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Clinical Indicators for the Readiness of Ventilator Discontinuance

Once the original reason for placing the patient on the ventilator has been resolved, there are a number of bedside studies that can be used to help determine the patient's readiness to be weaned from the ventilator (Table 11.14). It should be strongly stressed, however, that none of the currently used indices is 100% reliable in confirming the patient's readiness for a successful ventilator weaning attempt. Good clinical judgement and common sense also must be added to the mix. That said, common tools used to assess the patient's readiness for ventilator weaning include the arterial oxygen tension to fractional concentration of oxygen ratio (PaO2/FIO2 ratio), the alveolar-to-arterial partial pressure

of oxygen difference [P(A-a)O2], the maximum inspiratory pressure (MIP), the airway occlusion pressure at 0.1 second (P0.1), the P0.1/MIP

ratio, the vital capacity (VC), spontaneous minute ventilation (VEsp), maximum voluntary ventilation (MVV), the pressure time index (PTI),7 and the rapid shallow breathing index (RSBI).8 The cuff-leak test is another semiquantitative measure of readiness to discontinue ventilator support. If the patient can breathe around a deflated endotracheal tub cuff, he or she probably will be able to breathe even easier once it is removed.

TABLE 11.14

Clinical Indicators Used to Predict Readiness for Ventilator Discontinuance

Additional criteria used to evaluate the patient's readiness to be weaned from the ventilator include the patient's (1) cardiovascular stability (e.g., heart rate, blood pressure, cardiac output, and cardiac rhythms), (2) psychologic condition (e.g., fear, anxiety, and stress), and (3) central nervous system functions (e.g., stable ventilatory drive, adequate secretion clearance [i.e., coughing, deep breathing, or gag reflex and swallowing]), and (4) level of alertness and agitation before weaning. Table 11.15 shows the Richmond Agitation-Sedation Scale (RASS), which is a commonly used scale for measuring the agitation or sedation level of the patient, is incorporated in Protocol 11.2.9

FIGURE 11.7 Barotrauma. (Modified from Korones, S. B. [1986]. High-risk newborn infants [4th ed.]. St. Louis, Mosby.)

Note that this listing of VALI “causes” does not include oxygen toxicity, which is often confused with VILI/VALI, and ARDS, a diagnosis most accurately based on its cellular morphology.

Similar to barotrauma, volutrauma is caused by high ventilator pressures and volumes, but in the case of volutrauma, alveolar rupture does not occur. Volutrauma is described as the result of microscopic release of alveolar-capillary membrane inflammatory mediators (e.g., cytokines, complement, prostanoids, and leukotrines) caused by high lung volumes and pressures. The released mediators in turn lead to increased alveolar-capillary permeability, pulmonary edema, and impaired transmembrane oxygen delivery. Ventilator patients who demonstrate poor ventilator-patient synchrony, declining lung compliance, increased pulmonary shunting, falling PaO2/PAO2 ratios, and an increased WOB may all

be suffering from VALI.

Studies have suggested that ventilator plateau pressures (Pplat) is the most reliable single measurement to assess the risk for barotrauma in ventilated patients. Monitoring of peak airway pressures is also helpful, especially in patients in whom pulmonary compliance is a problem.

Lung Protective Strategies

The generally accepted lung protective strategies to avoid and treat VALI are low tidal volumes, low peak and plateau pressures, and permissive hypercapnia. A good example of this ventilation strategy can be reviewed under the General Management section in Chapter 28, Acute Respiratory Distress Syndrome. The use of NIV before, during, and after intubation makes good physiologic sense and in selected cases is definitely helpful. Box 11.5 provides an overview of common lung protective strategies.

Box 11.5

Protective Lung Strategies—Preventive and Therapeutic*

Ventilator Strategies

•Ventilator settings

•Low tidal volumes

•Low inspiratory flow rate

•Avoid spontaneous breathing as much as possible

•Early use of assisted breathing techniques

•Noninvasive ventilation (NIV)

•Neurally Adjusted Ventilatory Assist (NAVA)

•Use of “best PEEP” based on detrimental PEEP titration

•Rigorous use of ventilator graphics

•Consider use of chest computed tomography and ultrasound

Other Techniques and Strategies

•High-frequency ventilation

•Prone positioning (controversial).

•Use if PaO2/FIO2 <150 or best PEEP >10 cm H2O

•Permissive hypercapnia

•Careful control of fluid therapy/monitor central venous pressure

•Careful early use of sedation and paralysis

•Use of low-dose corticosteroids early and late

*Best modes/modalities still not agreed upon.

