The US media seem to be making a big thing of a recent article published ahead of print which demonstrates an association between increased mortality from trauma and the insertion of an intravenous line with or without the administration of fluid.
This was a retrospective cohort study of over 770 000 patients from the National Trauma Data Bank. Approximately half (49.3%) received ‘prehospital IV’, which could mean fluids, or could just mean insertion of an intravenous cannula: ‘we could not definitively differentiate IV fluid administration versus IV catheter placement alone‘.
Unadjusted mortality was significantly higher in patients in the prehospital IV group, although the abstract inaccurately reports this to be ‘in patients receiving prehospital IV fluids‘ (4.8% vs. 4.5%, P < 0.001).
Multivariable logistic regression was used to examine the relationship between prehospital IV and mortality in the 311,071 patients with complete data. After adjustment, prehospital IV patients had significantly higher mortality than those without a prehospital IV. The odds ratio of death associated with prehospital IV placement was 1.11 (95% CI 1.06–1.17). When Dead-On-Arival patients were excluded from the group as a whole, the association persisted (OR 1.17, 95% CI 1.11–1.23).
On subgroup analyses, the association between IV placement and excess mortality was maintained in nearly all patient subsets; the effect was more exaggerated in penetrating trauma victims.
Media speculation as to the reason for this association abounds, like USA Today‘s ‘those who are given pre-hospital IV fluids are actually 11% more likely to die than those who aren’t, not only because of transport delays but also in part because of the increased risk for bleeding that can accompany a fluid-induced increase in blood pressure‘. However the study did not record any pre-hospital times and could not tell which patients received fluid, let alone what the effect of fluid on blood pressure was.
The authors are open about this and other limitations: ‘The NTDB did not report prehospital transport times or differentiate urban versus rural care. Thus, we could not examine whether excess mortality in patients treated with IVs was directly associated with delays in transport to definitive care. We were also not able to control for transport time within the multiple regression model or perform a stratified analysis by urban versus rural patients. Perhaps this analysis would have identified a subset of patients who may benefit from IV placement‘.
No doubt this will be added to the pile of mainly hypothesis-generating literature quoted by the scoop-and-run brigade whose black-and-white worldview includes paramedics who want to delay proper treatment and a homogeneous trauma population whose lives can only be saved by a trauma surgeon in a hospital. Those who have evolved colour vision find this an interesting, but hardly practice-changing study; caution regarding injudicious fluid administration has been the game plan for many civilian and military pre-hospital providers since early last decade, and it is clear that different patients with different injury patterns, different degrees of physiological derangement, and different distances from the right hospital will continue to have different clinical needs specific to their presentation, some of which are likely to be of benefit if provided in the field, through an intravenous line.
Prehospital Intravenous Fluid Administration is Associated With Higher Mortality in Trauma Patients: A National Trauma Data Bank Analysis
Ann Surg. 2010 Dec 20. [Epub ahead of print]
Tag Archives: Trauma
A tracheal tube in the chest
Intercostal catheters can kink, obstruct, or get pulled out. These hazards are greater during transport of the patient. Critical care and retrieval medicine doctors in Queensland, Australia (where many people are having a bad time right now) have invented an elegant alternative: using a cuffed tracheal tube in the pleural space instead. It can be attached to a Heimlich valve.
They even used a bit of science to demonstrate its effectiveness, by creating pneumothoraces and haemothoraces in sheep and comparing the tracheal tube with a standard intercostal catheter (ICC).
The method for insertion is simple:
- Breach the pleura
- Insert a 14 Fr Cook intubating bougie into the thoracic cavity
- Railroad a 7.0 mm internal diameter tracheal tube (ETT) into the chest cavity
- Inflate the cuff
- Retract the tube until resistance is felt.
- Remove the ETT connector
- Attach a Heimlich valve
The results of the comparison are convincing: ‘The ETT proved faster to insert for both sheep. This was likely because it did not require suturing. Both the ETT and the ICC were comparable in draining blood. It was noted that neither tube was particularly effective when the haemothorax was positioned ‘side-up’. When turned ‘side-down’, both tubes successfully drained blood. Despite having multiple drainage ports, the ICC required more manipulation and was noted to kink. Conversely, the ETT with a single lumen and a Murphy eye, was stiffer and drained a similar amount of blood without the catheter having to be milked.’
