CRITICAL CARE UPDATE
Selections from Current Concepts in General Surgery and Trauma Update, presented September 2005, by the
University of New Mexico Health Sciences Center, Department of Surgery
| NEW ISSUES IN NEUROTRAUMA —Howard Yonas, MD, Professor and Chair, Department of Neurosurgery, University
of New Mexico School of Medicine, Albuquerque
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| Management of head injury: control airway and perfusion; examine patient early; document hypoxia or hypotension
early; avoid mandatory administration of mannitol (destabilizes patient and promotes diuresis, hypotension, and bleeding);
aggressive therapy indicated if patient deteriorates; studies show steroids have no benefit; assume spine unstable
and manage
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| Therapeutic hypothermia: National Acute Brain Injury Study: Hypothermia (NABISH)—patients randomized to
33°C or normal temperature on arrival at emergency department (ED) and maintained for 48 hr; hypothermia showed no
benefit, except in patients <45 yr of age and patients with temperature of 35°C to 36°C on arrival at ED; NABISH II—
ongoing trial assessing rapid cooling of patients (in NABISH trial, average time to cooling 8 hr); iced saline one strategy;
note—after lowering temperature, warm patient very slowly and monitor potassium and other electrolytes
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| Prognostic factors: poor prognosis—old age; low Glasgow Coma Scale (GCS) score; fixed and dilated pupils; injuries
on computed tomography (CT), eg, hemorrhage in brainstem, loss of grey-white integrity; subarachnoid hemorrhage;
hypotension; hypoxia; intracranial pressure (ICP) problems
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 | Patients with intracranial mass lesion: triage patient immediately to operating room (OR) and remove mass lesion; improved
outcome if lesion removed in 1 to 2 hr (mortality 70%-80% if lesion not removed within 5 hr); minimize secondary
injuries—if brainstem herniated and blood unable to escape midbrain, hemorrhages can occur that dissociate
reticular activating system from cerebral hemispheres; surgery—usually involves large craniotomy; remove clot and,
if contused, temporal lobe; do not hesitate to leave off bone flap; goal to decompress brain; hypotension—important
to avoid hypotension before decompression; time-depth relationship between cerebral perfusion pressure (CPP) and
blood flow, ie, when blood flow reaches zero, few minutes before irreversible ischemia occurs
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| Patients with no mass lesion: stabilize patient by medical means; Cool Line catheter may replace central venous pressure
(CVP) line catheter for monitoring fluids and temperature; use arterial line and ICP monitor; speaker normally uses external
ventriculostomy drainage (EVD) catheter to drain spinal fluid and monitor ICP; if ventricles too small for catheter,
use solid-state monitor
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| Cerebral blood flow (CBF) and perfusion pressure: closer ICP gets to CPP, less perfusion to brain; ICP and
CPP can be measured with simple monitor and can act as surrogate markers for CBF; goal to achieve difference of 60
mm Hg between ICP and CPP (children likely can go down to 40 mm Hg); hyperemic brain (high CBF) can occur with
high ICP and low CPP; causes of high ICP—not always brain swelling caused by clot accompanied by decrease in
CBF; high CBF another potential cause; xenon CT—quantitative; high resolution; easily repeatable; no allergic reaction
because xenon noble gas; cost effective; soon able to perform at bedside; produces blood flow maps; noninvasive; can
distinguish areas of zero, penumbral, and normal blood flow; can help determine whether patient at risk for ischemia;
study—goal CBF 30 to 39 mL/100 g per minute; hyperventilation exacerbates most brain injuries and can create diffuse
panhemispheric ischemia, so important to maintain CO2 in therapeutic range; conclusion—situation too complex to
monitor and manage using ICP and CPP alone; Lund approach—to prevent ICP problems, maintain fluid volume, increase
hematocrit (Hct) and osmolarity, and avoid vasopressors; associated with mortality of 10%, compared to 30% in
United States
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| Confounding variables: hypoxia; hyperthermia—Pittsburgh study showed that in 80% of patients, temperature during
first week after injury (subarachnoid hemorrhage) 38.5°C; metabolism increases 10% per 1°C increase in temperature; brain
temperature 0.5°C to 1°C higher than core body temperature; anemia—Hct of 33% needed to maintain O2 delivery; avoid
water; brain ischemia—keep bed flat for one day, then elevate; brain tends to be ischemic on first day after injury due to
severe vasoconstriction; sedation—speaker uses short-acting drugs and concerned about use of lorazepam (Ativan) in high
doses
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| Treatment strategy: goal CO2 33 mm Hg; goal temperature 36°C; angiography, blood flow, and perfusion studies indicated
if CT inconclusive; monitor for development of mass lesion requiring removal; drain, paralyze, and sedate if ICP troublesome;
intracranial blood flow studies sometimes indicated if CO2 <30 mm Hg, especially in children; hypertonic saline
