SLIDE 1: Biomechanics and Medical Diagnosis of HVI in Adults and Children – An Illustration of the CIREN Model Dorraine Watts, RN, PhD Honda Inova Fairfax CIREN Chris Sherwood, MS University of Virginia for Children’s National Medical Center CIREN SLIDE 2: Introduction HVI – Hollow Viscous Injury Complicated diagnosis and treatment Common injury in automobile crashes Children at risk due to smaller anatomy SLIDE 3: Abdominal Anatomy [photos] * Diaphragm * Liver * Stomach * Spleen * kidney [CT scan] * Kidney * Spleen SLIDE 4: Abdominal “Solid” Organs Liver - 27% of total blood flow Spleen- 5% of total blood flow Kidneys - 22% of total blood flow Pancreas Adrenal Glands SLIDE 5: Abdominal “Solid” Organs * Primary Injury Concern - Hemorrhage * Diagnosis - Accurate SLIDE 6: Abdominal “Hollow” Organs Stomach Small Intestine Duodenum, Jejunum, Ileum Large Intestine Ascending, Transverse, Descending, Sigmoid Gall Bladder Urinary Bladder SLIDE 7: Abdominal “Hollow” Organs Primary Injury Concern: * Spillage of Contents - Sepsis * Diagnosis - Inaccurate SLIDE 8: HVI Issues * Trauma surgeons are increasingly managing blunt abdominal trauma non-operatively * Intestinal injuries that were previously discovered at laparotomy for solid organ injuries may be missed with non-operative management * In older reports, delays in diagnosis of less than 12-24 hours were associated with limited morbidity and no mortality * Longer delays result in significantly increased morbidity and mortality SLIDE 9: Surgeon’s Dilemma * There is no well-publicized consensus among trauma surgeons as to the optimal way to diagnose occult intestinal injury * Debate over using exploratory surgery as a diagnostic tool focuses on whether or not the risks associated with a non-therapeutic laparotomy outweigh the morbidity and mortality associated with a delay in the diagnosis of small bowel injury ================= SLIDE 10: Diagnosis and Management of Blunt Small Bowel Injury: A Survey of the Membership of the American Association for the Surgery of Trauma Brownstein, Bunting, Meyer, Fakhry University of North Carolina, Chapel Hill, NC and the Inova Regional Trauma Center, Falls Church, VA The purpose of this study was to survey the membership of the AAST regarding current diagnostic approaches in the management of patients with suspected small bowel injury, and evaluate their perceptions of the morbidity and mortality associated with a delay in diagnosis SLIDE 11: Conclusions Significant variation exists in the diagnostic approach * Surgeons underestimated the morbidity of non-therapeutic laparotomy and the mortality associated with a delay in diagnosis * The lack of consensus regarding the diagnostic approach may have undesirable effects on injured patients SLIDE 12: Hollow Viscous Injury and Small Bowel Injury in Blunt Trauma: An analysis of 275,557 trauma admissions from the EAST Multi-Institutional Trial EAST Multi-Institutional HVI Research Group Watts DD, Fakhry SM et al. J of Trauma, 54:289-294, 2003 SLIDE 13: Conclusions * Motor Vehicle Crashes (MVC) was the most frequent mechanism of injury in patients with perforating SBI * Logistic regression models of CT data yielded no useful discriminators in predicting SBI * Patients from MVCs had a relative risk (RR) of SBI of 1.7 * The non driver position increased the risk of perforating SBI (RR = 1.9, 95% CI 1.6-2.3) * Use of a seat belt increased the risk of perforating SBI (RR = 2.4 , 95% CI 2.0-2.8) * Delay in treatment of SBI injuries increased treatment complications SLIDE 14: Risk The presence of an abdominal seatbelt mark was the most significant risk factor, carrying a 4.7 increase in relative risk (95% CI 3.7 - 5.9) So 2 ways CIREN data can assist this field 1 – Prevention – by learning more about the injury mechanisms to reduce risk of these injuries 2 – Diagnosis is very important in this injury. If factors can be determined which indicate high risk of this type of injury, can help medical personnel in treatment course SLIDE 15: Biomechanics Research Hollow Viscous Organs SLIDE 16: Frontal Crashes Seatbelt, Steering Wheel SLIDE 17: [diagram] position of lap belt relative to pelvis belt across anterior superior iliac spines SLIDE 18: [diagrams] SUBMARINING SLIDE 19: Reasons for Booster Seats Practical concerns - Prevent slouching due to leg length - Slouching degrades fit for both