Tag Archives: critical care

Acute Med, All Updates, ICU, Resus

The opposite of acute kidney injury?

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Prescribing in the critically ill patient can be a challenge due to a number of factors impacting on pharmacology:

  • variable enteral absorption and interaction with enteral feed
  • less protein binding in hypoalbuminaemic states
  • extravascular volume expansion with fluid loading and capillary leak can alter the volume of distribution
  • altered hepatic metabolism of drugs
  • impaired renal excretion
  • accumulation of toxic metabolites
  • removal by renal replacement therapy
  • interaction with other drugs

There’s another factor to bear in mind, though, which has been recently highlighted in the context of antibiotic prescription: that of Augmented Renal Clearance (ARC).
Some ICU patients have supraphysiologic renal function. Several studies have demonstrated significant numbers of ICU patients with higher than normal creatinine clearance. This is thought to be due to varying combinations of the following factors:

  • Low systemic vascular resistance and increased cardiac output leading to increased renal blood flow
  • Above factors enhanced by aggressive fluid and vasoactive therapy in pursuit of haemodynamic targets
  • These lead to increase delivery of solute to the kidneys and increased clearance

This can have implications for prescribing: the serum creatinine will not identify these patients, but it is possible that ARC will result in less effective therapy for a given dose of a renally-excreted drug, for example beta-lactam antibiotics.
An editorial by critical care physician Dr Andrew Shorr highlights the inadequacy of basing prescribing recommendations on data from the ex-vivo interaction between drug and pathogen:

‘To believe that all patients will respond in the same fashion and with the same trajectory is to become handcuffed by the median response noted in clinical trials……….The central fallacy of the bug-drug approach is that it misses the key role of the host.’

Sub-therapeutic initial β-lactam concentrations in select critically ill patients: association between augmented renal clearance and low trough drug concentrations
Chest. 2011 Dec 22. [Epub ahead of print] Free Full Text
Antibiotics in the critically ill: the bug, drug, host triad
Chest. 2012 Jul 1;142(1):8-10 Free Full Text

All Updates, ICU, PHARM, Resus

Size matters when you're sick

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A nice example of a difference between elective anaesthesia and critical care practice when it comes to airway management is the selection of appropriate tracheal tube size when intubating, which is highlighted in a recent Anaesthesia article.
In recent years progressively smaller tubes have been used in anaesthesia in pursuit of decreased tracheal injury, sore throat, and hoarseness and increased ease of placement.
Patients likely to remain intubated for some time due to critical illness, however, may benefit from larger diameter tubes for the following reasons:

  • Accumulation of biofilm debris, which increases with duration of intubation – this can significantly decrease the luminal internal diameter, but is less likely to be significant with larger tubes.
  • Work of breathing during weaning: spontaneous breathing trials prior to extubation require patients to breathe through tracheal tubes. Volunteer studies have demonstrated that work of breathing increases as tube diameter decreases.
  • Bronchoscopes and suction catheters: the standard adult ICU fibreoptic bronchoscope has a diameter of 5.7 mm with a 2-mm suction channel to enable adequate suction, which limits the tracheal tube to those larger than 7.5–8.0 mm, and even with an 8.0-mm tube, the bronchoscope occupies more than 50% of the tube diameter, which can lead to ventilation issues during bronchoscopy.

The authors conclude by recommending:


‘If admission to ICU is contemplated then the time-honoured ‘8.0 for females, 9.0 for males’ is a reasonable rule of thumb, unless circumstances dictate otherwise, e.g. in difficult airways or particularly small patients.’

Size matters: choosing the right tracheal tube
Anaesthesia. 2012 Aug;67(8):815-9

Acute Med, All Updates, ICU

Unknown unknowns and pleural effusions

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There are plenty of unknowns when it comes to management of pleural effusions on the ICU, which led to a paper with an eye-catching title1.
Mechanically ventilated patients frequently have pleural effusions detected by radiological investigations. Whether to drain them is a common conundrum for intensivists. A systematic review of the literature showed that drainage often improves oxygenation and has a low complication rate2.
While it may have the added advantage of assisting diagnosis and guiding therapy, there is a paucity of literature demonstrating improved patient-orientated outcomes with the routine drainage of pleural effusions in ventilated patients.
 
