Non-invasive BP in shock

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

In CPR depth is good, but how deep to compress?

Some defibrillators have accelerometers capable of measuring chest compression depth during CPR. This allowed a study correlating compression depth with survival in out of hospital cardiac arrest.
More than half of patients received less than the 2005 recommended chest compression depth of 38–51 mm and >90% received less than the 2010 recommended depth of >50 mm. There was an inverse relationship between rate and depth, ie. rescuers had a tendency to ‘push hard, push slow’ or ‘push soft, push fast’.

The authors state:
We found an association between adequate compression depth and good outcomes but could not demonstrate that the 2010 recommendations are better than those from 2005. Although we believe that compression depth is an important component of CPR and should be measured routinely during cardiac arrest resuscitation, we believe that the optimal depth is currently unknown.

BACKGROUND: The 2010 international guidelines for cardiopulmonary resuscitation recently recommended an increase in the minimum compression depth from 38 to 50 mm, although there are limited human data to support this. We sought to study patterns of cardiopulmonary resuscitation compression depth and their associations with patient outcomes in out-of-hospital cardiac arrest cases treated by the 2005 guideline standards.

DESIGN: Prospective cohort.

SETTING: Seven U.S. and Canadian urban regions.

PATIENTS: We studied emergency medical services treated out-of-hospital cardiac arrest patients from the Resuscitation Outcomes Consortium Epistry-Cardiac Arrest for whom electronic cardiopulmonary resuscitation compression depth data were available, from May 2006 to June 2009.

MEASUREMENTS: We calculated anterior chest wall depression in millimeters and the period of active cardiopulmonary resuscitation (chest compression fraction) for each minute of cardiopulmonary resuscitation. We controlled for covariates including compression rate and calculated adjusted odds ratios for any return of spontaneous circulation, 1-day survival, and hospital discharge.

MAIN RESULTS: We included 1029 adult patients from seven U.S. and Canadian cities with the following characteristics: Mean age 68 yrs; male 62%; bystander witnessed 40%; bystander cardiopulmonary resuscitation 37%; initial rhythms: Ventricular fibrillation/ventricular tachycardia 24%, pulseless electrical activity 16%, asystole 48%, other nonshockable 12%; outcomes: Return of spontaneous circulation 26%, 1-day survival 18%, discharge 5%. For all patients, median compression rate was 106 per minute, median compression fraction 0.65, and median compression depth 37.3 mm with 52.8% of cases having depth <38 mm and 91.6% having depth <50 mm. We found an inverse association between depth and compression rate ( p < .001). Adjusted odds ratios for all depth measures (mean values, categories, and range) showed strong trends toward better outcomes with increased depth for all three survival measures.

CONCLUSIONS: We found suboptimal compression depth in half of patients by 2005 guideline standards and almost all by 2010 standards as well as an inverse association between compression depth and rate. We found a strong association between survival outcomes and increased compression depth but no clear evidence to support or refute the 2010 recommendations of >50 mm. Although compression depth is an important component of cardiopulmonary resuscitation and should be measured routinely, the most effective depth is currently unknown.

What is the role of chest compression depth during out-of-hospital cardiac arrest resuscitation?
Crit Care Med. 2012 Apr;40(4):1192-8

Helicopters and improved trauma survival

A large retrospective study has shown increased trauma survival associated with helicopter transport. The reason is unclear and may be multifactorial: faster speed, greater access to trauma centres, higher exposure of crews to trauma, different crew skill mix and so on are all possibilities.

An interview of less than five minutes with one of the authors describes the study:

Context Helicopter emergency medical services and their possible effect on outcomes for traumatically injured patients remain a subject of debate. Because helicopter services are a limited and expensive resource, a methodologically rigorous investigation of its effectiveness compared with ground emergency medical services is warranted.

Objective To assess the association between the use of helicopter vs ground services and survival among adults with serious traumatic injuries.

Design, Setting, and Participants Retrospective cohort study involving 223 475 patients older than 15 years, having an injury severity score higher than 15, and sustaining blunt or penetrating trauma that required transport to US level I or II trauma centers and whose data were recorded in the 2007-2009 versions of the American College of Surgeons National Trauma Data Bank.

Interventions Transport by helicopter or ground emergency services to level I or level II trauma centres.

Main Outcome Measures Survival to hospital discharge and discharge disposition.

