one, and the following publication is indeed very useful for this purpose!
The 2017 ACC Expert Consensus Decision Pathway on Management of Bleeding in Patients on Oral Anticoagulants very nicely summarises current evidence and expert opinion on these issues. But the very best are their excellent figures, providing all the answers you need: simple and very understandable!
What is a Critical Bleeding?
Do I Need any Laboratory Tests Before?
What Treatment Should I Give the Patient for Reversal?
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