1. A pseudo-Rumsfeldian approach to pleural effusions in mechanically ventilated patients.
Crit Care. 2011 Mar 11;15(2):132 Free Full Text
2. Utility and safety of draining pleural effusions in mechanically ventilated patients: a systematic review and meta-analysis.
Crit Care. 2011;15(1):R46 Free Full Text
[EXPAND Click to read abstract]

INTRODUCTION: Pleural effusions are frequently drained in mechanically ventilated patients but the benefits and risks of this procedure are not well established.

METHODS: We performed a literature search of multiple databases (MEDLINE, EMBASE, HEALTHSTAR, CINAHL) up to April 2010 to identify studies reporting clinical or physiological outcomes of mechanically ventilated critically ill patients who underwent drainage of pleural effusions. Studies were adjudicated for inclusion independently and in duplicate. Data on duration of ventilation and other clinical outcomes, oxygenation and lung mechanics, and adverse events were abstracted in duplicate independently.

RESULTS: Nineteen observational studies (N = 1,124) met selection criteria. The mean PaO2:FiO2 ratio improved by 18% (95% confidence interval (CI) 5% to 33%, I2 = 53.7%, five studies including 118 patients) after effusion drainage. Reported complication rates were low for pneumothorax (20 events in 14 studies including 965 patients; pooled mean 3.4%, 95% CI 1.7 to 6.5%, I2 = 52.5%) and hemothorax (4 events in 10 studies including 721 patients; pooled mean 1.6%, 95% CI 0.8 to 3.3%, I2 = 0%). The use of ultrasound guidance (either real-time or for site marking) was not associated with a statistically significant reduction in the risk of pneumothorax (OR = 0.32; 95% CI 0.08 to 1.19). Studies did not report duration of ventilation, length of stay in the intensive care unit or hospital, or mortality.

CONCLUSIONS: Drainage of pleural effusions in mechanically ventilated patients appears to improve oxygenation and is safe. We found no data to either support or refute claims of beneficial effects on clinically important outcomes such as duration of ventilation or length of stay.

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Acute Med, All Updates, ICU, Resus

Confidential stuff – in hospital cardiac arrests

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A new report describes room for improvement in the care of cardiac arrest patients in hospital1.
The National Confidential Enquiry into Patient Outcome and Death (NCEPOD) aimed to describe variability and identify remediable factors in the process of care of adult patients who receive resuscitation in hospital, including factors which may affect the decision to initiate the resuscitation attempt, the outcome and the quality of care following the resuscitation attempt, and antecedents in the preceding 48 hours that may have offered opportunities for intervention to prevent cardiac arrest.
Data were captured over a 14 day study period in late 2010 from UK hospitals, and were reviewed by an expert panel.
The summary is available here. I have picked out some findings of interest:

  • An adequate history was not recorded in 70/489 cases (14%) and clinical examination was incomplete at first contact in 117/479 cases (24%).

  • Appreciation of the severity of the situation was lacking in 74/416 (18%).

  • Timely escalation to more senior doctors was lacking in 61/347 (18%).

  • Decisions about CPR status were documented in the admission notes in 44/435 cases (10%). This is despite the high incidence of chronic disease and almost one in four cases being expected to be rapidly fatal on admission.

  • Where time to first consultant review could be identified it was more than 12 hours in 95/198 cases (48%).

  • Appreciation of urgency, supervision of junior doctors and the seeking of advice from senior doctors were rated ‘poor’ by Advisors.

  • Physiological instability was noted in 322/444 (73%) of patients who subsequently had a cardiac arrest.

  • Advisors considered that warning signs for cardiac arrest were present in 344/462 (75%) of cases. These warning signs were recognised poorly, acted on infrequently, and escalated to more senior doctors infrequently.