Results A total of 61 909 patients were transported by helicopter and 161 566 patients were transported by ground. Overall, 7813 patients (12.6%) transported by helicopter died compared with 17 775 patients (11%) transported by ground services. Before propensity score matching, patients transported by helicopter to level I and level II trauma centers had higher Injury Severity Scores. In the propensity score–matched multivariable regression model, for patients transported to level I trauma centers, helicopter transport was associated with an improved odds of survival compared with ground transport (odds ratio [OR], 1.16; 95% CI, 1.14-1.17; P < .001; absolute risk reduction [ARR], 1.5%). For patients transported to level II trauma centers, helicopter transport was associated with an improved odds of survival (OR, 1.15; 95% CI, 1.13-1.17; P < .001; ARR, 1.4%). A greater proportion (18.2%) of those transported to level I trauma centers by helicopter were discharged to rehabilitation compared with 12.7% transported by ground services (P < .001), and 9.3% transported by helicopter were discharged to intermediate facilities compared with 6.5% by ground services (P < .001). Fewer patients transported by helicopter left level II trauma centers against medical advice (0.5% vs 1.0%, P < .001).

Conclusion Among patients with major trauma admitted to level I or level II trauma centers, transport by helicopter compared with ground services was associated with improved survival to hospital discharge after controlling for multiple known confounders.

Association Between Helicopter vs Ground Emergency Medical Services and Survival for Adults With Major Trauma

JAMA, April 18, 2012—Vol 307, No. 15 1602-10 Full Text

Intubation of the critically ill in Scotland

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

Extubation guidelines

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

Australasian ED Airway Registry

Managing the emergency airway is one of the most important and risky things we do. We have a responsibility to record, monitor, report and improve our performance.

In the US, the National Emergency Airway Registry has been running for over a decade and has significantly contributed to our airway knowledge base.

In the UK, the NAP4 audit provided fascinating and scary insight into complications of emergency airway management.

Pre-hospital registries have been developed, like Minh Le Cong’s Flying Doctor Emergency Airway Registry; and many of us are now contributing to the Airway Management Study in Physician Manned Helicopter Emergency Medical Services (AIRPORT) study.

Now there is an opportunity for Australasian emergency departments to contribute to a national audit.

Dr Toby Fogg FACEM, emergency physician at Royal North Shore Hospital in Sydney, who began the registry, explained in a recent Life in The Fast Lane response:

I have been running an airway registry in the ED at The Royal North Shore Hospital in Sydney for the last 2 years.

I presented the first 18 months of data at the ASM in Sydney last year and I must admit, they showed room for improvement!.

One of the many things we have subsequently done is introduced a Pre Intubation Checklist which I have published, along with our preliminary findings, at

I am happy for people to download the file and use it as is, or with appropriate modifications.

Furthermore I would love to hear from anyone keen to undertake an Airway Registry in their own ED — a PDF of the data collection form we use is also on the website.

As the authors of the NAP4 study conclude, it is essential we all audit our practice of this potentially high risk procedure.

Dr Toby Fogg uses his C-MAC video laryngoscope to demonstrate the audit form

Background: Successful airway management is one of the cornerstones of care for critically ill or injured patients in the Emergency Department (ED). The risks of intubation are known to be higher in this environment than in the operating theatre (OT) yet there are no published data on airway management in an Australian ED.

Objectives: To describe the practice of intubation in the ED of a tertiary hospital in Australia, with particular emphasis on the number of attempts, adjuncts used, the seniority of staff involved and the rate of complications.

Methods: A prospective, observational study.

Results: Over the 18-month study period, 295 episodes of intubation occurred with a total of 345 attempts. Consultant supervision occurred in 69.8% of cases, registrars made the first attempt at intubation in 57.5% and SRMOs in 31.0% of the patients. 83.7% of the patients were intubated at the first pass with a further 13.0% intubated one the second attempt. This leaves 10 patients (3.4%) that required ≥3 attempts, 4 (1.4%) ≥4 attempts and 1 (0.4%) required a 5th attempt. Difficult laryngoscopy, as defined by Cormack and Lehane grade III or IV, occurred in 24% of the first attempts. Bougies were used in 36% of attempts, whilst a stylet in 35%. Video laryngoscopy was used in 47.5% of attempts. Complications occurred in 28%.

Discussion: The success rate within two attempts is comparable to the anaesthetic literature, and although high, the rate of complications is comparable to data from EDs overseas. The rate of difficult laryngoscopy, however, is surprisingly high. The study has prompted a significant review of airway training and management within the ED at Royal North Shore Hospital and the results of the interventions will be monitored.

