Closed mechanical injuries

Transcription

1 Dr. Csébi, Péter Surgical Departement Closed mechanical injuries I. The main types of closed mech. injuries commotion, contusion, compression, rupture II. Closed mech. injuries of different parts of the body thorax, head, spine, abdomen, pelvis, extremities III. Polytrauma, multiple organ failure The main types of closed mech. injuries 1. Commotion Sudden shaking of the cells decreased function temporarly a) Focal commotion focal shock b) Entire body c. generalised shock f. i.: brain, spine, thorax 2. Contusion Short-acting pressure on the tissues + consequent hydrodinamic effect vessel and tissue damage a) First grade suffusion b) Second grade haematoma c) Third grade necrosis f.i..:..: brain, spine, thorax, abdominal wall, eyeglobe, joint etc. Suffusion and haematoma 1

2 3. Compression a) Long-acting pressure on the tissues decreased tissue perfusion and metabolism necrosis b) Repated blunt trauma anaemia and hyperaemia alternate with each other acute subacute inflammation e.g.:.: decubital ulcer, callus, hygroma Haematoma Callus Tyloma Hygroma Decubital ulcers 2

3 4. Rupture Overextension of the tissues rupture Pl.: muscle and tendon, joint capsule ligaments, organs Closed mech. injuries of the brain Mild injury: cerebral commotion Severe injury: cerebral contusion haemorrhage, necrosis cerebral oedema The main goal of the therapy is to prevent any increase in brain volume which could result in increased intracranial pressure and is a potentional cause of brain damage! Coup contrecoup injury Human brain CT images Haematoma Contused human brain Contusion Intraparenchymal haemorrhage Therapeutic protocol: to goal is to decrease the intracranial pressure! The most important factors: Oxygen inhalation Mannit infusion mg/kg iv. slowly (20 min.), can be repeated after 4 hours. Furosemid 2-6 mg/kg iv., im. Analgesia Diazepam 0,5-1 mg/kg iv. in case of seizures Corticosteroid is contraindicated! (Brain Trauma Foundation) Surgical decompression (craniectomy) 3

4 Closed mech. injuries of the spine Mechanical damage of the nerves and vessels (commotion, contusion, compression, laceration, rupture) Circulatory, metabolic and biochemical changes Persistant mechanical compression Central ischaemia, peripheral hyperaemia, haemorrhage, haematoma necrosis Therapy: The secondory spinal cord damage (circulatory, metabolic, biochemical) develops in the first 3-8 hours. Start the medical and surgical treatment in the first 3-8 hours to achieve the best result!! Medical treatment: Strict cage rest, opioid painkillers. ((Human protocol: Methyl-prednisolon 30 mg/kg/15 min. iv., continue it in infusion in a dosage of 5,4 mg/kg/hour for 23 hours. Efficacy is very questionable in vet. med.!!)) Surgical treatment: reposition, decompression and stabilisation as soon as possible!!!! Note: take care for urinary control in every 6 hours! Urinary catheter if necessary. 4

5 C 5 fracture Post op. We must suspect thoracic injury in every serious traumatic case! Trauma of the thoracic cavity is often life threatening! Hit-by car (HBC), falling from a height (high-rise syndrome), big-dog-little-dog interactions etc. In a survey with 600 HBC cases, thoracic injury was in 60%! There is thoracic or abdominal injury in 16% of limb fracture cases! Crazy! 5

6 Pneumothorax PTX is the most common of the trauma- associated pleural space diseases In up to 47 % of cases with thoracic trauma! 25 % high-rise dogs 63 % high-rise cats! 38 % of dogs with skeletal injury Pneumothorax Retraction of the lung from the chest wall Consolidation of lung lobes Heart is floating on a cushion of air Pneumothorax Pneumothorax Haemothorax Accumulation of blood in the pleural space. May result from injury of the vessels in the thoracic wall, pulmonary vessels, great vessels or the heart Incidence is 8,7% in traumatic fore limb fractures! Haemothorax Pleural fissure lines Retraction of the lung Positive silhouette with the heart and diaphragm (difficult to identify their specific borders) 6

7 Haemothorax Haemothorax Haemothorax Diaphragmatic hernia Acute rise in intra-abdominal abdominal pressure can be the cause Incidence is 5,8% of dogs sustaining fractures as a result of motor vehicle accidents. Diaphragmatic hernia Diaphragmatic hernia Evidence of liver lobes, bowel loops, or spleen or stomach within the pleural space Empty abdomen Concurrent PTX/HTX or pulmonary contusion is common 7

8 Diaphragmatic hernia Stomach in the thorax is surgical emergency! Pulmonary contusion Compression decompression injury of the chest wall that results in haemorrhage and edema leading to alveolar collapse and lung consolidation. Very common!!! We must suspect it in every rib fracture case! Radiographic evidence may not be present immediately after trauma, and may worsen over the first one-to-twotwo days. Pulmonary contusion Patchy interstitial or alveolar densities Rib fracture, flail chest Underlying pulmonary trauma is likely the primary player in ventilatory and respiratory dysfunction seen in patients with severe rib fractures and flail chest. Rib fractures should serve as a flag for underlying pulmonary contusion 8

9 Pneumomediastinum Pneumomediastinum Large airway rupture Alveolar rupture Oesophageal rupture Cervical wounds Closed mechanical injuries of the thorax 1. Biomechanical aspects : Inflated paperbag effect diaphragmatic rupture (severe compression of the thorax and the abdomen) airway rupture (compression of the lung with closed larynx) Direct effect: e.g.:.: fracture. Secondary injury of the parenchymal organs because of the fast moving (contusion) 2. Pathophysiology: Etiology is different pathophysiology is uniform! Pain 1. ventilation 2. humoral effects 1. Ventilatory movements coughing mechanism alveolar hypoventilation, airway obstruction alveolar hypoxia and shunt- perfusion. Vitalcapacity, increased respiratory rate, functional dead space. 9

