Overview of Respiratory Function

The major function of lungs and pulmonary circulation as the pulmonary system is to deliver oxygen (O₂) to cells and remove carbon dioxide (CO₂) from the cells (gas exchange). The adequacy of oxygenation and ventilation is measured by partial pressure of arterial oxygen (PaO₂) and partial pressure of arterial carbon dioxide (PaCO₂). The pulmonary system also functions as a blood reservoir for the left ventricle when it is needed to boost cardiac output; as a protector for the systemic circulation by filtering debris/particles; as a fluid regulator so water can be kept away from alveoli; and as a provider of metabolic functions such as surfactant production and endocrine functions.

Terminology in Respiratory

• Alveolus—air sac where gas exchange takes place
• Apex—top portion of the upper lobes of lungs
• Base—bottom portion of lower lobes of lungs, located just above the diaphragm
• Bronchoconstriction—constriction of smooth muscle surrounding bronchioles
• Bronchus—large airways; lung divides into right and left bronchi
• Carina—location of division of the right and left main stem bronchi
• Cilia—hairlike projections on the tracheobronchial epithelium, which aid in the movement of secretions and removal of debris
• Compliance—ability of the lungs to distend and change in volume relative to an applied change in pressure (eg, emphysema—lungs very compliant; fibrosis—lungs noncompliant or stiff)
• Dead space—ventilation that does not participate in gas exchange; also known as wasted ventilation when there is adequate ventilation but no perfusion, as in pulmonary embolus or pulmonary vascular bed occlusion. Normal dead space is 150 mL.
• Diaphragm—primary muscle used for respiration; located just below the lung bases, it separates the chest and abdominal cavities
• Diffusion (of gas)—movement of gas from area of higher to lower concentration
• Dyspnea—subjective sensation of breathlessness associated with discomfort, often caused by a dissociation between motor command and mechanical response of the respiratory system as in:
  • Respiratory muscle abnormalities (hyperinflation and airflow limitation from chronic obstructive pulmonary disease [COPD]).
  • Abnormal ventilatory impedance (narrowing airways and respiratory impedance from COPD or asthma).
  • Abnormal breathing patterns (severe exercise, pulmonary congestion or edema, recurrent pulmonary emboli).
  • Arterial blood gas (ABG) abnormalities (hypoxemia, hypercarbia).
• Hemoptysis—coughing up of blood
• Hypoxemia—PaO₂ less than normal, which may or may not cause symptoms (Normal PaO₂ is 80 to 100 mm Hg on room air.)
• Hypoxia—insufficient oxygenation at the cellular level due to an imbalance in oxygen delivery and oxygen consumption (Usually causes symptoms reflecting decreased oxygen reaching the brain and heart.)
• Mediastinum—compartment between lungs containing lymph and vascular tissue that separates left from right lung
• Orthopnea—shortness of breath when in reclining position
• Paroxysmal nocturnal dyspnea—sudden shortness of breath associated with sleeping in recumbent position
• Perfusion—blood flow, carrying oxygen and CO₂ that passes by alveoli
• Pleura—serous membrane enclosing the lung; comprised of visceral pleura, covering all lung surfaces, and parietal pleura, covering chest wall and mediastinal structures, between which exists a potential space
• Pulmonary circulation—network of vessels that supply oxygenated blood to and remove CO₂-laden blood from the lungs
• Respiration—inhalation and exhalation; at the cellular level, a process involving uptake of oxygen and removal of CO₂ and other products of oxidation
• Shunt—adequate perfusion without ventilation, with deoxygenated blood conducted into the systemic circulation, as in pulmonary edema, atelectasis, pneumonia, COPD
• Surfactant—fluid secreted by alveolar cells that reduces surface tension of pulmonary fluids and aids in elasticity of pulmonary tissue
• Ventilation—movement of air (gases) in and out of the lungs
• Ventilation-perfusion (V/Q) imbalance or mismatch—imbalance of ventilation and perfusion; a cause for hypoxemia. V/Q mismatch can be due to:
  • Blood perfusing an area of the lung where ventilation is reduced or absent.
  • Ventilation of parts of lung that are not perfused.

