SUMMARYTrauma victims are at high risk of development of inadequate tissue oxygenation, anaerobic metabolism and tissue acidosis. This will lead to multiple organ dysfunction syndrome or death. To maximize chances for survival, treatment priorities must focus on rapid resuscitation and rapid hemostasis.The aim of the work is a comparison between the usage of normalization of each of cardiac index (CI) [one of the global tissue oxygenation indices] and gastric intramucosal pH (pHi) [one of the regional tissue perfusion indices] as resuscitation end point to find out which one is the best for providing better outcome in mechanical trauma adult shocked patients.Physiologically, respiratory gas transport is the amount of O2 transported to tissues and the amount of CO2 that removed by blood.Oxygen transport system involves four components. These are (1) whole blood oxygen content (CaO2), (2) oxygen delivery (DO2), (3) oxygen uptake (VO2), and (4) oxygen extraction ratio.Carbon dioxide transport system includes diffusion of CO2 out of the tissue cells to blood, and transported to alveoli as plasma protein combined CO2 (7%), Hgb.CO­2 (23%) and HCO3- (70%).Proper tissue oxygenation is essential for normal cell function. It needs continuous adequate O2 supply to tissue cells. Adequate O2 supply to tissue needs (1) normal O2 balance (i.e. VO2 = MRO2), (2) absence of both oxygen deficit, oxygen debt, and (3) flow independent O2 consumption.Global tissue hypoxia develops when systemic O2 delivery is insufficient to meet O2 demand of the tissues. Regional tissue hypoxia develops when regional O2 delivery is insufficient e.g. gastrointestinal tract hypoxia when O2 supply by splanchnic circulation became insufficient.Shock is a life-threatening disturbance of hemodynamics that results in failure to maintain adequate perfusion (oxygenation) of vital organs. The varieties of circulatory shock are the following; (1) hypovolemic (hemorrhagic), (2) cardiogenic and (3) distributive.The hypovolemic (hemorrhagic) shock is due to external or internal hemorrhage with consequence hypovolemia and its related manifestations (decreased venous return, decreased cardiac output, decreased blood pressure, … etc.).The stages of hemorrhagic shock are three; (1) compensated, (2) uncompensated, and (3) irreversible. According to the volume, the lost blood is classified into 4 classes; class I (up to 750 ml of blood volume lost), class II (750-1500 ml of blood volume lost), class III (1500-2000 ml of blood volume lost) and class IV (³ 2000 ml of blood volume lost).Evaluation of hypovolemic shocked patients include; (1) history (type of trauma, associated diseases, concurrent drugs … etc.), (2) physical examination (consciousness, airway, hemodynamic .. etc), (3) laboratory studies (CBC, electrolytes, glucose level, kidney functions, coagulation profile … etc), (4) imaging studies (X-ray, chest, pelvis and long bone and scan of the skull and cervical vertebral column).Treatment of hemorrhagic shocked patient includes; (1) prehospital care as splitting of fractures, cervical spine immobilization rapid transport of the patient and initiate appropriate treatment in the field. (2) Emergency department care which has three goals; (a) maximization of oxygen delivery, (b) control of further blood loss and (c) fluid resuscitation.Cardiogenic shock is the inability of the heart to generate sufficient output to maintain adequate tissue perfusion. It is due to heart failure which is precipitated by variety of the diseases as vulvular heart disease, cardiomyopathy, cardiac tamponade, acute myocardial infarction etc.Cardiogenic shock is manifested by low blood pressure, tachycardia, pallor, low pulse pressure, increased central venous pressure...etc. Management of cardiogenic shock includes oxygen, nitroglycerine, asprine, morphine and intravenous fluid administration, sometimes intra-aortic balloon pump needed.Distributive shock is insufficient tissue perfusion especially for vital organs due to blood volume shift from central core organs to the massively dilated peripheral vascular beds especially venous blood vessel.According to the causes of distributive shock, there are 3 varieties. These are (i) neurogenic, (ii) septic, and (iii) anaphylactic and anaphylactoid.Shock in trauma patients is mainly due to hemorrhage but also there are many other causes as cardiac tamponade, tension pneumothorax spinal cord injury etc.Assessment of tissue perfusion give us an idea about DO2/VO2. This assessment may be global or regional.The methods of assessment of global tissue perfusion (oxygenation) include heart rate, blood pressure, respiratory rate, capillary refill, shock index, SVO2, ETCO2, serum lactate, base deficit, and cardiac output measurement.The methods of assessment of regional perfusion (oxygenation) depend on the body system to be assessed. GIT perfusion is assessted by gastric tonometry and sublingual tonometry. Skeletal muscle perfusion is assessed by near infrared spectroscopy (NIRS). Cerebral tissue oxygenation is assessed by electron paramagnetic resonance oxymetry. Urinary bladder perfusion is assessed by fiberoptic multisensor probe.Trauma is structural, physiological, or psychological changes due to subjection of the body to one or more of inflecting causes of trauma.The causes of trauma are classified intro: (a) iatrogenic as injury of any organ during