Assessment and treatment of poor tissue perfusion in the critically ill
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Assessment and treatment of poor tissue perfusion in the critically ill patient. Kenneth J. Drobatz, DVM, MSCE Professor, Section of Critical Care University of Pennsylvania Outline Why is tissue perfusion important? – Define shock – Consequences of poor tissue perfusion(shock) What causes poor tissue perfusion? Physical assessment of tissue perfusion. Objective assessment of tissue perfusion. Therapy of poor tissue perfusion. – Reperfusion injury Monitoring of therapy of poor tissue perfusion. Why is tissue perfusion so important? Provides oxygen to the tissues. Provides nutrients to the tissues. Removes tissues. metabolic wastes from the Shock Decrease in effective blood flow and oxygen delivery to tissues that does not meet the demand of the issues (Muir 1990). Delivery of oxygen does not meet the oxygen requirements of the tissues. Na+ Na+ Na+ Na+ ADP ATP ADP ATP K+ K+ K+ Mitochondria ATP K+ TCA O2 Na+ ATP K+ ATP O2 ADP ATP TCA ATP ATP ATP ADP K+ ATP Glycolysis K+ Na+ ATP Nucleus ATP ADP ATP ADP K+ ADP Na+ Na+ K+ ATP ADP K+ ATP ADP Na+ Na+ ATP Decreased tissue perfusion………………..Decreased O2……….. Decreased ATP: H20 H20 Na+ K+ H20 Na+ Na+ H20 K+ K+ K+ Na+ K+ ATP Na+ K+ H20 Na+ Na+ K+ Nucleus K+ K+ K+ H20 Na+ Na+ Na+ H20 H20 Decreased Tissue Perfusion Cell swelling. Increased intracellular calcium Calcium: – causes membrane damage. – Mitochondrial injury – release of iron. – Activates phospholipase A2 • Increased leukotrienes/prostaglandins Free radical production Consequences of Poor Tissue Oxygen Delivery: Acronymitis SIRS – Systemic inflammatory response syndrome. CARS – Compensatory anti-inflammatory response syndrome. MODS – Multiorgan dysfunction syndrome MOF – Multiorgan failure. Bone RC. Sir Isaac Newton, sepsis, SIRS and CARS. Critical Care Medicine. 24(7): 1125-1128. 1996 SIRS Fever Hyperglycemia Leukocytosis with L shift Hyperdynamic cardiovascular state Generalized Vasculitis Peripheral Edema Tissue Oxygen Delivery Blood oxygen content Hb concentration Hb/O2 Saturation Plasma O2 content Cardiac Ouput Heart Rate Preload Stroke Volume Contractility Afterload Cardiac Output Heart Rate Preload Stroke Volume Afterload Contractility Classifications of Altered Tissue Perfusion Cardiogenic Hypovolemia DCM Severe fluid loss HCM Hemorrhage Endstage MR Third space fluid Myocarditis Conduction disturbance Distributive Sepsis Endotoxemia Anaphylaxis Trauma? Obstructive Tamponade PTE IC Tumors GDV Altered tissue perfusion can be due to a variety of causes, but not all these causes result in altered tissue perfusion. So…..how do we recognize altered tissue perfusion……………………? Physical assessment Objective assessment? Tissue Perfusion Physical Assessment Physical evaluation: – mucous membrane color – capillary refill time – pulse rate and quality – cardiac auscultation, rhythm – rectal temperature – extremity temperature Tissue Perfusion Physical Assessment Physical examination evidence of poor/abnormal tissue perfusion: – – – – tachycardia/bradycardia/arrhythmia weak, bounding, irregular pulses hyperemic, pale mms, gray, cyanotic mm’s this doesn’t tell us about other areas Tissue Perfusion Objective Assessment? ECG Arterial blood pressure measurement Central venous pressure Urine output Pulmonary artery catheter Lactate concentration Gastrointestinal pH Venous oxygen concentration? PCV,TS, colloid oncotic pressure Tissue Perfusion Assessment There is no single parameter that provides the overall answer. Tissue perfusion assessment requires a combination of clinical signs, physical parameters, objective parameters and response to treatment. If parameters do not agree with assessment, reassess! Physical Assessment Tissue Perfusion MM color, CRT, HR, PQ, Extremity Temp, Rectal Temp, Urine Output Abnormal Tissue Perfusion Cardiogenic Hypovolemia Distributive/Sepsis Auscult Heart Cardiac Abns? Murmur, Arrhythmia Consider Cardiogenic Normal Cardiac Auscultation? Consider Distributive/ Sepis Consider Hypovolemia Altered/poor Tissue Perfusion Determining Initial Therapy at Presentation 2 Questions What does the heart sound like? What do the lungs sound like? Altered/poor Tissue Perfusion Initial Therapy Give Don’t fluids? give fluids? Altered/poor Tissue Perfusion Initial Therapy Poor/Altered Tissue Perfusion Auscult Heart Abnormal Normal Lung Sounds Abnormal? Don’t give fluids or caution with fluids –could be cardiogenic cause Judicious fluid therapy Exceptions exist as for any algorithm! Highly unlikely cardiogenic cause –can give fluids Hypovolemia/Sepsis Fluid Bolus 90 ml/kg-Dog 40-60ml/kg-Cat Hypertonic Saline? Reassess Continue Crystalloids? Reassess Database Consider Invasive Monitoring Colloids Hetastarch Dextran 70 Positive Inotropes? Dobutamine Dopamine Blood Products Whole Blood Packed RBCs Plasma Hb Substitutes Pressor Agents? Dopamine