2014 Mod II ECRN CE Condell Medical Center EMS System Site Code: E-1214 Prepared by: Sharon Hopkins, RN, BSN, EMT-P

Transcription

1 The Traumatically Injured Patient 2014 Mod II ECRN CE Condell Medical Center EMS System Site Code: E-1214 Prepared by: Sharon Hopkins, RN, BSN, EMT-P 1

2 Objectives Upon successful completion of this module, the ECRN will be able to: 1. Describe the purposes of data collection in injury prevention, trauma registry, and quality improvement. 2. Describe the association between mechanism of injury and anticipated injury patterns. 3. Describe components of the trauma assessment process for stable and unstable patients 4. Describe the criteria for determining transport to a Level I versus Level II Trauma Centers. 2

3 Objectives cont d 5. Describe presentations and interventions for a variety of critical injuries. 6. Describe critical invasive procedures instituted in the field for critically injured patients. 7. Given a variety of scenarios, assign the appropriate trauma triage criteria to the patient 8. Describe the process for removing an IO needle and the King airway 9. Review the ventilation rate of a patient via a BVM for the infant, child, and adult. 3

4 Objectives cont d 10. Review case scenarios presented. 11. Review responsibilities of the preceptor role. 12. Discuss the use of tourniquets (CAT) and QuikClot tools in Region X. 13. Successfully complete the post quiz with a score of 80% or better. 4

5 Data Collection Process used to identify problems/issues and remedy them Process of gathering and measuring information Accurate data is essential Results drive decision making Focus is on objective, not subjective, information 5

6 Focus of Data Collection Move from I think there is a problem to Data indicates the problem is In past, medical practices have been based on medical knowledge, intuition, and judgment Care provided needs to be best practice ( evidenced based practice ) Based on best available clinical and scientific evidence available in literature 6

7 Data Collection Injury Prevention Changes over the years driven by data Restraints consisted of lap belt in the front seat only (early 1900 s) Now lap and shoulder belts are positioned throughout vehicle Early air bags for driver only Now air bags all around vehicle Opposing roadways had no separation; head on collisions more common Hard to find a major roadway without some separation (i.e.: concrete barrier, grass) 7

8 Data Collection State Trauma Registry Hospitals submit data to the State of Illinois specifically for patients with traumatic injuries Again, data drives change Without specific, accurate data, evidence based changes difficult to formulate 8

9 Trauma Transports By The Numbers* Volume of trauma transports in Region X Total transports reported to IDPH 2011 = 5914 Total transports reported to IDPH 2012 = 6084 Total transports reported to IDPH 2013 = 5954 Snapshot of CMC totals reported to IDPH Total (Cat I 208; Cat II 729) Total (Cat I 181; Cat II 792) March 2014 total - 96 (Cat I - 15; Cat II - 16) * Patients included IF admitted or transferred out 9

10 Mechanism of Injury (MOI) Refers to how a person was injured Kinetics is the science of analyzing the MOI Documentation describing the MOI is the data used to drive decisions Needs to be detailed i.e.: Why and how patient fell MOI can influence assessment and interventions Changes to product design/structure and use can be generated after review of data 10

11 MOI Due to collected data, energy patterns can be predicted and allow the healthcare provider to focus on probable and most likely injuries anticipated Vehicle collisions Falls Penetrating trauma Explosions 11

12 MOI Falls most common but Over 1 / 3 of deaths result from MVC Best you could do for a patient??? Maintain a high index of suspicion for injuries 12

13 Trauma Assessment Process Scene safety and size up Primary or initial assessment AVPU, ABC s and c-spine control Transport decision Rapid trauma assessment or focused exam Detailed secondary assessment Ongoing assessment 13

14 Trauma Assessment Process Be methodical Be repetitive Perform the same steps on all calls Can modify steps based on type of call Builds muscle memory If you always do something, you ll never NOT do something 14

15 Trauma Intervention Priorities Identify life threats in primary assessment Continue to look for life threats with every additional assessment Correct airway problems Establish adequate oxygenation & ventilation Control external hemorrhage Direct pressure, pressure points, tourniquets, hemostatic agents Expedite transport to appropriate facility Need to determine category trauma to make this decision 15

