Focused Preanesthetic Assessment of the Respiratory System

Focused Preanesthetic Assessment of the Respiratory System

A comprehensive respiratory assessment includes history, physical examination and diagnostic tests that provide information about respiratory function. However, bedside clinical assessment provides vital information about respiratory function. It is important for nurse anesthetists to be able to perform a basic respiratory assessment.

History: Ask the Following

• Have you had a cough or cold recently, or do you have one now? If the patient who gives a history of a recent or current upper or lower respiratory tract infection, one has to weigh the risks of the squeal of endotracheal intubation and postponing elective surgery might be necessary. In a patient whose upper respiratory tract infection is not severe, and where it is thought that only brief anesthesia, is needed, it may not be necessary to cancel the surgery. However, one should bear in mind that nasal congestion secondary to an upper respiratory tract infection will render the unconscious patient more prone to upper airway obstruction after the induction of anesthesia.
• Do you smoke cigarettes), do you have an early morning cough? If so, do you bring up sputum? The questions pertaining to smoking, early morning cough and the production of sputum are an attempt to assess the degree to which the patient has changes in lung function induced by the use of cigarettes or other pathological processes. These changes include an induced reactive airway situation, alternations in cilia activity and alterations in the production of mucous by the goblet cells. Discussion on for how long to quit smoking has to discussed with the surgeon and patient
• Do you have bronchitis or asthma? The questions on the presence of bronchitis and asthma through the history, physical examination and appropriate testing lead to investigation of the degree of airway dysfunction and consequent reduction in the efficiency which the alveoli are ventilated. One should look at the drug therapy that is being used, the frequency of drug use and the patient's subjective experience of relief obtained through drug therapy. One should also make plans for the maintenance of therapy over the perioperative period when, as the use of drugs normally taken orally may not be possible. Advice patients to continue their medication until the morning of the operation day. Consider stress dose if patients are under steroid medication.
• Have you had tuberculosis or pneumonia? The question on the prior history of tuberculosis or pneumonia is aimed at establishing the possibility of anatomical and physiological changes in the lung which may be of significance in terms of anesthetic management. In addition, the physician should be alert to the possibility of the presence of tuberculosis, albeit in the quiescent form.
• Can you climb a flight of stairs without getting breathless? The question on climbing a flight of stairs and the exercise efforts of the patient are aimed at attempting to gain some understanding of the functional integrity of the cardio-respiratory system. It is imperative therefore to ask questions about the level of physical activity of patients. Can they walk a mile without undue difficulty? When did they last do so? Questions of this nature can provide excellent information regarding the patients' functional cardio-respiratory status.

Physical Examination

With the patient sitting, examine the patient's anterior and posterior chest. Chest inspection allows you to see visible external signs of respiratory function. Observe the duration of the inspiratory/expiratory cycle (2:3 ratio). Prolonged expiration occurs when an individual has difficulty expelling air. Note the patient's respiratory pattern and breathing rhythm. In a healthy adult, inaudible respirations should occur between 12 and 20 times each minute. Observe for intercostal retractions, nasal flaring, or pursed lip breathing, all of which indicate airflow obstruction and poor ventilation. Intercostal retractions are visible indentations between the ribs as the intercostal muscles aid in breathing. Nasal flaring describes intermittent outward movements of the nostrils with each inspiration. Pursed lip breathing refers to partial closure of the lips to allow air to be expired slowly.

Rapid, shallow breathing is called tachypnea, sign of respiratory and cardio vascular problem. Rapid deep breathing, known as hyperpnea or hyperventilation, occurs as a result of physical exercise, anxiety, and metabolic acidosis. Kusmaul breathing characterized by slow, deep breaths, occurs in patients with diabetic acidosis and coma. Bradypnea, or a much slower than normal respiratory rate, is seen in patients with drug-induced respiratory depression, and increased intracranial pressure. Cheyne-Stokes breathing occurs when there are periods of deep breathing alternating with periods of apnea. A Cheyne-Stokes breathing pattern may be seen in a patient with heart failure, drug-induced respiratory depression, uremia, or brain damage. Ataxic breathing, also known as Biot's breathing, is characterized by unpredictable irregularity. Biot's breathing may be seen in patients with respiratory depression and brain damage at the level of the medulla.

Assess skin color: Provides information about the efficiency and basic functioning of the respiratory system. If hypoxic (low in oxygen), the skin will appear pale as hypoxia causes vasoconstriction. The blue skin coloring known as cyanosis, which can be observed in nail beds, lips and mouths, tip of nose, and earlobes, is usually associated with hypoxia. Cyanosis is an indication that there isn't enough oxygen to maintain the oxygen saturation level at above 80%; this is serious and should be reported immediately.