Data from Gutierrez TM, Pelosi P, Rocco PRM: Ventilator-induced lung injury, Eur Respir Mon 55: 1–18, 2012.

Ventilator Malfunctions

Finally, an important hazard of mechanical ventilation is ventilator malfunction—problems with the ventilator itself. Although this is rare, ventilator malfunction is a possibility and always should be under the respiratory therapist's surveillance. Suspect ventilators should be switched out immediately.

Charting the Progress of Ventilated Patients

The sicker the patient, the more carefully done must be the charting of the patient's progress or lack of it. Box 11.6 lists some areas in which the Protocol Therapist may wish to add terms like “Doing Well” or “Not Doing Well” to the Assessment portion of his Progress Note. Items that appear in such an assessment will obviously call for up-regulation, down-regulation, or change of the patient's respiratory care program, and use of such terms is thus strongly encouraged.

Box 11.6

Status Reporting in Ventilated Patients

Items Worth Reporting in the Assessment Portion of Progress Notes

c.1 and 2 only

d.2 and 3 only

9.A 67-year-old man with chronic obstructive pulmonary disease presented in the emergency department with acute alveolar hyperventilation superimposed on chronic ventilatory failure. He was taken to the intensive care unit and placed on a noninvasive ventilation (NIV) system with supplemental oxygen at an FIO2 of 0.40. Arterial blood gas values are as follows: pH 7.22, PaCO2 84, 33, PaO2 43, SaO2 71%. At this time, which of the following would be the most appropriate treatment?

a.Change the patient to invasive ventilation

b.Increase the FIO2

c.Recommend a sedative

d.Change the NIV mask

10.A 57-year-old woman presents in the coronary care unit in respiratory distress. She is alert and appropriately answering the doctor's questions. Her vital signs are as follows: heart rate 145, blood pressure 170/110, and respiratory rate 32. She appears cyanotic, and her breath sounds reveal bilateral crackles. Arterial blood gases on a nonrebreathing oxygen mask are pH 7.51,

PaCO2 27, 21, and PaO2 46. Based on this information, which of the following would you recommend to initially treat the patient?

a.Invasive ventilation

b.Continuous positive airway pressure mask

c.Noninvasive ventilation

d.Nonrebreathing oxygen mask

1Key clinical indicators of hypoxemic respiratory failure include a decreased arterial oxygen tension (PaO2), an increased alveolar-arterial oxygen tension gradient [P(A-a)O2], a decreased arterial-to-alveolar oxygen tension ratio (PaO2/PAO2 ratio), a decreased arterial oxygen tension to fractional inspired oxygen ratio (PaO2/FIO2 ratio (see Table 11.8), and/or an increased pulmonary shunt (QS/QT). See Table 11.11 for clinical indicators of hypoxemic respiratory failure, page 164.)

2Most commercial jet aircraft fly at cruising altitudes between 30,000 and 40,000 feet. The barometric pressure (PB) at sea level is about 760 mm Hg (14.7 psi). At 30,000 feet above sea level, the PB is about 226 mm Hg (4.4 psi); at 40,000 feet, the PB is about 104 mm Hg (2.7 psi). To

prevent people from losing consciousness from the lack of oxygen at these high cruising altitudes, the plane's cabin is pressurized to an altitude between 6000 to 8000 feet, which provides a barometric pressure between 609 mm Hg (11.8 psi) and 563 mm Hg (10.9 psi), respectively.

3In the Chinese train, the ambient oxygen is increased by only 3 percentage points (from 21% to 24%), but this is enough to result in symptomatic improvement for its passengers. It is not practical to pressurize whole buildings in a process called oxygen conditioning, but pressurization of entire hospital rooms is now being done at selected sites.

4In addition to the patient's ABG status discussed here, key clinical indicators of hypercapnic respiratory failure are also reflected in the patient's tidal volume (VT), respiratory rate (breaths per minute), maximum inspiratory pressure (MIP), vital capacity (VC), and work of

breathing (e.g., minute ventilation and dead-space/tidal volume ratio [VD/VT ratio]). For further discussion of these important points, see Table 11.9, Criteria for Instituting Mechanical Ventilation, page 169.

5Often the patient initially demonstrates acute alveolar hyperventilation superimposed on chronic ventilatory failure before becoming fatigued, when acute ventilatory failure superimposed on chronic ventilatory failure develops. Clinically, this condition is called impending ventilatory failure.

