Chest x-rays often miss pneumothoraces in the trauma room. These are occult pneumothoraces. A study using agreement by two fellowship trained radiologists as the gold standard for CXR interpretation showed that 80% of these were truly occult, ie. not detectable by the radiologists from CXR and only demonstrable on CT. Of those seven cases that could or should have been identified by emergency physicians (ie. ‘missed’ pneumothoraces) subcutaneous emphysema (5), pleural line (3), and deep sulcus sign (2) were detected by the radiologist reviewers.
This serves both as a reminder of the signs to look for on CXR for pneumothorax, and of the inadequacy of plain radiography in trauma patients. The authors advise in their discussion that ‘Thoracic ultrasonography may be the ideal diagnostic modality as it has a high sensitivity for the detection of PTX and it may be performed quickly at the bedside while maintaining spinal precautions’.
If you don’t know how to detect a pneumothorax with ultrasound yet, have a look here.
Occult Pneumothoraces Truly Occult or Simply Missed: Redux
J Trauma. 2010 Dec;69(6):1335-7
Category Archives: All Updates
HEMS transport may be predictor of survival
Helicopters are controversial in EMS circles, particularly in the United States, which seems to have a high number of Helicopter Emergency Medical Services (HEMS) crashes. Although this may in part be a reflection of a large increase in HEMS missions, and the factors contributing to crash fatalities have been studied, it makes sense to limit HEMS missions to those that are likely to make a difference to the patient. Advantages of HEMS services may include the ability to deliver a patient more rapidly to the most appropriate facility, as well as being able to convey a highly skilled team more rapidly to the scene.
Analysis of patients from the National Trauma Databank identified 258,387 subjects transported by either helicopter (HT) (16%) or ground ambulance (GT) (84%). HT subjects were younger (36 years ± 19 years vs. 42 years ± 22 years; p < 0.01), more likely to be male (70% vs. 65%; < 0.01), and more likely to have a blunt mechanism (93% vs. 88%; < 0.01) when compared with GT subjects.
For every dead-on-arrival (DOA) subject in the HT group, there were 498 survivors compared with 395 survivors for every DOA subject in the GT group. When comparing indicators of injury severity, patients transported by helicopter were more severely injured (mean ISS and percentage with ISS > 15), were more likely to have a severe head injury, and were more likely to have documented hypotension or abnormal respiratory when compared with those transported by ground ambulance. Furthermore, HT subjects also had longer length of stay, higher rates for ICU admission, and mechanical ventilation, as well as an increased requirement for emergent surgical intervention.
interestingly, this study shows that <15% of HT patients nationally are discharged within 24 hours. This is much lower than the 24.1% reported previously, suggesting that the degree of over-triage may not be as significant on the national level as reported in smaller studies.
Overall survival was lower in HT subjects versus GT subjects on univariate analysis (92.5% vs. 95.6%; < 0.01). Stepwise univariate analysis identified all covariates for inclusion in the regression model. HT became an independent predictor of survival when compared with GT after adjustment for covariates (OR, 1.22; 95% CI, 1.18– 1.27; < 0.01).
Helicopters and the Civilian Trauma System: National Utilization Patterns Demonstrate Improved Outcomes After Traumatic Injury
J Trauma. 2010 Nov;69(5):1030-4
National Transportation Safety Board HEMS data
Expert not happy with cricoid
Evidence-based medicine reminds us to beware ‘experts’. However, here’s one self-described expert who talks some sense. Doctor (Doktor?) HJ Priebe from the University Hospital Freiburg in Germany suggests the risk of harm outweighs the risk of benefit from this procedure:
‘Despite the lack of evidence for its effectiveness and evidence for numerous deleterious effects, cricoid pressure is still considered a standard of care during rapid sequence induction, and its application is considered mandatory in patients at high risk for gastric regurgitation. However, by using cricoid pressure, we may well be endangering more lives by causing airway problems than we are saving in the hope of preventing pulmonary aspiration. It is dangerous to consider cricoid pressure to be an effective and reliable measure in reducing the risk of pulmonary aspiration and to become complacent about the many factors that contribute to regurgitation and aspiration. Cricoid pressure is not a substitute for optimal patient preparation. Ensuring optimal positioning and a rapid onset of anesthesia and muscle relaxation to decrease the risk of coughing, straining or retching during the induction of anesthesia are likely more important in the prevention of pulmonary aspiration than cricoid pressure.
‘At the time of Sellick’s description of the technique of cricoid pressure, morbidity and mortality from pulmonary aspiration during the induction of anesthesia in the surgical population in general, and the obstetric population in particular, were of great concern. At that time, the concept of cricoid pressure was highly attractive. However, during the past 48 years, many aspects of anesthetic management have considerably changed, and knowledge has advanced. By today’s standards, cricoid pressure can no longer be considered an evidence-based practice. This is why more and more anesthetists (including myself) no longer apply cricoid pressure.‘
Vielen Dank, Herr Doktor!
