Perioperative Assessment of Asthma Patients
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Transcript of Perioperative Assessment of Asthma Patients
Perioperative Assessment of Asthma PatientsPresented by Ri 胡殿詮 冉景儀
Instructed by CR 劉治民Date: 2006/03/28
Introduction: Peri-OP Assessment of Asthma Patients
• PPC (postoperative pulmonary complications) of asthmaAtelectasisPneumonia or bronchitisBronchospasm (reflex bronchoconstriction during airway instrumentation)HypoxemiaRespiratory failureProlonged mechanical ventilationIntrapulmonary shuntingPneumothoraxRetained secretions
• Difficulty in PPC research & epidemiologic studyLack of consensus in PPC definition
Objects
• Correlation between anesthesia & PPC• Correlation between surgery & PPC• Preoperative assessment of asthmatic patients• Suggestion for surgical asthmatic patients
Correlation BetweenAnesthesia & PPC
Correlation Between Anesthesia & PPC: GA
• Reflex bronchoconstriction during airway instrumentationASA: severe bronchospasm → 90% death or irreversible brain damage
• Mechanical & functional changes of pulmonary system during GAAlteration in diaphragm movement (more ventilation in upper lung & less ventilation in lower lungs)→ V/Q mismatch→ Shunt & dead-space ventilation, increased AaO2 gradient→ Reduction in FRC→ Atelectatic plaques in dependent portion of lungs
• Airway hyper-responsitivity during GA↓Number & activity of alveolar macrophages↓Mucociliary clearance↓Surfactant release↑Alveolar-capillary permeability↑Activity of pulmonary NOS↑Sensitivity of pulmonary vasculature to neorohumoral mediators
Correlation Between Anesthesia & PPC: GA
• Neuro-muscular blockers↓ Hypoxic drive to ventilateMore common in Pancuronium use
• Neuro-chemical changes during GA↓ Peripheral chemoreceptor response to hypoxemia↓ CNS response to hypercapnia
(both IV & inhaled agent at subanesthetic concentration as 0.1 MAC)
Prolonged postoperative hypoxemia
GA → Increased PPC rate!
Correlation Between Anesthesia & PPC
Strategy• Regional anesthesia
No requirement of airway manipulationLess impact on ventilatory controlNo ”unopposed parasympathetic hyperactivity”No neuromuscular blockade
• Post-OP epidural analgesiaHowever….• No evidence of lower PPC rate in regional anesthesia or post-OP epidur
al analgesia• Warner’s study of > 1500 asthma patients: PPC rates for regional & regi
onal anesthesia were similarWarner DO et al., Perioperative respiratory complications in patients with asthma. Anesthesiology 85 (1996), pp. 460–7
Correlation Between Anesthesia & PPC: GA
• Bronchospasm prevention: Pretreatment with lidocaine & salbutamol
→ significantly attenuate FEV1 decrease
Salbutamol → Lidocaine
Saline → LidocaineSaline → Dyclonine
H. Groeben, M. Schlicht, S. Stieglitz et al., Both local anesthetics and albutamol pretreatment affect reflex bronchoconstriction in volunteers with asthma undergoing awake fiberoptic intubation. Anesthesiology 97 (2002), pp. 1445–1450
Salbutamol → Dyclonine
Correlation BetweenSurgery & PPC
Correlation Between Surgery & PPC
Risk group: thoracic and upper abdominal surgery• Diaphragm dysfunction (due to reflex inhibition of phrenic nerve output)
→ Decreased vital capacity & FRC (~50% of baseline after laparotomy, returning toward normal over 1-2 weeks)
→ V/Q mismatch→ Atelectasis, hypoxemia, etc.
• Surgical trauma → Increased airway tone & reactivity→ Exposure of airway irritants → bronchospasm!
Correlation Between Surgery & PPC
Strategy• Laparoscopic procedures: better or not?
Improved FEV1, FRC, arterial oxygenation, ventilation
However….• Still associated with diaphragm dysfunction• No evidence of PPC rate reduction
Preoperative Assessment of Asthmatic Patients
Preoperative Assessment of Asthmatic Patients
• History taking & Identification of risk group• Pulmonary function test• ABG or other laboratory study
Preoperative Assessment of Asthmatic Patients: Risk
Risk group for PPC • General
Age > 70y/oCigarette smokingRenal failurePoor nutrition
• Asthma relatedRecent asthma attackRecent use of anti-asthma therapy for symptomatic controlPast history of endotracheal intubation for asthma management
• Surgery & anesthesia relatedEmergent surgeryThoracic, vascular, or upper abdominal surgeryBlood loss > 4U PRBC (2000mL)Anesthetic time > 180 minutesGeneral anesthesia with endotracheal intubation
Preoperative physical status of patients according to the American Society of
Anesthesiologists Class Definition
1 A normal healthy patient 2 A patient with mild systemic disease and no functional
limitations 3 A patient with moderate to severe systemic disease that results
in some function limitation 4 A patient with severe systemic disease that is a constant threat
to life and functionally incapacitating 5 A moribund patient who is not expected to survive 24 hrs with
or without surgery 6 A brain-dead patient whose organs are being harvested E If the procedure is an emergency, the physical status is
followed by an E (i.e., 2E)
Preoperative Assessment of Asthmatic Patients: Risk
Kroenke et al.: ASA classification of asthma patients vs. PPC • Class 4: ~46%• Class 3: ~28%• Class 2: ~10%
Preoperative Assessment of Asthmatic Patients
• History taking & Identification of risk group• Pulmonary function test• ABG or other laboratory study
Preoperative Assessment of Asthmatic Patients: PFT
Pulmonary function test: Controversial!• Significance of Pre-OP PFT:
Identification of asymptomatic patients with chronic lung disease, rather than risk stratification of clinically-diagnosed asthmatic patients
• Application in Pre-OP assessmentAssess bronchospasm induced by provocation testResponse to bronchodilators
Preoperative Assessment of Asthmatic Patients: PFT
• H.R. Smith et al.(1992) FEV1 < 80% of predicted values or airway resistance > 0.35kpascal/l/s→ Repeat test 15-20 minutes after beta-2 agonist inhalation→ If improvement >15% → Pre-OP beta-2 agonist
• GINA Workshop Report (updated 2004)If FEV1 < 80% of personal best → brief course of steroidDose: prednisolone 40~60 mg/dayStart time: 1-2 days prior to surgeryEnd time: within 24 hours after surgery
1. H.R. Smith, C.G. Irvin and R.M. Cherniack, The utility of spirometry in the diagnosis of reversible airway obstruction. Chest 101 (1992), pp. 1577–1581