surgery, rib fracture during CPR and (b) non-iatrogenic as mechanical (blunt and sharp), thermal, barometric … etc.The mechanisms of mechanical trauma depends on the inflecting cause. Blunt object produces trauma by one of the following mechanisms; (i) compression, (ii) shear and (iii) over pressure. Sharp object produced trauma by separating and crushing the tissues along its passage in the tissues.The commonest blunt trauma are: (I) Closed vehicular collision; (a) front impact collisions (as stearing wheal syndrome, windscreen syndrome and dashboard syndrome), (b) lateral impact collisions, (c) rear impact collisions, (d) rotational collision and (e) rollover, (II) Open vehicular collisions, (III) Falls from a height and (IV) Pedstrian collisions.The commonest sharp trauma are; (i) stap wound and (ii) missile wounds.Trauma either accidental or surgical results in alternation of nearly all physiologic systems. Stimuli that initiate the physiologic response to trauma are acute blood loss, shock, hypoxia, acidosis and hypothermia. The mediators of the responses to trauma are sympathoadrenal axis, hypothalamic-pitutary-adrenal axis, antidiuretic hormone, rennin and angiotensin, endogenous opioid, locally produced mediators, and toxic free radicals.Physiologic response to trauma includes psychologic changes, altered vital sings, edema, impaired oxygen transport, altered metabolism, altered coagulation and altered immunity.Assessment and management of trauma patients includes, preparation, triage, primary survey (ABCDES), resuscitation, adjuncts to primary survey and resuscitation secondary survey, adjuncts to secondary survey, continued post resuscitation monitoring and re-evaluation and definitive care.Complications of trauma patients are bleeding and coagulopathy, cardiovascular failure, respiratory failure, embolism, acute renal failure, dysfunction of immune system, sepsis and multiple system organ failure. Psychatric complication, mortality and economic complications.Scoring systems to evaluate trauma patient are divided into physiological, anatomical and combined. Physiological scoring systems are trauma score for adult, trauma score for children, age specific pediatric trauma score for children, Glasgow coma scale for adult, Glasgow coma scale for children and APACHE score. The anatomical scoring systems include abbreviated injury score, injury severity score. The combined physiological and anatomical scoring systems include, trauma injury severity score, trauma index score and circulation, respiration, abdomen, thorax, motor and speech score.Anesthetic management of trauma patient included preoperative evaluation and preparation, establishment of the suitable anesthesia and postoperative care. Preoperative evaluation and preparation include; (i) pre-anesthetic history (of the scene of the accident, pre existing diseases, previous operation, allergy and drug therapy), (ii) physical exmaination with concentration on the state of respiration, circulation and nervous system, and signs of difficulties of intubation, pneumothorax, myocardial contusion, and pericardial tamponade,(iii) investigations to evaluate acid base and electrolytes status beside ECG and X ray for chest and cervical spines.General anesthesia is the technique of choice for patients with multiple injuries. All patients are considered to have full stomach. So in cooperative patients the best way to protect airway is by awake intubation. In uncooperative patient intubation after rapid sequence induction of general anesthesia in the best, provided that the facilities to avoid aspiration are available.The best drug for maintenance of general anesthesia are narcotic analgesics, low concentration of volatile anesthetics and muscle relaxant with no cardiovascular side effects as pipecuronium. During operation, crystalloid, colloid and blood can be given. Monitoring of HR, rhythm, BP, ETCO2, temperature, urine output, intravascular volume status is essential. Postoperatively, extubation of trauma patients following emergency surgery should be delayed until the patient has recovered gag and cough reflexes to protect airway. Critical care unit should be reserved for the unstable trauma patient for monitoring, mechanical ventilation, fluid administration, warming, nutritional support and laboratory investigations.This study was carried out in the emergency room, operating room and surgical intensive care unit, of Zagazig University Hospital, under the supervision of Anesthesiology Department, after approval of the local ethics committee.It is a prospective randomized clinical study that was carried upon 40 decompensated hemorrhagic shocked patients of both sex who exposed to mechanical blunt trauma patients. The volume of blood loss of these patients was of class III or IV. Their age were ranged from 20-50 years old and their body weights were ranged from 70-80 kgThe exclusion criteria were head trauma, and any patient with evidence of hepatic, renal, respiratory or cardiac problems.On admission rapid assessment of patient’s airway, breathing, circulation (HR, blood pressure), conscious level by GCS were done. Also for every patients at least 2 wide pore peripheral I.V lines (16 gauge) were inserted for administration of drugs and resuscitative fluids.After that these patients were transported to the operating room where all patients were intubated under