Cricoid pressure: an expert’s opinion
Minerva Anestesiol 2009;75:710-4 – Full text
Just as well really, because these guys show many people don’t know how to do it anyway! Cases were identified in which pressure was mistakenly applied to the thyroid cartilage and even the sternocleidomastoid muscles!
Variable application and misapplication of cricoid pressure
J Trauma. 2010 Nov;69(5):1182-4
Negative laparotomy
The complication rate after a negative or nontherapeutic laparotomy is reported to be substantial but most of this reported morbidity is because of associated injuries and is not related to the abdominal exploration. On the other hand, the morbidity and mortality associated with a delay in taking the injured patient to the operating room is well recognised. A retrospective study attempts to show that when injury severity (using TRISS) is controlled for, negative laparotomy did not significantly increase the complication burden compared with no laparotomy in blunt abdominal trauma patients.
“Never Be Wrong”: The Morbidity of Negative and Delayed Laparotomies After Blunt Trauma
J Trauma. 2010 Dec;69(6):1386-92
Flat IVC on CT associated with deterioration
BACKGROUND: : We aimed to investigate the value of the diameter of the inferior vena cava (IVC) on initial computed tomography (CT) to predict hemodynamic deterioration in patients with blunt torso trauma.
METHODS: : We reviewed the initial CT scans, taken after admission to emergency room (ER), of 114 patients with blunt torso trauma who were consecutively admitted during a 24-month period. We measured the maximal anteroposterior and transverse diameters of the IVC at the level of the renal vein. Flat vena cava (FVC) was defined as a maximal transverse to anteroposterior ratio of less than 4:1. According to the hemodynamic status, the patients were categorized into three groups. Patients with hemodynamic deterioration after the CT scans were defined as group D (n = 37). The other patients who remained hemodynamically stable after the CT scans were divided into two groups: patients who were hemodynamically stable on ER arrival were defined as group S (n = 60) and those who were in shock on ER arrival and responded to the fluid resuscitation were defined as group R (n = 17).
RESULTS: : The anteroposterior diameter of the IVC in group D was significantly smaller than those in groups R and S (7.6 mm ± 4.4 mm, 15.8 mm ± 5.5 mm, and 15.3 mm ± 4.2 mm, respectively; p < 0.05). Of the 93 patients without FVC, 16 (17%) were in group D, 14 (15%) required blood transfusion, and 8 (9%) required intervention. However, of the 21 patients with FVC, all patients were in group D, 20 (95%) required blood transfusion, and 17 (80%) required intervention. The patients with FVC had higher mortality (52%) than the other patients (2%).
CONCLUSION: : In cases of blunt torso trauma, patients with FVC on initial CT may exhibit hemodynamic deterioration, necessitating early blood transfusion and therapeutic intervention.
Predictive Value of a Flat Inferior Vena Cava on Initial Computed Tomography for Hemodynamic Deterioration in Patients With Blunt Torso Trauma
J Trauma. 2010 Dec;69(6):1398-402
Great Ultrasound site
I recently had the pleasure of talking to some of the folks from the Henepin County Medical Centre Department of Emergency Medicine. What an inspiring group they are (they were the ones who wrote this article)!
They now have an awesome website at www.hqmeded.com with great ultrasound cases as well as other online lectures. Awesome.
H1N1 Update from UK Intensive Care
H1N1 Update 16 December 2010 sent from the UK Intensive Care Society
As many of you will already be aware, the predicted second wave of swine flu seems to becoming a reality. The HPA have received information that there has been a rise in the number of confirmed H1N1 cases and has restarted regular teleconferences to discuss the current situation and to disseminate the latest advice and information. The initial teleconference was held last Friday and the first question asked was how many cases have units seen. Although the total numbers were not high, the fact that there are confirmed cases throughout the UK gave support to the decision that hospitals should prepare for an increase in the numbers.
Subsequent updates have confirmed that the case numbers are rising and although not all patients admitted to ICUs with a suspected diagnosis of H1N1 have required mechanical ventilation or had H1N1 confirmed. As of Wednesday this week the numbers of H1N1 related ICU cases had risen to 140. An additional concern is that the number of cases with probable H1N1 referred for ECMO is now 13 and this has resulted in a policy that there should be support for all the centers in the UK who can provide ECMO.
It is still too early to predict what the level escalation is going to be required, but there are real concerns that the combination of adverse weather conditions, the current financial restrictions in the NHS, and an H1N1 peak could place ICUs in a more seriously challenging situation than occurred in the previous outbreak.