16 Transportation Destination Who Goes Where??? Highest level Trauma Center within 25 minutes of transport time Unstable systolic B/P on 2 consecutive readings Adult < 90 systolic Peds < 80 systolic Category I trauma patient Closest Trauma Center Category II trauma patient The lucky patient with a significant MOI! 16

17 Transport Destination cont d Closest appropriate comprehensive ED Patient NOT categorized as I or II but who has suffered a traumatic injury Closest comprehensive ED The patient with NO airway This includes GEC and Vista s Emergency Center in Lindenhurst 17

18 Category I Trauma Patient Unstable Vital Signs GCS <13 with blunt head injury Trying to avoid categorizing all patients with altered level of consciousness NOT due to trauma (i.e.: under the influence of ETOH and drugs Respiratory rate <10 or >29 (Per Region X SOP guidelines for field personnel) 18

19 Category I Trauma Patient Anatomy of Injury Penetrating injuries to head, neck, torso, groin Combination trauma with burns >20% 2 or more proximal long bone fractures 2 or more body regions with potential life or limb threats Unstable pelvis Flail chest (Per Region X SOP guidelines for field personnel) 19

20 Category I Trauma Patient Anatomy of Injury cont d Limb paralysis and/or sensory deficits above wrist or ankle Open or depressed skull fracture Amputation proximal to wrist or ankle (Per Region X SOP guidelines for field personnel) 20

21 Category II Trauma Patient Mechanism of Injury Ejection from auto Death in same passenger compartment Motorcycle crash >20 mph or with separation of rider from bike Rollover unrestrained Falls >20 feet Peds falls >3x body length Pedestrian thrown or run over (Per Region X SOP guidelines for field personnel) 21

22 Category II Trauma Patient Mechanism of Injury cont d Auto vs pedestrian/bicyclist with > 5mph impact Extrication > 20 minutes High speed MVC Speed >40 mph Intrusion >12 inches Major deformity >20 inches Basically, a very lucky patient with significant MOI which increases the risk of injury (Per Region X SOP guidelines for field personnel) 22

23 Category II Trauma Patient Co-morbid Factors Increased risk of morbidity or mortality related to co-existing factors Age <5 without car/booster seat Bleeding disorders or on anticoagulants Pregnancy >20 weeks Renal disease requiring dialysis (Per Region X SOP guidelines for field personnel) 23

24 Anticoagulants Why are these an issue with trauma? Increases the risk of bleeding internal and external Can you name the 6 more commonly used anticoagulant medications that can increase the risk of bleeding for trauma patients? Coumadin / Warfarin Xarelto Pradaxa Elaquis Lovenox Note: Plavix & ASA are antiplatelets 24

25 Level I and II Trauma Center Operations IDPH Administrative Rules and Regs require Staffing availability requirements by specialty Immediate, 30 minutes, 60 minutes response Transfer agreements for unique cases (ie: burns) List of equipment per level trauma center Minimum performance QI to be performed Guidelines for contents of operating protocols Including measures to avoid going on by-pass Staff training Type of public education offered 25

26 IO Access When there is a need to have access for medication administration and alternative peripheral sites have failed or are not available Needle inserted into bone marrow cavity A non-expandable space 26

27 Treatment Interventions - IO Indications per Region X SOP s Shock, arrest, or impending arrest Unconscious/unresponsive or conscious critical patient without IV access 2 unsuccessful IV attempts or 90 second duration or no visible sites Note: EMS stock replenished 1 for 1 use through ED 27

28 IO cont d Contraindications Insertion into extremity with fracture Infection at insertion site Previous orthopedic procedure Knee replacement, previous IO within 48 0 Pre-existing medical condition Inability to locate landmarks Significant edema 28

29 IO Sites Primary site proximal tibia Secondary site for adults proximal humerus Not developed anatomically in children <5, therefore not recommended < 5y/o If EMS is anticipating humeral site in the pediatric patient 5-15 years-old, EMS to contact Medical Control for guidance 29

30 Proximal Tibia Insertion Site Flat surface below growth plate and medial to tibial tuberosity Palpate 2 fingers below patella to tibial tuberosity (approx. 2 cm) Leg needs to be straight Not always palpable in very young Palpate 1 finger width medially EZ IO to big toe 30

31 Humeral Insertion Site Place patient s hand over navel and elbow adducted to body (tucked back in line with spine) Palpate with thumb moving up the humeral bone Palpate to the most prominent rounded protrusion greater tubercule Rotate fingers around site to confirm Site is anterior to midline of arm 31