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Biologic and Genetic Principles on Nursing

The impact of genetics on nursing is significant. The American Nurses Association (ANA) officially recognized genetics as a nursing specialty. This effort was spearheaded by the International Society of Nurses in Genetics (ISONG), which also initiated credentialing for the Advanced Practice Nurse in Genetics and the Genetics Clinical Nurse. ANA and ISONG have collaborated in the establishment of a scope and standards of practice for nurses in genetics practice. Essential Nursing Competencies and Curricula Guidelines for Genetics and Genomics were finalized in 2006. They reflect the minimal genetic and genomic competencies for every nurse regardless of academic preparation, practice setting, role, or specialty.

Cell as The Basic Unit of Biology

• Cytoplasm—contains functional structures important to cellular functioning, including mitochondria, which contain extranuclear deoxyribonucleic acid (DNA) important to mitochondrial functioning.
• Nucleus—contains 46 chromosomes in each somatic (body) cell, or 23 chromosomes in each germ cell (egg or sperm).

Chromosomes

Each somatic cell with a nucleus has 22 pairs of autosomes (the same in both sexes) and 1 pair of sex chromosomes. Females have two X sex chromosomes; males have one Y sex chromosome and one X sex chromosome. Normally, at conception, each individual receives one copy of each chromosome from the maternal egg cell (1 genome) and one copy of each chromosome from the paternal sperm cell (1 genome), for a total of 46 chromosomes (2 genomes). Karyotype is the term used to define the chromosomal complement of an individual, for example, 46, XY, as is determined by laboratory chromosome analysis. Each chromosome contains 800 to 3,000 genes.

 

Genes

Gene is the basic unit of inherited information. Each copy of the human genome in the nucleus has about 30,000 genes. Cells also have some nonnuclear genes located within the mitochondria within the cytoplasm. Alternate forms of a gene are termed alleles. For each gene, an individual receives one allele from each parent, and thus has two alleles for each gene on the autosomes and also on the X chromosomes in females. Males have only one X chromosome and, therefore, have only one allele for all genes on the X chromosome; they are hemizygous for all X-linked genes. At any autosomal locus, or gene site, an individual can have two identical alleles (homozygous) for that locus or can have two different alleles (heterozygous) at a particular locus. Genotype refers to the constitution of the genetic material of an individual; for practical purposes it is commonly used to address a specific gene pair. For example, the gene for sickle cell disease, the gene for cystic fibrosis, or the gene for familial polyposis. Phenotype refers to the physical or biochemical characteristics an individual manifests regarding expression of the presence of a particular feature, or set of features, associated with a particular gene. Each gene is composed of a unique sequence of DNA bases.

 

DNA: Nuclear and Mitochondrial

• Human DNA is a double-stranded helical structure comprised of four different bases, the sequence of which codes for the assembly of amino acids to make a protein—for example, an enzyme. These proteins are important for the following reasons:
  • For body characteristics such as eye color.
  • For biochemical processes such as the gene for the enzyme that digests phenylalanine.
  • For body structure such as a collagen gene important to bone formation.
  • For cellular functioning such as genes associated with the cell cycle.
• The four DNA bases are adenine, guanine, cytosine, and thymine-A, G, C, and T.
• A change, or mutation, in the coding sequence, such as a duplicated or deleted region, or even a change in only one base, can alter the production or functioning of the gene or gene product, thus affecting cellular processes, growth, and development.
• DNA analysis can be done on almost any body tissue (blood, muscle, skin) using molecular techniques (not visible under a microscope) for mutation analysis of a specific gene with a known sequence or for DNA linkage of genetic markers associated with a particular gene.

Normal Cell Division

Mitosis occurs in all somatic cells, which, under normal circumstances, results in the formation of cells identical to the original cell with the same 46 chromosomes.

Meiosis, or reduction division, occurs in the germ cell line, resulting in gametes (egg and sperm cells) with only 23 chromosomes, one representative of each chromosome pair.

During the process of meiosis, parental homologous chromosomes (from the same pair) pair and undergo exchanges of genetic material, resulting in recombinations of alleles on a chromosome and thus variation in individuals from generation to generation.

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Using Electrocardiography (ECG) to Measures the Heart's Electrical Activity

Prepare the machine by placing the ECG machine close to the patient's bed, and plug the power cord into the wall outlet. To accommodate the precordial leads and minimize electrical interference on the ECG tracing, remove the electrodes if the patient is already connected to a cardiac monitor. Keep the patient away from objects that might cause electrical interference, such as equipment, fixtures, and power cords.

