Operation in patients with asthmaPts with asthma are thought to be at high risk for pulmonary complications

to develop during the periop and postop period and these complications may lead to serious morbidity

Patients with untreated bronchial obstruction and hyperreactivity are at higher risk for periop complications

Neverthelss how long a patient should be treated before undergoing airway instrumentation and surgery and whether this should include systemic corticosteroids is unknown

LITERATURE• The low frequency of adverse outcomes in anesthesia practice limits the

ability of researchers to conduct prospective randomized controlled trials to identify best practices

• Bronchospasm severe enough to require treatment probably occurs in the range of 1 in 250 patients anesthesized however 4 % incidence of asthma in general population makes asthma a significant risk factor for an adverse outcome

• It is unknown whether asthma can be linked to the rare severe outcome attributed to bronchospasm

Periop respiratory complications in patients with asthma

Between 1979-1991, in Mayo Clinics Cohort study706 patients with asthma receive surgical procedure

Perioperative bronchospasm and laryngospasm was surprisingly low (12pts , 1.7%, one of them developped postop respiratory failure)

The risk increased in older pts and in those with active disease

Warner DO Anesthesiology 1996; 460

• ASA database declared 88 bronchospasm in 3533 closed claims during 1975-1994, it has showed 28 (32%) of pts who experienced a morbid event had a history of asthma and 10 more (11%) had a history of COPD or smoking. 90% bronchospasm was associated with intubation

Cheney et al 1991; 932

• Univ of Washington Med Center 70 (0.23%) in 30654 consecutive anesthetic pts had clinically significant bronchospasm, 10% of these pts had a history of asthma

Postner KL, Am j Med Qual1994;129

• In Japan, 105 pts with reactive airway disease, the incidence of intra or postop bronchospasm was not associated with duration of asthma, severity of disease, duration of the anesthesia and operation or FEV1. Intubation and the proximity of the latest asthmatic attack to the operation date were related

Kumeta Y et al Masui 1995;396

•Vener et al reported periop bronchospasm in 23 , postop respiratory complications in 7% of 206 children with asthma (not related to asthma severity or chronic use of bronchodilators)

Vener et al Can J Anesthesiol 1991;A55.

•Olsson et al reported 0.80 % intraop bronchospam in 3210 pts with asthma vs 0.16% in nonasthmatics

Olsson et al Acta Anesthesiol Scand 1987;344.

In a retrospective study, 0.81% frequency of bronchospasm in 486 asthmatics and 0.13% in 16535 nonasthmatics

Forrest et al Anesthesiology 1992;3

In a blinded auscultation 25% of asthmatics wheezed after iv induction anesthesia

Pizov Anesthesiology 1995;111

Postoperative pulmonary complications (PPC)

PneumoniaBronchospasm(History of asthma is not predictive for bronchospasm)Unexplained feverExcessive bronchial secretionAtelectasisRespiratory failure

PPC occured more frequently than cardiac complications (9.6% vs 5.7%)

Lawrence WA J Gen Intern Med 1995;671.

Preop evaluation of ashmaticsHistorySymptoms Suboptimal antiinflammatory therapySide effects of treatmentsAspirin /NSAID intoleranceRecent RTI (not related with recent URTI, Warner O Anesthesioloy 1996)Frequent exacerbations Hospital visitsPrior severe attack (intensive care, mechanical ventilation)

Physical examination

To detect acute bronchospasmTo detect active lung infectionTo detect chronic lung disease and right heart failure

Woods BD Br J Anesthesia 2009

How can we prevent peri- and postoperative pulmonary complications in asthma?

InvestigationsPFTABGECGChest X-Ray

Assessment of riskPFT (The degree of airway obstruction assessed by FEV1 is not a significant independent risk factor for the development of postop respiratory failure after abdominal surgery. It should be viewed as management tool to optimize preoperative pulmonary function not to assess risk)

Preparation of patients with asthma for surgery.

*It should be tailored to the needs of the individual patient

*Symptoms should be optimally controlled in patients with asthma in elective surgery

*Premedication alloys anxiety, improves work of breathing, averts the induction of bronchospasm. Benzodiazepins are safe and do not alter bronchial tone (midazolam)

*In pts first evaluated immediately before operation steroid+ beta2 agonists+anticholinergics

Warner DO Anesthesiology 2000; 1467

*All patients should be encouraged to quit smoking, risk factor for PPCs (within approximately 2 months before surgery)

*Smoking cessation (at least 4 wks) resulted in a relative risk reduction of 41% postop complications (Wound healing and pulmonary complications)

Mills E Am J Med 011;124:144

Preop corticosteroid?• Between 1986-2002, 190 asthmatics who underwent 249 procedures treated

with preoperative corticosteroids/compared with general surgical population in the same hospital

• 14 (5.6%) postop bronchospasm• 9(3.6%) postop infection• 4(1.6%) wound infection

There was no statistical difference between groups Su FW J Allergy Clin Immunol 111 (2): s127

• In a retrospective cohort design of 71 asthmatics, 3 pts (4.5%) developed mild postoperative bronchospasm, five (5.6%) developed postoperative infections

Kabalin et a lArch Intern Med. 1995;155:1379.

