Interaction between Sedation and Weaning: How to Balance Them? Guillermo Castorena MD Fundacion Clinica Medica Sur Mexico

Interaction between Sedation and Weaning: How to Balance Them? Guillermo Castorena MD Fundacion Clinica Medica Sur Mexico

Balance is not that easy!

Weaning Weaning is the liberation of a patient from mechanical ventilatory support. It is a process, not an outcome, and it starts when the decision is taken to intubate a patient. Weaning is thus not the same thing as extubation, rather extubation may be seen as the culmination of the weaning process

Criteria for weaning Resolution of the underlying cause of acute respiratory failure. Hemodynamic stability, defined as no need for vasoactive/inotropic drugs. Adequate neurological status. Preferably absence of fever. Adequate gas exchange as indicated. Partial pressure of carbon dioxide adjusted to bring blood ph into the normal range.

Sedation Sedation in the ICU should be aimed at keeping the patient comfortable but easily arousable Deep sedation with or without muscle relaxants is rarely indicated Analgosedation is administered to relieve patient anxiety and discomfort and to facilitate treatment and nursing

Sedatives: Definition A sedative is a substance that depresses the central nervous system, resulting in calmness, relaxation, reduction of anxiety, and sleepiness. Sedatives also may cause slowed breathing, slurred speech, staggering gait, poor judgment, and slowed reflexes. Society of Critical Care Medicine 2014 8

Sedatives used in the ICU Diazepam Midazolam Lorazepam Propofol Dexmedetomidine Ketamine Society of Critical Care Medicine 2014 9

Sedatives: Effects Sedatives: Effects Sedatives are anxiolytic and amnestic. Sedatives do not have any analgesic properties (except for dexmedetomidine and ketamine). Society of Critical Care Medicine 2014 10

Effects of sedation on the weaning process. Opioids, benzodiazeines and hypnotics affect: Central respiratory drive Muscular activity o Oropharynx o Thoracic wall o Diaphragm Bronchomotor tone Pulmonary vascular resistance

Goals of agitation Therapy Agitation: - motor restlessness resulting from any type of internal discomfort such as pain, delirium or anxiety. Goal- treat the underlying internal discomfort, while maintaining an awake patient who is able to follow commands.

Optimal Level of Sedation Ideal: A patient who is calm, comfortable, and easily arousable corresponds to the following scores: o Ramsay Sedation Scale 2 o Riker Sedation-Agitation Scale 4 o Richmond Agitation-Sedation Scale 0 13 Society of Critical Care Medicine 2014

Pain at Rest is Common in ICU Patients 154 surgical and 76 medical patients assessed twice daily o Pain - numerical rating scale or behavioral pain scale o Agitation - Richmond Agitation-Sedation scale Incidence of pain was 51% o No difference between medical and surgical pts. 36% of surgical and 63% of medical patients received no preventative analgesics Medical pts. had higher pain scores Chanques G et al. Anesthesiology 2007; 107:858 Society of Critical Care Medicine 2014 14

Continuous IV Sedation Prolongs MV Observational study of 242 mechanically ventilated patients in Barnes-Jewish MICU 93 (38 %) pts received continuous infusions (lorazepam and/or fentanyl), 64 (26 %) received bolus, and 85 (35%) received no sedation Duration of mech ventilation, length of ICU and hospital stay longer for pts receiving continuous sedation Kollef MH et al. Chest 1998; 114:541 Society of Critical Care Medicine 2014 15

Pain: Defined Unpleasant sensory and emotional experience associated with actual or potential tissue damage, or described in terms of such damage Subjective Unrecognized and undertreated in ICU patients Society of Critical Care Medicine 2014 16

Visual Analog Scale

Behavioral Pain Scale 18 Society of Critical Care Medicine 2014

Critical-Care Pain Observation Tool Critical-Care Pain Observation Tool Indicators o Facial expression o Body movements o Muscle tension: evaluated by passive flexion and extension of upper extremities o Compliance with ventilator (intubated patient) or vocalization Score 0-8 o 0=no pain o 8=worst pain Society of Critical Care Medicine 2014 19

Analgesia: Definition Blunting or absence of pain or noxious stimuli Jacobi J, Fraser GL, Coursin DB, et al. Clinical practice guidelines for the sustained use of sedatives and analgesics in the critically ill adult. Crit Care Med. 2002;30:119-141. Society of Critical Care Medicine 2014 20