32 Humeral Site Alternate Methods to Identify Keep hand over navel, elbow adducted Using heel of your hand, strike at prominence top of arm Site feels like golf ball OR Slide fingers down from top of shoulder As soon as drop off palpated, come down 1 finger breadth and anterior 1 finger breadth 32

33 IO Sizing Pink 15 mm; 15 G Blue 25 mm; 15 G Yellow 45 mm; 15 G 15 mm if you can feel bone just under skin; generally for infants 3-39 kg (6.5-88#) 25 mm general population for tibial placement 45 mm adult humeral site and obese leg 33

34 IO Equipment IO needle package IO needle EZ-connect tubing Florescent arm band Driver Syringe with NS for flushing Primed normal saline (NS) IV bag Material to cleanse site Pressure bag Material to secure needle 34

35 IO Needles What s with the black hash marks??? Purpose to validate appropriate length of needle for site chosen Advance needle into site until bone touched If you can see a black hash mark, you have enough needle left to be secured into bone If no hash mark visible, withdraw needle from skin, move to next size needle and resume placement 35

36 Confirming IO Placement Needle stands up by self Flushes without resistance No evidence of infiltration Fluid flows with pressure bag Can squeeze bag manually until pressure bag in place but may not be enough pressure 36

37 Pain Control For IO Infusion What causes pain during fluid infusion? Infusion of fluids into a non-expandable space How do you fix it per Region X SOP s? Lidocaine 50 / 60 / mg over 60 seconds; wait 60 seconds For peds: 1mg/ kg up to 50 mg Company recommended to inject Lidocaine before initial flush if anticipated Infusion can be stopped any time to instill Lidocaine for pain control 37

38 Removal of IO Needle Prior to removal of IO needle, have alternate IV site established Remove EZ connect tubing Attach syringe to needle hub Gives something to grab Keep twisting in clockwise fashion and gently pull at same time Keep twisting and pulling to remove Place band-aid over site 38

39 Why Do IO s Fail??? Catheter not flushed following insertion Pressure bag not in place FYI - Manually squeezing IV bag may not produce high enough pressure Wrong size needle chosen Too short therefore not entered into bone Drilled too deep and punctured through the bone 39

40 Treatment Interventions King Airway Indications Cardiac or respiratory arrest Inability to place ETT in unresponsive patient without a gag reflex Contraindications Height less than 4 feet Presence of gag reflex Ingestion of caustic substance Known esophageal disease 40

41 Gag Reflex Purpose Protects the airway How to test for presence Stroke eyelashes or tap space between eyes looking for blink reflex Blink and gag reflexes are protective Disappear at same time Testing for one sheds light on other one Note: about 1 / 3 of adults have gag reflex 41

42 King Airway Sizing Color coded sizes Size 3 yellow Size 4 red Size 5 - purple Based on patient's height Yellow size 3 for 4 5 foot height Red size 4 for 5 6 foot height Purple size 5 for over 6 foot height 42

43 King Airway Equipment King airway properly sized Large syringe Yellow size 3 initial balloon inflation 50 ml air Red size 4 initial balloon inflation 70 ml air Purple size 5 initial balloon inflation 80 ml air Water soluble lubricant Avoid smearing lubricant over distal air passages on airway 43

44 King Airway Confirmation Ventilations attempted immediately on patient resistance will be met until tube withdrawn into position Perform usual steps Bilateral rise and fall of chest observed 5 point auscultation Absent epigastric sounds Bilateral breath sounds Capnography Qualitative/colormetric - yellow Note: This is a blind insertion You will not visualize vocal cords 44

45 Removal King Airway Have suction available Have alternate method ready Extract ALL air from single cuff Size 3 holds ml air Size 4 holds ml air Size 5 holds ml air Remove King airway 45

46 Why do King Airways Fail??? Failure to choose correct size airway Failure to initially insert airway deep enough Failure to inflate cuff sufficiently Failure to pull King airway out far enough 46

47 Treatment Interventions Quick Trach Indications All other conventional methods to ventilate patient have failed Contraindications Tracheal transection Other less invasive techniques allows ventilation of patient (i.e.: they are successful) 47