Preop corticosteroid?Between 1973-1986, 68 asthmatics underwent 92 surgical procedures,(68

were on inhled/oral corticosteroids)

All of them administered 100 mg hydrocortisoneX3 day before surgery41 of them administered outpatient prednisone on a daily basis for 1

week before surgery

9.7% postop complication (asthma+infection)

Overall no statistically significant difference when compared with all surgical patients

Pien LC et al J All Clin Immunol 1988;82:696

Systemic cs are safe?• In a meta analysis, no increase in complication rate in 2500 pts undergoing

surgery with preop 15-30 mg/kg methylprednisolone, Decrease of pulmonary complications , mainly in trauma patients

Sauerland et al Drug Safe 2000; 119.

• No increased incidence of postop infection or delayed wound healing in 89 patients with asthma treated with cs in 3-7 preop days

Kaballu et al Ann Intern Med

Preop cs vs beta agonist

• 41 patients with reversible airway obstruction (newly diagnosed or not received therapy for at least 1 month) were studied

3x2 puffs salbutamol for 5 days3x2 puffs salbutamol+ Methylprednisolone 40mg/day for 5 days 2 puffs salbutamol preinduction

• Both salbutamol groups improved lung function to a similar extent (within 24 hours).However, the only group receiving steroids had a much lower incidence of wheezing after intubation

Silvanus et al Anesthesiology 2004; 1052

The administration of systemic corticosteroids is recommended

To reduce airway hyperesponsiveness in severe asthmatic subjects

In pts who are suffering from acute asthma just before surgery

In patients who might have depressed adrenal-pituitary response (systemic cs -5-20 mg/day prednisone for greater than2-3 wks within the the last 6 months of patients or pts who have taken greater than the conventional recommended doses of inhaled cs)

Treatment:100 mg hydrocortisone (20 mg methyl prednisolone or 25 mg prednisolone)x3 taper dose by half per day to maintenance level

The anesthetic plan

Bronchospam can be provoked by laryngoscopy, tracheal intubation, airway suctioning, cold inspired gases and tracheal extubation

Mechanical airway irritation by endotracheal intubation in volunteer mild asthmatics resulted in more than 50% reduction in FEV1 and lidocain and beta 2 agonist reduced this response to %20

Groeben et al Anesthesiology 2002; 579

Regional anesthesia

Spinal or epidural anesthesia (to avoid tracheal intubation)

Anxiety or pain during regional anesthesia can precipitate bronchospasm!!!!

Potential advantages of epidural (rather than spinal) includes less motor block of respiratory muscles

Combo (Epidural postop anesthesia +general anesthesia) …reduction of postop complications because of earlier extubation, better mobilisation and coughing and improved diaphragmatic function

Intraoperative management

•Morphine can induce bronchospasm through histamine release but not clinically significantly •Propofol appears superior to thiopenthal Eames et l Anesthesiology 1996, 1307

•Ketamine has excellent induction characteristics and induces bronchodilatation, (possibly by interfering with the endothelin pathway, stimulating sympathetic system, attenuating vagal reflexes)

•Topical anesthetics to the airways can provoke bronchospasm in asthmatics by stimulation of airway irritant receptors from the aerosol

•Deep general anesthesia using a potent inhalational anesthetic provides excellent protection against bronchospasm. Potent inhalational agents produce dose dependent bronchodilatation (halothane is superior at lower concentrations). They directly attenuate airway reflexes in addition to directly relaxing airway smooth muscle

•Lidocaine can prevent bronchospasm by attenuating sensory responses to airway instrumentation or irritation

•Latex allergy

•Anesthetic maintenance with isoflurane or sevoflurane have protective bronchodilation, but desflurane provokes bronchoconstriction in smokers

•Ventilatory mode to avoid auto PEEP by using higher insp flow rates or smaller tidal volues than usual

Woods BD Br J Anesthesia 2009

Neuromusular blockade

•D-tubocurarine, and atracurium provoke histamine release (administration the agent in divided doses or pretreatment with anti histamines)

•Reversal of neuromuscular blockade is risk for provoking bronchspasm . Anticholinesterase might impair metabolism of acetylcholine at nerve terminal allowing activation of muscarinic receptor on airway smooth muscle (minimized with a muscarinic antagonist)

Acute intraoperative bronchospasm

Signs of acute bronchospasm(wheezing or silent chest)Peak insp pressure elevationDecrease of the slope of the expiratory CO2 curveProlonged expiratory phaseVisible slowing or lack of chest fall

The patient should immediately be switched to bag ventilation, compliance can be assessed (the bag will not fill on exhalation)

Differential diagnosis includes1-mucous plugging or kinking of endotracheal tube2-pulmonary edema3-tension pnx4- unilateral wheeze ( unilateral intubation or foreign body)

Woods BD Br J Anesthesia 2009

Treatment

Deepining of anesthesia (Increased concentration of volatile anesthetic gases (isoflurane and sevoflurane), light anesthesia can trigger autonomic reflexes

Beta 2 agonist inhalation in larger doses (8-10 puffs followed by 2 puffs every 10 min)Cs (1-2 mg/kg methylprednisolone)Ipratropium bromide ( 6 puffs followed by 2 puffs every 10 min)

If it remains refractory epinephrine 1/1000 0.5 mg sc Heliox (%21-30 O2) Mgsulphate 1.2-2 g iv Lidocain 1.5- 2 mg/kg iv

Emergence and postop careAlertness!!!

