FTP 303-Unit 1 Introduction to critical care.pdf

FTP 303: Introduction to Intensive care unit (ICU) UNIT 1: Critical Care Therapy Dr N. Mshunqane (x3235) Objectives of this study unit: At the end of this study unit you must be able to: - Define the Critical care and critical care unit. - Discuss the indications for...

FTP 303: Introduction to Intensive care unit (ICU) UNIT 1: Critical Care Therapy Dr N. Mshunqane (x3235) Objectives of this study unit: At the end of this study unit you must be able to: - Define the Critical care and critical care unit. - Discuss the indications for admission into ICU. - Understand the importance of a multidisciplinary team. - Name the outcome measuring tools used to assess prognosis of patients in ICU. - Understand indications and the role of physiotherapy in ICU. - Explain the importance of providing early physical rehabilitation to patients in the ICU. - Understand the criteria for discharging the patient from ICU. Learning assumed to be in place: Anatomy Physiology Pharmacology Pathology Assessment and treatment techniques for managing respiratory conditions, from first to third year. INTESIVE CARE UNIT (ICU)  INTRODUCTION Critical care: A specialised care of patients whose conditions are life-threatening and who require comprehensive care and constant monitoring from specialist equipment and medications in order to ensure homeostasis. - usually this type of care is rendered in intensive care units (ICU). ICU: specialised unit that caters for patients with multiple injuries or organ failure that requires close monitoring which cannot be provided in general wards.  Introduction cont: Common conditions managed in ICUs include: - trauma - multiple organ failure, examples: respiratory failure, renal failure, congestive cardiac failure etc. - Adult respiratory distress syndrome (ARDS) - Sepsis - Post operative conditions, examples: post abdominal surgery with respiratory complications, post open heart surgery, post organ transplant etc.  The ICU Team The unit is equipped with facilities that confirm correct diagnosis and treatment of all life threatening disorders. It should consist of the following multidisciplinary team. - Medical staff include: Intesivists and all Specialists - Nursing staff- critical care nurse - Pharmacists - Physiotherapist- critical care trained physiotherapist, respiratory therapist  The ICU Team cont: - Dietitians - Occupational therapist - Speech therapist  Indications for ICU Admission Patients in respiratory failure and in need of ventilator support and continuous vasoactive drug infusions. - Examples: PaO2 < 60mmHg at 60% FIO2 (Poly face mask) : Hyperventilating patients, RR> 35 breaths per minute and respiratory distress. : PaCO2 > 45mmHg (severe respiratory acidosis). Patients with chronic comorbid conditions who develop acute severe medical or surgical illness. - These are patients with two or more organ failure and require ventilator support and close monitoring.  Indications for ICU Admission cont: Hemodynamically unstable patients receiving invasive monitoring and vasoactive drugs in high care. - These are patients presenting with the following vital signs and laboratory results: A. Vital signs: - Pulse < 40 or > 150 beats/minute - Systolic arterial pressure < 80 mm Hg or 20 mm Hg below the patient's usual pressure - Diastolic arterial pressure > 120 mm Hg - Mean arterial pressure < 60 mm Hg  Indications for ICU Admission cont: B. Laboratory blood test results: - Serum sodium < 110 mEq/L or > 170 mEq/L - Serum potassium < 2.0 mEq/L or > 7.0 mEq/L - Serum glucose > 800 mg/dl - Serum calcium > 15 mg/dl - pH < 7.1 or > 7.7 Patients that need two or more organ systems support, e.g patients sustained multiple trauma and are also neurological compromised.  Indications for ICU Admission cont: Patients who are presenting with specific acute conditions or diseases the require close monitoring. - Examples: a) Cardiac - Acute myocardial infarction with complications - Pulmonary oedema - Cardiogenic shock or shock of any kind - Acute congestive heart failure with respiratory failure - Eclampsia or pre-eclampsia b) Pulmonary - Airway obstruction, pulmonary emboli with hemodynamic instability.  