general anesthesia for the intended surgical procedure. Then nasogastric or orogastric tonometric catheter was inserted and the non-invasive cardiac output sensor was connected between enotracheal tube and breathing circuit. Central venous catheter for monitoring of intravascular volume and for withdrawal of blood samples and intra-arterial line for arterial blood samples were inserted too.General anesthesia was inducted by rapid sequence intravenous administration of sleep dose of kelamine HCl and suxamethonium 1 mg/kg and was maintained by incremental doses of ketamine if patient is hypotensive or inhalational with low concentration of Halothane and fentanyl 0.1 mg/h. if blood pressure is accepted. Pancronium 0.04 mg/kg/h. intravenous was used to assess mechanical ventilation by 100% O2 during surgery.The arterial blood gases and the hematocrit level were evaluated every 10 minutes till the end resuscitation point, then every day for 15 days. Liver function, kidney function, cardiac enzymes and coagulation profiles were evaluated every two days for 15 days. The resuscitative fluid mixture was blood/Ringer lactate, it was given as rapid as we can according to the advanced trauma life support course guidelines, till each of CI and pHi reached the intended normal value in randomly half number of selected patients.For patients who need mechanical ventilation post-operatively in ICU, they were kept on fentanyl 0.1 mg/h, midazolam 3 mg/1/2 h and atracurium 10 mg/h intravenously.According to the resuscitation end point, the selected patients were divided into two equal groups.Group I (Global group):In this group, the resuscitation was ended when cardiac index (CI) became equal or just above 4 L/min/m2.Group II (Regional group):In this group, the resuscitation was stopped when pHi became equal or just above 7.32.If the intended resuscitation end point was still below the desired values in spite of administration of adequate volume of resuscitative fluid mixture, dopamine 5 mg/kg/min was given in case of low blood pressure and normal CVP and dobutamine 3 mg/kg/min was administered in case of low blood pressure and high CVP.When the intended resuscitation end point was reached, the rate of fluid administration and the blood/Ringer lactate ratio was readjusted to maintain the reached end point constant and to keep haematocrite value above 30.During resuscitation and during the first 24 hours after resuscitation we monitored the various global and regional tissue oxygenation, arterial blood gases and haematocrit level.After reaching the corresponding end point of resuscitation the following were detected and recorded in each group:· Success rate to reach the corresponding resuscitation end point within 12 hours.· Optimizing time of CI and pHi.· The values of the various global and regional tissue oxygenation indices at each resuscitation end point of both groups.· The percent of the resulting corrective changes of various global and regional tissue oxygenation indices values from the pre resuscitation values at each resuscitation end point of both groups.· The incidence of patient with persistent low pHi:· Incidence and severity of MODS.· Mortality rate.· Correlation between global and regional tissue oxygenation indices.From this study, it was found no significant difference among the corresponding various demographic data, surgical and anesthesia time, distribution of various surgical procedure and pre-resuscitation value of global and regional tissue oxygenation indices of both groups. The success rate to reach the corresponding resuscitation end point was similar in both group. The time needed to optimize pHi was significantly longer than the time needed to optimize CI. At the resuscitation end point the values of CI, BE, pHi, PrCO2 and Pr-PaCO2 in group II were more better than the corresponding values in group I and the other tissue oxygenation indices values (HCO3 and lactate) were statistically similar.Although the incidence of MODS in group II was numerically less than that of group I but statistically it was found no significant difference between them. The severity score values of MODS in group I was significantly more higher than in group II patients.Also, the mortality rate was numerically higher in group I than in group II patients, but statistically, there was no significant difference between them. Moreover, there was negative correlation between serum lactate level and pHi value, positive correlation between serum lactate level and PrCO2 and Pr-PaCO2, positive correlation between HCO3- level and pHi value but there were no correlation among the values of BE, CI and regional tissue oxygenation indices.In conclusion, normalization of pHi was superior to normalization of CI as resuscitation end point in traumatic shocked patients because normalization of pHi was associated with more corrective changes to global and regional tissue oxygenation indices and hence less morbidity and mortality.For these reasons we recommended normalization of pHi as resuscitation end point for traumatic shocked patients especially tonocap is available in our hospital and in some other hospitals. Also we recommend training of junior anesthetist to use tonocap. If the tonocap is not available we can depends on the usage of normalization of each of lactate and HCO3 as a safe resuscitation end point in mechanical trauma shocked patients.