  • There was no evidence of escalation to more senior staff in patients who had multiple reviews.

  • Advisors considered that the cardiac arrest was predictable in 289/454 (64%) and potentially avoidable in 156/413 (38%) of cases.

  • The Advisors reported problems during the resuscitation attempt in 91/526 cases (17%). Of these, 36/91 were associated with airway management.

  • Survival to discharge after in-hospital cardiac arrest was 14.6% (85/581).

  • Only 9/165 (5.5%) patients who had an arrest in asystole survived to hospital discharge.

  • Survival to discharge after a cardiac arrest at night was much lower than after a cardiac arrest during the day time (13/176; 7.4% v 44/218; 20.1%).

 
In the opinion of the treating clinicians, earlier treatment of the problem and better monitoring may have improved outcome:

Compare these findings with a smaller scale confidential enquiry into the care of patients who ended up in intensive care units, published exactly 14 years ago by McQuillan et al2:
“The main causes of suboptimal care were failure of organisation, lack of knowledge, failure to appreciate clinical urgency, lack of supervision, and failure to seek advice.”
One of the co-authors of the McQuillan study, Professor Gary Smith , has spent years improving training in and awareness of the importance of recognition of critical illness, and pioneered the “ALERT” Course TM: Acute Life-threatening Emergencies, Recognition, and Treatment. Professor Smith provides commentary on the NCEPOD report and the slides are available here, including a reminder of the ‘Chain of Prevention’3.

It’s a shame these issues remain a problem but it is heartening to see NCEPOD tackle this important topic and provide recommendations that UK hospitals will have to act upon. It is further credit to the vision of Pete McQuillan, Gary Smith and their colleague Bruce Taylor (another co-author of the 1998 confidential inquiry). These guys opened my eyes to the world of critical care and trained me for 18 months on their ICU, which remains a beacon site for critical care expertise and training. Without their inspiration, I may not have ended up in emergency medicine-critical care and I doubt very much that Resus.ME would exist.

1. Cardiac Arrest Procedures: Time to Intervene? (2012)
National Confidential Enquiry into Patient Outcome and Death (NCEPOD)
2. Confidential inquiry into quality of care before admission to intensive care
BMJ 1998 Jun 20;316(7148):1853-8 Free Full Text
[EXPAND Click to read abstract]


OBJECTIVE: To examine the prevalence, nature, causes, and consequences of suboptimal care before admission to intensive care units, and to suggest possible solutions.

DESIGN: Prospective confidential inquiry on the basis of structured interviews and questionnaires.

SETTING: A large district general hospital and a teaching hospital.

SUBJECTS: A cohort of 100 consecutive adult emergency admissions, 50 in each centre.

MAIN OUTCOME MEASURES: Opinions of two external assessors on quality of care especially recognition, investigation, monitoring, and management of abnormalities of airway, breathing, and circulation, and oxygen therapy and monitoring.

RESULTS: Assessors agreed that 20 patients were well managed (group 1) and 54 patients received suboptimal care (group 2). Assessors disagreed on quality of management of 26 patients (group 3). The casemix and severity of illness, defined by the acute physiology and chronic health evaluation (APACHE II) score, were similar between centres and the three groups. In groups 1, 2, and 3 intensive care mortalities were 5 (25%), 26 (48%), and 6 (23%) respectively (P=0.04) (group 1 versus group 2, P=0.07). Hospital mortalities were 7 (35%), 30 (56%), and 8 (31%) (P=0.07) and standardised hospital mortality ratios (95% confidence intervals) were 1.23 (0.49 to 2.54), 1.4 (0.94 to 2.0), and 1.26 (0.54 to 2.48) respectively. Admission to intensive care was considered late in 37 (69%) patients in group 2. Overall, a minimum of 4.5% and a maximum of 41% of admissions were considered potentially avoidable. Suboptimal care contributed to morbidity or mortality in most instances. The main causes of suboptimal care were failure of organisation, lack of knowledge, failure to appreciate clinical urgency, lack of supervision, and failure to seek advice.