Percussion is an assessment technique which produces sounds by the examiner tapping on the patient's chest wall. Percussion helps to determine whether the underlying tissues are filled with air, fluid, or solid material.

Palpation is an assessment technique in which the examiner uses the surface of the fingers and hands to feel for abnormalities. Assessment data that can be obtained through palpation includes identifying chest movement symmetry, chest skeletal abnormalities, tenderness, skin temperature changes, swelling, and masses.

Auscultation is the technique of listening to the sounds of the chest with a stethoscope. The movement of air in and out of the respiratory system produces breath sounds. Breath sounds are transmitted through the chest wall and may be heard through the diaphragm (flat piece) of a stethoscope placed firmly against the chest wall. Auscultation of the lungs is the most important examining technique for assessing airflow through the tracheobroncheal tree.

Ask the patient to sit with his arms folded across the chest with the hands resting, if possible, on the opposite shoulders. This position moves the scapulae partly out of the way and increases access to the lung fields. Instruct the patient to breathe deeply with his mouth open. Listen carefully for at least one full breath in each location. Observe the patient for light-headedness or fatigue and allow the patient to rest as often as necessary.

The patterns of normal breath sounds are created by the effect of body structures on air moving through airways. In addition to their location, breath sounds are described by:

• Duration (how long the sound lasts),
• Intensity (how loud the sound is),
• Pitch (how high or low the sound is), and
• Timing (when the sound occurs in the respiratory cycle).

Common Normal Breath Sounds

• Tracheal breath sounds are heard over the trachea. These sounds are harsh and sound like air is being blown through a pipe.
• Bronchial sounds are present over the large airways in the anterior chest near the second and third intercostal spaces; these sounds are more tubular and hollow- but not as harsh as tracheal breath sounds. Bronchial sounds are loud and high in pitch with a short pause between inspiration and expiration; expiratory sounds last longer than inspiratory sounds.
• Bronchovesicular sounds are heard in the posterior chest between the scapulae and in the center part of the anterior chest. Bronchovesicular sounds are softer than bronchial sounds, but have a tubular quality. Bronchovesicular sounds are about equal during inspiration and expiration; differences in pitch and intensity are often more easily detected during expiration.
• Vesicular sounds are soft, blowing, or rustling sounds normally heard throughout most of the lung fields. Vesicular sounds are normally heard throughout inspiration, continue without pause through expiration, and then fade away about one third of the way through expiration.
• In a normal air-filled lung, vesicular sounds are heard over most of the lung fields, bronchovesicular sounds are heard between the 1st and 2nd interspaces on the anterior chest, bronchial sounds are heard over the body of the sternum, and tracheal sounds are heard over the trachea.

Normal findings on auscultation include:

• Loud, high-pitched bronchial breath sounds over the trachea
• Medium pitched bronchovesicular sounds over the mainstream bronchi, between the scapulae, and below the clavicles
• Soft, breezy, low-pitched vesicular breath sounds over most of the peripheral lung fields.

Abnormal Breath Sounds

• The absence of sound and/or the presence of "normal" sounds in areas where they are normally not heard: For example, bronchial (loud & tubular) breath sounds are abnormal in peripheral areas where only vesicular (soft & rustling) sounds should be heard. When bronchial sounds are heard in areas distant from where they normally occur, the patient may have pneumonia or compression of the lung. These conditions cause the lung tissue to be dense.
• Crackles (or rales) are caused by fluid in the small airways or atelectasis. Crackles are referred to as discontinuous sounds; they are intermittent, nonmusical and brief. Crackles are often described as fine, medium, and coarse. Fine crackles are soft, high-pitched, and very brief. You can simulate this sound by rolling a strand of hair between your fingers near your ear, or by moistening your thumb and index finger and separating them near your ear. Coarse crackles are somewhat louder, lower in pitch, and last longer than fine crackles.
• Crackles may be heard on inspiration or expiration. The popping sounds produced are created when air is forced through respiratory passages that are narrowed by fluid, mucus, or pus. Crackles are often associated with inflammation or infection of the small bronchi, bronchioles, and alveoli. Crackles that don't clear after a cough may indicate pulmonary edema or fluid in the alveoli due to heart failure or adult respiratory distress syndrome.
• Wheezes are whistling sounds that are heard continuously during inspiration or expiration. They are caused by air moving through airways narrowed by constriction or swelling of airway or partial airway obstruction. Wheezing is often found in people with asthma and is also associated with bronchitis and heart disease.
• Stridor refers to a high-pitched harsh sound heard during inspiration. Stridor is caused by obstruction of the upper airway, is a sign of respiratory distress and thus requires immediate attention.
• Whenever there is abnormal finding during auscultations inform and discus with the operating physician or if it is elective consult medical side