International Trauma Anesthesia and Critical Care Society (ITACCS). Vienna, Austria, May 21-23, 1998.
TraumaCare '98, the 11th Annual Trauma Anesthesia and Critical Care Symposium and World Exposition, was attended by more than 500 anesthesiologists, intensivists, emergency medicine physicians, nurses, paramedics, and military personnel. Forty-three countries were represented.
Resuscitation for Trauma during the 20th Century
In the keynote presentation, Peter Safar (Pittsburgh, PA) reviewed milestones in resuscitation medicine. Lessons learned from military experience during conflicts of war have shown that appropriate resuscitation depends more on efforts to stop bleeding after trauma than on the fluid used for resuscitation. Recent research has identified several areas that need to be delineated with regard to fluid administration before surgery: no fluid resuscitation, limited fluid resuscitation, and limited fluid resuscitation with hypothermia.
At the Resuscitation Institute, Dr. Safar has studied the concept of “suspended animation”(SA) for the purpose of protecting and preserving the organism for 1-2 h using profound hypothermia. Because of the logistical difficulty in achieving such temperatures in the clinical setting, new research focuses on pharmacologic means of inducing SA. Mild-to-moderate (not profound) hypothermic states are being investigated.
Airway Management for Trauma
M. Frass (Vienna, Austria), who developed the Combitube, discussed its use in trauma. The Esophageal Tracheal Combitube (Kendall Sheridan, Argyle, NY) combines the functions of an endotracheal and an esophageal obturator airway.
A. Karlin (New York, NY) spoke about confirmation of endotracheal tube (ETT) placement by standard methods (i.e., capnography) and less conventional but reliable methods such as the bulb technique: a bulb compressed and then placed on the end of an ETT will reexpand if the ETT has been placed in the trachea, but it will remain collapsed if the ETT is in the esophagus. This is a portable, consistent, easy method for confirming ETT placement in the field.
J. Nolan (Bath, UK) summarized the risks of the laryngeal mask airway (LMA) in trauma patients, one of which is aspiration. Studies published in the United Kingdom report that blood, not stomach contents, is the primary aspirate during prehospital airway management. The new intubating LMA is now used routinely in the United Kingdom for elective surgery.
Prehospital Trauma Care
The topics covered in this forum were mountain rescue, urban and rural care, aeromedical rescue, and the care of entrapped patients. An extrication workshop was presented by members of the Helsingborg (Sweden) fire brigade. In European countries, it is common for anesthesiologists to be involved in the prehospital care of trauma victims. This presentation was an opportunity for anesthesiologists from the United States to familiarize themselves with the demands of field medicine.
Difficulties in conducting human research trials in traumatology were discussed. Limitations include informed consent issues, variability of prehospital treatment, and interactions between iatrogenic hypotension caused by anesthetics and analgesics and that caused by hypovolemia. Current research focuses on fluid resuscitation (specifically, the ideal targeted blood pressure before hemostasis), brain resuscitation, and mild hypothermia to improve outcome from traumatic brain injury (TBI).
The neurotrauma panel, chaired by E. Frost (New York, NY) and C. Spiss (Vienna, Austria), covered specific aspects of physiology and treatment after TBI and concluded with case discussions.
Discussing the epidemiology and pathophysiology of TBI, O. Kempski (Mainz, Germany) reviewed statistics of long-term disability after neurotrauma. Not only is the primary brain injury a concern, but also patients are at risk for secondary injury from either inflammatory mediators, adding to parenchymal damage, or diffuse axonal injury. Both can increase intracranial pressure (ICP), which is seen in 70% of patients with TBI.
J. Ghajar (New York, NY), who supports maintenance of normocapnia for management of TBI, discussed ICP monitoring. Dr. Ghajar recommends intraventricular catheter placement not only as a monitoring technique but also as a therapeutic maneuver to control ICP by draining cerebrospinal fluid (CSF).
C. Spiss spoke on the use of SjO2(jugular venous bulb oxygen) saturation) monitoring as a method of determining cerebral blood flow (CBF) and metabolism after TBI. Studies with SjO2monitoring have shown the cause of desaturations to be primarily hypocapnia (45% in one series), followed by a decrease in CBF, then elevated ICP. Frequent SjO(2) desaturations are correlated with poorer outcome.