CONCLUSIONS: The management of airway, breathing, and circulation, and oxygen therapy and monitoring in severely ill patients before admissionto intensive care units may frequently be suboptimal. Major consequences may include increased morbidity and mortality and requirement forintensive care. Possible solutions include improved teaching, establishment of medical emergency teams, and widespread debate on the structure and process of acute care.

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3. In-hospital cardiac arrest: is it time for an in-hospital ‘chain of prevention’?
Resuscitation. 2010 Sep;81(9):1209-11
[EXPAND Click to read abstract]


The ‘chain of survival’ has been a useful tool for improving the understanding of, and the quality of the response to, cardiac arrest for many years. In the 2005 European Resuscitation Council Guidelines the importance of recognising critical illness and preventing cardiac arrest was highlighted by their inclusion as the first link in a new four-ring ‘chain of survival’. However, recognising critical illness and preventing cardiac arrest are complex tasks, each requiring the presence of several essential steps to ensure clinical success. This article proposes the adoption of an additional chain for in-hospital settings–a ‘chain of prevention’–to assist hospitals in structuring their care processes to prevent and detect patient deterioration and cardiac arrest. The five rings of the chain represent ‘staff education’, ‘monitoring’, ‘recognition’, the ‘call for help’ and the ‘response’. It is believed that a ‘chain of prevention’ has the potential to be understood well by hospital clinical staff of all grades, disciplines and specialties, patients, and their families and friends. The chain provides a structure for research to identify the importance of each of the various components of rapid response systems.

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Acute Med, All Updates, ICU, Resus

Thrombolytic Therapy in Unstable Patients with PE

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Most of us would give strong consideration to giving thrombolytics to patients with massive pulmonary embolism (PE), which is in keeping with many guidelines. Some physicians remain reluctant to do so, often citing the lack of good evidence. It is true that large scale RCTs have not been done in this population. The authors of this recent retrospective study state:


There are no definitive trials that prove the value of thrombolytic therapy in unstable patients with pulmonary embolism. It is extremely remote that a randomized controlled trial will be performed in the future. We therefore analyzed the database of the Nationwide Inpatient Sample to test the hypothesis that thrombolytic therapy reduces case fatality rate in unstable patients with acute pulmonary embolism.

They demonstrate a striking difference in mortality when thrombolysis is given to unstable patients with PE, which is further reduced with the addition of a vena cava filter. ‘Unstable’ was defined as having a listed code for shock or ventilator dependence.

Associated comorbid conditions were more often present in those who did not receive thrombolytic therapy than in those who did. However in their discussion the authors add:


Although unstable patients who received thrombolytic therapy had fewer comorbid conditions than those who did not, this would not explain the difference in case fatality rate because unstable patients with a primary diagnosis of pulmonary embolism and none of the comorbid conditions…also showed a lower case fatality rate with thrombolytic therapy. Therefore, differences in comorbid conditions in this group were eliminated as a possible cause of the lower case fatality rate in unstable patients who received thrombolytic therapy.

They round off their conclusion with:


Despite the marked reduction of case fatality rate with thrombolytic therapy in unstable patients, only 30% of unstable patients received it, and the proportion receiving thrombolytic therapy is diminishing. On the basis of these data, thrombolytic therapy in combination with a vena cava filter in unstable patients with acute pulmonary embolism seems indicated.

Many thanks to Dr Daniel Horner for highlighting this paper.


BACKGROUND: Data are sparse and inconsistent regarding whether thrombolytic therapy reduces case fatality rate in unstable patients with acute pulmonary embolism. We tested the hypothesis that thrombolytic therapy reduces case fatality rate in such patients.

METHODS: In-hospital all-cause case fatality rate according to treatment was determined in unstable patients with pulmonary embolism who were discharged from short-stay hospitals throughout the United States from 1999 to 2008 by using data from the Nationwide Inpatient Sample. Unstable patients were in shock or ventilator dependent.