The Royal North Shore Hospital Emergency Department Airway Registry. A Prospective Observational Study of Airway Management in a Tertiary Hospital Emergency Department in Sydney, Australia
Annesley N,Vassiliadis J, Kerry Hitos K, Fogg T
Emerg. Med. Australas. 24 (Suppl. 1):27-28

Study authors Toby Fogg and Nick Annesley demonstrate the 'Happiness Triad'

Red cell transfusion guidelines

The AABB (formerly the American Association of Blood Banks has issued guidelines on red blood cell transfusion1, providing some number-based targets which may be helpful for some practitioners or organisations. Editorialist and heavyweight intensivist Jean-Louis Vincent argues for a more individual patient-based assessment2, and highlights some of the weaknesses of existing studies, in particular the often quoted but now fairly old TRICC study3 which suffered from poor recruitment and the possible lack of applicability to modern practice now that leucodepleted products are used.

Prof Vincent states:

Transfusion decisions need to consider individual patient characteristics, including age and the presence of CAD, to estimate a specific patient’s likelihood of benefit from transfusion. The decision to transfuse is too complex and important to be guided by a single number.

Description: Although approximately 85 million units of red blood cells (RBCs) are transfused annually worldwide, transfusion practices vary widely. The AABB (formerly, the American Association of Blood Banks) developed this guideline to provide clinical recommendations about hemoglobin concentration thresholds and other clinical variables that trigger RBC transfusions in hemodynamically stable adults and children.

Methods: These guidelines are based on a systematic review of the literature on randomized clinical trials evaluating transfusion thresholds. We performed a literature search from 1950 to February 2011 with no language restrictions. We examined the proportion of patients who received any RBC transfusion and the number of RBC units transfused to describe the effect of restrictive transfusion strategies on RBC use. To determine the clinical consequences of restrictive transfusion strategies, we examined overall mortality, nonfatal myocardial infarction, cardiac events, pulmonary edema, stroke, thromboembolism, renal failure, infection, hemorrhage, mental confusion, functional recovery, and length of hospital stay.

Recommendation 1: The AABB recommends adhering to a restrictive transfusion strategy (7 to 8 g/dL) in hospitalized, stable patients (Grade: strong recommendation; high-quality evidence).

Recommendation 2: The AABB suggests adhering to a restrictive strategy in hospitalized patients with preexisting cardiovascular disease and considering transfusion for patients with symptoms or a hemoglobin level of 8 g/dL or less (Grade: weak recommendation; moderate-quality evidence).

Recommendation 3: The AABB cannot recommend for or against a liberal or restrictive transfusion threshold for hospitalized, hemodynamically stable patients with the acute coronary syndrome (Grade: uncertain recommendation; very low-quality evidence).

Recommendation 4: The AABB suggests that transfusion decisions be influenced by symptoms as well as hemoglobin concentration (Grade: weak recommendation; low-quality evidence).

1. Red Blood Cell Transfusion: A Clinical Practice Guideline From the AABB
Ann Intern Med. 2012 Mar 26. [Epub ahead of print] Full Text

2. Indications for Blood Transfusions: Too Complex to Base on a Single Number?
Ann Intern Med. 2012 Mar 26. [Epub ahead of print] Full Text

3. A Multicenter, Randomized, Controlled Clinical Trial of Transfusion Requirements in Critical Care
N Engl J Med 1999; 340:409-417 Full Text

Ventilated patients better able to communicate pain with dexmedetomidine

A multicentre European trial on intensive care units showed dexmedetomidine was non-inferior to midazolam or propofol in achieving target sedation levels, but patients were better able to communicate pain compared with midazolam and propofol. Dexmedetomidine reduced duration of mechanical ventilation compared with midazolam, but not compared with propofol.

Context Long-term sedation with midazolam or propofol in intensive care units (ICUs) has serious adverse effects. Dexmedetomidine, an α2-agonist available for ICU sedation, may reduce the duration of mechanical ventilation and enhance patient comfort.

Objective To determine the efficacy of dexmedetomidine vs midazolam or propofol (preferred usual care) in maintaining sedation; reducing duration of mechanical ventilation; and improving patients’ interaction with nursing care.

Design, Setting, and Patients Two phase 3 multicenter, randomized, double-blind trials carried out from 2007 to 2010. The MIDEX trial compared midazolam with dexmedetomidine in ICUs of 44 centers in 9 European countries; the PRODEX trial compared propofol with dexmedetomidine in 31 centers in 6 European countries and 2 centers in Russia. Included were adult ICU patients receiving mechanical ventilation who needed light to moderate sedation for more than 24 hours (midazolam, n = 251, vs dexmedetomidine, n = 249; propofol, n = 247, vs dexmedetomidine, n = 251).

Interventions Sedation with dexmedetomidine, midazolam, or propofol; daily sedation stops; and spontaneous breathing trials.

Main Outcome Measures For each trial, we tested whether dexmedetomidine was noninferior to control with respect to proportion of time at target sedation level (measured by Richmond Agitation-Sedation Scale) and superior to control with respect to duration of mechanical ventilation. Secondary end points were patients’ ability to communicate pain (measured using a visual analogue scale [VAS]) and length of ICU stay. Time at target sedation was analyzed in per-protocol population (midazolam, n = 233, vs dexmedetomidine, n = 227; propofol, n = 214, vs dexmedetomidine, n = 223).