10 2. Humoral effect = STRESS-reaction Adrenerg effect vasoconstriction pulmonary hypertension shunt perfusion hypoxia Decrease of the breathing surface Intrapleural fluid or air, airway exsudate, lung tissue damage gas distribution Damage of the thorax s structural integrity Multiple rib fractures or flail chest ventilation Pulmonary contusion Atelectasis, haemorrhage, laceration + humoral effect histamine + prostaglandine (inflammatory reaction- Acut Respiratory Distress Syndrome) fluid accumulation in the airways damage of the surfactant gas distribution Causes: 1. Shunt circulation Hypoxaemia 2. Abnormalities of the oxygen diffusion Shunt circulation The alveolar ventilation (V) and alveolar perfusion (P) is different in the specific areas of the lung, but there are compensatory mechanisms. If the rate of V/P is decreased, there is no V, only P. This is the shunt circulation, without gas distribution. Causes: Abnormalities of the oxygen diffusion Increased diffusion route (ARDS) Decreased ventilatory surface (surfactan!) Decreased contact time Decreased blood volume in the capillary vessels 10

11 Pain, structural damage, decreased ventilatory surface, lung tissue damage hypoxia Therapy: ANALGESIA CAGE REST OXYGEN DIURETIC ACIDOSIS CORRECTION MUCOLYTICS BRONCHODILATATORS (ANTIBIOTIC) Surgical interventions ((Artificial breathing, IPPV)) Heart contusion Muscle haemorrhage, rupture alterations of the heart s electrical activity Symptoms: arrythmia, murmurs, muffling of the heart sounds (cardiac tamponade) Diag. imaging: ECG, US! Therapetic procedures (eg.: PTX, laceratio pulmonum) in details: Surgery Surgeryof the thorax lecture! Therapy: digitalis, β receptor blokking, (pericaridiocentesis) Pericardial effusion myocardial contusion, arrythmia In some cases cardiomegaly Closed abdominal injuries - Polytraumatisation in many cases! - Liver, spleen, pancreas, kidney, mesenterium ( intestinal ischaemia), ureter, urinary bladder Tense abdominal muscles, borborygmi, bloody urine, fluid accumulation (blood, urine, exsudatum) Detailed: Surgery of the acute abdomen lecture! Traumatic abdominal hernia Abdominal free fluid 11

12 Rupture of the urinary bladder Injury of the pelvis The pelvical injuries * often contains severe soft tissue injuries too! - Urinary bladder, ureter, urethra - nerve damages (n. ischiadicus!) - vessels - abdominal injuries - rectum - and anus Polytrauma in many cases! *Detailed: Small animal orthopedics lecture! Extremities Contusion direct effect Distorsion indirect effect Ligament s injury Luxation Fracture Polytrauma and multiple organ failure Polytrauma: multiple organs are damaged or isolated pulmonary contusion alone or isolated severe brain damage alone A single organ failure can be life-threatening too, but multiple organ failure will multiply the risk! Detailed: Small animal orthopedics lecture! Patomechanism: Multiple organ failure (MOF) - Most severe late onset complication. - Multiple organ failure, mutual induction, continous decompensation, more and more severe organ damages exitus - The cause is multifactorial, but the patomechanism is similiar in every organ. Trauma, infection, ischaemia Local aspecific inflammation Systemic aspecific inflammation Systemic inflammatory response syndrom SIRS Humoral and cellulary response Inflammatory mediator production 12

13 Physiologically the inflammatory mediators + cellular and humoral antiinflammatory response eliminates the damaging agents, the antigens. The process is controlled by fine autoregulation. In case of polytraumatisation the balanced autoregulation is destroyed by the massive amount of antigens. self-destructiv process develops SIRS: endothelial cell damage Permeability Oedema, blood leakage Organ s function The neutrophils adhere to capillary walls in massive amounts. Neutrophils release proteases and toxic oxygen radicals, the same chemicals they use to kill microbes, but these toxic chemicals are now being dumped onto the vascular endothelial cells. This results in damage to the capillary walls. Clinical signs: - Hyperthermia or hypothermia - Tachypnoe - Tachycardia - Leucocytosis or leukopenia acute lung, kidney, liver, heart failure, ulcers, pancreatitis, encephalopathy, DIC, anaemia, endocrin crisis, muscle atrophy etc. Thank you for your attention! Shearing-injury injury 13

14 Effects of the injury: tissue compression, loss of soft tissues, contaminated wounds, thermal effect (excessive heat), often secondary infection Serious skin defect damage of several nutritive vessels necrosis Effects of the injury: tissue compression, loss of soft tissues, contaminated wounds, thermal effect, often secondary infection burn (conbustion) necrosis Treatment: - Lavage, debridement of the wound. Necrectomy if necessary. Note: try to excise every dead tissue instead of nerves and vessels! - Proper bandaging until wound healing. - Surgical treatment in case of instability (fracture, luxation) (fixateur externae) Compartement-syndrom Cause: tissue compression oedema developing + haematoma formation in case of fractures vessel, nerve, muscle compression decreased microcirculation muscle contracture, necrosis Note: Compartement can be the result of inproper bandaging technique! Treatment: - Decompression with incising the skin and muscle sheath, puncturing of the haematomas Prevention of iatrogenic compartement-s.: The bandage should elicit higher pressure at the distal part than at the proximal part of the limb!! 14