RESULTS: Among unstable patients with pulmonary embolism, 21,390 of 72,230 (30%) received thrombolytic therapy. In-hospital all-cause case fatality rate in unstable patients with thrombolytic therapy was 3105 of 21,390 (15%) versus 23,820 of 50,840 (47%) without thrombolytic therapy (P< .0001). All-cause case fatality rate in unstable patients with thrombolytic therapy plus a vena cava filter was 505 of 6630 (7.6%) versus 4260 of 12,850 (33%) with a filter alone (P<.0001). Case fatality rate attributable to pulmonary embolism in unstable patients was 820 of 9810 (8.4%) with thrombolytic therapy versus 1080 of 2600 (42%) with no thrombolytic therapy (P<.0001). Case fatality rate attributable to pulmonary embolism in unstable patients with thrombolytic therapy plus vena cava filter was 70 of 2590 (2.7%) versus 160 of 600 (27%) with a filter alone (P<.0001).
CONCLUSION: In-hospital all-cause case fatality rate and case fatality rate attributable to pulmonary embolism in unstable patients was lower in those who received thrombolytic therapy. Thrombolytic therapy resulted in a lower case fatality rate than using vena cava filters alone, and the combination resulted in an even lower case fatality rate. Thrombolytic therapy in combination with a vena cava filter in unstable patients with acute pulmonary embolism seems indicated.

Thrombolytic Therapy in Unstable Patients with Acute Pulmonary Embolism: Saves Lives but Underused
Am J Med. 2012 May;125(5):465-70

All Updates, ICU, Kids, Ultrasound

Not a pin cushion

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This is the daughter of my friend. Avery is only seven months old and has survived a critical illness and is thankfully now fully recovered. Her Dad has nothing but praise for the medical and nursing staff who cared for her. But one thing could have been better. Avery endured multiple attempts at vascular access without ultrasound guidance.

If you were her parent, and you were an emergency physician with galaxy-class expertise in emergency ultrasound, how would you react? Complaints? Incident forms? Outrage?
How about education? For free. Accompanied by lavish praise for the experts who treated Avery and made her better.
Avery’s Dad is ultrasound podcaster and gentleman Dr Matt Dawson. He is offering FREE ultrasound training to anyone who wants to improve their vascular access skills.
Are there nurses, physicians, or technicians in your ED or ICU that could improve their care with this training? Please consider sending them for this training. To register for the course, and to read Avery’s full story, go to notapincushion.com.
And if you’re already comfortable with ultrasound-guided vascular access, then visit the site anyway, as there is some education here for all of us: how to turn a gut-wrenchingly distressing experience into something positive that will benefit countless others. I am thoroughly inspired.
Best wishes to an amazing family.
Cliff

All Updates, ICU, Kids

Passive leg raise predicted fluid responsiveness in kids

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Passive leg raising (PLR) is a great ‘free reversible fluid challenge’ to see if a shocked or hypotensive patient is likely to respond to volume therapy. A new study assesses its applicability in children.
PLR predicted fluid responders with 85% specificity but a lack of response did not rule out fluid responsiveness. Also, the effect of the PLR on cardiac index measured by echocardiography was the only way of predicting response – there was no relation to the more easily monitored effects of PLR on systolic blood pressure or heart rate.
Want to learn how to measure cardiac output using ultrasound? Mike Mallin from the Emergency Ultrasound Podcast shows you how here


OBJECTIVE: Fluid challenge is often used to predict fluid responsiveness in critically ill patients. Inappropriate fluid expansion can lead to some unwanted side effects; therefore, we need a noninvasive predictive parameter to assess fluid responsiveness. We want to assess the hemodynamic parameter changes after passive leg raising, which can mimic fluid expansion, to predict fluid responsiveness in pediatric intensive care unit patients and to get a cutoff value of cardiac index in predicting fluid responsiveness in pediatric patients.

DESIGN: Nonrandomized experimental study.

SETTING: Tertiary academic pediatric intensive care.

PATIENTS: Children admitted to pediatric intensive care.

