Diseases

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© Springer Nature Switzerland AG 2021

R. Reti, D. Findlay (eds.)Oral Board Review for Oral and Maxillofacial Surgerydoi.org/10.1007/978-3-030-48880-2_14

14. Respiratory Diseases

Jaclyn A. Tomsic1  , Alireza Ashrafi3, Ray EnglishIII3 and Kiara Brown2
(1)

University Hospitals, Department of Surgery, Cleveland, OH, USA
(2)

Mercy Hospital, Oral Facial Surgery Institute, St. Louis, MO, USA
(3)

Tufts Medical Center, Oral and Maxilofacial Surgery, Boston, MA, USA
 
 
Jaclyn A. Tomsic
Keywords

Lung volumesCystic fibrosisAsthmaChronic obstructive pulmonary disease (COPD)Functional residual capacity (FRC)Pulmonary embolus (PE)COVID-19Novel coronavirusPandemicSeasonal allergiesVasomotor rhinitisPerennial allergic rhinitis

Lung Volumes and Capacities (Fig. 14.1)

  • Total lung capacity (TLC) is the total volume of air that can be contained in the lung.

  • Functional residual capacity (FRC) is the volume of air in the lungs after normal exhalation.

  • Expiratory reserve volume (ERV) is the volume of air that can still be expired after normal exhalation.

  • Inspirational reserve capacity (IRC) is the maximum volume of air that can be inspired at the end of normal inspiration.

  • Forced vital capacity (FVC) is the maximum volume of air that can be exhaled.

  • Residual volume (RV) is the volume of air remaining in the lungs at the end of forced exhalation.

  • Inspiratory capacity (IC) is the maximum volume of air that can be inspired.

  • Tidal volume (VT) is the volume of air during normal inspiration.

  • Vital capacity (VC) is the total volume of air that can be expired after maximum inhalation.

  • Forced expiratory volume (FEV1) is air that can be expired in 1 second.

  • FEV1/FVC ratio represents the proportion of vital capacity that is expired in the first second of forced expiration. Normal value is 80%.

  • FRC serves as a reservoir of oxygen. FRC increases with obstructive lung disease and decreases with lung restrictive disease. FRC is also low in the pediatric population.

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Fig. 14.1

Lung volumes. (Reprinted with permission from Mayer A and Maier L. Murray and Nadel’s Textbook of Respiratory Medicine. Elsevier Health. 2016)

Categories of Lung Disease (Table 14.1)
Table 14.1

Categories of pulmonary disease with examples

Obstructive

Restrictive parenchymal

Restrictive extraparenchymal

Asthma

Pulmonary fibrosis

Myasthenia gravis

COPD

Sarcoidosis

Diaphragm paralysis

Cystic fibrosis

Radiation-induced interstitial lung disease

Muscular dystrophy

   

Obesity

   

Kyphoscoliosis

Asthma

Asthma: Chronic obstructive disease with bronchiolar inflammation and hyperresponsiveness that displays reversible, variable, and recurrent airway obstruction.

  • Diagnosis: Asthma is a clinical diagnosis, which can be confirmed with a positive response to bronchodilator during a pulmonary function test.

Asthma Signs and Symptoms

  • Wheezing

  • Dyspnea

  • Chest tightness

  • Cough both productive and nonproductive

  • Tachypnea

  • Atopy – greatest risk factor for the development of asthma

Classification and Treatment of Asthma (Table 14.2)
Table 14.2

Classification of asthma and treatment regimen

Asthma classification

Symptom frequency

Night-time symptom

FEV1

β adrenergics

Steroids

Leukotriene inhibitor

Cromolyn

Mild intermittent

<2 per week

<2 per month

>80%

Short acting

<2 days per week

No

Alternative

No

Mild persistent

>2 per week

>2 per month

>80%

Short acting

>2 days per week, but not daily and not more than 1 time on any day

Inhaled low-dose

Yes

Alternative

Moderate persistent

Daily

>1 night/week

60–80%

Short acting daily, can add long acting

Inhaled med-dose

Yes

PRN

Severe persistent

Continuous

Frequent

<60%

Short >2 × /day and can add long acting

Inhaled and high-dose systemic

Yes

PRN

Status Asthmaticus

  • Bronschospasmic episode that does not respond to treatment and is considered life threatening.

Treatment

  • Supplemental oxygen to maintain an SaO2 of >90%.

  • β2-agonists by metered dose inhaler every 15–20 minutes.

  • Intravenous corticosteroids.

  • IV magnesium sulfate.

  • Epinephrine 0.3 mg 1:1000 administered subcutaneously.

  • Tracheal intubation for a PaCO2 > 50 mm Hg.

