SUBJECT: Oxygen Therapy

PURPOSE: To define procedure for ordering and administering oxygen therapy other than with mechanical ventilators and hyperbaric chambers.

PROCEDURE: Administration of oxygen therapy other than with mechanical ventilators and hyperbaric chambers.

POLICY:

1. Physician order: follow order for device and liter flow unless it would result in incorrect use of device.

2. Standing orders: Oxygen therapy may be initiated or modified when indicated. Oxygen started based on oxygen therapy policy must be written on order page in chart (e.g. "Supplemental oxygen at 1.5 LPM by nasal cannula started per CMC oxygen policy due to SaO2 87% on room air.")

3. Unless otherwise specified in physician written order, titrate supplemental oxygen to achieve SaO2 > 90%, or PaO2 > 60mmHg using the smallest possible amount of supplemental oxygen.
  1. Unless otherwise specified in physician order, do not titrate supplemental oxygen to lower levels than the patient uses at home.

INDICATIONS:

1. Documented hypoxemia:

In adults, children, and infants older than 28 days: arterial oxygen tension (PaO2) of < 60 mmHg or arterial oxygen saturation (SaO2) of < 90% in subjects breathing room air or with PaO2 and/or SaO2 below desirable range for specific clinical situation.

In neonates: Due to the presence of fetal hemoglobin which has a high affinity for oxygen shifting the oxyhemoglobin dissociation curve to the left, a PaO2 < 50 mmHg and/or SaO2 < 88% or capillary oxygen tension (PcO2) < 40 mmHg (PcO2 correlates poorly with PaO2. If PaO2 is not obtained, monitor SpO2 or transcutaneous PO2 in conjunction with the PcO2) are considered indicators of hypoxemia.

2. An acute care situation in which hypoxemia is suspected--substantiation of hypoxemia is required as soon as possible following initiation of therapy.

Severe trauma

Acute myocardial infarction

Short-term therapy (e.g., post-anesthesia recovery)

CONTRAINDICATIONS:

No specific contraindications to oxygen therapy exist when indications are judged to be present.

PRECAUTIONS AND/OR POSSIBLE COMPLICATIONS:

With FIO2 > or = 0.5, absorption atelectasis, oxygen toxicity, and or depression of ciliary and/or leukocytic function may occur.

With PaO2 > or = 60 mmHg, ventilatory depression may occur in spontaneously breathing patients with elevated PaCO2 (this is controversial).

Supplemental oxygen should be administered with caution to patients suffering from paraquat poisoning and to patients receiving bleomycin.

During laser bronchoscopy, minimal levels of supplemental oxygen should be used to avoid intratracheal ignition.

Fire hazard is increased in the presence of increased oxygen concentrations.

Bacterial contamination associated with certain nebulization and humidifications systems is a possible hazard.

IN NEWBORNS:

In premature infants PaO2 of > 80 mmHg should be avoided because of the possibility of retinopathy of prematurity.

Increased PaO2 can contribute to closure or constriction of the ductus arteriosus-a possible concern in infants with ductus-dependent heart lesions.

Bronchopulmonary dysplasia (BPD) is a chronic lung disorder that may affect infants who require extensive oxygen therapy.

EQUIPMENT:

Low-flow systems deliver 100% oxygen at flows that are less than the patient's inspiratory flowrate (i.e. the delivered oxygen is diluted with room air) and, thus, the oxygen concentration inhaled (FIO2) may be low or high, depending on the specific device and the patient's inspiratory flowrate.

Nasal cannulas can provide 24-40% oxygen with flowrates up to 6 L/min in adults (depending on ventilatory pattern), but in newborns and infants flows should be limited to a maximum of 2 L/min. Oxygen supplied to adults via nasal cannula at flowrates less than or equal to 4 L/min need not be humidified.

Masks with reservoir bags (partial rebreathers and non-rebreathers) are designed to provide FIO2s of 0.5 or greater. In practice, both partial and non-rebreathers function in a similar manner and provide FIO2 of about 0.6 (depending on mask fit and ventilatory variables) provided the flowrate is sufficient to keep the reservoir bag inflated during inspiration. Higher FIO2 is possible depending on mask fit, oxygen flow rate, and ventilatory variables.

Patients who have been receiving transtracheal oxygen at home may continue to receive oxygen by this method provided no problems present. If difficulties related to the transtracheal route of administration appear, oxygenation should be assured by other means.

High-flow systems deliver a prescribed gas mixture-either high or low oxygen concentrations at flowrates that exceed patient demand.

Venturi masks can accurately deliver predetermined oxygen concentration to the trachea up to 40%. Venturi masks rated at 50% or higher usually do not deliver flowrates adequate to meet the inspiratory flowrates of adults in respiratory distress.

Aerosol masks, tracheostomy collars, T-tube adapters, and face tents can be used with high-flow supplemental oxygen systems. The gas flow can be humidified by large-reservoir humidifier (or a continuous aerosol generator if specifically ordered by physician). Some aerosol generators cannot provide adequate flows at high oxygen concentrations.

Supplemental oxygen may be administered to newborns and infants by hood (headbox), with the high-flow oxygen source provided by heated humidifiers.

MONITORING / EQUIPMENT:

All oxygen delivery systems are checked at least once per day.

More frequent checks by calibrated analyzer are necessary in systems susceptible to variation in oxygen concentration (e.g. hoods, high-flow blending systems) applied to patients with artificial airways delivering a heated gas mixture, applied to patients who are clinically unstable or who require an FIO2 of 0.50 or higher.

 

Oxygen to hoods (headboxes) in the nursery is analyzed at least every 2 hours and may be monitored continuously with a circuit/system check at least every 4 hours.

FREQUENCY:

Oxygen therapy should be administered continuously unless the need has been shown to be associated only with specific situations (e.g. exercise and sleep).

INFECTION CONTROL:

Under normal circumstances, low-flow oxygen systems (including cannulas and simple masks) do not present clinically important risk of infection and need not be routinely replaced. High-flow systems that employ heated humidifiers and aerosol generators, particularly when applied to subjects with artificial airways, can pose important risk of infection.

High-flow systems that employ heated humidifiers and aerosol generators will be changed every day.

SOURCES:

AARC Clinical Practice Guideline - Oxygen Therapy in the Acute Care Hospital; Respir Care 1991;36:1410-1413.

Dantzker DR, MacIntyre NR, Bakow ED. Comprehensive Respiratory Care. W.B. Saunders Company 1995.

Barnhart SL, Czervinske MP. Perinatal and Pediatric Respiratory Care W.B. Saunders Company 1995.

Barnhart SL, Czervinske MP. Perinatal and Pediatric Respiratory Care. Copyright 1995, WB Saunders Company.

Hanson CW 3rd, Marshall BE, Frasch HF, Marshall C. Causes of hypercarbia with oxygen therapy in patients with chronic obstructive pulmonary disease. Crit Care Med 1996; 24(1):23-28.

Dick CR, Liu Z, Sassoon CSH, Berry RB, Mahutte CK. O2-induced change in ventilation and ventilatory drive in COPD. Am J Respir Crit Care Med 1997;155: 609-614.

Gomersall C.D., Joynt G.M., Freebairn R.C., Lai C. 1998. Randomized controlled pilot study of oxygen therapy for hypercapnic patients with an acute exacerbation of COPD. Chest 114:319S

American Thoracic Society. Standards for the diagnosis and Care of Patients with Chronic Obstructive Pulmonary Disease. Am J Respir Crit Care Med 1995; 152:S77-S120.