48 Quick Trach Sizing Size 4.0 mm ID patients >77# (35 kg) Size 2.0 mm ID patients between 22 and 77# (10 35 kg) Needle cricothyrotomy patients < 22# (10 kg) Kits replaced through EMS stock in ED 48

49 Quick Trach Equipment Contained in one kit Size 4.0 or 2.0 pre-assembled cricothyrotomy unit Attached 10 ml syringe Connecting tubing Padded neck strap Add to kit PPE s Cleansing material BVM 49

50 Quick Trach Landmark Identification With patient supine, neck hyperextended if no neck injury suspected Cricothyroid membrane located Located between thyroid cartilage (Adam s apple) and cricoid cartilage Start at sternal notch and run finger upward First rigid landmark is cricoid cartilage Cricothyroid membrane just above cartilage 50

51 Landmark Identification Alternative Method Prominence of Adam s apple palpated Slowly palpate finger downward Finger drops off into cricothyroid membrane 51

52 Quick Trach Confirmation Audible escape of trapped air Ability to aspirate air via syringe during insertion Ability to ventilate Quick Trach 1 breath every 6 8 seconds Observation of bilateral rise and fall of chest 52

53 Why do Quick Trachs Fail??? Improper identification of landmarks Blockage lower down/ more distal in airway system Improper insertion of device Not removing red stopper Potential for barotrauma (i.e.: subcutaneous emphysema or pneumothorax) if exhalation is inadequate and airway pressure is elevated 53

54 What Is Your Impression??? Review the following slides Based on MOI and presenting signs and symptoms, determine your general impression Discuss intervention priorities as described in Region X SOP s 54

55 What Would You Do??? Patient was unrestrained driver involved in head-on with tree Patient is in shock All peripheral veins are collapsed What would be your alternative to inserting a peripheral IV??? Evaluate extremities for IO access What would block use of this site? Fracture of extremity or infection at intended site 55

56 What Would You Do??? Patient becomes unconscious and unresponsive while eating EMS is unable to ventilate even after repositioning & performing the Heimlich What could be the next interaction? Visualize the airway with blade and handle Have Magill forceps available For unrelieved obstruction, what device would be appropriate to use? Prepare for insertion QuickTrach or needle cricothyrotomy 56

57 What Do You Think??? How do you find the cricothyroid membrane??? Start at notch and run finger up to first bony ring Go to soft spot above the cricoid cartilage OR Palpate down to the Adam s apple prominence Slide finger over prominence into soft space 57

58 What Would You Do??? A patient is in full arrest and in VF CPR is ongoing following defibrillation What is your next action IV access or insertion of advanced airway??? Gain IV access You need a route for drug administration You should already have airway secured via BVM What are the sites for IO insertion if necessary? First site of choice is proximal tibia Back-up site is humeral head 58

59 What Do You Think??? How do you find the proximal tibial landmark??? Palpate the distal edge of the patella (knee cap) Leg must be straight Flexed knee alters the landmark 2 fingers below patella palpate the tibial tuberosity prominence Not always palpable in the young Move 1 finger width medially 59

60 What Do You Think??? How do you find the humeral head landmark??? Patient s elbow MUST be tucked back and adducted; hand resting over navel Landmark not prominent when arm moved forward Palpate humeral head slightly forward from midline Aim drill tip to space between sternum and spine 60

61 Here s the story A patient has shallow, slow respirations They do not respond to a sternal rub There is no change after Narcan administration Blood glucose level is 72 61

62 What Do You Think??? What measures can be utilized to protect the patient s airway airway??? Positioning Easiest technique; least often used Suction ready If used, limited to 10 seconds and suction applied during withdrawal Placement of advanced airway ETT attempted first in the field King airway placed if unable to place ETT 62

63 What Do You Think??? How is the King airway sized??? By patient height How far down is the King airway inserted initially? Until the colored hub is even with the teeth or lip line When are the cuffs inflated on the King??? When the device is inserted up to the hub Inflate with volume printed on side of tube and on packaging Reposition tube by pulling it out until bagging is easy and you observe rise and fall of chest 63

64 Triage Practice Category I or Category II Review the following slides Answer per the Region X SOP s for field personnel Determine if the patient is a Category I, II, or non-category trauma patient Be prepared to explain your rationale 64