Indications for ICU Admission cont: - Massive hemoptysis c) Neurological - Intracranial haemorrhage, Acute subarachnoid haemorrhage, Coma, Meningitis, Drug overdose d) Endocrine - Diabetic ketoacidosis  Severity of Illness Scoring Systems for ICU van Aswegen and Morrow, (2015) discussed the factors that influence the risk of mortality after admission to ICU and the significance of the scoring systems as outcome measures. The following factors influence the risk of mortality in ICU: - Age - Severity of acute illness - Pre-existing medical condition - Emergency admission to ICU  Severity of Illness Scoring Systems for ICU cont: APACHE II ("Acute Physiology and Chronic Health Evaluation II") is a severity-of-disease classification system and most widely used, (Knaus et al., 1985; van Aswegen and Morrow, 2015). It is applied within 24 hours of admission of a patient to an ICU. The scale ranges from 0 to 71, (ICU patient ranges 10-20). It is computed based on a patient’s age and 12 other physiologic measurements. Scores of > 20 correspond to more severe disease and a higher risk of death.  Severity of Illness Scoring Systems for ICU cont: APACHE II Each patient is assigned a score based on their age and the following physiological measurements/ variables. - PaO2 (depending on FiO2) - Potassium (serum) - Temperature (rectal) - Creatinine - Mean arterial pressure (MAP) - Hematocrit - pH (arterial) - White blood cell count - Heart rate - GCS - Respiratory rate - Sodium (serum) APACHE does not have anatomical injury component, therefore it is not the best tool for trauma patients, hence other scoring tools such as SAPS II and III are used.  Severity of Illness Scoring Systems for ICU cont: Glasgow Coma Scale Used to assess the level of consciousness in patients who are not sedated. Ranges from 3 to 15 Scored on best motor, verbal and eye movement responses Patient in coma and unresponsive is scored at 3, and a fully awake patient is scored at 15. It is important to remember that intubated and mechanically ventilated patients are scored out of 10.  GCS scale cont: Eye opening: Best motor response: - Spontaneous 4 - Obeys commands 6 - To speech 3 - Localises pain 5 - To pain 2 - Withdraws 4 - No response 1 - Flexion 3 - Extension 2 - No response 1 Best Verbal response: - Orientated 5 - Confused speech 4 - Inappropriate words 3 - Incomprehensive sounds 2 - No response 1  Severity of Illness Scoring Systems for ICU cont: Anatomic and Physiologic scores These scores were developed to predict outcomes for patients who present with anatomical injuries (trauma patients). Although there is a variety of outcome measuring tools that were developed for assessing anatomic and physiologic parameters in patients who suffered traumatic injuries, tools that are easy to use and accurate are preferred in the clinical settings. TRISS (trauma and injury severity score), was developed in 1983 and it takes into consideration whether the patient suffered blunt or penetrating injury.  Morbidity Scoring Systems SOFA, Sepsis-related Organ Failure Assessment score was developed in 1994 to assess the degree of organ dysfunction that critical ill patients develop overtime. It was renamed Sequential Organ Failure Assessment in 1996. Scored from 0 to 4, where higher score represent high mortality rate and lower scores represent normal organ functioning. Consists of scores for six organ systems: brain, cardiovascular, coagulation, renal, hepatic and respiratory. Criteria for Discharging a Patient From ICU There must be adequate airway and strong cough to clear secretions. Adequate respiratory effort and blood gases must be normal. Patient must be haemodynamically stable, not on inotropes. Neurologically, the patient must have adequate conscious level, strong cough and swallowing well (gag reflex). Renal function should be adequate. Adequate pain control. Indications of Physiotherapy in ICU Physiotherapy is reported to be an integral part of patient management in the intensive care unit (ICU), (Denehy and Berney, 2006). Physiotherapists are involved in: - Manual airway clearance techniques - Suctioning - Positioning - Ventilator hyperinflation - Weaning - Passive movements - Exercises - Mobilisation  Role of Physiotherapy in ICU Two main roles of Physiotherapy in ICU: 1. Cardiopulmonary management 2. Early mobilisation Cardiopulmonary management Both intubated and spontaneously breathing patients - Prevent respiratory complications  Role of Physiotherapy in ICU cont: - Promote clearance of secretions - Improve oxygenation - Improve lung volumes Benefits of Early Mobility in ICU - Improves blood sugar homeostasis - Enhances cardiovascular function - Enhances endothelial function - Decreases chronic inflammation - Regulates hormone levels - Preserves musculoskeletal and neuromuscular integrity - Decreases depression and improves cognition Early mobilisation in ICU Walking in ICU  Precautions and Contra-indications of Physiotherapy in ICU Precautions: are determined according to specific conditions that are treated. Contra-indications: physiotherapy is safe because there are no adverse effects associated with physiotherapy in ICU for as long as the following are included: - Knowledge of anatomy and physiology - Knowledge of and skill to execute a basic holistic assessment in an ICU patient. - Knowledge and good application of physiotherapy techniques guided by of clinical reasoning, (Hanekom et al, 2015). REVIEW OF ANATOMY OF LUNGS REVIEW OF ANATOMY OF LUNGS cont:  Physiology of Breathing Breathing cycle is composed of: - Inspiration - Expiration Ventilation (V): movement of air in and out of the lungs Respiration: Gaseous exchange Perfusion (Q): blood flow in the lungs/ movement of blood in the lungs. Pressure differences result in movement of air from the atmosphere to the lungs.  