6The authors would like to thank the Respiratory Care Department at the Kettering Health Network (KHN), in Dayton, Ohio, for providing their Ventilator Initiation, Management, and Weaning Protocols. In addition, the authors ask the reader to note a difference in the Protocols presented in this chapter compared with earlier editions of this volume. Simple branching logic algorithms, as seen in the Protocols in Chapter 10, The Therapist-Driven Protocol Program, are no longer used. They are replaced by a series of steps, which follow one on the other, recycling back and forth between steps if needed. Some steps in these protocols are missing because there is no precise descriptive significant ventilator management activities in these sections that are not disease-specific. Kettering Health Network (KHN) maintains disease-specific critical care and ventilator care management competencies required for therapists treating patients with end-stage COPD, severe pneumonia, aspiration pneumonia, congestive heart failure/cardiogenic pulmonary edema, ARDS and VILI/VALI (see VILI/VALI discussion on page 174).

7The pressure time index (PTI) is a measure of strength and endurance combined into one value. It combines the strength measurement of esophageal pressure and the maximum inspiratory pressure with the endurance value of respiratory time fraction. The normal range is 0.5 to 1.2. Criteria for successful ventilator weaning are less than 0.15 to 0.18.

8The rapid shallow breathing index (RSBI) is the ratio of the spontaneous respiratory frequency (f) to tidal volume (VT) and is calculated as follows (the RSBI is also abbreviated as f/VT):

The normal range is 60 to 90 breaths/min per liter. The successful discontinuance from mechanical ventilation is more likely to occur when the RSBI is less than 105 breaths/min per liter within the first minute of a spontaneous breathing trial.

9Other scales used to measure the patient's alertness include the Ramsay scale, the Agitation-Sedation Scale, and the COMFORT scale for pediatric patients.

10American College of Chest Physicians (ACCP), American Association for Respiratory Care (AARC), and the Society of Critical Care Medicine (SCCM) Evidence-Based Weaning Guidelines Taskforce.

provide subjective data.

O Objective information is the data the respiratory therapist can measure, factually describe, or obtain from other professional reports or test results. Objective data include the following:

•Heart rate

•Respiratory rate

•Blood pressure

•Temperature

•Breath sounds

•Cough effort and efficiency

•Sputum production (volume, consistency, color, and odor)

•Arterial blood gas (ABG) and pulse oximetry data

•Pulmonary function study results

•X-ray reports

•Hemodynamic data

•Chemistry results

A Assessment refers to the practitioner's professional conclusion about the cause of the subjective and objective data presented by the patient. In the patient with a respiratory disorder, the cause is usually related to a specific anatomic alteration of the lung. The assessment, moreover, provides the specific reason why the respiratory therapist is working with the patient. For example, the presence of wheezes are objective data (the clinical

indicator) to verify the assessment (the cause) of bronchial smooth muscle constriction; an ABG with a pH of 7.18, a PaCO2 of 80 mm Hg, an of 29 mm/L, and a PaO2 of 54 mm Hg are the objective data to verify the assessment of acute ventilatory failure with moderate hypoxemia. The presence

of coarse crackles is a clinical indicator to verify the assessment of secretions in the large airways.

P Plan is/are the therapeutic interventions chosen to remedy the cause identified in the assessment. For example, an assessment of bronchial smooth muscle constriction justifies the administration of a bronchodilator; the assessment of acute ventilatory failure justifies mechanical ventilation.

I Implementation is the actual administration of the specific therapy plan. It documents exactly what was done, when, and by whom. These data are often recorded in the “Progress Notes” of the Traditional Chart.

E Evaluation is the collection and reporting of measurable data regarding the effectiveness of the therapy plan and the patient's response to it. For example, an ABG assessment may reveal that the patient's PaO2 did not increase to a safe level in response to oxygen therapy. The terms better or

worse are often used in this section of the chart.

R Revision refers to any changes that may be made to the original therapy plan in response to the evaluation. For example, if the PaO2 does not increase appropriately after the implementation of oxygen therapy, the respiratory therapist might further increase the patient's FIO2 until the desired PaO2 is reached.

For the new practitioner, a predesigned SOAP form is especially useful in the (1) rapid collection and systematic organization of important clinical data, (2) formulation of an assessment (i.e., the cause of the clinical data), and (3) development of a treatment plan. For example, consider the case example and SOAP progress note shown in Fig. 12.1.

FIGURE 12.1 Completed predesigned SOAP form (see SOAP Case Example).

Although the SOAP form or format may not be automatically transferable into the computer-based record (see later), it is an instrument of tremendous help in organizing otherwise often disorganized and incomplete “progress notes” in the traditional hospital record.

