EXTUBATION

Dr Farhan ShaikhConsultant pediatric Intensisvist

Rainbow Children’s Hospital

Extubation is described as the discontinuation of an artificial airway.

• The child should be capable of maintaining a patent airway and generating adequate spontaneous ventilation.

• Should have good central inspiratory drive,• adequate cough strength to clear secretions,

and laryngeal function, • Adequate nutritional status, and • clearance of sedative and neuromuscular

blocking effects

Patients may need re-intubation immediately or after some interval due to •inappropriately timed extubation, •progression of underlying disease,•development of a new disorder.

Sometimes, in marginal patients extubation can be done with the expectation that the need for re-intubation is likely.

Assessment of Extubation Readiness

Successful completion of 30–120 minute spontaneous breathing trial (SBT) demonstrating adequate respiratory pattern and gas exchange, hemodynamic stability, and subjective comfort

(Farias et al., 2001; Esteban et al., 1997; Esteban et al., 1999; Vallverdu et al., 1998; Ely et al., 1999)

1-Temporarily stop the enteral feeds

2- Reduce the FiO2 to 0.5%

3- Reduce the PEEP to 5cmH2O

Evaluate the SpO2 by pulse Oxymetry:a.If the SpO2 is below 95% and the FiO2 is less than 0.5 then increase to 0.5b.If the SpO2 is above 95% change to the PSV mode as per the size of ETT….•3 to 3.5 mm: 10cmH2O3 to 3.5 mm: 10cmH2O•4 to 4.5 mm: 8 cmH2O4 to 4.5 mm: 8 cmH2O•5 mm or larger : 6 cm H2O5 mm or larger : 6 cm H2Oc. Monitor the SpO2,effective Vt and respiratory rate

Assessment:The patient is potentially ready for extubation if1.The SpO2 is over 95%2.The effective Vt is over 5ml/kg3.The respiratory rate is within the goal range for age..

AGE GOAL RANGE

Under 6 months 20 to 60 breathes/min

6 months to 2 years 15 to 45 breaths/min

2 to 5 years 15 to 40 breaths/min

Over 5 years 10 to 35 breaths/min

Precautions

• Extubation should take place during a period of the day when adequate physician, nursing and therapist staffs are readily available.

• Monitoring and continuous evaluation of the patient is necessary

• Presence of skilled personnel who can reintubate the patient is necessary.

– Appropriate level of consciousness

(Redmond et al., 1996; Harel et al., 1997; Coplin et al., 2000)

– Adequate airway protective reflexes (Harel et al., 1997; Coplin et al., 2000)

– Easily managed secretions (Epstein, 2002; Epstein, 2001; Harel et al., 1997; Coplin et al., 2000)

– Evidence of stable nonrespiratory functions (Rothaar & Epstein, 2003; Sapijaszko et al., 1996; Smith & Shneerson, 1995; Scheinhorn et al., 1995)

– Electrolyte values within normal range (Cerra, 1987; Aubier et al., "Effect of hypophosphatemia," 1985; Aubier et al., "Effects of

hypocalcemia," 1985)

• Malnutrition decreases respiratory muscle function and ventilatory drive.

(Pingleton & Harmon, 1987; Lewis et al., 1986; Doekel et al., 1976; Larca &Greenbaum, 1982; Bassili & Deitel, 1981

• Patient must have no intake of food or liquid by mouth for a period of time prior to airway manipulation.

(Lyons et al., 2002; ; American Academy of Pediatrics [AAP], 1992)

• Prior to extubation, all of the equipment necessary for re-intubation should be available at the bedside in case of acute decompensation.

• Racemic or Levo epinephrine should be available for aerosolization in case of acute airway edema after extubation.

EQUIPMENT AND MATERIALS

• Intubation Equipment (these items are contained in the bedside intubation boxes):

• Laryngoscope and blades (appropriate size for patient)

• Proper size endotracheal tubes (include a smaller endotracheal tube than previously in place due to the possibility of laryngeal/tracheal edema)

• Tape or tube fixation device

• Stylet

• Scissors,Sterile gloves

• Suction, Suction catheters

• Oxygen to be administered post extubation via mask/nebulizer system

Procedure

• Hyper oxygenate the patient with 100% O2 prior to extubation.

