Ventillator Associated Pneumonia DR. MAHMOUD IBRAHIM

Ventilator Associated Pneumonia (VAP) VAP is pneumonia that occurs in patients intubated and on mechanical ventilation for at least 48 hours. •15% - 50% patients with VAP die •varies with patient population and organism type •Highest VAP mortality occurs inpatients with -severe illness -infection with non-fermentative Gram negative bacilli e.g. Acinetobacter sp., etc. •Increases length of stay >6 ICU days •Cost $10,000 - $40,000

Etiology of VAP Early onset Late onset •Occurs in first 4 days of hospitalization •More likely to be caused by Moraxella catarrhalis, H. influenzae, or Strept. pneumoniae Late onset •Occurs 5 or more days into hospitalization •Often caused by Gram-negative bacilli, or S. aureus (including MRSA), yeasts, fungi, legionellae and Pneumocystis carnii

Pathogenesis of VAP Results from - Aspiration of secretions (Micro aspirate) - Colonization of aero-digestive tract - Contaminated respiratory or other medical equipment

VAP Pathogens •Staphylococcus aureus - 24 VAP Pathogens •Staphylococcus aureus - 24.4% •Pseudomonas aeruginosa - 16.3% •Enterobacter spp - 8.4% •Acinetobacter baumannii - 8.4% •Klebsiella pneumoniae - 7.5% •Escherichia coli - 4.6% •Candida spp - 2.7% •Klebsiella oxytoca - 2.2% •Coagulase-negative staphylococci - 1.3%

RISK FACTORS Pre-existing conditions •Head trauma •Coma •Nutritional deficiencies •Immunocompromised •Multi organ system failure •Acidosis •Co-morbidities •History of smoking or pulmonary disease

Diagnosis of VAP: These are non specific: VAP has been diagnosed by clinical criteria. These are non specific: *Fever....... drug reaction, extrapulmonary infection, blood transfusion . *Pulmonary infiltrates.......... Pulmonary haemorrhage, chemical aspiration, pleural effusion, congestive heart failure, tumor . Fever and pulmonary infiltrates....... fibroproliferation of late acute respiratory distress syndrome, atelectasis, pulmonary embolism.

Decisions based on clinical criteria resulted in inappropriate ttt of many patients without pneumonia (Fagon et al., Chest 1993).

Previously Specific Standard Criteria for Diagnosis of VAP Culture of tracheal aspirates are not very useful in establishing the VAP, although such cultures are highly sensitive, their specificity is low even when they are cultured quantitatively.

Specific Standard Criteria for Diagnosis of VAP (cont.) *Histopathologic examination of lung tissue........lung biopsy. *positive pleural fluid culture. *lung autopsy.

Recently Bronchoscopic Diagnostic Technique: Two Bronchoscopic techniques are used: 1-Protected specimen brush(PSB) 2-Bronchoalveolar lavage examination (BAL). Both techniques are effective in diagnosis of VAP as the standard specific criteria

Direct Non-Bronchoscopic (Blind)Technique: This involve passage of a catheter or a telescopic catheter through the endotracheal tube with advancement to a wedge position in the lung

Paradigm for Diagnosis of VAP New or Persistent Infiltrates Pathogenic Bacteria

NHSN(National Health Safety Network) surveillance definition for VAP Paient must fulfill each of the three categories below:

VAP Surveillance •Follow NHSN protocols •Work with ICU and respiratory therapy staff to develop alerting process •Monitor ventilated patient for Positive cultures Temperature chart/log Pharmacy reports of antimicrobial use Change in respiratory secretions

Referred to as “Ventilator-associated events” (VAE) Surveillance Changes, 2013 }{ New approach: a surveillance definition algorithm that detects a broad range of conditions/complications that occur in mechanically ventilated patients Referred to as “Ventilator-associated events” (VAE) Includes criteria for •Ventilator-associated conditions (VAC) •Infection-related ventilator-associated conditions (IVAC) •Possible VAP •Probable VAP

VAE/VAP Surveillance Definition Patient must be ventilated more than 2 calendar days Patient must have >2 calendar days of stability or improvement of oxygenation followed by >2 calendar days of worsening oxygenation. Earliest date of event for VAE is mechanical ventilation day 3 (first day of worsening oxygenation). First possible day that VAC criteria can be fulfilled is mechanical ventilation day 4

Pneumonia Surveillance Definition Surveillance definition can be met by 3 different criteria Clinically defined pneumonia (PNU1) Pneumonia with specific laboratory findings (PNU2) Pneumonia in immuno-compromised patients (PNU3)