Epinephrine Norepinephrine Phenylephrine Vasopressin Fluids/Sympathomimetic Drug Doses Crystalloids (D:90ml/kg, C: 40-60ml/kg) Synthetic Colloid (D:5ml/kg boluses not over 20ml/kg/day,C:2 – 5 ml/kg boluses) Oxyglobin (10 – 30 ml/kg, don’t exceed 10ml/kg/h) 15ug/kg/min, C: 2.5-5 ug/kg/min Whole blood 20 – 30 ml/kg Packed RBCs 5-15 ml/kg Epinephrine: 1-10 ug/kg/min Phenylephrine: 5-20 ug/kg IV q 10-15 min then 0.1-0.5 ug/kg/min) 7.5% Hypertonic saline 46 ml/kg Dopamine: 1 – 10 ug/kg/min Dobutamine: D: 5- Norepinephrine: 0.52ug/kg/min Vasopressin: 0.5 – 1 mU/kg/min Pericardial Effusion: Initial Approach Oxygen supplementation by mask IV catheter place: collect blood for analysis. Fluid Therapy? Place ECG Rapid echocardiography if possible Thoracic radiographs Pericardiocentesis Pericardiocentesis: Equipment 14 – 16 gauge over the needle catheter No. 11 scalpel blade Side holes 20 cc syringe IV extension tubing Three-way stopcock Red top tube and purple top tube to for clinicopathologic evaluation Pericardiocentesis: Preparation Right side vs left side Lateral recumbency vs sternal Sterile Preparation Sedation vs no sedation Location: usually between 4th and 6th ribs at the costochondral junction. Local lidocaine block Skin relief incision Pericardiocentesis: Preparation Right side vs left side Lateral recumbency vs sternal Sterile Preparation Sedation vs no sedation Location: usually between 4th and 6th ribs at the costochondral junction. Local lidocaine block Skin relief incision Pericardiocentesis: Preparation Right side vs left side Lateral recumbency vs sternal Sterile Preparation Sedation vs no sedation Location: usually between 4th and 6th ribs at the costochondral junction. Local lidocaine block Skin relief incision Pericardiocentesis: Preparation Right side vs left side Lateral recumbency vs sternal Sterile Preparation Sedation vs no sedation Location: usually between 4th and 6th ribs at the costochondral junction. Local lidocaine block Skin relief incision Pericardiocentesis: Procedure Pericardiocentesis: Procedure Pericardiocentesis: Post Tap Reperfusion Injury Altered perfusion, “no-reflow” Toxic oxygen radical production. Further membrane damage. Hyperkalemia Hyperlactatemia Reperfusion Injury Clinically Unproven Drugs Allopurinol (Burroughs Welcome, 30 mg/kg divided q 8 – 12 hours). Mannitol 20% (Baxter), 0.5-2 g/kg IV slowly DMSO,(Syntex Animal Health), 1 g/kg IV over 45 minutes Deferoxamine mesylate (CIBA), 5-15 mg/kg IV during CPR, 50 mg/kg IV over 5 minutes to prevent reperfusion injury in dogs with GDV) Altered Tissue Perfusion Monitoring Response To Therapy Monitor response to therapy: – Physical parameters – ECG – Arterial blood pressure measurement – Central venous pressure – Urine output – Pulmonary artery catheter – Lactate concentration – Gastointestinal pH – Venous oxygen concentration? – PCV,TS, colloid oncotic pressure Altered Tissue Perfusion Monitoring Response To Therapy Renal failure Gastrointestinal compromise – Bacterial translocation ARDS Disseminated intravascular coagulation Brain dysfunction Nutrition? Altered Tissue Perfusion Other Thoughts Corticosteroids for Shock – Highly Controversial – Reported Experimental Benefits(very high dose) • • • • • Antiinflammatory Improve membrane stability Improved microcirculation Improved intermediary metabolism Improved survival in some studies – Results of clinical studies conflicting – “Shock is a complex disease and, consequently the efficacy of such treatments such as corticosteroids is a complex question whose answer is not yet known” Haskins 2005 Altered Tissue Perfusion Other Thoughts Low dose corticorticosteroids in refractory hypotensive septic shock: – Recent evidence is accumulating that people with septic shock have relative adrenal insufficiency. – Lower dose corticosteroids may be beneficial in people with septic shock. – Human and veterinary clinical studies are ongoing. Altered Tissue Perfusion Other Thoughts Doses ¾ ¾ ¾ ¾ used in people: Hydrocortisone 100 mg TID X 5 days. Hydrocortisone 100 mg, followed by CRI if 0.18mg/kg/h X 6 days. Hydrocortisone 50 mg q6hrs X 7 days. Prednisolone 5 mg @ 6am and 2.5 mg @ 6pm X 10 days. Altered Tissue Perfusion Other Thoughts Delayed hypotensive resuscitation – Used in acute and ongoing abdominal hemorrhage – Resuscitate to a minimally acceptable blood pressure. – Surgical correction of hemorrhage and then “normal” resuscitation. – More studies needed – Applicable to veterinary medicine? Altered Tissue Perfusion Summary History and physical parameters give the most rapid and encompassing information regarding the presence of altered tissue perfusion and it’s underlying cause. Early and aggressive resuscitation (fluids, colloids, blood products, sympathomimetics). Monitor response to therapy and adjust accordingly. Identify underlying cause rapidly and treat. Monitor of consequences of severe altered tissue perfusion. Questions?