Explain the procedure to the patient as you set up the machine to record a 12-lead ECG. Tell him that the test records the heart's electrical activity and it may be repeated at certain intervals. Also, tell him that the test typically takes about 5 minutes. Emphasize that no electrical current will enter his body.

Have the patient lie in a supine position in the center of the bed with his arms at his sides. You may raise the head of the bed to promote his comfort. Expose his arms and legs, and drape him appropriately. His arms and legs should be relaxed to minimize muscle trembling, which can cause electrical interference.

Place the patient's hands under his buttocks to prevent muscle tension if the bed is too narrow. Also use this technique if the patient is shivering or trembling. Make sure his feet aren't touching the bed board.

Select flat, fleshy areas to place the electrodes. Avoid muscular and bony areas. If the patient has an amputated limb, choose a site on the stump. If an area is excessively hairy, clip it. Clean excess oil or other substances from the skin to enhance electrode contact.

Apply the electrode paste or gel or the disposable electrodes to the patient's wrists and to the medial aspects of his ankles. If you're using paste or gel, rub it into the skin. If you're using disposable electrodes, peel off the contact paper and apply them directly to the prepared site, as recommended by the manufacturer's instructions. To guarantee the best connection to the leadwire, position disposable electrodes on the legs with the lead connection pointing superiorly.

If you're using paste or gel, secure electrodes promptly after you apply the conductive medium. This prevents drying of the medium, which could impair ECG quality. Never use alcohol or acetone pads in place of the electrode paste or gel because they impair electrode contact with the skin and diminish the transmission quality of electrical impulses.

Connect the limb leadwires to the electrodes. Make sure the metal parts of the electrodes are clean and bright. Dirty or corroded electrodes prevent a good electrical connection.

You'll see that the tip of each leadwire is lettered and color-coded for easy identification. The white or RA leadwire goes to the right arm; the green or RL leadwire, to the right leg; the red or LL leadwire, to the left leg; the black or LA leadwire, to the left arm; and the brown or V₁ to V₆ leadwires, to the chest.

Now, expose the patient's chest. Put a small amount of electrode gel or paste on a disposable electrode at each electrode position.

If your patient is a woman, be sure to place the chest electrodes below the breast tissue. In a large-breasted woman, you may need to displace the breast tissue laterally.

Check to see that the paper speed selector is set to the standard 25 mm/second and that the machine is set to full voltage. The machine will record a normal standardization mark—a square that's the height of two large squares or 10 small squares on the recording paper. Then, if necessary, enter the appropriate patient identification data.

If any part of the waveform extends beyond the paper when you record the ECG, adjust the normal standardization to half-standardization. Note this adjustment on the ECG strip because this will need to be considered in interpreting the results.

Now you're ready to begin the recording. Ask the patient to relax and breathe normally. Tell him to lie still and not to talk when you record his ECG. Then press the AUTO button. Observe the tracing quality. The machine will record all 12 leads automatically, recording three consecutive leads simultaneously. Some machines have a display screen so you can preview waveforms before the machine records them on paper.

When the machine finishes recording the 12-lead ECG, remove the electrodes and clean the patient's skin. After disconnecting the leadwires from the electrodes, dispose of or clean the electrodes, as indicated.

 

 

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Educational and Competency Requirements for The Administration and Supply of Medications by Nurses in Rural and Remote Areas

Following are the areas of responsibility that rural and remote nurses must accept if medication management is to become part of their legal practice.

Knowledge of Medicines:
Nurses should have contemporary knowledge of pharmacology for safe and appropriate nursing practice in rural and remote communities. The nurse also must have sound knowledge and skills relating to medications in their facility’s approved medication list. Another requirement is that the nurse should have reasonable access to and familiarity with the resources available for collaboration, consultation/reference in regards to the use of medications.
Relevant and appropriate clinical educational preparation and competency assessment will support best practice in the administration and supply of medication by registered nurses in rural and remote settings.

Knowledge of Law:
The nurse must have knowledge of the statutory and common laws, which govern medication use by registered nurses, for practice.

Civil laws, statutory acts and regulations establish the standard of the delivery of appropriate and safe care to patients. Knowledge of the legislative requirements is essential to ensure registered nurses’ practise within the law.

Assessment of Competency:
The practice of initiating, administering and supplying medications in rural or remote areas should be confined to registered nurses who have demonstrated competency in these areas.
An assessment of competency should include:

• Knowledge and skills for patient assessment and diagnosis
• An examination of medication knowledge.
• A test of competency in medication calculations.
• Knowledge of the medication schedules as they impact on clinical practice.
• A clinical/practical assessment of compliance with protocols in the practice context.