INTERVENTION: Hemodynamic parameters were assessed at baseline, after passive leg raising, at second baseline, and after volume expansion (10 mL/kg normal saline infusion over 15 mins).

MEASUREMENTS AND MAIN RESULTS: We measured the heart rate, systolic blood pressure, and stroke volume and cardiac index using Doppler echocardiography. The hemodynamic parameter changes induced by passive leg raising were monitored. Among 40 patients included in the study, 20 patients had a cardiac index increase of ≥10% after volume expansion (responders). Changes in heart rate, systolic blood pressure, and stroke volume after passive leg raising did not significantly relate to the response to volume expansion. There was significant relation between changes in cardiac index to predict fluid responsiveness (p = .012, r = .22, 95% confidence interval 1.529 to 31.37). A cardiac index increase by ≥10% induced by passive leg raising predicted preload-dependent status with sensitivity of 55% and specificity of 85% (area under the curve 0.71 ± 0.084, 95% confidence interval 0.546-0.874).

CONCLUSION: The concomitant measurements in cardiac index changes after the passive leg raising maneuver can be helpful in predicting who might have an increase in cardiac index with subsequent fluid resuscitation.

The role of passive leg raising to predict fluid responsiveness in pediatric intensive care unit patients.
Pediatric Critical Care Medicine. 13(3):e155-e160, May 2012

All Updates, ICU, Resus

Non-invasive BP in shock

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In the management of the shocked patient, we sometimes get a little fixated on the need for an arterial line. This is in part due to previous studies suggesting non-invasive blood pressure (NIBP) measurements were inaccurate in the critically ill. This appears no longer to be the case with modern oscillometric devices and carefully chosen cuff sizes. This recent study showed mean arterial pressure (MAP) measured non-invasively from the arm closely correlated with invasive measurements. NIBP was effective at identifying hypotension and recording the response to therapy. Although patients with severe occlusive arterial disease were excluded, the study did include a number of shocked patients on vasoactive therapies.
Systolic and diastolic pressures were not accurate. This should not be surprising since, as the authors explain:
“oscillometric devices directly measure the MAP and only extrapolate systolic arterial pressure and diastolic arterial pressure, using proprietary algorithms”
Thia study suggests that NIBP measurement of MAP from the arm is accurate but, if contraindicated, the ankle (or even the thigh in older sedated patients) may be a suitable alternative site permitting a reliable detection of hypotensive and therapy-responding patients.

OBJECTIVE: In the critically ill, blood pressure measurements mostly rely on automated oscillometric devices pending the intra-arterial catheter insertion or after its removal. If the arms are inaccessible, the cuff is placed at the ankle or the thigh, but this common practice has never been assessed. We evaluated the reliability of noninvasive blood pressure readings at these anatomic sites.
DESIGN: Prospective observational study.
SETTING: Medical-surgical intensive care unit.
PATIENTS: Patients carrying an arterial line with no severe occlusive arterial disease.
INTERVENTION: Each patient underwent a set of three pairs of noninvasive and intra-arterial measurements at each site (arm, ankle, thigh [if Ramsay sedation scale >4]) and, in case of circulatory failure, a second set of measurements after a cardiovascular intervention (volume expansion, change in catecholamine dosage).
MEASUREMENTS AND MAIN RESULTS: In 150 patients, whatever the cuff site, the agreement between invasive and noninvasive readings was markedly higher for mean arterial pressure than for systolic or diastolic pressure. For mean arterial pressure measurement, arm noninvasive blood pressure was reliable (mean bias of 3.4 ± 5.0 mm Hg, lower/upper limit of agreement of -6.3/13.1 mm Hg) contrary to ankle or thigh noninvasive blood pressure (mean bias of 3.1 ± 7.7 mm Hg and 5.7 ± 6.8 mm Hg and lower/upper limits of agreement of -12.1/18.3 mm Hg and -7.7/19.2 mm Hg, respectively). During acute circulatory failure (n = 83), arm noninvasive blood pressure but also ankle and thigh noninvasive blood pressure allowed a reliable detection of 1) invasive mean arterial pressure 10%) increase in invasive mean arterial pressure after a cardiovascular intervention (area under the receiver operating characteristic curve of 0.99 [0.92-1], 0.90 [0.80-0.97], and 0.96 [0.87-0.99], respectively).
CONCLUSION: In our population, arm noninvasive mean arterial pressure readings were accurate. Either the ankle or the thigh may be reliable alternatives, only to detect hypotensive and therapy-responding patients.