65 Triage Practice #1 A patient passed out at a local event and was found lying in the grass Minor laceration right palm with broken bottle lying near patient Definite evidence of excessive ETOH consumption GCS (3, 2, 5) Total 10 Is this a Category I trauma patient due to GCS <13? No; no evidence of blunt head injury 65

66 Triage Practice #2 Upon EMS arrival, the patient is standing at the roadside Patient was restrained driver in rollover; self extricated What category trauma is this? Not Category I or II restrained in a rollover Can this patient sign a refusal for transportation? Yes, if they are alert and oriented x3 and understand the risks and benefits But, due to MOI transport should be encouraged Requires a full, documented assessment 66

67 Triage Practice #3 A patient was struck by a forklift and hit on the right chest wall They are more comfortable with shallow respirations and not moving around Palpation indicates crepitations over multiple areas of the rib cage; SpO 2 94% Lung sounds are diminished but present You suspect a flail chest What category trauma is this??? Category I flail chest 67

68 Triage Practice #4 A patient required extrication of 25 minutes Respiratory rate of 32 and shallow Unstable pelvis Penetration of thigh What meets criteria for a Category I patient? Respiratory rate >29 and unstable pelvis What meets criteria for a Category II patient? Extrication >20 minutes 68

69 Triage Practice #5 Patient slipped in garage and hit head GCS 15; alert and oriented Med history: Allopurinol, hydrochlorothiazide, Xarelto, Lipitor Does this patient meet criteria for Category I, II, or non-category??? Category II co-morbidity on anticoagulant (Xarelto) Increased risk for internal bleeding 69

70 Case Review Review following cases Decide general impression Discuss interventions for Ems based on the Region X SOP s 70

71 Case Review #1 EMS at scene of a low speed MVC vs pole 67 y/o unconscious driver; GCS 11 (3, 3, 5) Multiple facial lacerations Obvious deformity to wrist What is the rhythm strip & implications??? Sinus brady with ST elevation; obtain 12 lead EKG to assess for acute MI 71

72 Case Review #1 What are your suspicions??? Driver passed out due to low heart rate Driver passed out due to AMI Driver had AMI that caused MVC Driver had MVC and then AMI EMS is now caring for a trauma and acute medical patient What Category trauma are they??? Category I GCS <13 with evidence blunt head injury 72

73 Case Review #1 12 Lead EKG Is there ST elevation? ST elevation II, III, avf Inf wall MI 73

74 Case Review #1 What are the implications to care based on working diagnosis? Patient needs routine trauma care Patient also requires care for AMI Can ASA be given if patient not alert? Hold ASA; EMS to report to Medical Control Does he need NTG? No complaints of chest pain so usually held in field FYI - Some cardiologists do tend to use it for decreasing pre-load even in absence of chest pain Remember to screen for additional contraindications B/P, Viagra use (already know inferior wall MI), nitrate allergy 74

75 Case Review #2 EMS called for an adult patient that fell from a 2 nd floor balcony Eyelids flutter to touch Moaning and groaning Flexes right arm, extends left arm What is the GCS??? Eye opening 2 Verbal response 2 Motor response 3 (give best score possible) 75

76 Case Review #2 Injuries found after assessment Scalp laceration Forehead hematoma Flail chest right Deformed right humerus Right tib/fib deformity Left femur deformity 76

77 Case Review #2 VS: B/P 82/56; P 124; R 24 shallow; SpO 2 91% What interventions does the patient require? Manual c-spine control Supplemental oxygen IV access Limited access to peripheral site If IO, site choice limited to left humerus Fluid challenge 200 ml increments B/P goal 90 systolic as guideline 77

78 Case Review #2 What Category trauma is this patient and why? Category I GCS <13 with blunt head injury Flail chest 2 or more long bone fractures Anatomical injury and unstable vital signs are used to indicate a Category I trauma patient MOI used to indicate a Category II trauma patient 78

79 Case Review #2 As a Category I trauma patient, where does this patient get transported to? Highest level Trauma Center within 25 minutes transport time 79

80 Case Review #2 What is this rhythm? Sinus tachycardia Does this patient require Adenosine? No!!!; consider the cause and treat the cause 80

81 Case Review #2 - Discussion When is Adenosine administered in Region X SOP s? Adult stable narrow complex SVT Adult stable wide complex monomorphic VT Assumed to be SVT with aberrancy until proven otherwise Peds probable SVT with adequate and poor perfusion Peds possible VT with adequate perfusion 81