Knowledge of clinical assessment and medication use is essential to enable the nurse to make an informed decision about the initiation of safe and appropriate treatment. Competency in medication/IV calculations may reduce the risk of dose/rate errors. It is the nurse’s responsibility to have knowledge of current schedules to practise in accordance with the relevant legislation. Current literature indicates that a significant number of nursing students have serious numeracy skill deficits and that even if these skills are mastered, they can deteriorate if not continually exercised.

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Materials of Bandaging

Bandaging is both a science and an art. The proper bandage, properly applied, can aid materially in the recovery of the patient. A improperly or carelessly applied bandage can cause discomfort to the patient and may imperil his life.

Bandages are employed to hold dressings, to secure splints, to create pressure, to immobilize (make immovable) joints and in correcting deformity. Bandages should never be used directly over a wound. They should only be used over a dressing.

Various materials, such as gauze, flannel, crinoline, muslin, linen, rubber, and elastic webbing are employed in making bandages. Gauze is used most frequently because it is light, soft, thin, porous, readily adjusted, and easily applied. Flannel, being soft and elastic, may be applied smoothly and evenly, and as it absorbs moisture and maintains body heat, is very useful for certain conditions. Crinoline, rather than ordinary gauze, is used in making plaster of paris bandages, the mesh of the crinoline holding the plaster more satisfactorily than gauze. Muslin is employed in making bandages because it is strong, inexpensive, readily obtainable, and can be used more than once. For the latter reason, muslin bandages are usually employed in bandage practice. Muslin should be soaked in water to cause shrinkage, dried, and finally ironed to remove wrinkles. A large piece of this material may be easily torn into strips of the desired width. Rubber and elastic webbing are used to afford firm support to a part. The webbing is preferable to the pure rubber bandage. It permits the evaporation of moisture.

Bandage material is commonly made into either a triangular bandage, a roller bandage, or a manytailed bandage.

 

 

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ECG Waveforms And Components

The electrocardiogram (ECG) is a graphic recording ofelectric potentials generated by the heart.The signals are detected by means of metal electrodes attached to the extremities and chest wall and are then amplified and recorded by the electrocardiograph. ECG leads actually display the instantaneous differences in potential between these electrodes.

The clinical utility of the ECG derives from its immediate availability as a noninvasive, inexpensive, and highly versatile test. In addition to its use in detecting arrhythmias, conduction disturbances, and myocardial ischemia, electrocardiography may reveal other findings related to life-threatening metabolic disturbances (e.g., hyperkalemia) or increased susceptibility to sudden cardiac death (e.g., QT prolongation syndromes). The widespread use of coronary fibrinolysis and acute percutaneous coronary interventions in the early therapy of acute myocardial infarction has refocused attention on the sensitivity and specificity of ECG signs of myocardial ischemia.

An electrocardiogram (ECG) waveform has three basic components: the P wave, QRS complex, and T wave. These elements can be further divided into the PR interval, J point, ST segment, U wave, and QT interval.

P wave and PR interval

The P wave represents atrial depolarization. The PR interval represents the time it takes an impulse to travel from the atria through the atrioventricular nodes and bundle of His. The PR interval measures from the beginning of the P wave to the beginning of the QRS complex.

QRS complex

The QRS complex represents ventricular depolarization (the time it takes for the impulse to travel through the bundle branches to the Purkinje fibers).

The Q wave appears as the first negative deflection in the QRS complex; the R wave, as the first positive deflection. The S wave appears as the second negative deflection or the first negative deflection after the R wave.

J point and ST segment

Marking the end of the QRS complex, the J point also indicates the beginning of the ST segment. The ST segment represents part of ventricular repolarization.

T wave and U wave

Usually following the same deflection pattern as the P wave, the T wave represents ventricular repolarization. The U wave follows the T wave, but isn't always seen.

QT interval

The QT interval represents ventricular depolarization and repolarization. It extends from the beginning of the QRS complex to the end of the T wave.

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What Are Involve at Planning of Care?

Planning involves three subsets: setting priorities, writing expected outcomes, and establishing target dates. Planning sets the stage for writing nursing actions by establishing where we are going with our plan of care. Planning further assists in the final phase of evaluation by defining the standard against which we will measure progress.