Airway obstructionLaryngospasmBronchospasmPoor ventilationHypoxemia

Repeat beta 2 agonist before emergence if wheezing persists

Adequate analgesia

Reversal of neuromuscular block (neostigmin increases bronchospasm and causes bradycardia and increases secretion)

Extubation when still deeply anesthesized

Woods BD Br J Anesthesia 2009

CASE -1

Ayşe K 42 year-old asthmatic patient Inpatient in Gynecology wardWith abdominal hysterectomy indicationPreop pulmonology consultation was indicated

HistoryShe has had asthma since childhood, wheezind and dyspnea in association with URTI, smoking (+)

SymptomsLast episode of wheezing, dyspnea and cough 1 week before surgery

Triggering factorsHouse dust mite, URTI

HospitalisationNo previous admission

Pharmacological therapyInhaled corticosteroids with prn short acting beta 2 agonists no previous use of systemic steroids

Physical examinationWheezing but she denies recent URTI

Next step ?

A-Chest roentgenogram

B-ABG

C-PFT

D-All of them

They do not alter anesthetic management in an asymptomatic stable asthmatic patients

However, in acute asthma

*Chest X-Ray would be useful to determine a cause for acute bronchospasm such as infection

*PFT would be useful to determine the degree of airway obstruction and response to further bronchodilator therapy

*ABG most frequently shows hypoxemia and hypocarbia in acute attack, hypercarbia indicates severe or longstanding airway obstruction and increases risk for pulmonary complication during surgery

Next concern

Pharmacologic therapy is appropriate?

Primary goal is to decrease the risk of intra operative bronchospasm

Which ones sould be added?

A-Anticholinergics?B-Xanthine deriatives?C-Antileukotrienes?D-Systemic corticosteroids?E- Beta agonists?

Pharmacologic therapy

Beta adrenergic agonists

Methylxanthines

Anticholinergics

Corticosteroids

Antileukotrienes

Intraoperative bronchospasm

In the middle of the operation , with the trachea intubation and anesthesia with halothane 0.5%+ nitrous oxide (66%),

Ayse begins to wheeze.

Anesthezist assumed that wheezing is related to light anesthesia and increased halothane to 1%

The wheezing subsided but then recurred after 20 minutes

In Ayse’s case, wheezing is relieved after administration of aerosols of albuterol and ipratropium bromide

Emergence

In Ayse’s case, the recent intra operative bronchospasm might increase the likelihood of wheezing during emergence

What can be done?

Extubate the trachea in the presence of a high exhaled concentration of a volatile anesthetic

Bronchodilator aerosols can be administered during emergence

A poorly controlled asthmatic patient on oral steroids presents for emergency manipulation of a fractured radius. He is slightly breathless and wheezy at rest.

Preop management

Regional anesthesia with preop nebulised bronchodilators+ İv steroidHe/she requires steroid supplementation perioperatively and maintenance

Drugs considered safe for asthmatics

Induction Propofol, etomidate, ketamine, midazolam Opioids Pethidine, fentanyl, alfentanil Muscle relaxants Vecuronium, suxamethonium, rocuronium, pancuronium Volatile agents Halothane, isoflurane, enflurane, sevoflurane, ether (nitrous oxide)

SUMMARY

Meta analysis reviewing 222 articles between 1995-2005

•For adequate sedation, benzodiazepines are safe

•It is preferrable to avoid airway instrumentation and regional anesthesia should always be considered.

•When regional anesthesia is not feasible and general anesthesia is required prophylactic antiobstructive treatment, volatile anesthetics, propofol, opioids and an adequate choice of muscle relaxants minimize the risk

• Intubation may provoke bronchospasm and should be carried out under adequate anaesthesia, usually with opioid cover. The use of face masks and laryngeal masks result in less airway irritation

•For inhalational anesthetics, halothan, sevoflurane and isoflurane have been recommended not desflurane

•For intravenous anesthetics, ketamine has sympathomimetic bronchodilatory properties

•Propofol, a widely used short-acting iv anesthetic, has a direct airway smooth muscle relaxant effect

•Muscle relaxant type depending on muscarinic receptor type should be used carefully, the reversal of its effect by neostigmine should be avoided

•Local anesthetics such as lidocaine (iv, inhalation) can block bronchoconstriction reflex

Burburan et al Minerva Anesth 2007; 357.