lap and shoulder belt - Reduces misuse of shoulder belt SLIDE 20: Lap Belt Only – Seat Belt Syndrome - HVI - Lumbar Spine < Gumler et al., 1982 > SLIDE 21: SIDE IMPACT SLIDE 22: INJURIES * Contusion, perforations, transections, lesions * Mechanisms of Injury - Increased intraluminal pressure - Perforation from rib and pelvic fractures - Shearing or crushing against spine - Deceleration (relative motion from fixed attachments - mesentery) SLIDE 23: [diagram] “Blowout” of Intestines caused by high intraluminal pressures Steering Wheel or Lap Belt Loading SLIDE 24: [bar chart] BELT USE/ PERCENTAGE OF VEHICLES WITH DRIVER AIRBAG There is another phase here in late 80s and early 90s of a 2 point belt. It was shown to have higher rates of liver injuries, when lap belt not used. This will not be included in data we present. SLIDE 25: AIS = 2 Hollow Viscous Injury Sources - Frontal Impact 1977-1979 Front: -Steering Assembly -Instrument Panel (52%) Side Interior: -Surface -Armrests (9%) Belt Restraint (4%) SLIDE 26: AIS = 3 Abdominal Injury Distribution - Frontal Impact - Liver (30%) - Kidney (22%) - Spleen (22%) - Digestive (12%) SLIDE 27: Early Research Focused on Steering Wheel Contact SLIDE 28: Abdominal Injury Corridors Squirrel Monkeys, Rhesus Monkeys, Baboons, Pigs This parameter is sort of a stress term combined with a duration term. Higher stress (higher force, lower area) and higher duration result in higher injury values. HVI, or lower abdomen, have higher values because they have lower mass, and are more distensible. This allows them to move out of the way, more so than liver, spleen, etc. SLIDE 29: Porcine Test * Test frame mounted on Hyge sled (Delta V=32 km/h) * Anesthetized subject supported by suspension suit attached to trolley * Lower steering wheel rim impacted torso at liver SLIDE 30: Abdominal Impact Tests [diagram] SLIDE 31: There is another phase here in late 80s and early 90s of a 2 point belt. It was shown to have higher rates of liver injuries, when lap belt not used. This will not be included in data we present. SLIDE 32: AIS = 3 Hollow Viscous Injury Sources - Frontal Impact 1988 - 1994 * Belt Restraint (56%) * Front: -Steering Assembly (39%) * Side Interior: -Surface -Armrests (5%) Importance of normalizing injury to restraint type SLIDE 33: AIS = 3 Abdominal Injury Distribution - Frontal Impact - Liver (38%) - Spleen (23%) - Digestive (17%) - Kidney (4%) SLIDE 34: Seatbelt Loading of Abdomen Injuries Mesentery Duodenum Small bowel Large bowel Cecum SLIDE 35: There is another phase here in late 80s and early 90s of a 2 point belt. It was shown to have higher rates of liver injuries, when lap belt not used. This will not be included in data we present. SLIDE 36: AIS = 2 Hollow Viscous Injury Sources - Frontal Impact 1993-1997 * Belt Restraint (59%) * Front: -Steering Assembly -Instrument Panel (27%) * Side Interior: -Surface -Armrests (15%) SLIDE 37: AIS = 3 Abdominal Injury Distribution - Frontal Impact Liver (35%) Spleen (31%) Digestive (15%) Kidney (7%) Urogenital (N/A) SLIDE 38: [diagram] Unbelted occupant with airbags SLIDE 39: [post-crast photos from dummy test - airbag deployed] Steering Wheel Contact Despite Airbag SLIDE 40: Airbag Loading of Abdomen [point-of-contact photos from dummy test - airbag deploying] - Injuries Colon, Mesentery, Peritoneum < Cadaveric tests with loading to abdomen Hardy et al. (2001)> SLIDE 41: Recent Advances Force Limiter Improve torso pitch Lap belt pretensioners Reduce slack and submarining risk Trosseille et al. (2002) Steffan et al. (2002) SLIDE 42: Steering wheel impacts to abdomen Dummy and cadaver < Shaw et al. (2004) > SLIDE 43: Hollow Viscous Injury Analysis of CIREN Data SLIDE 44: CIREN Query * Hollow Viscous Injury * No rollovers * No ejections * 16 years and older * Driver and Front Right Passenger SLIDE 45: 61% of HVI in Frontal Crash with PDOF 330-30 33% in Right (30-150) or Left (210-330) SLIDE 46: Demographics of CIREN HVI Cases - FRONTAL CRASHES Incidence 39 / 856 drivers had HVI (4.6%) 12 / 224 pass had HVI (5.4%) Injuries 62 injuries - 39 drivers 25 injuries - 12 passengers 39 drivers – 50% Belted, 50% Unbelted 12 pass – All Belted SLIDE 47: Demographics of CIREN HVI Cases - SIDE CRASHES Incidence 18/348 NEAR Side had HVI (4.6%) 9 / 132 FAR Side had HVI (6.8%) Injuries 24 injuries - 18 NEAR Side 23 injuries - 9 FAR Side 18 NEAR