For this reason, it is recommended that clinicians should once again have a low threshold for considering the possibility of H1N1 in patients who are referred to intensive care. Trusts should reconvene regular meetings to plan for any necessary expansion of critical care services. It is important that staff have up to date training in the use of personal protection equipment. One of the most important points learned from the first outbreak was that early antiviral therapy can reduce the need for mechanical ventilation and it is recommended that any patients admitted to hospital with a history and symptoms suggestive of an influenza-like illness should be given antiviral therapy.
The following points were made in the HPA–led teleconference on 10 December:
- be vigilant: have a low threshold for considering the diagnosis.
- start antivirals whenever there is a suspicion of flu (oseltamivir 75or 150 mg bd po).
- In patients with resistance or not tolerating NG medication, there is an IV preparation which is currently undergoing clinical trial. GSK produces it (zanamavir) and may provide it on patient-name compassionate grounds.
- Use ARDSnet ventilation especially for those with normal lung compliance.
- Consider HFO for those with poor compliance
- Fluid restrict patients
- Consider referral for ECMO early if conventional ventilation is failing. ECMO beds are occupied almost all occupied by ‘flu patients and elective surgery has been curtailed to accomodate them. Surge funding has been agreed for extra ECMO. In cases where conventional ventilation is failing and there are no other options, patients should be referred to Glenfield before seven days of MV.
- HPA adviced has not changed with respect to infection control measures; these can be found here:http://www.dh.gov.uk/prod_consum_dh/groups/dh_digitalassets/@dh/@en/@ps/documents/digitalasset/dh_110899.pdf
- The RCoA site still has an adult practice note from last year which will be updated
- The HPA link to seasonal flu can be found here:http://www.hpa.org.uk/Topics/InfectiousDiseases/InfectionsAZ/SeasonalInfluenza/Guidelines/
- There will be advice re pregnant women after discussion with the RCOG
- In some cases, URT specimens may be negative in severe cases and LRT samples may be needed for the diagnosis.
- Point of care testing may have inadequate sensitivity for this strain of H1N1
The current rate is 21.5/100,000.
We aim to provide updates on the ICS website and copy of this document is available to download via http://www.ics.ac.uk/ under ‘Latest News – H1N1 Latest News’.
Update by the Executive Committee of the Intensive Care Society.
Sent from the email of:
Pauline Kemp
Head of Secretariat
Passive leg raising during CPR
Measuring end-tidal carbon dioxide (ET CO2 ) is a practical non-invasive method for detecting pulmonary blood flow, reflecting cardiac output and thereby the quality of CPR. It has also been shown to rise before clinically detectable return of spontaneous circulation (ROSC).
Passive leg raising (PLR) increases venous return and may therefore augment cardiac output and in a cardiac arrest this may be reflected by an elevation in ETCO2.
A Swedish observational study of 126 patients with out of hospital cardiac arrest due to a likely cardiac aetiology underwent tracheal intubation with standardised ventilation and chest compressions (either manually or using the LUCAS device, as part of larger study of mechanical chest compressions according to a cluster design). Patients were stratified to receive either PLR to 20 degrees or no PLR. ETCO2 was measured during CPR, either for 15min, or until the detection of ROSC.
During PLR, an increase in ETCO2 was found in all 44 patients who received PLR within 15s (p=0.003), 45s (p = 0.002) and 75 s (p = 0.0001). Survival to hospital discharge was 7% among patients with PLR and 1% among those without PLR (p = 0.12). Among patients experiencing ROSC (60 of 126), there was a marked increase in ETCO2 1 min before the detection of a palpable pulse.
Passive leg raising during cardiopulmonary resuscitation in out-of-hospital cardiac arrest—Does it improve circulation and outcome?
Resuscitation. 2010 Dec;81(12):1615-20
UK Military Clinical Guidelines
In the United Kingdom, The Academic Department of Military Emergency Medicine at the Royal Centre for Defence Medicine produces Clinical Guidelines for Operations on behalf of Surgeon General under the direction of Defence Professor of Emergency Medicine.
These guidelines, last updated in May 2010, are available on line here:
**UPDATE JUNE 2011** I have received correspondence that this document is now out of date. The link is however still active and the document makes for interesting reading.
Brain chain
Therapeutic hypothermia (TH) has been associated with improved outcomes in term infants who present with moderate hypoxic-ischaemic encephalopathy (HIE). However, in the three major studies the time to initiate cooling was at approximately 4.5 postnatal hours. Many newborns are referred to specialist centres where cooling takes place from outlying hospitals (‘outborn’). It may be the case that earlier initiation of TH could improve outcomes, leading Takenouchi and colleagues to propose a ‘Chain of Brain Preservation’.
‘Given that most infants are outborn, a time sensitive education metaphor termed Chain of Brain Preservation may facilitate early recognition of high risk infants and thus earlier treatment.‘
Chain of Brain Preservation—A concept to facilitate early identification and initiation of hypothermia to infants at high risk for brain injury
Resuscitation. 2010 Dec;81(12):1637-41