Noninvasive monitoring of blood pressure in the critically ill: Reliability according to the cuff site (arm, thigh, or ankle)
Crit Care Med. 2012 Apr;40(4):1207-13

All Updates, ICU, Resus

Intubation of the critically ill in Scotland

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Hi folks! Cliff has given me the helm of his blogsite for this week whilst he is teaching prehospital and critical care ultrasound with the Americans at Castlefest 2012
He invited me to write an article on this latest paper in British Journal of Anaesthesia on Scottish ICU audit of emergency tracheal intubation. For those who don’t know, Cliff has a proud Scottish heritage and this paper is a useful audit of his home land’s performance of this critical care intervention. I have done airway audits and this one is quite a reasonable 4 month effort albeit not every ICU in Scotland participated, which is not unusual for those wanting to do these kind of audits. Airway management gets a bit personal and some find review of their emergency airway performance to be confronting. It should not be. Now it’s a fine distinction but its important to be clear on this. A FAILED AIRWAY DOES NOT MEAN YOU ARE A FAILURE!! FAILED OXYGENATION IS ANOTHER STORY….
There are always recurring themes from audits like these and I will highlight a few.
The first and foremost, is the absolutely essential role of capnography for tracheal tube confirmation and monitoring of airway patency and ventilator status. My FDEAR aeromedical intubation audit showed this was an issue of patient safety that should be improved.
This Scottish ICU study revealed that capnography was used in only 54% of emergency intubations despite the vast majority being in hospital locations where such monitoring is available! This is a recurring theme amongst emergency airway audits and coroners reports like this one.
Paradoxically this Scottish audit had a high number of intubating doctors with greater than 24 months of anaesthetic training and one hypothesis I have is that as doctors become more confident in emergency intubations, perhaps less reliance is felt required on monitoring like capnography? In human factors research into anaesthetic related crises, we call this the invulnerability or superman complex : “If I say the tube has gone in, I must be right!”
Secondly, the length of anaesthetic training of the intubating doctor appeared related to overall airway success rates and a low complication rate. There was only one surgical airway required over the 4 month period and 794 recorded intubations. The authors discuss though the potential problems that may face up and coming critical care doctors in the United Kingdom who may not be exposed to terms of anaesthetic training of up to 2 years. My own personal view is that it does not and should not matter where you get your emergency airway training but it should be structured and specific to the work that you are going to do. Learning to do epidural anaesthesia in laboring women might not be so helpful for the bilateral pneumonia swine flu patient with a BMI of 50! And certainly no point learning to use airway equipment that you will rarely or never have available where you normally work!
Thirdly and I find this fascinating having heard talks and debates on this topic by Dr Scott Weingart and Dr Paul Mayo, but in this Scottish paper of bloody sick patients needing intubation, 8% were performed without paralytics at all and overall intubation success and number of attempts were not significantly different compared to the paralytic assisted group. My view is that overall in critically ill patients , paralytics are your friend as these folks need the airway secured, one way or another. However this paper and Dr Mayo’s work certainly demonstrate that sedation only intubation is successful and is a reasonable alternative.
Finally, 61% of these emergency intubations utilized propofol and there was an association with post intubation hypotension (systolic <70mmHg). Ketamine use was low at 3% and I think this just reflects the greater anaesthetic training of the doctors in the study. I am aware Cliff has done a previous podcast rant on Propofol assasins
I don’t want to rant and am not as good at it as Cliff. BUT Choose your poison carefully! This paper reminds us what we all know. The milk of amnesia has issues! Ask the Jackson family!
Anyway that’s enough for this paper. I gotta pick myself off the floor again after listening to Cliff’s propofol rant..
– Dr Minh Le Cong, Royal Flying Doctor Service, Australia