Setting Priorities
With the sicker, quicker problem discussed earlier, you are going to find yourself in the situation of having identified many more problems than can possibly be resolved in a 1- to 3-day hospitalization (today’s average length of stay). In the long-term care facilities, such as home health, rehabilitation, and nursing homes, long-range problem solving is possible, but setting priorities of care is still necessary.

Several methods of assigning priorities are available. Some nurses assign priorities based on the life threat posed by a problem. For example, Ineffective Airway Clearance would pose more of a threat to life than the diagnosis Risk for Impaired Skin Integrity. Some nurses base their prioritization on Maslow’s Hierarchy of Needs. In this instance, physiologic needs would require attention before social needs. One way to establish priorities is to simply ask the patient which problem he or she would like to pay attention to first. Another way to establish priorities is to analyze the relationships between problems. For example, a patient has been admitted with a medical diagnosis of headaches and possible brain tumor. The patient exhibits the defining characteristics of both Pain and Anxiety. In this instance, we might want to implement nursing actions to reduce anxiety, knowing that if the anxiety is not reduced, pain control actions will not be successful. Once priorities have been established, you are ready to establish expected outcomes.

Expected Outcomes
Outcomes, goals, and objectives are terms that are frequently used interchangeably because all indicate the end point we will use to measure the effectiveness of our plan of care.

Several guidelines for writing clinically useful expected outcomes:

1. Expected outcomes are clearly stated in terms of patient behavior or observable assessment factors.
2. Expected outcomes are realistic, achievable, safe, and acceptable from the patient’s viewpoint.
3. Expected outcomes are written in specific, concrete terms depicting patient action.
4. Expected outcomes are directly observable by use of at least one of the five senses.
5. Expected outcomes are patient centered rather than nurse centered.

Establishing Target Dates
Writing a target date at the end of the expected outcome statement facilitates the plan of care in several ways:

1. Assists in “pacing” the care plan. Pacing helps keep the focus on the patient’s progress.
2. Serves to motivate both patients and nurses toward accomplishing the expected outcome.
3. Helps patient and nurse see accomplishments.
4. Alerts nurse when to evaluate care plan.

Target dates can be realistically established by paying attention to the usual progress and prognosis connected with the patient’s medical and nursing diagnoses. Additional review of the data collected during the initial assessment helps indicate individual factors to be considered in establishing the date. For example, one of the previous expected outcomes was stated as “Accurately return-demonstrates self-administration of insulin by 9/11.”

The progress or prognosis according to the patient’s medical and nursing diagnosis will not be highly significant. The primary factor will be whether diabetes mellitus is a new diagnosis for the patient or is a recurring problem for a patient who has had diabetes mellitus for several years.

For the newly diagnosed patient, we would probably want our deadline day to be 5 to 7 days from the date of learning the diagnosis. For the recurring problem, we might establish the target date to be 2 to 3 days from the date of diagnosis. The difference is, of course, the patient’s knowledge base.

Now look at an example related to the progress issue. Mr. X is a 19-year-old college student who was admitted early this morning with a medical diagnosis of acute appendicitis. He has just returned from surgery following an appendectomy. One of the nursing diagnoses for Mr. X would, in all probability, be Pain. The expected outcome could be “Will have decrease in number of requests for analgesics by [date].” In reviewing the general progress of a young patient with this medical and nursing diagnosis, we know that generally analgesic requirements start decreasing within 48 to 72 hours. Therefore, we would want to establish our target date as 2 to 3 days following the day of surgery. This would result in the objective reading (assume date of surgery was 11/1): “Will have decrease in number of requests for analgesics by 11/3.”

To further emphasize the target date, it is suggested that the date be underlined, highlighted by using a different-colored pen, or circled to make it stand out. Pinpointing the date in such a manner emphasizes that evaluation of progress toward achievement of the expected outcome should be made on that date. In assigning the dates, be sure not to schedule all the diagnoses and expected outcomes for evaluation on the same date. Such scheduling would require a total revision of the plan of care, which could contribute to not keeping the plan of care current. Being able to revise single portions of the plan of care facilitates use and updating of the plan. Remember that the target date does not mean the expected outcome must be totally achieved by that time; instead, the target date signifies the evaluation date.

Once expected outcomes have been written, you are then ready to focus on the next phase—implementation. As previously indicated, the title supported by this book for this section is “Nursing Actions.”

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