used increasingly in combination with mannitol to reduce brain swelling; late decompressive surgery used increasingly for
refractory problems (decreases ICP but no data show improved outcomes); barbiturate coma or cooling may be beneficial
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| Future therapeutic interventions: Licox monitoring system—measures O2 levels in brain; provides early warning
of deterioration in pulmonary status and blood flow; evidence that brain O2 delivery can be increased by raising PaO2 ; 2
laboratory studies and 1 clinical study show supernormal O2 levels benefit patients; suggests that very high levels of O2
may be indicated during trauma transfer; CBF and O2 —data now being provided using small probes in brain;
microdialysis—placement of small leads at time of trauma facilitates removal of chemicals such as glutamate, lactate,
and pyruvate, and provides information on whether changes in O2 and CBF translate into brain injury; bedside system
can provide results within 20 min of sampling; probe placement—CT important in guiding placement of probes into
penumbral (at-risk) area, not dead area; bedside CT—major complication rate of 20% associated with moving patient
from ICU to scanning unit; portable CT scanner for head and neck available soon
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| DIAGNOSTIC PERITONEAL LAVAGE AS A DIAGNOSTIC AID FOR ABDOMINAL STAB WOUNDS —Thomas R.
Howdieshell, MD, Associate Professor, Department of Surgery, University of New Mexico School of Medicine, Albuquerque
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| Anatomic regions of potential injury: anterior abdomen—from costal margins to inguinal ligaments and between
anterior axillary lines; flank—between anterior and posterior axillary lines, scapular tip, and iliac crest; back—between
posterior axillary lines, scapular tips, and iliac crest; thoracoabdomen—in men, line drawn from nipple to scapular tip; in
women, from xiphoid to scapular tip; boundaries are fourth intercostal space anteriorly and eighth intercostal space posteriorly
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| Goals of conservative management or selective observation: reduce rate of unnecessary laparotomy (reported
to be 27%-63%), ie, patients hemodynamically stable with no peritoneal findings or evisceration can be managed selectively
(morbidity and mortality rates due to unnecessary laparotomy reported to be 40% and 3%, respectively); shorten or
prevent hospitalizations; reduce cost
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| Serial abdominal examination for determining need for laparotomy
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| Literature review: from 1960 to 2005, 3307 patients underwent serial abdominal examination as selection for laparotomy;
false-positive rate 3% to 18%; false-negative rate 2% to 16%; morbidity 21%; mortality 1%; only 3 deaths, of which 2
due to complications other than surgical procedure; Ryder Trauma Center study (2005)—of 650 patients, 68% had
change in examination warranting laparotomy (false-negative 11%); of these, all had change in vital signs or physical
findings within 12 hr (majority within 6 hr); conclusion that patients undergoing serial abdominal examination be observed
for 12 hr
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| Diagnostic peritoneal lavage (DPL) for determining need for laparotomy: in patient with stab wound to anterior
abdomen, perform local wound exploration; if fascia intact, discharge patient; if fascia and/or peritoneum violated,
perform DPL using open or closed technique (closed technique faster and has similar safety; preferred method)
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| Factors affecting lavage cell count: technique—open or closed; quantity of fluid returned from lavage—
literature suggests 100 to 500 mL sufficient; 1 L of fluid instilled into abdominal cavity, so speaker believes return of 10%
(100 mL) unlikely adequate evaluation; adequate mixing of lavage bag—if bag not gently mixed before obtaining sample,
considerable variability may exist in cell volumes sent to laboratory
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| DPL closed technique: prepare and drape abdomen just below umbilicus; important to decompress stomach and urinary
bladder before beginning procedure; infiltrate local anesthesia (must be lidocaine with epinephrine); make small
stab incision 2 finger breadths below umbilicus and insert 18-gauge needle at 45° to 60° angle, aiming toward pelvis; insert
J wire through needle (if wire does not track smoothly, remove needle and start over); when wire placed, take needle
out and insert dialysis catheter using Seldinger technique; gross blood on aspiration indicates positive lavage and mandates
laparotomy; if lavage negative, infuse 1 L of saline into peritoneal cavity (can vapor lock if air in line)
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| Literature review of DPL for anterior abdominal wall stab wounds: variability exists depending on red
blood cell (RBC) count criteria (eg, 100,000/mm3 , 50,000/mm3 , or 10,000/mm3 ); study—in 123 patients, 5% of patients
with RBC <100,000/mm3 developed change in physical examination that prompted laparotomy; 4% had RBC
>100,000/mm3 , but laparotomy revealed no injury that required repair; review—over 50 yr, 1400 patients had DPL for
anterior abdominal wall stab wounds; false-positive rate 25%, false-negative rate 9%, low morbidity, and limited mortality
