I. Subject: Continuous Positive Airway Pressure CPAP by Continuous Flow Device II. Policy: Continuous Positive Airway Pressure CPAP by the Down's system will be instituted by Respiratory Therapy personnel upon a physician's order. III. Indications: Adequate spontaneous minute ventilation and one or more of the following: A. Generalized diffuse acute restrictive lung disease characterized by: 1) Decreased pulmonary compliance 2) Decreased Functional Residual Capacity (FRC) 3) Refractory hypoxemia 4) Increased intrapulmonary shunting B. Stabilization of the chest wall following chest trauma C. Pulmonary edema D. Atelectasis IV. Hazards: A. Barotrauma 1) Pneumothorax B. Decreased venous return with decreased cardiac output. C. Worsening of V/Q relationships with subsequent hypoxemia and hypercardia (hypoventilation). D. Gastric distension with mask CPAP. E. Aspiration of gastric contents with mask CPAP. F. Facial erosion/erythema with mask CPAP. G. Pneumocephalus 1
V. Contraindications: Although no true contraindications have been identified in the literature, the list could possibly include patients with unstable facial fractures, extensive facial lacerations, laryngeal trauma, or a recent tracheal or esophageal anastomosis. Patients at risk for vomiting (those with gastrointestinal bleeding or ileus) may also need to be excluded. In patients who have had recent gastric surgery, the risk/benefit ratio must be considered. CPAP should be used with caution in patient with low cardiac outputs and inpatients with cerebral edema and increased ICP. VI. Rationale: The physiologic goals of CPAP are to increase the functional residual capacity (FRC), with it's accompanying increase in PaO2, and a decrease in intrapulmonary shunt (Qs/Qt), work of breathing, and oxygen consumption. Benefits of CPAP increase to a maximum or optimal level above which physiologic benefits begin to decline progressively. The most important goal of mask CPAP as compared to conventional CPAP is to avoid tracheal intubation and mechanical ventilation. The use of CPAP as a mechanical aid to lung expansion in cases of atelectasis has been demonstrated. It is typically applied via a face mask for 20 to 30 minutes as often as necessary to maintain expansion. VII. Materials: CPAP mask and headstrap (T-piece is used if intubated patient) CPAP valves (2.5, 5.0, 7.5, 10.0, 12.5, 15.0, 17.5, 20.0 cm H2O) or adjustable CPAP valve Flow generator Corrugated tubing Oxygen blender (optional) Oxygen analyzer Proximal airway pressure monitor with low pressure alarm Large bacteria filter for entrainment port on the flow generator Small bacteria filter for proximal pressure line Humidification device- CPAP by mask which incorporates room air entrainment, requires no supplemental humidification at FIO2 < 50%. CPAP mask that utilizes a blender and delivers an FIO2 > 50% requires supplemental humidification because of dry wall gases. Also, in all cases, when the Down's CPAP valves are used to provide CPAP for an intubated patient, humidification is also required. A humidifier and heated wire circuit may be used in the intubated patient. Temperature Probe VIII. Procedure: A. Check order: Compare the requisition with the physician's order to ensure that no discrepancies exist. 2
B. Review Chart: On the patient's chart identify all pertinent data in the following areas: History and physical, admitting diagnosis, progress notes, arterial blood gas analysis, and chest x-rays. Based on the patient data, identify the following: 1) Conditions that indicate the need for CPAP 2) Potential hazards of CPAP for the patient C. Maintain Asepsis: While performing the remainder of this procedure, it is expected that asepsis will be maintained. This includes washing hands before, after and at any time contamination is suspected. D. Obtain equipment: Collect the equipment and supplies as mentioned in item VII above. E. Assemble equipment: Continuous CPAP: 1) Attach bacteria filter to air entrainment port on CPAP generator. 2) Attach corrugated tubing between generator outlet and humidifier canister inlet port. 3) Cut corrugated tubing and place T-adaptor between generator outlet and humidifier canister inlet port to place oxygen analyzer probe. 4) Attach humidifier canister to heater. 5) Attach the inspiratory limb of a heated wire ventilator circuit to the outlet port of the humidifier canister. 6) Connect the distal and proximal temperature probes into their ports on the circuit. 7) Connect the proximal airway pressure monitoring line to the pressure monitor with the small bacteria filter in-line. Intermittent CPAP: 1) Attach 50 psi wall adaptor to CPAP generator. 2) Attach bacteria filter to CPAP generator entrainment port. 3) Connect sufficient lengths of corrugated tubing from CPAP generator outlet to reach patient. 4) Cut corrugated tubing and insert T-piece adaptor for oxygen analyzer probe in line just distal to generator outlet. 3