2. GINA Workship Report (updated 2004). Global Strategy for the Asthma Management and Prevention.
Preoperative Assessment of Asthmatic Patients
• History taking & Identification of risk group• Pulmonary function test• ABG or other laboratory study
Preoperative Assessment of Asthmatic Patients: ABG
• Baseline ABG: not necessaryNo help in risk assessment or stratification
• Other laboratory test: no evidence of any improvement in pre-OP assessment for PPC
• Pulse oximetry: non-invasive, cost-effective, supplements the history & PE findings
Suggestions for Surgical Asthmatic Patients
Suggestion: Pre-OP Assessment & Preparation
History taking & risk identification• Age > 70y/o• Cigarette smoking• Renal failure• Poor nutrition• Use of systemic steroid within the past 6 months• Asthma severity• Recent Asthma attack• Past history of endotracheal intubation for asthma management• Emergent surgery• Thoracic, vascular, or upper abdominal surgery• Blood loss > 4U PRBC (2000mL)• Anesthetic time > 180 minutes• General anesthesia with endotracheal intubation• PFT: FEV1 < 80% of personal best
Suggested Protocol: Pre-OP Assessment & Preparation
• Use of systemic steroid within the past 6 months →Regimen: Hydrocortisone 100mg q8h ivStart time: 1-2 days prior to surgeryEnd time: within 24 hours after surgery
• PFT: FEV1 < 80% of personal best →Regimen: Prednisolone 40-60 mg/day poStart time: 1-2 days prior to surgeryEnd time: within 24 hours after surgery
• No need of tapering dose• Prolong post-OP steroid use: increased infection rate, poor
wound healing
GINA Workship Report (updated 2004). Global Strategy for the Asthma Management and Prevention.
Suggested Protocol: Pre-OP Assessment & Preparation
• Wheezing before OPInhaled beta-2 adrenergic agents & corticosteroid→ If no improvement, defer the elective surgery
• Reversible airway obstruction or severe bronchial hyperreactivityRegimen: Methylprednisolone 0.5-1.0 mg/kg po &
Salbutamol 3x2 puffsStart time: 48 hours prior to surgery
1. M.T. Silvanus, H. Groeben and J. Peters, Corticosteroids and inhaled salbutamol in patients with reversible airway obstruction markedly decrease the incidence of bronchospasm after tracheal intubation. Anesthesiology 100 (2004), pp. 1052–1057.
2. International Asthma Report, National Institute of Health, International consensus report on diagnosis and treatment of asthma. European Respiratory Journal 5 (1992), pp. 601–641
Suggested Protocol: Pre-OP Assessment & Preparation
• Pretreatment of combined inhaled beta-2 agonist & systemic corticosteroid
M.T. Silvanus, H. Groeben and J. Peters, Corticosteroids and inhaled salbutamol in patients with reversible airway obstruction markedly decrease the incidence of bronchospasm after tracheal intubation. Anesthesiology 100 (2004), pp. 1052–1057.
Suggested Protocol: Post-OP Care & Management
• Serial ABG & CxR follow up• Peri-OP oxygen supplementation• Incentive spirometry• Adequate pain relief (avoid NSAID in patients with past history of aspiri
n-induced asthma)• Consider theophylline administration (bronchodilator, respiratory stimula
nt, diaphragm inotrope)• Consider post-OP epidural analgesia
Thank you for your attention!
Reference
1. Rock P, Passannante A. Preoperative assessment: pulmonary. Anesthesiology Clinics of North America 2004; 22:77-91.
2. GINA Workship Report (updated 2004). Global Strategy for the Asthma Management and Prevention.
3. Paul C. Tamul, William T. Peruzzi. Assessment and management of patients with pulmonary disease. Critical Care Medicine 2004; 32(4): S137-45.
4. H. Groeben. Strategies in the patient with compromised respiratory function. Best Practice & Research Clinical Anaesthesiology 2004; 18(4): 579-594 .
5. H. Groeben, M. Schlicht, S. Stieglitz et al., Both local anesthetics and albutamol pretreatment affect reflex bronchoconstriction in volunteers with asthma undergoing awake fiberoptic intubation. Anesthesiology 97 (2002), pp. 1445–1450
6. Warner DO et al., Perioperative respiratory complications in patients with asthma. Anesthesiology 85 (1996), pp. 460–7
7. H.R. Smith, C.G. Irvin and R.M. Cherniack, The utility of spirometry in the diagnosis of reversible airway obstruction. Chest 101 (1992), pp. 1577–1581
8. M.T. Silvanus, H. Groeben and J. Peters, Corticosteroids and inhaled salbutamol in patients with reversible airway obstruction markedly decrease the incidence of bronchospasm after tracheal intubation. Anesthesiology 100 (2004), pp. 1052–1057.
9. International Asthma Report, National Institute of Health, International consensus report on diagnosis and treatment of asthma. European Respiratory Journal 5 (1992), pp. 601–641