Although the SOAP form may initially appear long and time-consuming, the experienced respiratory therapist and assessor can typically condense and abbreviate SOAP information in a few minutes (primarily at the patient's bedside) in just a few short statements. Typically, a written SOAP form uses only 1 to 3 inches of space in the patient's chart. For example, the information presented in Fig. 12.1 may actually be documented in the patient's chart in the following abbreviated form.2

SOAP Case Example*

A 26-year-old man arrived in the emergency department having a severe asthmatic episode. On observation, his arms were fixed to the bed rails, he was using his accessory muscles of inspiration, and he was using pursed-lip breathing. The patient stated that “it feels like someone is standing on my chest. I just can't seem to take a deep breath.” His heart rate was 111 beats per minute, and his blood pressure was 170/110. His respiratory rate was 28 and shallow. Hyperresonant notes were produced on percussion. Auscultation revealed expiratory wheezing and coarse crackles bilaterally. His chest x-ray film revealed a severely depressed diaphragm and alveolar hyperinflation. His peak expiratory flow was 165 L/min. Even though

his cough effort was weak, he produced a large amount of thick white secretions. His arterial blood gases showed pH of 7.27, PaCO2 of 62, of 25, and PaO2 of 49 (on room air).

*Subjective and objective data presented in bold.

S—“It feels like someone is standing on my chest. I can't take a deep breath.”

O—Use of acc. mus. of insp.; HR 111, BP 170/110, RR 28 & shallow, pursed-lip; hyperresonance; exp. whz; diaph. & alv. hyperinfl.; PEFR 165; wk. cough; lg. amt. thick/white sec.; pH

7.27, PaCO2 62; 27; PaO2 49.

A—Bronchospasm; hyperinflation; poor ability to mob. tk. sec.; acute vent. fail. with severe hypox.

P—Aerosolized Medication Protocol (albuterol qid); Airway Clearance Protocol (CPT & PD qid), Mechanical Ventilation Protocol, ABG 30 min.

After the treatment has been administered, another abbreviated SOAP note should be made to determine whether the treatment plan needs to be up-regulated or down-regulated. For example, if the ABG data obtained after the implementation of the plan (outlined in the SOAP form) showed that the patient's PaO2 was still too low, it would be appropriate to revise the

original treatment plan by increasing the FIO2 on the mechanical ventilator. Fig. 12.2 illustrates objective data, assessments, and treatment plans commonly associated with respiratory disorders.

with one another.

Basic computer knowledge and skills are usually taught through the institution's in-service education department. Each nursing station usually has multiple data entry stations, laptops, and tablets available for charting. Printers are also readily accessible throughout institutions and clinics. The entire patient record or just a part of it may be retrieved and printed. Today, many health care practitioners use hand-held bedside computer documentation systems. Bedside computer devices, referred to as point-of-care (POC) systems, commonly include specific clinical prompts for data entry, which result in records that are more accurate and complete.

Good charting skills are essential to critical thinking and patient assessment—they provide the basic means to collect clinical data, analyze it, assess it, and formulate a treatment plan.

Furthermore, good charting skills document the effectiveness of patient care and adjustments of the treatment plan in response to its effectiveness. Without good charting systems and skills, the practitioner merely administers health care without a predetermined (and recorded) goal.

Historically, respiratory therapists have focused on treating patients with specific disease entities and implementing physicians’ orders. Little planning was done by respiratory therapists to individualize their treatments for a specific patient. Today, a systematic, patient-specific problem-solving approach to respiratory care, based on broad theoretic knowledge, combined with technical expertise and communication skills, is essential and is the focus of this textbook. Indeed, in some quarters, the old term “therapist-driven protocols” (TDPs) (see page 132) has been replaced with “patient-focused respiratory care protocols” emphasizing this way of thinking.

Telemedicine

Telemedicine (also referred to as “telehealth” or “e-health”) uses modern audiovisual technology that allows health care professionals an excellent way to evaluate, diagnose, and treat patients in remote locations. For example, telemedicine allows the health care practitioner the ability to (1) conduct real-time interactive videoconferencing with patients, other caregivers, and consultants; (2) send and receive patient medical files, radiologic images, and health informatics data; (3) perform remote monitoring (e.g., vital signs or sleep apnea episodes); (4) attend medical education seminars; (5) consult with other experts when needed; and (6) attend patient case conferences (grand rounds) without having to travel from one location to another or to take away valuable time from their patients.