Electrophysiologic monitoring was discussed by W. Loffler (Linz, Austria). Electroencephalography (EEG) has been used in patients with TBI to localize anatomic injury (lateralizing findings) and to gauge treatment (i.e., effects of pharmacologic agents). Correlation has been found between the absence of specific positive and negative amplitudes of somatosensory-evoked potentials and an increase in frequency with persistence vegetative states. Brainstem evoked potentials are not altered in barbiturate coma and can be used to identify uncal herniation or predict impending neurologic deterioration.
C. Werner (Munich, Germany) discussed first-tier treatment of patients after TBI. Prophylactic hyperventilation therapy is no longer recommended to control ICP. Although it decreases cerebral blood volume, which is desirable, it also decreases CBF, possibly at the expense of cerebral perfusion pressure (CPP). Therefore, current recommendations are for the use of hyperventilation only as a transient intervention when other methods of decreasing ICP (sedation, osmotic diuretics, paralysis) have failed.
Second-tier treatment was discussed by U. Illievich (Vienna, Austria) with a review of the use of hypothermia in the treatment of patients with TBI. Hypothermia therapy is targeted to specific temperatures: mild, 34-36.5 [degree sign]C; moderate, 28-33.5 [degree sign]C; deep, 17-27.5 [degree sign]C; and profound, 4-16.5 [degree sign]C. Moderate-to-profound hypothermia enhances cerebral tolerance for ischemic episodes and decreases CMRO2.
J. P. Jantzen (Hannover, Germany) discussed anesthesia and fluid management in TBI. Resuscitation with normal saline reduces colloid oncotic pressure and may worsen posttraumatic cerebral edema compared with hetastarch or blood. Glutamate-containing fluids for nutritional support should be avoided.
Costs of Trauma Critical Care
A session on the costs of critical care for trauma patients was chaired by A. Sutcliffe of Queen Elizabeth Hospital in Birmingham, England. Presentations were made by trauma anesthesia/critical care specialists from the United States, Norway, Belgium, Germany, Austria, Italy, and England.
The session opened with a presentation titled “Finance of Trauma Care Worldwide” by C. M. Grande, Executive Director of ITACCS. Dr. Grande summarized the current state of affairs in trauma care as somewhat contradictory. Many third-party payers still have not realized the significant effect of injury and its attendant costs on their entire liability for providing and paying for all health care. One problem lies in the identification and coding of trauma cases: they are sometimes arbitrarily designated “orthopedic” or “neurologic” cases, diluting the heterogeneity of trauma care.
In the “third world,” trauma care is ignored for a different reason. Here, government and public health officials recognize the tremendous costs of providing effective trauma care services and seem to have decided against becoming involved in these services. Although the World Health Organization (WHO) recently recognized trauma as “the disease of the next millenium” and is beginning to shift its interests and resources to deal with this problem, one of the challenges remains how to provide effective “low-tech” trauma care. Representatives from various countries described how trauma care resources are allocated, pointing out the largest sections attributing to costs.
Pediatric Trauma Issues
The pediatric trauma session covered a broad range of topics related to critical management issues in pediatric trauma. The session was cochaired by G. Rasmussen and K. Horsten (Vanderbilt University, Nashville, TN).
The first lecture, by T. Martin (Arkansas Children's Hospital), dealt with initial assessment and airway management in pediatric trauma. G. Rasmussen talked about cardiovascular resuscitation and fluid management issues. Initial resuscitation and recognition of shock are of paramount concern. J. Berman (University of Texas, Galveston, TX) discussed vascular access and the use of intraosseous infusion in resuscitation. P. Meyer of Hopital Necker (Paris, France) discussed traumatic brain injury in children and the potential users of low-volume resuscitation and of transcranial Doppler and imaging in delineating and predicting severity of injury.
Critical Care after Major Trauma
R. Clark (Pittsburgh, PA) began with a presentation on “Apoptosis and Cellular Death following TBI.” Apoptosis is a Greek term meaning the “dropping off or falling off of petals from flowers or of leaves from trees.” In the 1970s, it was adopted to define the type of cell death seen after certain types of injury-a “programmed cell death”-which is regulated by recently identified specific cell genes. A review of molecular mechanisms and markers for this programmed cell death and their role in TBI was included.