Patient Management

  • Assess the severity of asthma at the preoperative visit. Investigate frequency, triggers, hospitalizations/ER visits, and need for intubation. Patient with a history of recent hospitalizations, a history of poorly controlled disease (e.g., moderate or severe persistent), or history of hospitalizations that require intubation should be treated in a hospital setting.

  • For elective cases, optimization of disease should be achieved and postponement of elective surgery until resolution of symptoms for at least 6 weeks [1].

  • Assess oxygen saturation levels on room air (<95% is concerning).

  • Auscultation of chest to rule active disease processes such as wheezing. A silent chest does not preclude the possibility of bronchospasm.

  • Prophylactic preanesthetic use of β2-agonist inhaler to reduce chances of bronchospasm is recommended. Very light sedation or deep general anesthesia is desired to avoid stage II, which increases odds of laryngospasm/bronchospasm.

  • Use of anesthetic agents that result in bronchodilation is preferred, such as propofol, ketamine, sevoflurane, and isoflurane. Desflurane is very pungent and should be avoided.

  • Liberal use of intravenous hydration is recommended to make airway secretions less viscous.

  • Medications that result in histamine release should be avoided such as meperidine and morphine. Also, opioids should be used judiciously to decrease the risk of chest wall rigidity.

  • Use of adenosine and other nonspecific β-blockers (e.g., Labetalol) should be avoided since they will result in bronchoconstriction.

  • Be cautious using NSAIDs and cyclooxygenase inhibitors as this can induce an asthma attack and rash. Some patients may have Samter’s triad (nasal polyps, ASA sensitivity, and asthma) and are also sensitive to the aforementioned drugs.

  • Be aware of signs and symptoms of bronchospasm and status asthmaticus. Contact EMS for suspected status asthmaticus.

Cystic Fibrosis (CF)

Cystic Fibrosis: Autosomal recessive disease resulting in altered chloride and water transport (CFTR gene) across epithelial cells; this prevents sodium reabsorption by epithelial sodium channels. Can impact the respiratory, gastrointestinal, and reproductive systems.

  • Diagnosis: Sweat chloride concentration exceeding 60 mEq/L in addition to one or more of the following: chronic airway disease, exocrine pancreatic insufficiency, or cystic fibrosis in a first-degree relative. At birth, failure of passing meconium is highly suggestive of CF.

  • Patients have a high incidence of respiratory infections that manifest as productive cough, pansinusitis, and dyspnea.

  • Patients may also exhibit signs of malabsorption including diarrhea, constipation, and greasy smelly stools.

  • Salty crystal accumulation on skin and salty tasting skin.

  • Heat and exercise intolerance.

  • Infertility due to azoospermia and atresia of the vas deferens may also be present.

  • Signs of fat-soluble deficiency:

    • Vitamin E – peripheral neuropathy and hemolytic anemia.

    • Vitamin K – decreased efficacy of vitamin k–dependent factors and increased bleeding susceptibility.

    • Vitamin D – risk for reduced bone density.

    • Vitamin A – impaired vision in low light setting and dry skin.

  • Decreased FEV1 and FEV1: FVC ratio.

Treatment

  • Currently no cure for CF exists.

  • The main goals are proactive treatment of airway infection; many are on at least one antibiotic prophylactically to suppress infection, usually azithromycin.

  • Acute pulmonary functions are treated empirically. Sputum cultures should be taken prior to the initiation of therapy.

  • Chest therapy and use of dornase alfa to loosen secretions are commonly utilized.

  • Involvement of pancreas leading to diabetes is common. Thickened bile secretions can lead to biliary obstruction and eventually cirrhosis. Lack of digestive enzymes may lead to malabsorption and difficulty in absorbing fat-soluble vitamins A, D, E, and K. Patients are treated with pancreatic enzyme replacement.

  • Failure of these major organs might require pancreatic, lung, or liver transplant.

Patient Management

  • Management of these patients is best carried out with the aid of pulmonologist or cystic fibrosis specialist.

  • Optimization of pulmonary status in terms of management of secretions and infections is the key.

  • Active infections must be ruled out prior to surgery.

  • Consider chest physiotherapy prior to surgery.

  • Electrolytes, LFTs, and chest radiographs are useful prior to anesthesia along with continuation of medications.

  • Risk of developing a pneumothorax is risk high (nitrous oxide should be avoided).

  • Procedure should be carried out later in the day to allow for clearance of secretions that have accumulated overnight.

  • Ketamine is relatively contraindicated due to increased secretions.

  • Prophylactic β agonist with metered dose inhaler is recommended.

  • Irritant vapors such as isoflurane such and desflurane are less useful than sevoflurane [2].

  • Short-acting anesthetic agents such as propofol and sevoflurane may be the most appropriate choice.

  • Consider arterial line for frequent blood gas monitoring [2].

  • Avoid nasal intubation if possible due to higher incidence of polyposis [2].

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Jul 23, 2021 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Diseases
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