Clinical Practice Guidelines for Cases with Pneumonia associated with Pandemic H1N infection As of 7 August 2009

Transcription

1 Clinical Practice Guidelines for Cases with Pneumonia associated with Pandemic H1N infection As of 7 August 2009 This Clinical Practice Guideline contains basic information to be considered when caring for cases with pneumonia. Physicians are advised to apply them appropriately to individual patients on a case by case basis. 1) Diagnosis A patient with a presentation consistent with pandemic H1N and signs / symptoms of pneumonia as follows: 1.1 Signs / symptoms raising suspicion of pneumonia include: a. Rapid respiration Age Respiratory Rate <2 months >60 times/minute 2-12 months >50 times/minute 1-5 years >40 times/minute >5 years >30 times/minute Youngsters and adults >24 times/minute b. Shortness of breath (dyspnoea)/chest pain c. Abnormal breath sounds d. SpO2<=95% without additional oxygenation It is recommended that all these cases have a chest x-ray. 1.2 Chest x-ray signs of pneumonia - At an early stage, it may be possible to detect increased bronchovascular markings or signs consistent with cardiogenic pulmonary congestion. A chest x-ray should be repeated on the following day to confirm the diagnosis. - The majority of chest x-rays show unilateral or bilateral interstitial infiltration. Lobar or multi-lobar infiltration x-ray appearances are rare. 2) Hospitalization It is recommended that all the cases with pneumonia, or suspected of pneumonia be hospitalized. 3) Influenza virus detection It is important to confirm the diagnosis in all cases with RT-PCR. Specimens are collected by taking nasopharyngeal swabs or throat swabs (2-3 swabs/case) to get epithelial cells, or by endotracheal aspirate in cases with pneumonia. 4) Drug administration 4.1 Antivirals - Oseltamivir should be given to the patient immediately without waiting for laboratory confirmation. Treatment with antiviral drugs should be for 5 days. If the patient presents in a critical condition; or is still in a critical condition despite having been provided with medical care for 5 days, he/she should be treated for an additional 5 days (10 days in total). 1

2 - Oseltamivir should normally be continued (to complete a full treatment course) even if laboratory tests are negative. Antiviral drugs should only be discontinued mid-course if the clinical picture is consistent with pneumonia due to another cause. - Oseltamivir and zanamivir may be considered as combination therapy in patients with severe illness, or who show little response to medical treatment. - The dosage of oseltamivir for adult patients is: 75mg twice daily. However, double doses (150mg twice daily) can be given to obese patients. - The dosage of oseltamivir for paediatric patients: Body Weight/Age Dosage >40kg 75mg twice per day >23-40kg 60mg twice per day >15-23kg 45mg twice per day <15kg (over the age of 1) 30mg twice per day 6-11months 25mg twice per day 3-5 months 20mg twice per day <3 months 12m twice per day g - For patients with nephropathy (creatinine clearance 10-30ml/minute), only one dose (75mg) of oseltamivir is administered daily. - The adult dosage of zanamivir is 10mg twice per day The drug must be delivered by inhalation into the respiratory tract. It can be administered to children over the age of 5 years at the same dosage as for adults. 4.2 Antibacterials Consideration should be given to adding antibacterials for 5-7 days in patients with pneumonia. 4.3 Systematic corticosteroid Consideration should be given to giving mg of hydrocortisone or dexamethasone per day to all patients with severe symptoms of pneumonia. Administering corticosteroid to children and infants should be considered on a case by case basis. It may be prudent to administer methylprednisolone (2mg/kg/day) to severely ill children and infants. 4.4 Bronchodialators - +_ Inhaled corticosteroid should be administered to the patients with wheezing (rhonchi), excessive cough, and unusual airway resistance while being ventilated. - Nebulization should be avoided (especially with patients that can breathe); a metered-dose inhaler (MDI) should be used instead and with a spacer. 5) Fluid administration -Carefully balance fluid intake/output, but be wary of over hydration. - Ventilation of patients with severe symptoms of pneumonia is mandatory. A balanced intake/output of fluid or slight dehydration is recommended for patients with acute respiratory distress syndrome (ARDS) who are haemodynamically stable. If the patient has severe hypoxaemia, administering a diuretic like furosemide is recommended to mitigate the possibility of pulmonary oedema. 2