• Suction the endotracheal tube adequately with pre and post hyper-oxygenation and then suction the pharynx above the endotracheal tube cuff.

Remove tape or Tube Fixation System (TFS) which secures the endotracheal tube.

Deflate the cuff or cut the pilot balloon.

Ask the patient to take a deep breath and to cough, apply vacuum, and at the peak of inspiratory effort, rapidly remove the tube.

Administer humidified oxygen therapy.

Continue to evaluate the patient post extubation for signs of respiratory compromise.

POST PROCEDURE Continuously assess the patient

• Patient’s comfort and ease of breathing.• adequate gas exchange by an arterial blood gas analysis at appropriate intervals usually 30 min to 60mins) following extubation. Mechanical ventilation by Susan P Pilbeam et al 4th edn ch.22

•Incentive spirometry, cough and deep breathing exercises and patient mobilization, to be performed in conjunction with the nursing staff.

Possible post extubation problems

• Hoarseness, sore throat, and cough • Subglottic edema causing stridor• Risk of aspiration • Increased WOB from secretions, airway obstruction,

postextubation laryngospasm.Ely EW etal :Effects on the duration of mechanical ventilation of identifying patients capable of breathing

spontaneously.N Engl J Med 335:1864,1996

• Post extubation stridor

• Extubation failure

Post Extubation Stridor

• Minor– Audible high pitched inspiratory wheeze with

respiratory distress

• Major– Severe respiratory distress needing tracheal

reintubation secondary to upper airway obstruction

• Prolonged intubation can lead to edema, inflammation, and ulceration– Level of cords and cuff site

• Incidence– 2-22% of patients intubated > 24 hrs

• Increases mortality and prolonged ICU stay

• Typically occurs shortly after extubation

• Also occurs after 36hrs of extubation

• Reintubation rate is 1-10%

• It resolves in 24 hours

• It is more common in patients with frequent coughing episodes and in patients who move more frequently while intubated.

• More prevalent in children 1–4 years of age,

• Also in association with any type of surgery in the head/neck area.

Kemper, et al. Crit Care Med, 1991; 19:352.)

How to predict post extubation stridor?

Air leak test•Clinician deflates the cuff of ETT, places the stethoscope directly over larynx and gives a manual breath, the rush of gas around the ET should be heard

•If this air leak sound is heard with peak pressures of less than 20cmH2O, the child is unlikely to have the stridor post extubationMechanical ventilation by Susan P Pilbeam et al 4th edn ch.22

• In present generation of ventilators, a leak is displayed on the screen of ventilator, if more than 20%, then chance of post extubation stridor are less

• Using corticosteroids to prevent stridor after extubation has not proven effective for neonates or children.

• However, given the consistent trends towards benefit, this intervention does merit further study, particularly for high risk children or neonates.

Khemani RG, Randolph A, Markovitz B. Corticosteroids for the prevention and treatment of post-extubation stridor in neonates, children and adults. Cochrane Database of Systematic Reviews 2009, Issue 3.

• In adults, multiple doses of corticosteroids begun 12-24 hours prior to extubation do appear beneficial for patients with a high likelihood of post extubation stridor.

Khemani RG, Randolph A, Markovitz B. Corticosteroids for the prevention and treatment of post-extubation stridor in neonates, children and adults. Cochrane Database of Systematic Reviews 2009, Issue 3.

• In one study dexamethasone was given as 0.2mg/kg/dose, 6 to 12 hours before extubation and every 6 hours afterwards for a total of six doses with beneficial results.

• Such a protocol with some modifications can be followed if there is risk of post extubation stridor (absent leak at the time of extubation, prolonged ventilation beyond 5 to 7 days, difficult or traumatic intubation etc)

Mechanical ventilation by Susan P Pilbeam et al 4th edn ch.22

Treatment of Stridor

• Steroids (Dex 0.2mg/kg/dose q8-12 hrs)

• Nebulized epinephrine– 0.5ml of 2.25% racemic epinephrine OR 1% l-

epinephrine– Aerosilized levo-epinephrine is as effective as racemic

epinephrine in the Mx of post extubation laryngeal edema in children (Nutman et al., 1994)

– Try NPPV until the effect of steroids starts (Susan Pilbeam et al:Mechanical Ventilation.Physiological and Clinical applications.4th Edn

– Heliox (Kemper et al., 1990; Kemper et al., 1991)

• Consider reintubation

Fiberoptic bronchoscopy

For patients with post-extubation complications such as stridor or obstruction, may provide

•direct airway inspection and therapeutic interventions (secretion clearance, instillation of drugs, removal of aspirated foreign objects) (Liebler & Markin, 2000; Walker & Forte, 1993).