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| Oreskovich and Carrico (1983): all patients receiving DPL underwent laparotomy; for RBC 100,000/mm3 , 68 of 72 patients
had injury (mostly solid organ); for RBC 50,000/mm3 to 100,000/mm3 , fewer injuries (again, mostly solid organ);
for RBC 10,000/mm3 to 50,000/mm3 , more hollow viscus injuries; for RBC <1000/mm3 , no injuries; no patient
had white blood cell (WBC) count >500/mm3 (possibly due to DPL being performed within 3 hr); algorithm—if local
wound exploration negative for fascial violation, discharge patient; if exploration positive, perform DPL; if RBC
<1000/mm3 , admit patient due to concerns about safety of DPL; if RBC >1000/mm3 , perform laparotomy
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| Ultrasonography (US) for determining need for laparotomy: Scalea et al (2001)—in 75 patients with penetrating
injury, 54 patients had negative Focused Assessment with Sonography for Trauma (FAST) examination; 22 false
negatives (41%); overall sensitivity 46%; negative predictive value 60%; similar accuracy for stab and gunshot wounds
(negative predictive value better for stab wounds); little more accurate for back wounds, compared to anterior abdomen
and flank wounds
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| Laparoscopic evaluation of anterior abdominal stab wounds: study (1999)—for blunt and penetrating
trauma, laparoscopy reduced unnecessary laparotomy rate 63%; missed injury rate 1%, procedural complication rate 1%;
Ivatury et al (1997)—in 510 patients (316 stab wounds, 194 gunshot wounds), laparoscopy performed on hemodynamically
stable patients with positive local wound exploration; 277 patients (54%) had either no peritoneal penetration or no
injury requiring laparotomy; laparoscopy used as therapeutic tool in 26 patients, avoiding laparotomy; in patients who underwent
laparotomy because of positive laparoscopic screening, 52 (25%) had nontherapeutic laparotomy, ie, no injury required
repair; DeMaria et al (2000)—of 54 hemodynamically unstable patients with anterior abdominal stab wounds, all
underwent DPL, then randomized to laparotomy or laparoscopy (not based on DPL results); laparotomy avoided in 55% of
patients who underwent laparoscopy (nontherapeutic laparoscopy rate 19%); DPL (cutoff RBC <5000/mm3 ) accuracy
72%, laparoscopy accuracy 81%; if patient stable and local wound exploration negative, discharge patient; if exploration
positive, perform DPL; if exploration grossly positive, perform laparotomy; if RBC >5000/mm3 , perform laparoscopy to
determine need for laparotomy
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| Triple-contrast CT for determining need for laparotomy: Scalea et al (2001)—75 patients with anterior abdominal
wounds received CT; 26 patients had positive CT (defined as evidence of peritoneal violation, ie, free air or
fluid, contrast leak, or visceral injury); 18 received laparotomy (8 managed without surgery); 49 patients had negative
CT, of which 47 managed without surgery and 2 had change in physical examination that warranted laparotomy; accuracy
95%, negative predictive value 98%
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| Wounds to left thoracoabdomen
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| Mandatory laparotomy: study (1989)—95 patients with stab wounds to left thoracoabdomen underwent laparotomy;
19% had occult diaphragmatic injury; 72% had associated injury, eg, in colon or stomach; majority had minimal radiographic
findings
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| DPL: literature review—for RBC 100,000/mm3 , significant false-negative rate in some series; for RBC 10,000/mm3 ,
false-negative rate <5%
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| Laparoscopy: study (1997)—57 patients underwent laparoscopy for stab and gunshot wounds; 32% had injury to diaphragm
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| Digital exploration: Colombian study (2001)—82 patients received digital exploration for stab wounds; 51 patients had
hole in diaphragm determined by digital palpation (50 had injury); in 25 patients with negative digital exploration, integrity
of diaphragm confirmed by thoracoscopy
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| Wounds to back and flank: speaker believes triple-contrast CT proven to have lowest false-positive and false-negative
rates
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| Conclusions: mandatory laparotomy for anterior abdominal stab wounds associated with high nontherapeutic laparotomy rate
(27%-63%); selective management safe; local wound exploration rules out peritoneal violation in 33% of patients; serial examination
for 12 hr, DPL at RBC <1000/mm3 , and triple-contrast CT appear to have lowest false-negative rates for hollow viscus
injury; laparoscopy effective screening tool for anterior abdominal wound and good diagnostic study for thoracoabdominal
wound; FAST has limited accuracy for penetrating trauma and concerning negative predictive value for stab wounds; triple-
contrast CT proven accurate for back and flank wounds and likely to become part of abdominal wound management
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Educational Objectives
| The goal of this program is to educate the listener about new issues in neurotrauma and diagnostic peritoneal lavage (DPL).