Physiology of Breathing cont: Three gas laws govern the process of respiration: 1. Boyle’s law = Inspiration 2. Dalton’s law= partial pressures of gases 3. Henry’s law= transport of gases TASK: Name the muscles responsible for inspiration!!  Ventilation/Pefusion (V/Q) Relationships The normal V/Q = 1 If it is expressed in a value less than 1 it means ventilation is decreased If more than 1 perfusion is decreased An area with no ventilation (and thus a V/Q of zero) is termed "shunt“ eg. chronic bronchitis, asthma, atelectasis An area with no perfusion is termed dead space eg. pulmonary embolus  V/Q Relationships cont: Anatomical Shunt Dead space ventilation Pulmonary blood flow is adequate Ventilation is present but pulmonary but alveolar not well ventilated- blood flow but alveoli are poorly wasted perfusion perfused. So ventilation is wasted Most common cause of hypoxaemia Either there is not enough blood or in critical care setting increasing the blood is blocked= causes include myocardial and ventilatory work decreased pulmonary perfusion and pulmonary embolus. 2-5% of CO that normally bypasses The amount of air in conducting the pulmonary arterial system eg. airways not participating in gaseous bronchial ,pleural and coronary exchange. Shallow breathing – a circulation greater % of the inspired volume will ventilate the anatomic dead space Matching of Ventilation and Blood Flow in Alveoli 35  V/Q Relationships cont: Perfusion is greater at the bases of the lung due to gravitational forces, therefore as a patient changes position blood flow will always be greatest in the dependent region. Ventilation also improves down the lung in the spontaneously breathing patient due to intrapleural pressure changes. The alveoli at the apex are far more expanded than the bases and have a higher resting volume this results in less change in volume with inspiration NB: Position the patient in side lying for effective oxygenation.  V/Q Relationships cont: Physiologic Shunt Dead space ventilation Atelectasis and bronchospasm are MV can result in overdistended causes of physiologic shunt alveoli where alveolar pressure exceeds capillary pressure In diseases where capillary damage and intravascular coagulation occur such as burns, sepsis. An increased deadspace will result in an increase in carbon dioxide and an increase in WOB and minute ventilation Oxygen Movement in Lungs and Tissues 38  Respiratory Failure Can be defined as: A PaO2 of less than 60mmHg on an FiO2 of more than 50% (hypoxaemia)-failure of oxygenation. A PaCO2 of more than 50 mmHg with a pH of 7.25 or less (hypercapnia) Clues to the presence of Respiratory failure: - increase in RR - a decrease in TV - increase in work of breathing(paradoxical breathing), - excessive use of accessory muscles and complaints of dyspnoea NB: This is the indication for admission to ICU  Airway Maintenance The purpose of airway maintenance is to ensure adequate ventilation. Artificial airways are commonly used to establish patency and to control the airway. The following necessitate airway maintenance: - Partial or complete airway obstruction, e.g. aspiration of food, secretions, blood because of absent reflexes. - Oedema/ inflammation of the upper airway - Facilitation of secretion removal - Provision of a closed system for the initiation of mechanical ventilation  References Hanekom S, van Aswegen H, Plani N and Patman S. 2015. Developing minimum clinical Stands for physiotherapy in South African Intensive care units: the nominal group technique in action. Journal of Evaluation in Clinical Practise, 21: 118-127. Puthucheary ZA, Rawal J, McPhail M, Connolly B, Ratnayake G, Chan P, Hopkinson NS, Padhke R, Dew T, Sidhu PS et al: Acute Skeletal Muscle Wasting in Critical Illness. Jama 2013. Kress JP, Hall JB: ICU-acquired weakness and recovery from critical illness. N Engl J Med 2014, 370(17):1626-1635. Baldwin MR, Reid MC, Westlake AA, Rowe JW, Granieri EC, Wunsch H, Dam TT, Rabinowitz D, Goldstein NE, Maurer MS et al: The feasibility of measuring frailty to predict disability and mortality in older medical intensive care unit survivors. J Crit Care 2014, 29(3):401-408.