J. Hoyt (Pittsburgh, PA), past president of the Society of Critical Care Medicine, reviewed “ARDS and Respiratory Monitoring.” The institution of large tidal volumes in positive-pressure ventilation (PPV) in the ICU came from the recognition of the occurrence of hypoxia during anesthesia in the operating room, thought to be caused by atelectasis. It was believed that tidal volumes of 12-15 ml/kg would alleviate this problem. The recognition of barotrauma secondary to PEEP led to the concept of “lung-protective” strategies such as limited airway pressures and tidal volumes of 6-8 ml/kg, which then led to a decrease in minute ventilation and resultant hypercapnia or “permissive hypercapnia.” Recent studies have not shown an improvement in mortality statistics with the use of lung protective mechanisms. New monitoring devices include a pneumotacograph in conjunction with a capnometer, which will give CO2elimination and dead space determinations breath by breath. The areas of the curve generated will delineate airway (anatomic) from alveolar dead space and CO2elimination.
Dr. Hoyt addressed the controversies surrounding pulmonary artery catheterization. Pitfalls of the use of PA catheters relate to rigid adherence to the values measured by the catheter, rather than use of the PA catheter as a tool in assisting with bedside physiologic management. The relationship between PA occlusion pressure (PAOP) and left ventricular end diastolic volume (LVEDV) is unreliable because there is not always a correlation between pressure and volume (compliance in critical illness is not static). The value of the PA catheter is its ability to monitor flow and to measure mixed-venous O2saturation. These determinations can be translated into a hemodynamic profile of oxygen delivery and oxygen consumption at the cellular level.
D. Porembka (Cincinnati, OH) spoke on nitric oxide (NO) versus partial liquid ventilation (PLV) in the treatment of ARDS. NO, when introduced into ventilated areas of the lung, improves ventilation/perfusion (V/Q) matching by local vasodilation. No systemic effects are seen as NO is inactivated by hemoglobin. Because it does not reach nonventilated lung units, shunt is not increased as with systemic vasodilators. A plateau effect is seen due to saturation of patent lung units, with no NO reaching collapsed alveoli. Recent clinical trials of liquid ventilation have gone from total to partial liquid ventilation with perfluorocarbons (PFCs). PFCs reach the dependent, nonventilated areas of the lung, permitting exchange of O2and CO2at the gas-liquid interface. An initial decrease in PaO2after instillation of PFC is thought to be caused by distribution of PFC to the dependent, previously non-"ventilated" lung units. Advantages of PFC are anti-inflammatory properties, decreases in surface tension, and reduction in the work of breathing. Instillation of 30 ml/kg fills FRC, which is adequate for gas exchange. Phase III studies in adult humans are in preparation.
D. Porembka also addressed the use of transesophageal echocardiography (TEE) in trauma patients. TEE can provide additional information in conjunction with PA catheters because falsely elevated PAOP may be the result of transmitted airway pressures or blunt myocardial injury. In addition, TEE is valuable in diagnosing aortic injury or ventricular dysfunction.
P. Gennann (Vienna, Austria) concluded the session with a presentation of the use of ASPECT (annular single photon emitted computed tomography) to measure CBF at the bedside. The ASPECT gantry is brought to the ICU. The scan is more sensitive than CT scanning for visualizing lesions, but it can be repeated only every 24-48 h because of the half-life of the radioactive tracer.
Human Factors in Trauma Management
A human factors session titled “Systems Failures in Trauma Management” included D. Scheidegger (Basel, Switzerland), who reported on problems in the operating room with hierarchies and communications between surgeons and anesthesiologists. S. Ternov (Lund, Sweden) showed how he applied industry-developed system failure investigation techniques in analysis of medical errors.
Maureen McCunn, M.D.
Assistant Professor of Anesthesiology, Trauma and Critical Care; R. Adams Cowley Shock Trauma Center; 22 South Greene Street; Baltimore, Maryland;firstname.lastname@example.org
(Accepted for publication September 24, 1998.)