Telemedicine provides the health care practitioner, the patient, and the patient's medical staff an effective and efficient way for everyone to communicate without having to leave their respective locations. Physician's management of patient's care (e.g., needed medications, tests, and therapy) is all conducted in a timely manner. In addition, telemedicine eliminates the possible transmission of infectious diseases between the patient and health care worker. This is especially an issue where methicillin-resistant Staphylococcus aureus (MRSA) is a concern. Today, telemedicine is being used daily, across dozens of countries, in hundreds of ways, including telenursing, telepharmacy, telecardiology, telepsychiatry, teleradiology, telepathology, teledermatology, teleaudiology, and teledentistry.

Health Insurance Portability and Accountability Act

In 2003 the Department of Health and Human Services (DHHS) proposed national rules that outlined the ways in which a patient's medical files should be used or shared with others. These rules were adopted as federal standards after the passage of the Health Insurance Portability and Accountability Act (HIPAA). Presently, HIPAA requires that all health care practitioners who have access to patient medical records prove that they have a plan to protect the privacy of the records. In essence, the HIPAA regulations protect the patient's privacy with specific rules outlining when, how, and what type of health care information can be shared. HIPAA gives the patient the right to know about and to control how his or her personal medical records will be used. The following provides a general overview of the HIPAA regulations:

•Both the health care provider and a representative of the insurance company must explain to patients how they plan to disclose any medical records.

•Patients may request copies of all their medical information and make appropriate changes to it. Patients also may ask for a history of any unusual disclosures.

•The patient must give formal consent should anyone want to share any health information.

•The patient's health information is to be used only for health purposes. Without the patient's consent, medical records cannot be used by either (1) a bank to determine whether to give the patient a loan or (2) a potential employer to determine whether to hire the patient.

•When the patient's health information is disclosed, only the minimum necessary amount of information should be released.

•Records dealing with a patient's mental health get an extra level of protection.

•The patient has the right to complain to the DHHS about violations of HIPAA rules.

One disadvantage of the HIPAA regulations, according to many health care practitioners, is that the health care provider must allocate large sums of money to comply with the HIPAA rules —dollars that might be better spent elsewhere. Critics also argue that this cost will probably be passed on to the consumer. In addition, many health care providers think that the quality of patient care will be compromised as a result of HIPAA, making it more difficult for various health care practitioners to obtain vital information regarding patient care.

For example, consider the potential HIPAA-related problems for a health care team in a Miami, Florida, hospital that is trying to obtain the pharmaceutical history—in a timely fashion—of an elderly, unconscious, non-intoxicated car accident victim whose medical records are in a Detroit, Michigan, hospital. Proponents of the HIPAA regulations argue that the urgent sharing of this patient's health record would be a trade-off made to ensure the privacy of his health care information and to treat him in a most effective manner. Regardless of the pros or cons of HIPAA regulations, the respiratory therapist—like all other health care providers—must comply with the current HIPAA regulations. The reader is advised to stay current on the “privacy” aspects of the HIPAA regulations because the entire HIPAA system is under close legislative scrutiny and debate at the present time.

Self-Assessment Questions

1.What is the process of adding written information to the patient's chart called?

1.Recording

2.Critical thinking

3.Documenting

4.Charting

a.2 only

b.3 and 4 only

c.1 and 3 only

d.1, 3, and 4 only

2.The admission sheet, physician's order sheet, and history sheet are all what type of patient records? 1. Source-oriented record

2.Problem-oriented medical record

3.Block chart

4.Traditional chart

a.2 only

b.4 only

c.3 and 4 only

d.1, 3, and 4 only

3.Which of the following is based on a sequential, objective, scientific, problem-solving method? 1. Source-oriented record

2.Problem-oriented medical record

3.Block chart

4.Traditional chart

a.1 only

b.2 only

c.4 only

d.3 and 4 only

4.According to the respiratory care protocol guide (see Fig. 12.2), bronchial breath sounds and dull percussion notes are associated with which of the following clinical assessments?

1.Air trapping

2.Bronchospasm

3.Atelectasis

4.Consolidation

a.2 only

b.3 only

c.1 and 2 only

d.3 and 4 only

5.Good charting should be an effective way to do the following:

a.__________________________________________

___________________________________________

________________________________________

b._______________________________________

________________________________________

____________________________________

c.______________________________________

___________________________________________

_____________________________________________

d._______________________________________________

_______________________________________________

_______________________________________________

6.A good problem-oriented medical record (POMR) should include a systematic approach that documents the following:

a.__________________________________________

__________________________________________

__________________________________________

b.__________________________________________

__________________________________________