Proposed advantages of this method include:
- More portable equipment
- Faster insertion
- Provides kit redundancy
- Does not require suturing
- Avoids operator trauma from any sharp edges such as a fractured rib. (No attempt was made to place a finger into the chest cavity in the ETT group).
- Allows for a smaller incision
- Less trauma to the insertion site
- Might also offer a back up, when conventional equipment has been exhausted.
The authors graciously note that both Portex and Cook have developed ICC kits that now go some way in supporting the original idea behind this study. These include flexible introducers (Portex) and guidewire insertion technique (Cook).
Appraisal of the endotracheal tube as an alternative to the intercostal catheter
Emerg Med Australas. 2010 Dec;22(6):573-4
Paramedic RSI in Australia
A prospective, randomized, controlled trial compared paramedic rapid sequence intubation with hospital intubation in adults with severe traumatic brain injury in four cities in Victoria, Australia. The primary outcome was neurologic outcome at 6 months postinjury.
Training
Paramedics already experienced in ‘cold’ intubation (without drugs) undertook an additional 16-hour training program in the theory and practice of RSI, including class time (4 hours), practical intubating experience in the operating room under the supervision of an anesthesiologist (8 hours), and completion of a simulation-based examination (4 hours).
Methods
Patients included in the study were those assessed by paramedics on road ambulances as having all the following: evidence of head trauma, Glasgow Coma Score ≤9, age ≥15 years, and ‘intact airway reflexes’, although this is not defined or explained. Patients were excluded if any of the following applied: within 10 minutes of a designated trauma hospital, no intravenous access, allergy to any of the RSI drugs (as stated by relatives or a medical alert bracelet), or transport planned by medical helicopter. Drug therapy for intubation consisted of fentanyl (100μg), midazolam (0.1 mg/kg), and succinylcholine (1.5 mg/kg) administered in rapid succession. Atropine (1.2 mg) was administered for a heart rate <60/min. A minimum 500 mL fluid bolus (lactated Ringers Solution) was administered. A half dose of the sedative drugs was used in patients with hypotension (systolic blood pressure <100 mm Hg) or older age (>60 years).
Cricoid pressure was applied in all patients. After intubation and confirmation of the position of the endotracheal tube using the presence of the characteristic waveform on a capnograph, patients received a single dose of pancuronium (0.1 mg/kg), and an intravenous infusion of morphine and midazolam at 5 to 10 mg/h each. If intubation was not achieved at the first attempt, or the larynx was not visible, one further attempt at placement of the endotracheal tube over a plastic airway bougie was permitted. If this was unsuccessful, ventilation with oxygen using a bag/mask and an oral airway was commenced and continued until spontaneous respirations returned. Insertion of a laryngeal mask airway was indicated if bag/mask ventilation using an oral airway appeared to provide inadequate ventilation. Cricothyroidotomy was indicated if adequate ventilation could not be achieved with the above interventions. In all patients, a cervical collar was fitted, and hypotension (systolic blood pressure <100 mm Hg) was treated with a 20 mL/kg bolus of lactated Ringers Solution that could be repeated as indicated. Other injuries such as fractures were treated as required. In the hospital emergency department, patients who were not intubated underwent immediate RSI by a physician prior to chest x-ray and computed tomography head scan.
Follow up
At 6 months following injury, surviving patients or their next-of-kin were interviewed by telephone using a structured questionnaire and allocated a score from 1 (deceased) to 8 (normal) using the extended Glasgow Outcome Scale (GOSe). The interviewer was blinded to the treatment allocation.
Statistical power
A sample size of 312 patients was calculated to achieve 80% power at an alpha error of 0.05. Three hundred twenty-eight patients met the enrollment criteria. Three hundred twelve patients were randomly allocated to either paramedic intubation (160 patients) or hospital intubation (152 patients). A mean Injury Severity Score of 25 indicated that many patients had multiple injuries.