3 6) Medical treatment for hypoxaemia 6.1 Supply the patient with oxygen through nasal cannulae, a simple mask, or a partial re-breathing mask to ensure SpO2>_95%. 6.2 Endotracheal intubation and ventilation is recommended in any of the following cases: - SpO2 is still less than 95% despite supply of > 10 LPM of oxygen through a partial re-breathing mask, - The patient appears to be in respiratory distress, e.g. signs like respiratory alternans or respiratory paradox. - The patient becomes excessively lethargic or agitated. - The patient is showing signs of ventilatory failure (dyspnoea or PaCO2>_45 mmhg). 7) Caring for patients who require ventilation 7.1 It is recommended that all patients requiring ventilation should be admitted into ICU. 7.2 An in-line closed-circuit suction catheter is recommended to prevent nosocomial infection. 7.3 Use of ventilators - Use of a ventilator with a filter at the exhalation port is recommended. - Avoid using a pressure cycling ventilator like the Bird Ventilator, since exhaled gases may be contaminated (unfiltered exhalation with high velocity may lead to nosocomial infection). - At the initial stage of ventilation, it is advisable to set the ventilator to any of the full support modes: i.e. volume-controlled ventilation, pressure-controlled ventilation, high-frequency ventilation (HFV), bi-level ventilation, and airway pressure release ventilation (APRV). - It is advisable to set the ventilator to any of the partial support modes: continuous positive airway pressure (CPAP), and pressure support ventilation (PSV) only when the patient has recovered and ventilation unlikely to be required for much longer. - Many ARDS patients respond to different settings of positive endexpiratory pressure (PEEP) ranging from low to moderate levels (<12-15 cmh2o), since the lung mechanics with this syndrome show a restrictive pattern. Higher settings of PEEP should be considered on a case by case basis. - The chest x-ray appearance of ARDS shows bilateral infiltrates with no evidence of heart failure (such as cardiomegaly or unusual high pulmonary artery wedge pressure). Usually, PaO2/FiO2<200 is seen on arterial blood gas analysis. 7.4 Recommendations for caring for paediatric patients, (i.e. where these are different from those of adult patients) Paediatric patients with ARDS - Set the ventilator to pressure-controlled CMV mode in the initial stage. Because severe lung pathology is common, paediatric patients are at risk of developing pneumothorax, pneumo-mediastinum and subcutaneous emphysema. It is therefore necessary to closely monitor peak airway pressure and plateau pressure. - When using peak airway pressure >30 cm H2O to ensure optimal chest ventilation, it is advisable to consider increasing inspiratory time to meet the desired tidal volume instead of increasing peak 3

4 airway pressure or decreasing the target values of tidal volume (paediatric patients tidal volume of 5-8 ml/kg predicted body weight is considered appropriate.) Apart from this, it is advisable to consider applying the permissive hypercapnia concept by monitoring blood ph together with PaCO2. (In case the physician has experience in lung recruitment and PEEP titration, he is advised to exercise his clinical judgement. The appropriate level of PEEP could begin at 8-10 cm H2O.) - When the child / infant shows signs of improvement after being supplied with 100% oxygen (FiO2 1.0), it is advisable to reduce the volume of oxygen (FiO2<0.6) whilst maintaining the target level of SpO2 to prevent oxygen toxicity that may possibly cause damage to lungs Recommended initial ventilation rate in paediatric patients: Age (year) Ventilation Rate (cycles/minute) < > Recommended inspiratory time in paediatric patients: Age (year) Inspiratory time (Ti) (second) < > ) Factors to consider before moving - Patients should be haemodynamically stable and not dependant on high doses of vasopressors. - Avoid moving if the patient requires FiO2>0.6 (to maintain SpO2>_95% or PaO2>_65 mmhg). 9) Patient movement 9.1 It is advisable to use a portable monitor to check EKG, NIBP, and SpO Before moving, it is recommended that the patient s ventilation be tested with a self inflating bag or a portable ventilator for at least 10 minutes. If desaturation is not detected, it is likely to remove the patient. 9.3 In case the patient is ventilated with a self inflating bag while he/she is being moved, it is advisable to practise as follows: - Connect an oxygen reservoir bag with PEEP and an exhalation port as well as set PEEP as it should be. - Constantly supply 0-15 LPM of oxygen (the maximum level of flow meter) to the patient. - Squeeze the oxygen reservoir bag at a moderate speed (adult patients: times/minute, pediatric patients: times/minute) 9.4 In case the patient is ventilated with a portable ventilator while he/she is being moved, it is advisable to use a volume ventilator and adjust ventilation to critical ventilator settings. 4

