Tag Archives: history

Trauma 20 Years Ago: CAVR For Hypothermia

Hypothermia is the bane of major trauma resuscitation, causing mortality to skyrocket. A number of rewarming techniques have been developed over the years. These are classified as passive (the patient generates their own heat) or active (we deliver calories to them), and noninvasive vs invasive. Rewarming speed increases as we move from passive to active and from noninvasive to invasive.

Continuous arteriovenous rewarming (CAVR) is one of the invasive techniques used today. Its use in humans was first reported 20 years ago this month. Larry Gentilello at Harborview in Seattle had experimented with this technique in animals, and reported one case of use in a human who had crashed his car into icy water. After a 20 minute extrication, the patient was pulseless with fixed and dilated pupils, but he regained pulse and blood pressure at the hospital.

The initial core temperature was 31.5C. Peritoneal, bladder and gastric lavage were carried out for warming, as was delivery of warm inspired gas via the ventilator. However, after an hour the temperature had dropped to 29.5C. CAVR was initiated as a last-ditch effort using a jerry-rigged Rapid Fluid Warmer from Level 1 Technologies. The core temperature was raised to 35C after 85 minutes.

The patient did have typical complications (ARDS, acute renal failure), but survived with recovery of his renal and pulmonary function, and a normal neurologic exam. At the time, the authors were unsure whether the complications were due to the near-drowning or the rapid rewarming.

Reference: Continuous arteriovenous rewarming: report of a new technique fo9r treating hypothermia. J Trauma 31(8):1151-1154, 1991.

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Trauma 20 Years Ago: Seatbelt Injuries

Seatbelt use has increased from 58% in 1994 to a high of 85% last year. We know that seatbelt use saves lives, but trauma professionals are also aware that they can create their own injuries as well. This is a positive trade-off, because belt use prevents injuries that are difficult to treat (e.g. severe brain injury) and produces a higher number of intra-abdominal injuries that are easy to treat.

The spectrum of injuries attributed to seat belt use was finally appreciated in a journal article published 20 years ago this month. The authors wanted to catalog the various injuries seen in belted and unbelted motor vehicle occupants. They reviewed data from the North Carolina Trauma Registry, one of the most sophisticated state registries at the time. Although there were over 21,000 records in the database, only 3,901 involved motor vehicle crashes and had complete data on seatbelt use.

This study found the following:

  • Mortality was higher in those not wearing their seat belts (7% vs 3.2%)
  • Unbelted had a much higher incidence of severe head injury (50% vs 33%)
  • Overall incidence of any abdominal injury was the same for both (14%)
  • GI tract injuries were more common in the belted group (3.4% vs 1.8%)
  • Solid organ injury was the same

Bottom line: This study sparked the recognition that seatbelts reduce severe head injury but increase the incidence of some hollow viscus injuries. About 514 severe head injuries were prevented in exchange for 21 additional abdominal injuries that were generally easily repaired. Good tradeoff!

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Reference: The spectrum of abdominal injuries associates with the use of seat belts. J Trauma 31(6):821-826, 1991.

Trauma 20 Years Ago: Continuous Epidural Analgesia for Rib Fractures

Rib fractures are painful, and lots of rib fractures not only hurt, but can lead to complications or death. We take for granted all the modalities we now have for pain relief with rib fractures:

  • IV narcotics
  • epidural analgesia
  • rib blocks
  • intrapleural analgesia
  • lidocaine patches
  • fracture fixation techniques
  • and more!

In April 1991, we were still trying to figure out if epidural analgesia was any better than IV narcotics. A small prospective study of 32 patients who were awake and alert and had at least 3 rib fractures were given either IV or epidural fentanyl. The drug was administered as an initial bolus, followed by a continuous infusion. A visual analog pain scale was used for titration.

Vital capacity increased significantly in both groups. Epidural analgesia also led to an improvement in maximum inspiratory pressure (which we now know as NIF). IV analgesia led to somewhat troubling increases in pCO2 and decreases in pO2, whereas epidural administration did not. Pain relief was better with the epidural, while side effects were similar.

The authors concluded that epidural analgesia offers several advantages over IV, and stated that it should be the preferred method for patients at high risk for complications following multiple rib fractures. This paper started us on the path to using the epidural for pain management with significant rib fractures.

Reference: Prospective evaluation of epidural and intravenous administration of fentanyl for pain control and restoration of ventilatory function following multiple rib fractures. J Trauma 31(4):443-451, 1991.

Trauma 20 Years Ago: ED Intubation For Head Injury Is Safe

How far we have come! It’s now commonplace to intubate trauma patients in the ED using rapid sequence induction followed by orotracheal tube placement. However, 20 years ago we were still gnashing our teeth about safety.

In 1991, the group at UMDNJ Newark looked at 100 consecutive trauma patients with suspected head injury who were paralyzed and intubated in the ED. Half of the intubations were performed by a surgeon, the other half by an anesthesiologist. Fifty seven patients were intubated orally and 40 nasally(!). Three required cricothyroidotomy after failure to intubate due to facial fractures.

The majority of these patients had head scans performed; 59% were positive and 15 required emergent neurosurgical procedures. No patients were found to have a neurologic deficit from the intubation even though seven were eventually found to have cervical spine injuries. Only one patient developed an aspiration pneumonia.

The authors concluded that paralysis and intubation in the ED was safe. It helped facilitate the diagnostic workup because they could control combative patients. Up to that time, the only alternative was heavy sedation, which carried its own risks. 

Interesting points on how far we have advanced:

  • Intubation in the ED did not used to be routine. There was a great deal of anxiety before this procedure
  • Nasal intubation was still fairly commonplace
  • The cricothyroidotomy rate was high
  • Intubation was usually performed by a surgeon or anesthesiologist