Side – 72% Belted, 18% Unbelted 9 FAR Side – 55% Belted, 45 % Unbelted SLIDE 48: Frontal Crashes Colon Driver N % all HVI 13 21 Passenger N % all HVI 7 28 Mesentery Driver N % all HVI 27 44 Passenger N % all HVI 5 20 Small Bowel Driver N % all HVI 12 19 Passenger N % all HVI 6 24 Bladder Driver N % all HVI 4 6 Passenger N % all HVI 0 0 Duodenum Driver N % all HVI 1 2 Passenger N % all HVI 3 12 Gallbladder Driver N % all HVI 3 5 Passenger N % all HVI 0 0 Stomach Driver N % all HVI 1 2 Passenger N % all HVI 4 16 Omentum Driver N % all HVI 1 2 Passenger N % all HVI 0 0 For Drivers, colon, mesentery, small bowel made up 84% of the HVI In passengers, injuries split more evenly, with no injuries to bladder, gallbladder or omentum The Driver had twice as many SW injuries with unbelted drivers, even though all drivers split evenly btw belted and unbelted SLIDE 49: SIDE CRASHES NEAR SIDE Colon N % all HVI 5 21 Mesentery N % all HVI 8 33 Small Bowel N % all HVI 1 4 Bladder N % all HVI 8 33 Duodenum N % all HVI 0 0 Gallbladder N % all HVI 0 0 Stomach N % all HVI 1 4 Omentum N % all HVI 1 4 FAR SIDE Colon N % all HVI 7 30 Mesentery N % all HVI 8 35 Small Bowel N % all HVI 6 26 Bladder N % all HVI 1 4 Duodenum N % all HVI 0 0 Gallbladder N % all HVI 0 0 Stomach N % all HVI 0 0 Omentum N % all HVI 1 4 For Drivers, colon, mesentery, small bowel made up 84% of the HVI In passengers, injuries split more evenly, with no injuries to bladder, gallbladder or omentum SLIDE 50: All Crash Types, AIS 2+ HVI Bondy 1977-79 – 7% belted CIREN 1996-2003 – 64% belted CRASH TYPE: Bondy Frontal 63% Side 24.4% CIREN Frontal 35% Side 34.6% INJURY SOURCE: Bondy SW 46% Belt 4% Side 18% Unknown 33% CIREN SW 25% Belt 50% Side 11% Unknown 13% For Drivers, colon, mesentery, small bowel made up 84% of the HVI In passengers, injuries split more evenly, with no injuries to bladder, gallbladder or omentum SLIDE 51: Frontal Crashes Elhagediab & Rouhana 1988-94 – AIS 3+ CIREN 1996-2003 – AIS 2+ Unbelted / no airbag Elhagediab 40% CIREN 15% Belted / no airbag Elhagediab 60% CIREN 14% Unbelted / airbag Elhagediab 0% CIREN 21% Belted / airbag Elhagediab 0% CIREN 51% SLIDE 52: HVI Injury Source Changes Over Time [bar chart] SLIDE 53: CIREN Case Examples For Drivers, colon, mesentery, small bowel made up 84% of the HVI In passengers, injuries split more evenly, with no injuries to bladder, gallbladder or omentum SLIDE 54: Case # 1 – Frontal Crash Belted Adult in Rear Seat [post-crash frontal exterior photo of vehicle] 1997 Honda Accord CDC: 12FYEW3 PDOF: 10 degrees Delta V: 33 km/h/21 mph SLIDE 55: Scene Diagram Showing Point of Impact SLIDE 56: Clavicle fx Jejunal perforation Age:53 Gender: Female Position: Right Rear Weight: 120 lbs. Height: 5’4” Safety Device: 3-point restraint SLIDE 57: INJURIES (ICD) Jejunal Perforation (863.20) AIS Severity 541424.3 Info source Surgery Aspect Right Contact Area SB Flank Contusion (922.8) AIS 590402.1 Info source exam Aspect Left Contact Area SB SLIDE 58: Case # 2 – Frontal Crash [overhead photo post-crash vehicle] Belted Adult Driver 1999 Kia Sportage SUV CDC: 12FDEW4 PDOF: 350 Delta V: 37 kmph/23 mph SLIDE 59: Scene Diagram Showing Point of Impact SLIDE 60: Age: 32 Gender: Male Position: Driver Weight: 340 lbs. Height: 6’2” Safety Devices: 3-point restraint Pretensioner Airbag Knee Airbag SLIDE 61: Steering Wheel Contact 340 pound driver Liver contusion Mesentery, Duodenum Lacerations Bilateral Femur fractures Metatarsal, navicular, cuboid fxs SLIDE 62: Case # 3 – Frontal Crash Misuse of Shoulder Belt, Child 2001 Toyota 4Runner SUV CDC: 11LYEW44 PDOF: 330 Delta V: 34 kmph/21 mph SLIDE 63: Scene Diagram Showing Point of Impact SLIDE 64: [photo] Lap Belt Age: 6 Gender: Male Position: Right Rear Weight: 42 lbs. Height: 42” Safety Device:3-point restraint with shoulder belt worn behind back * Jejunum serosal laceration * Mesentery contusion * Colon contusion * Retroperitoneal hematoma SLIDE 65: [post-crash exterior vehicle photo - right front quarterpanel] Case # 4 – Side Crash Belted Far Side Adult 1998 Toyota Camry CDC: 02RYAW3 PDOF: 50 deltaV: 44 kmph/27 mph SLIDE 66: [line drawing] Scene Diagram Showing Point of Impact SLIDE 67: Colon laceration / Pelvic fracture Age: 56 Gender: Female Position: Driver Weight: 146 lbs. Height: 5’4” Safety Device: 3-point restraint [xrays] Belt Load on Abdomen SLIDE 68: Questions?