5 9.5 If the patient needs to be moved to another healthcare facility, whenever possible the nearest hospital that can provide a sufficiently high level of care should be selected and the transfer should be properly scheduled. During transfer, the patient must be accompanied by a physician. Prevention of nosocomial infection Basic requirements in caring for patients 1. Admit patients requiring medical care to isolation rooms or in a cohort ward / building dedicated for pandemic influenza. 2. If patients require admission to an ICU, it is recommended to use a well-ventilated isolation room of one of the following types: 2.1 An airborne infection isolation room (AIIR) 2.2 A room ventilated by means of an extractor fan, which has at least 6 ACH (Air Changes per Hour). 2.3 If an isolation room is not available, always provide the patient with a bed that is placed at least 2 metres away from other patients, and in the path of any prevailing air current wind. 3. Ventilated patients should be suctioned with in-line suction catheters. If such equipment is not available, staff suctioning these patients are required to wear appropriate Personal Protective Equipment (PPE), including an N95 mask and a face shield or goggles and a disposable / re-usable cap and gown. After suctioning, this PPE must be removed appropriately. 4. Frequent cleaning of rooms and contaminated objects (side-guards, door knobs, computer keyboards etc.) with disinfectant is required. Staff undertaking this cleaning should also wear PPE (gowns, plastic pinafore dresses, gloves, and surgical masks). 5. PPE and other clothing contaminated with body fluid should be placed in appropriate containers after use and medical equipment should be disinfected. Prevention of nosocomial infection among medical professionals 1. Use of surgical masks a. Wear a single surgical mask in most cases (in accordance with the Ministry of Public Health s practice guide) b. Put on gloves and wear an N95 mask only when in close contact with patients to provide aerosol- generating medical procedures such as nebulization, respiratory therapy, suction, bronchoscopy, or autopsy etc. 2. It is advisable to wear goggles and a gown during intubation, when taking a nasopharyngeal swab and when providing close care for paediatric patients (because of the risk of contamination with droplets of phlegm or saliva from the patient) 3. PPE must be worn in the correct order: a gown, a surgical mask, goggles, and gloves. PPE must be taken off in the correct order: gloves, goggles, a gown, and a surgical mask (see illustrations). 5

6 4. While taking a nasopharyngeal swab, staff must wear gloves and a surgical mask, and goggles or a face shield; and sit beside the patient. 5. Strictly observe the principles of hand hygiene, as well as any other specific hygiene principles. 6. If any of staff fall ill with a seasonal flu, they are required to stop working immediately and receive a medical examination at the hospital. 7. The administration of chemoprophylaxis is not recommended since the disease is already widespread. Taking antiviral drugs to prevent infection may not be effective or feasible (i.e. to take continuously until the end of the outbreak). Wearing a surgical mask properly and observing the principles of hygiene are more acceptable and effective prevention measures. Prevention of the infection among the patients relatives 1. Relatives visiting patients in ICU should wear gowns and surgical masks, and wash their hands before touching anything after leaving the ward. 2. Only healthy individuals who can understand observe the basic principles of infection control should be allowed to visit patients. 3. Any relatives who are unwell with seasonal flu should not be allowed to visit patients. These clinical practice guidelines have jointly been prepared by The Infectious Disease Association of Thailand, Pediatric Infectious Disease Society of Thailand, The Thoracic Society of Thailand, The Thai Society of Critical Care Medicine, Infection Control Society, Thai Association of Pediatric Respiratory and Critical Care Medicine, The Royal College of Pediatricians of Thailand, Pediatric Society of Thailand, The Royal College of Physician of Thailand, and the Ministry of Public Health. 6