An alternative paradigm for surveillance: Ventilator Associate Conditions (VAC) Definition: ≥2 days of stable or decreasing daily minimum PEEP or FiO2 followed by Rise in daily minimum PEEP ≥3 cm H2O sustained ≥2 days or Rise in daily minimum FiO2 ≥20 points sustained ≥2 days

Infection Related Ventilator Associate Conditions (IVAC) Definition: VAC associated with alterations in WBC (<to 4 or ≥ 12) or temperature (< 36 or ≥ 38oC) within 2 days and Prescription of antibiotics continued ≥ 4 days

MANAGEMENT OF VAP PREVENTION TREATMENT

VAP Prevention Strategies (Modifiable Risk Factors) 1.Prevent aspiration of secretions •Maintain elevation of head of bed (HOB) (30-45 degrees) •Avoid gastric over-distention •Avoid unplanned extubation and re-intubation •Use cuffed endotracheal tube with in-line or subglottic suctioning •Encourage early mobilization of patients with physical/occupational therapy 2.Reduce duration of ventilation •Conduct “sedation vacations” •Assess readiness to wean from vent daily •Conduct spontaneous breathing trials

VAP Prevention Strategies - continued 3.Reduce colonization of aero-digestive tract •Use non-invasive ventilation methods when possible - i.e. CPAP, BiPap •Use oro-tracheal over naso-tracheal intubation, Naso-tracheal may cause sinusitis, which increases VAP risk •Use cuffed Endotracheal Tube(ETT) with inline or subglottic suctioning -Minimizes secretions above cuff; prevents contamination of lower airway •Avoid acid suppressive therapy for patients not at high risk for stress ulcer or stress gastritis - Increases colonization of the digestive tract

VAP Prevention Strategies - continued •Perform regular oral care with an antiseptic agent •Reduce the opportunities to introduce pathogens into the airway ‒Good hand hygiene ‒Glove use for contact with respiratory secretions or contaminated objects; follow with hand hygiene ‒Educate staff to avoid contaminating the ETT from patient’s mouth, introducing pathogens from patient’s other body sites or the environment

VAP Prevention Strategies - continued 4.Prevent exposure to contaminated equipment •Use sterile H20 to rinse reusable respiratory equipment •Remove condensate from ventilatory circuits •Change ventilatory circuit only when malfunctioning or visibly soiled •Store and disinfect respiratory equipment effectively

Interventions Implemented were as per the Canadian VAP Guidelines Prevention Recommendations ETT with subglottic secretion drainage Semi-recumbent positioning (≥45°) Oral care with Chlorhexidine Oral route of intubation Closed suctioning system New ventilator circuit for each patient Ventilator circuit changes only if soiled or damaged Heated humidifier changes every 5-7 days Change suctioning system only if blocked or damaged  Muscedere et al, JCC 2008

Daily assessment of readiness to extubate &”sedation vacation” VAP BUNDLE ELEMENTS Head of bed˃ 300 Daily assessment of readiness to extubate &”sedation vacation” Peptic ulcer disease prophylaxsis DVT prophylaxsis

Elevation of The Head of Bed (HOB): * Please remember to elevate the HOB>30 degree , and raise knees for all ventilated patients unless contraindicated . *Elevation of HOB has been correlated with reduction in the rate of the ventilator associated pneumonia. (Drakulovic Lancet, 1999)

The pathogenesis of VAP: Bacterial colonization of the stomach and oropharynx Subsequent pulmonary aspiration of contaminated secretion

Elevation of The Head of Bed (HOB)(cont.): *Drakulovic et al., conducted a randomized controlled trial in 85 mechanically ventilated patients assigned to semi-recumbent or supine position. *Supine patients had an incidence of suspected VAP of 34 percent , while the semi-recumbent patients has an incidence of 8 percent (p=0.003). (Drakulovic Lancet, 1999)

DVT Prophylaxis: *As elevation of head of bed may contribute to venous stasis and DVT. *The risk of venous thromboembolism is reduced if prophylaxis is consistently applied. *A clinical practice guideline recommends DVT prophylaxis for patients admitted to the ICU. (Geerts , Chest,2004)

PUD (Peptic Ulcer Disease) Prophylactic: *Stress ulceration are the most common cause of gastrointestinal bleeding in intensive care unit patients . *This predisposed to aspiration and VAP . * Thus applying PUD prophylaxis is a necessary intervention.

