(1)
Intensive Care Unit, Gennimatas General Hospital, Thessaloniki, Greece
(2)
Thoracic Surgery Department, Theagenio Cancer Hospital, Thessaloniki, Greece
26.1 Introduction
Although dyspnea is a well-known symptom of tumors involving the lung or pleura, shortness of breath is commonly present in patients with terminal cancer who do not have lung or pleura involvement. Dyspnea in cancer patients may be caused by the tumor itself, treatment of the tumor, medical complications of the debilitated state, or underlying lung or cardiac disease.
26.2 Analysis
Considering that lung cancer is the leading cause of cancer death in both men and women and that as many as 65 % of these patients experience dyspnea, the contribution of lung cancer to dyspnea in patients with terminal cancer is substantial. It is estimated that 30 % of patients with malignant disease will develop pulmonary metastasis at some time during the clinical course of their disease. Mechanisms for acute respiratory failure in patients with bronchogenic carcinoma include the following:
Acute respiratory failure in cancer patients with pulmonary or pleural involvement may be related to treatment of the carcinoma, for example, postradiation pneumonitis, postradiation lung fibrosis, or postpneumonectomy. The main respiratory modifications after thoracic surgery mostly lead to atelectasis, hypoxemia, acute respiratory failure, pneumonia, or bronchopulmonary fistula. Alternatively, acute respiratory failure in terminally ill cancer patients, including patients with lung cancer, may be related to chronic obstructive pulmonary disease caused by cigarette smoking. Furthermore, acute respiratory failure in terminally ill cancer patients may be a manifestation of the debility of terminal cancer. Reported causes include anemia, pulmonary embolism, and congestive heart failure. Moreover, acute respiratory failure in these patients most likely represents the debility of terminal cancer, which includes general muscle weakness and medical complications. These patients may be intubated for a long time.
1.
Replacement of lung tissue to the extent that a restrictive ventilator defect is produced
2.
Pneumonia, atelectasis, or whole-lung collapse occurring behind an occluded primary or segmental bronchus
3.
Entrapment of the phrenic nerve by tumor-filled mediastinal nodes and resulting diaphragmatic paralysis
4.
Lymphatic spread or interstitial edema, reducing lung compliance
Prolonged mechanical ventilation (MV) may be caused by
The most common cause is inspiratory respiratory muscle fatigue [3, 4], which is almost always multifactorial in etiology. Possible causes of inspiratory respiratory muscle fatigue are
The predictors of prolonged MV are based on the clinical judgment of the physicians, for example,
1.
Inadequate respiratory drive due to nutritional deficiencies, sedatives [1], central nervous system abnormality, or sleep deprivation
2.
Inability of the lungs to carry out gas exchange effectively
4.
Psychological dependency
1.
Nutritional and metabolic deficiencies resulting from hypokalemia, hypomagnesemia, hypocalcemia, hypophosphatemia, or hypothyroidism [5]
2.
Corticosteroids
3.
Chronic renal failure
4.
Systemic diseases with decreased protein synthesis and increased degradation and/or decreased glycogen stores
5.
Hypoxemia and hypercapnia
6.
Increased work of breathing due to disease, ventilator, or airway humidification devices
7.
Failure of the cardiovascular system
8.
Neuromuscular dysfunction/disease caused by drugs or critical illness polyneuropathy-myopathy [6]
1.
The patient who is unable to initiate spontaneous inspiratory efforts
2.
Predictive Models of Prolonged Mechanical Ventilation and Difficult Weaning
Postoperative Continuous Positive Airway Pressure (CPAP)
Noninvasive Mechanical Ventilation in Postoperative Spinal Surgery
Noninvasive Mechanical Ventilation in Tetraplegia
Criteria for Discharging Patients with Prolonged and Difficult Weaning from Intensive Care Unit to Weaning Center
Organization of a Weaning Unit
Inadequate oxygenation (Pao2/Fio2 < 200)
Related posts:
Predictive Models of Prolonged Mechanical Ventilation and Difficult Weaning
Postoperative Continuous Positive Airway Pressure (CPAP)
Noninvasive Mechanical Ventilation in Postoperative Spinal Surgery
Noninvasive Mechanical Ventilation in Tetraplegia
Criteria for Discharging Patients with Prolonged and Difficult Weaning from Intensive Care Unit to Weaning Center
Organization of a Weaning Unit
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