Success of intubation
Of the 157 patients administered RSI drugs, intubation was successful in 152 (97%) patients. The remaining 5 patients had esophageal placement of the endotracheal tube recognized immediately on capnography. The endotracheal tube was removed and the patients were managed with an oropharyngeal airway and bag/mask ventilation with oxygen and transported to hospital. There were no cases of unrecognised esophageal intubation on arrival at the emergency department during this study and no patient underwent cricothyroidotomy.
Outcome
After admission to hospital, both groups appeared to receive similar rates of neurosurgical interventions, including initial CT scan, urgent craniotomy (if indicated), and monitoring of intracranial pressure in the intensive care unit.
Favorable neurologic outcome was increased in the paramedic intubation patients (51%) compared with the hospital intubation patients (39%), just reaching statistical significance with P = 0.046. A limitation is that 13 of 312 patients were lost to follow-up and the majority of these were in the hospital intubation group. The authors do point out that the difference in outcomes would no longer be statistically significant whether one more patient had a positive outcome in the treatment group (P = 0.059) or one less in the control group (P = 0.061). The median GOSe was higher in the paramedic intubation group compared with hospital intubation (5 vs. 3), however, this did not reach statistical significance (P = 0.28).
More patients in the paramedic intubation group suffered prehospital cardiac arrest. There were 10 cardiac arrests prior to hospital arrival in the paramedic RSI group and 2 in the patients allocated to hospital intubation. Further detail on these patients is provided in the paper. The authors state that it is likely that the administration of sedative drugs followed by positive pressure ventilation had adverse hemodynamic consequences in patients with uncontrolled bleeding, and that it is possible that the doses of sedative drugs administered in this study to hemodynamically unstable patients were excessive and consideration should be given to a decreasing the dose of sedation.
Authors’ conclusions
The authors overall conclusion is that patients with severe TBI should undergo prehospital intubation using a rapid sequence approach to increase the proportion of patients with favorable neurologic outcome at 6 months postinjury. Further studies to determine the optimal protocol for paramedic rapid sequence intubation that minimize the risk of cardiac arrest should be undertaken.
Prehospital rapid sequence intubation improves functional outcome for patients with severe traumatic brain injury: a randomized controlled trial.
Ann Surg. 2010 Dec;252(6):959-65.
Victorian Ambulance Service protocols are available here, which include their current paramedic RSI protocol
Missed PTX signs on CXR
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
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
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
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.
Pre-hospital amputation
British trauma surgeon and pre-hospital pioneer Professor Keith Porter describes how to do a pre-hospital amputation in this months EMJ. Thankfully the procedure is only rarely necessary and often only requires cutting remaining skin bridges with scissors. The indications are:
- An immediate and real risk to the patient’s life due to a scene safety emergency
- A deteriorating patient physically trapped by a limb when they will almost certainly die during the time taken to secure extrication
- A completely mutilated non-survivable limb retaining minimal attachment, which is delaying extrication and evacuation from the scene in a non-immediate life-threatening situation
- The patient is dead and their limbs are blocking access to potentially live casualties
The recommended procedure is:
- Ketamine anaesthesia
- Apply an effective proximal tourniquet
- Amputate as distally as possible
- Perform a guillotine amputation
- Apply haemostats to large blood vessels
- Leave the tourniquet in situ
- Apply a padded dressing and transport to hospital
Remember: the requirement for prehospital amputation other than cutting minimal soft tissue bridges is rare. However pre-hospital critical care physicians should be trained and equipped to amputate limbs in order to save life. Probably good to have a Gigli saw in your pack and to familiarise yourself with its use, as shown here:
Prehospital amputation
Emerg Med J 2010 27: 940-942
Pelvic splint improved shock
Splinted any pelvises lately? Karim Brohi’s excellent trauma.org article outlines the strengths and weaknesses of the different devices on the market. One such is the T-POD, which has now been described in a small series in which its application to patients with unstable pelvic injury was associated with improved haemodynamics and decreased symphyseal diastasis.
Here’s a video demonstrating application of the device.
Effect of a new pelvic stabilizer (T-POD1) on reduction of pelvic volume and haemodynamic stability in unstable pelvic fractures
Injury Volume 41, Issue 12, December 2010, Pages 1239-1243 (Full text)