After hearing and assimilating this program, the clinician will be better able to:
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| 1. Manage patients with traumatic head injuries.
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| 2. Discuss the role of therapeutic hypothermia in the management of traumatic head injury.
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| 3. Evaluate patients with penetrating abdominal trauma.
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| 4. Use DPL as a diagnostic aid for penetrating abdominal trauma.
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| 5. Determine which patients with penetrating abdominal trauma are suitable for selective observation.
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Discussed on This Program
Lidocaine HCl with epinephrine [Octocaine, Xylocaine, Xylocaine MPF]
Mannitol [Osmitrol, Resectisol]
Suggested Reading
Alzamel HA, Cohn SM: When is it safe to discharge asymptomatic patients with abdominal stab wounds? J Trauma
58:523, 2005; Cahill WJ et al: Mechanisms of early brain injury after subarachnoid hemorrhage. J Cereb Blood Flow
Metab Feb 15[Epub ahead of print], 2006; Choi SC, et al: Misclassification and treatment effect on primary outcome
measures in clinical trials of severe neurotrauma. J Neurotrauma 19:17, 2002; Clifton GL et al: Fluid thresholds and
outcome from severe brain injury. Crit Care Med 30:739, 2002; Clifton GL et al: Hypothermia on admission in patients
with severe brain injury. J Neurotrauma 19:293, 2002; Clifton GL et al: Intercenter variance in clinical trials of
head trauma--experience of the National Acute Brain Injury Study: Hypothermia. J Neurosurg 95:751, 2001; Gupta R et
al: Xenon CT cerebral blood flow in acute stroke. Neuroimaging Clin N Am 15:531, 2005; Howdieshell TR et al:
Temporary abdominal closure followed by definitive abdominal wall reconstruction of the open abdomen. Am J Surg
188:301, 2004; Klein Y et al: Diagnostic peritoneal lavage through an abdominal stab wound. Am J Emerg Med 21:559,
2003; Powner DJ et al: CVP and PAoP measurements are discordant during fluid therapy after traumatic brain injury. J
Intensive Care Med 20:28, 2005; Pryor JP et al: Nonoperative management of abdominal gunshot wounds. Ann
Emerg Med 43:344, 2004; Rose JC et al: Continuous monitoring of the microcirculation in neurocritical care: an update
on brain tissue oxygenation. Curr Opin Crit Care 12:97, 2006; Servadei F et al: Evolving lesions in traumatic subarachnoid
hemorrhage: prospective study of 110 patients with emphasis on the role of ICP monitoring. Acta Neurochir
Suppl 81:81, 2002; Sriussadaporn S et al: Clinical uses of diagnostic peritoneal lavage in stab wounds of the anterior
abdomen: a prospective study. Eur J Surg 168:490, 2002; Tayal VS et al: FAST (focused assessment with sonography
in trauma) accurate for cardiac and intraperitoneal injury in penetrating anterior chest trauma. J Ultrasound Med 23:467,
2004; Tsikitis V et al: Selective clinical management of anterior abdominal stab wounds. Am J Surg 188:807, 2004;
Wintermark M et al: Comparative overview of brain perfusion imaging techniques. J Neuroradiol 32:294, 2005.
Faculty Disclosure
In adherence to ACCME guidelines, the Audio-Digest Foundation requests all lecturers to disclose any significant financial
relationship with the manufacturer or provider of any commercial product or service discussed. For this issue, the speakers
reported no conflict.
Drs. Yonas and Howdieshell gave their presentations at Current Concepts in General Surgery and Trauma Update,
presented September 7-9, 2005, in Albuquerque by the University of New Mexico Health Sciences Center, Department
of Surgery. The Audio-Digest Foundation thanks the speakers and the sponsor for their cooperation in the production
of this program.
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