5) CPAP generator may now be connected directly to oxygen supply wall outlet. F. Confirm patient: Ensure that the procedure is performed with the correct patient. G. Inform patient: Interact with the patient as follows: H. Implement procedure: 1) Introduce yourself by name and department, if not already acquainted. 2) Tell the patient what procedure is to be performed. 3) Explain the procedure by describing: a. What is to be performed b. How it is to be performed c. What the patient is expected to do d. What you will be doing e. How frequently it will be performed. 1) Attach all equipment together before entering patient's room. 2) Connect the blender oxygen line to the high-pressure oxygen source, and the air line to the high pressure compressed air source. 3) Attach the oxygen analyzer immediately distal to the flow generator. Prior to this, ensure that the analyzer is calibrated. 4) Connect the prescribed CPAP valve to the expiratory valve on the mask. 5) Adjust and attach the headstrap to the patient. 6) Attach the mask to the headstrap covering the patient's face without leaks. Inflating or deflating the mask cushion can be helpful in eliminating leaks. Use only enough mask seal pressure to eliminate leaks. 7) When mask is securely in place, adjust the FIO2 by turning air entrainment valve. Maximum counterclockwise rotation will deliver down to approximately 0.33. Maximum clockwise rotation will deliver 100% source gas. For FIO2 < 0.33, decrease source gas FIO2 by blender adjustment downward from 100% source gas and read FIO2 on oxygen analyzer. 8) If the patient is intubated, place a T-piece on the distal end of the inspiratory line and connect to the endotracheal tube or trach. Connect a 6 inch piece of corrugated tubing to the T-piece and place the CPAP valve on the end of this tube. 9) Set the low pressure alarm at a level 2-3 cm H2O below the desired CPAP 4
level and 20 second alarm delay. 10) Adjust flow rate by turning flow knob to achieve flow required to just maintain continuous flow without interruption during inspiration. Maximum flow rate is 70-80 l/min. I. Monitor patient: Determine the patient's response to therapy as follows: J. Conclude procedure: 1) Determine the pulse rate 2) Determine the respiratory rate (count for at least one minute) 3) Determine the arterial blood pressure 4) Observe respirations to identify any abnormalities in the breathing pattern. 5) Note any abnormalities in the patient's appearance or behavior. 6) Optional monitoring by pulse oximetry is desirable. 7) Allow breaks for removal of face mask 15-30 minutes every two (2) hours if tolerated. Complete the following tasks: 1) Assure that the call button is within the patient's reach. 2) Ask the patient if he has any needs. 3) Answer any questions as effectively as possible. K. Record results: Document intermittent CPAP therapy on the Respiratory Therapy Progress Notes as follows: 1) Date and time 2) Level of CPAP administered 3) FIO2 4) Means of delivery (mask or endotracheal tube) 5) Pulse before and after application of CPAP 6) Respiratory rate before and after application of CPAP 7) Abnormal patient characteristics 8) Therapy-related patient complaints. 9) Alarm settings 10) Therapist initials 11) Auscultation of breath sounds 5
Document continuous CPAP administration Q2 hour on the mechanical ventilation record as follows: L. Report observations: 1) Date and time 2) CPAP mode 3) FIO2 4) Respiratory Rate 5) Level of CPAP 6) Low pressure alarm setting 7) Aerodynamics (if performed) 8) Airway type and landmark 9) Airway temperature 10) Circuit change date 11) Therapist's initials 12) Auscultation of breath sounds (Q shift) Report the following information: 1) Report any significant adverse changes in the patient's condition to the nurse or physician whenever observed. 2) Following the implementation of the procedure, inform the appropriate personnel of patient requests, patient complaints, or unexpressed patient needs. 3) Following implementation of the procedure, report the nurse or physician any non-critical adverse reactions to the therapy and other pertinent observations of the patient's condition. 4) The physician should be notified if any of the following occur: a. Patient will not keep mask on b. Patient evidences a decrease in blood pressure c. Patient develops diaphoresis d. Patient develops increased shortness of breath 6