BACKGROUND: Complications associated with tracheal intubation may occur in up to 40% of critically ill patients. Since practice in emergency airway management varies between intensive care units (ICUs) and countries, complication rates may also differ. We undertook a prospective, observational study of tracheal intubation performed by critical care doctors in Scotland to identify practice, complications, and training.
METHODS: For 4 months, we collected data on any intubation performed by doctors working in critical care throughout Scotland except those in patients having elective surgery and those carried out before admission to hospital. We used a standardized data form to collect information on pre-induction physical state and organ support, the doctor carrying out the intubation, the techniques and drugs used, and complications noted.
RESULTS: Data from 794 intubations were analysed. Seventy per cent occurred in ICU and 18% occurred in emergency departments. The first-time intubation success rate was 91%, no patient required more than three attempts at intubation, and one patient required surgical tracheostomy. Severe hypoxaemia ( <80%) occurred in 22%, severe hypotension (systolic arterial pressure <80 mm Hg) in 20%, and oesophageal intubation in 2%. Three-quarters of intubations were performed by doctors with more than 24 months formal anaesthetic training and all but one doctor with <6 months training had senior supervision.
CONCLUSIONS: Tracheal intubation by critical care doctors in Scotland has a higher first-time success rate than described in previous reports of critical care intubation, and technical complications are few. Doctors carrying out intubation had undergone longer formal training in anaesthesia than described previously, and junior trainees are routinely supervised. Despite these good results, further work is necessary to reduce physiological complications and patient morbidity.

Tracheal intubation in the critically ill: a multi-centre national study of practice and complications
Br J Anaesth. 2012 May;108(5):792-9

All Updates, Guidelines, ICU, Resus

Extubation guidelines

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Tracheal extubation is a high risk procedure in anaesthesia and critical care. Until now most guidelines have focused on intubation, with little to guide the process of extubation. Complications may relate to the following issues:

  • Exaggerated reflexes – laryngospasm (which can lead to both hypoxia and negative pressure pulmonary oedema) and bronchospasm
  • Reduced airway reflexes
  • Dysfunctional laryngeal reflexes
  • Depletion of oxygen stores at extubation
  • Airway injury
  • Physiological compromise in other systems
  • Human factors

The goal is to ensure uninterrupted oxygen delivery to the patient’s lungs, avoid airway stimulation, and have a back-up plan, that would permit ventilation and re-intubation with minimum difficulty and delay should extubation fail.
The Difficult Airway Society has now published guidelines for the management of tracheal extubation, describing four steps:

Step 1: plan extubation.

Step 2: prepare for extubation.

Step 3: perform extubation.

Step 4: post-extubation care: recovery and follow-up.

During step 3, emphasis is on pre-oxygenation, positioning, and suction. This is followed by simultaneous deflation of the tracheal tube cuff and removal of the tube at the peak of a sustained inflation. This generates a passive exhalation, which may assist in the expulsion of secretions and possibly reduce the incidence of laryngospasm and breathholding.
The guideline refers to low-risk and at-risk extubations. ‘Low-risk’ (routine) extubation is characterised by the expectation that reintubation could be managed without difficulty, if required. ‘At-risk’ means the presence of general and/or airway risk factors that suggest that a patient may not be able to maintain his/her own airway after removal of the tracheal tube. ‘At-risk’ extubation is characterised by the concern that airway management may not be straightforward should reintubation be required.
These guidelines are written for the peri-operative patient but the text contains some interesting points that are pertinent to the ED or ICU patient. Some simple algorithms are presented:






Difficult Airway Society Guidelines for the management of tracheal extubation
Anaesthesia. 2012 Mar;67(3):318-40 Free full text

More guidelines from the Difficult Airway Society