Analgesics Used in the ICU Nonopioids o Acetaminophen o NSAIDs/Ketorolac o Carbamazepine,gabapentin, pregabalin o Ketamine Regional/neuraxial Analgesia o Epidural analgesia o Peripheral nerve blocks/catheters Opioids o Morphine o Hydromorphone o Fentanyl o Remifentanil Society of Critical Care Medicine 2014 21

Summary of Select Opioids Drug Mechanism of Action Onset (IV) Elimination Half-life (hrs) Primary Metabolic Pathway Active Metabolite s Equi- Analgesic IV dose (mg) Fentanyl µ agonist 1-2 min 2-4 N-dealkylation Yes 0.1 Hydromorphone µ agonist 5-15 min 2-3 Morphine Methadone µ agonist, weak δ and κ agonist µ agonist, weak N- methyl d- aspartate (NMDA) antagonist 5-10 min 3-4 1-3 d 15-60 Remifentanil µ agonist 1-3 min 0.05-0.17 Glucuronidatio n Glucuronidatio n N- demethylation Plasma esterases No 1.5 Yes 10 No N/A No N/A Society of Critical Care Medicine 2014 22

Analgo-Sedation The ICU is an hostile environment Pain is often the root cause of distress o o o o Anxiety Dyspnea Delirium Sleep deprivation

Analgesia-Based sedation Strategy Goal is to address pain and discomfort first, then add a hypnotic agent or other anesthetic agents Analgo-sedation Analgesia-first sedation Society of Critical Care Medicine 2014 24

Sedation Strategies Sedation protocols with daily sedation interruptions or maintenence of light levels of sedation Less is more strategy Bedside protocols for titrating sedation and analgesia Daily checklists SCCM : 2014

Kaplan Meier Curves of the Probability of Successful Weaning with Intermittent Mandatory Ventilation, Pressure-Support Ventilation, Intermittent Trials of Spontaneous Breathing, and a Once-Daily Trial of Spontaneous Breathing. Esteban A et al. N Engl J Med 1995;332:345-350.

Daily interruption of Sedative Infusions in Critically Ill Patients Undergoing MV Randomized trial of 128 MICU pqtients Intervention: daily interruption of all sedatives until patients were awake Control: interruption at discretion of clinicians Intervention Control Duration Mech Vent, days 4.9 7.3 ICU LOS, days 6.4 9.9 Hospital LOS 13.3 16.9 % days awake 8.5 9 Kress JP et al. N Engl J Med 2000: 342?1471

Awakening and Breathing Control Trial Ventilator-free Days Mean Median Time to discharge (days) From ICU From Hospital Intervention (n: 167) 14.7 20.0 9.1 14.9 Control (n: 168) 11.6 8.1 12.9 19.2 p-_ value 0.02 0.01 0.04 1-year mortality 44% 58% 0.01 Girard TD et al, Lancet 2008: 271: 126-134

Daily Awakenings and Early Physical and Occupational Therapy Intervention (n=49) Control (n= 55) P-value ICU Delirium (days) 2 4 0.03 Time in ICU with delirium (%) 33 % 57 % 0.02 Hospital Delirium (days) 2 4 0.02 Ventilator-free Days 23.5 21.1 0.05 Duration of Mech. Vent. (days) 3.4 6.1 0.02 ICU Length of Stay (days) 5.9 7.9 0.08 Schweickert WD et al. Lancet 2009;373:1874-82 Society of Critical Care Medicine 2014 29

Thoracic Epidural Analgesia or IV Morphine After Thoracoabdominal Esophagectomy Prospective observational study of 201 pts in Lund, Sweden treated with either thoracic epidural analgesia (n=166) or morphine PCA (n=35) Epidurals patients had less pain and fewer side effects Outcome, % (n) Epi IV p Sedation 1 (2) 17 (6) <0.001 Respiratory depression 0 (0) 6 (2) 0.03 Hallucinations 2 (4) 11 (4) 0.03 Confusion 0 (0) 11 (4) 0.001 Rudin A et al. J Cardiothorac Vasc Anes 2005; 19:350 Society of Critical Care Medicine 2014 30

Holistic approach to weaning Preservation of respiratory muscles. Maintenance of haemodynamic stability Nutrition and electrolyte status Attention to patient s motivation and engagement.

Sedation and Weaning

Thank you