Partial Pressure of Oxygen in aortic blood (Pa02) is/are decreased in all except:
C. PolycythemiaPa02 = measures oxygen in the blood (80-100mm Hg)Sa02 = measures tissue perfusion (pulse ox 95-100%)Pa02 (Partial Pressure of Oxygen in Arterial Blood)webapp1.dlib.indiana.edIt reflects the amount of oxygen gas dissolved in the blood. It primarily measures the effectiveness of the lungs in pulling oxygen into the blood stream from the atmosphere.Elevated pO2 levels are associated with:Increased oxygen levels in the inhaled airPolycythemiaDecreased PO2 levels are associated with:Decreased oxygen levels in the inhaled airAnemiaHeart decompensationChronic obstructive pulmonary diseaseRestrictive pulmonary diseaseHypoventilation"Cor pulmonale is a condition that causes the right side of the heart to fail. Long-term high blood pressure in the arteries of the lung and right ventricle of the heart can lead to cor pulmonale" - medlineplus.govType II Respiratory Failure Harrison 19th/1732This type of respiratory failure is a consequence of alveolar hypoventilation and results from the inability to eliminate carbon dioxide effectively.Mechanisms are categorized by impaired central nervous system (CNS) drive to breathe, impaired strength with failure of neuromuscular function in the respiratory system, and increased load (s) on the respiratory system.Reasons for diminished CNS drive to breathe include drug overdose, brainstem injury, sleep-disordered breathing, and severe hypothyroidism.Reduced strength can be due to impaired neuromuscular transmission (e.g., myasthenia gravis, Guillain-Barre syndrome, amyotrophic lateral sclerosis) or respiratory muscle weakness (e.g., myopathy, electrolyte derangements, fatigue)Type I Acute Hypoxemic Respiratory FailureHarrison 19th/1731This type of respiratory failure occurs with alveolar flooding and subsequent intrapulmonary shunt physiology. Alveolar flooding may be a consequence of pulmonary edema, pneumonia, or alveolar hemorrhage.Pulmonary edema can be further categorized as occurring due to elevated pulmonary microvascular pressures, as seen in heart failure and intravascular volume overload or ARDS ("low pressure pulmonary edema," This syndrome is defined by acute onset (<=1 week) of bilateral opacities on chest imaging that art not fully explained by cardiac failure or fluid overload and of shunt physiology requiring positive end-expiratory pressure (PEEP).Type I respiratory failure occurs in clinical settings such as sepsis, gastric aspiration, pneumonia, near-drowning multiple blood transfusions, and pancreatitis.The mortality rate among patients with ARDS was traditional very high (50-70%), although changes in patient care have led to mortality rates closer to 30% (see below(Davidson 22nd/664): How to interpret blood gas abnormalities in respiratory failure Type 1Type II Hypoxia (Pa02 <8.0kPa (60 mmHg)Normal or low PaC02 (<6.6 kPa (50 mmHg)Hypoxia (Pa02 <8.0 kPa (60 mmHg) Raised PaC02 (> 6.6 kPa (50 mmHg) AcuteChronicAcuteChronicH+--|- or |Bicarbonate---|CausesAcute asthma Pulmonary edema Pneumonia Lobar collapse Pneumothorax Pulmonary embolus ARDSCOPDLung fibrosis Lymphangitis Carcinomatosa Right-to-left shuntsAcute severe asthma Acute exacerbation of COPD Upper airway obstruction Acute neuropathies/paralysis Narcotic drugsPrimary alveolar hypoventilation Flail chest injuryCOPDSleep apnea KyphoscoliosisMyopathies/muscular dystrophy Ankylosing spondylitis
Pulmonary edema
Pulmonary Fibrosis
Polycythemia
Cor pulmonale
Respiratory