Sedation Interruption: Sedation in ICU has the benefit of reducing psychological problems to the patients . However heavy sedation is harmful and predispose to VAP by : 1-Inhibiting coughing. 2-Inhibiting mobilization. 3-Decreasing immune function. 4-Promoting aspiration. 5-Prolongs time on ventilator.

Optimal Sedation: 2-Cough , swallowing reflexes intact. 1-Awake and cooperative patient. 2-Cough , swallowing reflexes intact. 3-Add analgesia to the protocol . 4- Titration to a sedation score to avoid oversedating the patient . 5-Intermittent rather than continuous sedation. 6-Sedation vacation (sedation interruption).

Sedation Vacation: Application: commands at least once a day. *Hold sedation until patient is alert or can follow commands at least once a day. *After sedation interruption restart sedation at a fraction of the prior dose (1/2 or 3/4). *Kress et al .,conducted a randomized controlled trial in 128 adults mechanically ventilated patients receiving continuous infusion of sedative agents in a medical ICU, daily interruption of sedation resulted in a highly significant reduction in time spent on mechanical ventilation ,from 7.3 days to 4.9 days (p=0.004). (Kress, N Engl J Med,2000)

Mechanical Ventilation Weaning Protocol: *Non-physician driven weaning protocol (by nurses or respiratory therapists). *Daily assessment of readiness to wean from ventilator: -keep Vt and pressure low. -preextubation assessment and worksheet . -ETT cuff inflation via minimal leak technique to 20-25cmH2O(minimal occlusive pressure). *This reduce mechanical ventilation days and ventilation associated pneumonia . (Dries JTrauma,2006)

Oral Care: Designed for patients who are intubated or tracheostomized *Mouth care protocol. *Brush twice . *Swab every two hours. *Chlorhexidine rinse. *Apply mouth moisturizer. *Replace suction line, tubing every 24hours (Chlebicki, Crit Care Med,2007)

Other Consideration: *Proper hand washing technique. *Proper care of respiratory equipment. *Proper care of all ICU equipment (monitor, lines, syringes, pumps, ect....).

Non Invasive Ventilation (NIV): *To reduce need and duration of intubation and mechanical ventilation. *Many studies show a decrease in pneumonia and mortality in NIV group patients compared to invasive mechanical ventilation (Girou etal,2000). *Patients population in whom NIV has been effective are:- COPD, pulmonary edema, hypoxemic respiratory failure.

Type of NIV: 1-Negative pressure ventilation 2-Positive pressure ventilation (BIPAP or CPAP).

Negative non invasive ventilation: Ventilation by lowering the pressure surrounding the chest wall during inspiration and reversing the pressure to atmospheric level during expiration. The device augment the tidal volume by generating negative extra thoracic pressure.

Positive non invasive ventilation: Technique supplying positive pressure ventilation support to the airways through masks attached to a patients nose or mouth. CPAP......raise the functional residual capacity or open collapsing obstructed airways. BIPAP.....also reduce the inspiratory muscle load.

Patients in whom NIV is effective are : 1-Acute respiratory failure ~acute exacerbation of COPD. ~acute respiratory distress syndrom ARDS ~pneumonia. 2- Acute heart failure......decrease preload and afterload .....beneficial on cardiac output and blood pressure in addition to improved ventilation. 3-Weaning from mechanical ventilation.

Contra- indication to NIV: ~respiratory arrest ~inability to use mask because of trauma or surgery. ~excessive secretion ~hemodynamic instability ~impaired mental status

Antibiotics *The ATS (American thoracic society) has focus on pseudomonas aeruginosa as an important factor in the ttt algorism of VAP. *Patient with suspicious Pseudomonus aeruginosa..........combination therapy with a beta lactam antibiotic (penicillin or cephalosporin) plus quinolone or beta lactam with aminoglycoside .

Antibiotics (cont.) *Patient without suspicious of Pseudomonus aeruginosa.....second or third generation cephalosporin plus macrolide or quinolone . *Empiric initial therapy is started immediately upon presentation with VAP till cultures and gram stains of collected sputum is performed then therapy is tailored to these results.

Summary *VAP is an important cause of death in ICU. *It is a presentable disease. *VAP bundle may prevent the disease and enhance the outcome . *In the past the specific diagnosis of VAP was difficult and need invasive procedures. (Lung biopsy).

Summary *Bronchoscopy …….specific and sensitive diagnosis. *Antibiotics……. Should be started immediately then tailored according to culture and gram stains.

Thank You