Results Dexmedetomidine/midazolam ratio in time at target sedation was 1.07 (95% CI, 0.97-1.18) and dexmedetomidine/propofol, 1.00 (95% CI, 0.92-1.08). Median duration of mechanical ventilation appeared shorter with dexmedetomidine (123 hours [IQR, 67-337]) vs midazolam (164 hours [IQR, 92-380]; P = .03) but not with dexmedetomidine (97 hours [IQR, 45-257]) vs propofol (118 hours [IQR, 48-327]; P = .24). Patients’ interaction (measured using VAS) was improved with dexmedetomidine (estimated score difference vs midazolam, 19.7 [95% CI, 15.2-24.2]; P < .001; and vs propofol, 11.2 [95% CI, 6.4-15.9]; P < .001). Length of ICU and hospital stay and mortality were similar. Dexmedetomidine vs midazolam patients had more hypotension (51/247 [20.6%] vs 29/250 [11.6%]; P = .007) and bradycardia (35/247 [14.2%] vs 13/250 [5.2%]; P < .001).

Conclusions Among ICU patients receiving prolonged mechanical ventilation, dexmedetomidine was not inferior to midazolam and propofol in maintaining light to moderate sedation. Dexmedetomidine reduced duration of mechanical ventilation compared with midazolam and improved patients’ ability to communicate pain compared with midazolam and propofol. More adverse effects were associated with dexmedetomidine.

Dexmedetomidine vs midazolam or propofol for sedation during prolonged mechanical ventilation: two randomized controlled trials
JAMA. 2012 Mar 21;307(11):1151-60

Only when I laugh

A middle-aged martial arts enthusiast was training in Krav Maga, and participated in a high-contact punching and grappling sparring exercise in which his (younger, heavier) partner threw him to the ground and landed on him. During the throw the patient felt a ‘pop’ in his right side, and wondered whether he’d fractured a rib. During the subsequent five rounds against two additional sparring partners he noticed a clicking in the same area every time he was grappling, and pain in the right side when pushing up off the floor with his right arm. As a trained emergency physician, he assessed his own level of breathing comfort throughout the training to reassure himself he didn’t have a significant pneumothorax, and therefore elected to continue to fight in the interests of assessing his ability to defend himself while injured.

Pain on deep inspiration, coughing, and squeezing the chest suggested a fractured rib, so out of curiosity at work the next day he ultrasounded the area of maximum tenderness:

Discontinuity in cortex signifies rib fracture

Examination of the lung confirmed pleural sliding, B-lines, and ‘pearls on a string’, which excluded pneumothorax.

Sonography is more sensitive than radiography for the detection of rib fractures and may also detect costochondral junction injuries and disruption of costal cartilage1. This video from Hennepin County Medical Centre takes you through the simple procedure:

Although the management of rib fractures is no different from that of chest wall contusion, knowledge of the presence of fracture in this case is helpful to this patient in deciding when to return to the questionably sane ‘hobby’ of fighting bigger guys half his age.

The patient’s consent was obtained prior to the publication of the ultrasound image.

1. Sonography Compared with Radiography in Revealing Acute Rib Fracture
AJR Am J Roentgenol. 1999 Dec;173(6):1603-9.
Full text article

OBJECTIVE: This study was undertaken to compare the sensitivities of sonography and radiography for revealing acute rib fracture.

SUBJECTS AND METHODS: Chest radiography and rib sonography were performed on 50 patients with suspected rib fractures. Sonography was performed with a 9- or 12-MHz linear transducer. Fractures were identified by a disruption of the anterior margin of the rib, costochondral junction, or costal cartilage. The incidence, location, and degree of displacement of fractures revealed by radiography and sonography were compared. Sonography was performed again after 3 weeks in 37 subjects.

RESULTS: At presentation, radiographs revealed eight rib fractures in six (12%) of 50 patients and sonography revealed 83 rib fractures in 39 (78%) of 50 patients. Seventy-four (89%) of the 83 sonographically detected fractures were located in the rib, four (5%) were located at the costochondral junction, and five (6%) in the costal cartilage. Repeated sonography after 3 weeks showed evidence of healing in all reexamined fractures. Combining sonography at presentation and after 3 weeks, 88% of subjects had sustained a fracture.

CONCLUSION: Sonography reveals more fractures than does radiography and will reveal fractures in most patients presenting with suspected rib fracture. Further scientific studies are needed to clarify the appropriate role for sonography in rib fracture detection.