82 Permissive Hypotension Not a new concept; evidenced-based research has been underway Challenges the way we ve always done it just because that s the way we ve always done it Currently researching what parameters SHOULD be used to evaluate circulatory status of patient to determine condition status Currently use systolic blood pressure Region X SOP uses systolic >90 as guideline 82

83 Permissive Hypotension cont d What do we know? Achieving a normal B/P increases the hemorrhaging volume and increases mortality rates Infusing large amounts of crystalloid fluids Dilutes circulating blood volume left Dilutes/makes less effective remaining components (i.e.: clotting mechanisms) When B/P is normal, compensatory mechanisms of body not triggered to turn on 83

84 Permissive Hypotension cont d Why are we talking about this topic??? Informational Want to share current research underway Educational Could explain a Medical Control order to restrict fluid resuscitation Using critical thinking skills, could encourage dialogue with Medical Control regarding degree of fluid resuscitation in field for certain traumatically injured patients 84

85 Case Review #3 EMS is called for an adult who was clotheslined while riding their motorcycle EMS finds rider separated from motorcycle Unresponsive struggling to breathe EMS provides routine trauma care Manual c-spine control Initial/primary assessment Determined to be rapid transport 85

86 Case Review #3 What are the progression of steps for securing the airway??? Repositioning attempted Restrictions in place for this patient due to high suspicion for c-spine injury BVM attempted Rate 1 breath every 5 6 seconds Progress to ETT Requires in-line technique for placement Best performed with minimal 2 people 86

87 Case Review #3 If unable to pass ETT, then what in the field? In the field progresses to King airway A blind insertion technique Sizing according to patient height If unable to ventilate with BVM, then what??? Consider QuickTrach device How is this device sized? 4.0 for adults > 77# 2.0 for peds 22 77# 87

88 Reminder Ventilatory Rates via BVM Infant and child 1 breath every 3 5 seconds For documentation that would be assisted rate of breaths per minute 60 seconds (1 minute) 5 = 12 bpm 60 seconds (1 minute) 3 = 20 bpm Adult 1 breath every 5 6 seconds For documentation that would be assisted rate of breaths per minute 88

89 Reminder Ventilatory Rates via Advanced Airway Infant, child and adult Via ETT, King, combitube or any other advanced airway system 1 breath every 6-8 seconds For documentation that would be assisted rate of 8 10 breaths per minute 60 seconds (1 minute) 8 = 8 bpm 60 seconds (1 minute) 6 = 10 bpm 89

90 Future Developments in Region X Equipment Use of tourniquets Use of QuikClot 90

91 Tourniquets In general: Tourniquets used when other initial steps fail to control bleeding (i.e.: direct pressure) Tourniquet chosen needs to be minimally 4 wide or commercial device Needs to be placed just proximal to the wound but as distal as possible Once placed, a tourniquet should not be removed Replacements provided as EMS stock 91

92 QuickClot Hemostatic dressing used to promote clotting Used after failure of conventional methods* Direct pressure Pressure points Works with physical action Material placed over wound absorbs water molecules from blood to allow concentration of clotting factors *Note: Elevation not found to be effective OR harmful; if used would be in conjunction with direct pressure; never alone 92

93 Use of QuickClot Pilot study will be completed in Region X utilizing volunteer departments Participating departments will complete training Participating departments will report results via an evaluation form left for ED MD Results of pilot study to be discussed at Region X Trauma/EMS meetings for adoption decision Replacements supplied by individual EMS depts. during trial period 93

94 Preceptor Role Peer Review Often perform as a peer in this role You are of the same rank as the person you are overseeing Peer review based on current acceptable practices Feedback is timely, routine and a continual expectation Peer review fosters continuous learning Feedback is given as a dialogue Focuses on the level of the provider along the novice-to-expert continuum 94

95 Bibliography Bledsoe, B., Porter, R., Cherry, R. Paramedic Care Principles & Practices, 4 th edition. Brady Mistovich, J., Karren, K. Prehospital Emergency Care 9 th Edition. Brady Region X SOP s; IDPH Approved January 6, IDPH Administrative Code Subpart H Trauma Centers oll.pdf 95

96 Bibliography cont d KingLTD.pdf

97 Bibliography cont d