Extubation failure

• Failure: inability to sustain effective gasexchange without mechanical support within48 hours of extubation

• Incidence of extubation failure varies between 6 and 47%.

• A low rate (5%) is s/o too conservative approach at extubation & will lead to the risks associated with prolonged intubation

• A high percentage of extubation failure (over 30%) might indicate that clinicians are too aggressive with extubation criteria; presents the risks associated with re-intubation.

• An extubation failure rate of 10% to 19% seems to be clinically acceptable.

Susan Pilbeam et al:Mechanical Ventilation.Physiological and Clinical applications.Ch20.4th Edn

Effects of extubation failure on patient

• Increases length of stay and ventilation• Increases mortality and morbidity• Causes eight fold increase in risk of VAP Extubation failure in intensive care unit: Predictors and management Atul kulkarni etal. Indian J Crit Care

Med 2008;12:1-9

• Children requiring re-intubation within 48 hrshad significantly increased mortality than patients successfully extubated (20% vs. 2%, p< 0.001)

Estebari, AJRCCM, 2001.

Causes for Extubation Failure

Excessive resp effort 42%

Poor resp effort 24%

Inadequate gas exchange 18%

Cardiovasc insufficiency 10%

Neurologic 6%

• metabolic acidosis

• Hypophosphatemia or phosphate deficiency, may contribute to muscle weaknessand failure to wean. Values below normal (1.2 mmol/L) may impair respiratory muscle function.

• Hypokalemia

• Hypo-magnesemia

• Severe hypothyroidism may have impaired respiratory muscle function

Pierson DJ: Nonrespiratory aspects of weaning from mechanical ventilation,Respir Care 40:263,1995

Avoiding Extubation failure

General measures:•treatment of remediable causes of muscle weakness

•Avoid high carbohydrate diet

•manage excessive secretions and

•daily assessment for readiness to extubate, until predictors become more favorable

Specific measures:•Treatment of anemia

•Treatment of Heart failure

•Treatment of dyselectrolytemia (mainly K, Mg and Phosphate)

•NIV

NIV

• It may be beneficial after extubation if child still needs some ventilatory support

• In neonates and premature infants, continuous positive airway pressure (CPAP) is effective at preventing re-intubation

(De Paoli et al., 2002)

NIV

•Found to be useful in older children with chronic lung disease who have a strong cough reflex, and are hemodynamically stable with minimal secretions.•Not found to be very useful in adults in post extubation failure except in those with COPDs, but can be tried.Susan Pilbeam et al:Mechanical Ventilation.Physiological and Clinical applications.4th Edn Ch22

Tracheostomy

• Trachesotomy is an option in children requiring long term ventilatory support and failing extubation e.g. neuromuscular disorders, upper airway problems (e.g. subglottic stenosis etc)

Summary

• Failed extubation, or the need to reinsert an artificial airway following extubation, is not necessarily an indication of failed medical practice.

• An extubation failure rate of 10% to 19% is clinically acceptable. (Too low rates mean too conservative approach and too high rates mean too aggressive approach)

• Consider use of steroids before extubation in children at risk of post extubation stridor (absent leak at time of extubation,prolonged ventilation,difficult intubation or airway,etc)

• Extubate the child in day time in presence of important equipment and manpower so that post extubation problems can be managed well

Quality standards for Extubation

• Monitor and document all post extubation stridors, aspirations and failed extubations in the unit

• Monitor the factors causing these problems

Periodic auditing of all above parameters should be the part of quality control of the ICU

American Association for Respiratory Care (AARC). Removal of the endotracheal tube--2007 revision & update. Respir Care 2007 Jan;52(1):81-93.

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