內(nèi)科護(hù)理學(xué) 英語(yǔ) 考試資料Respiratory+Failure課件

1、Respiratory Failure 呼吸衰竭Respiratory FailureRespiratory Failure is a syndrome in which the respiratory system fails in one or both of its gas exchange function: oxygenation氧 & carbon dioxide 二氧化碳 elimination. PaO2 60 mmHg or PaCO2 50 mmHgAcute respiratory failure is present when alveolar ventilation

2、is inadequately to meet the bodys need; the lung can no longer adequately oxygenate the blood.Respiratory FailureRisk factor:The critically ill patientThe patient who has undergone recent abdominal 腹部or thoracic胸部surgery, as a result of splinting夾板of the incision切口, abdominal distention, restrictive

3、 bandages繃帶, tubes引流管, and reduced ventilation通氣減少because of pain.The extremely obese肥胖patient because of restriction of ventilation.The patient who has sustained a thoracic or spinal cord脊髓injuryThe comatose昏迷patient or patient with decreased level of consciousness and depression of the respiratory

4、 center.The patient who has lung disease or who smokes, especially when an infection develops or surgery is needed.The immunosuppressed免疫抑制patientsThe older adultsChronic respiratory failure - days or longer - pH is slightly decreased; allowing time for renal compensation and an increase in bicarbon

5、ate concentration ClassificationAcute respiratory failure - minutes or hours - pH 7.3 Type I: Hypoxemia Respiratory Failure低氧血癥呼吸衰竭 PaO2 60 mmHg with a normal or low PaCO2 Most common: Associated to all acute diseases of the lung Involve fluid filling or collapse塌陷of alveoli (cardiogenic or noncardi

6、ogenic pulmonary edema, pneumonia, hemorrhage出血)Classification Mechanisms of type I respiratory failureMechanisms that may cause hypoxemia and subsequent hypoxemic respiratory failure are: Ventilation-Perfusion (V/Q) mismatch通氣血流比例失調(diào)Shunts分流Diffusion abnormalities彌散障礙Alveolar ventilation肺泡通氣不足Mechan

7、isms of type I respiratory failureVentilation-Perfusion (V/Q) mismatch通氣血流（V / Q )比例失調(diào):alter (V/Q) relationship in the lungs or V/Q mismatch, is the most common cause of hypoxemia低氧血癥.The V/Q relationship means that where there is ventilation in the lungs, there must be matching blood perfusion to t

8、hat area for efficient gas exchange occur. In the normal lung the overall V/Q ratio is 0.8.Mechanisms of type I respiratory failureVentilation-Perfusion (V/Q) mismatchAn alteration or mismatch occurs if there is blood flow to areas of decrease or absent ventilation or if there is ventilation to area

9、s of decrease or absent blood flow. Examples of process that cause V/Q mismatch are: pneumoniam肺炎, atelectasis肺不張, chronic acute bronchitis, severe emphysema肺氣腫, asthma哮喘and pulmonary embolism肺栓塞.Mechanisms of type I respiratory failureShunts分流A shunt occurs when blood enters the arterial system動(dòng)脈系統(tǒng)

10、from venous system靜脈系統(tǒng)without being exposed to ventilated areas通氣區(qū)域of the lung. Essentially, the blood is shunted from the right to the left side of the heart without participating in gas exchange. Blood that has a PO2 similar to venous blood is mixed with arterial blood as it enters the left atrium

11、左心房of the heart.Mechanisms of type I respiratory failure3.Diffusion abnormalities擴(kuò)散異常Diffusion abnormalities indicates an impairment in the equilibration between the O2 pressure in the alveoli and in the pulmonary capillarie.Disease in which a a diffusion abnormalities may contribute to hypoxemia in

12、clude:Diffuse interstitial fibrosis彌漫性間質(zhì)纖維化Collagen vascular disease膠原血管疾病of the lung (e.g., scleroderma硬皮病, systemic lupus erythematosus系統(tǒng)性紅斑狼瘡)Asbestosis石棉病Sarcoidosis結(jié)節(jié)病Interstitial pneumonia間質(zhì)性肺炎Cardiogenic pneumonic edma心源性肺水腫Mechanisms of type I respiratory failureAlveolar hypoventilation (PaC

13、O250mmHg): is generalized decrease in ventilation of the lungs with buildup of CO2 in the blood.Although alveolar hypoventilation肺泡通氣不足is primarily a mechanism of type II respiratory failure, it is mentioned here because in can cause hypoxemia低氧血癥.Hypoventilation通氣過(guò)低is commonly the result of disease

14、s outside the lungs.Pathophysiologic effects of hypoxemiaHyhoxemia低氧血癥 occurs when the amount of oxygen in the blood is not adequate to support aerobic metabolism. CO2 is the waste product of aerobic metabolism有氧代謝. When O2 insufficiency persists, the cell must shift from aerobic to anaerobic metabo

15、lism無(wú)氧代謝.The waste product of anaerobic metabolism, lactic acid乳酸, is more difficult than CO2 to remove from the body because it has to be buffered with sodium bicarbonate碳酸氫鈉. When the body does not have adequate amounts of sodium bicarbonate to buffer lactic acid, metabolic acidosis代謝性酸中毒and cell

16、death occur.Pathophysiologic effects of hypoxemiaHyhoxemia低氧血癥and metabolic acidosis代謝性酸中毒have adverse effect on vital organs, especially the heart and central nervous system (CNS). Permanent brain damage may occur because of depressant effect on the brain.The heart try to compensate for the decreas

17、e O2 level by increasing heart rate and cardio output. As oxygenation decreases and acidosis increases, however, the heart muscle is unable to function and a slowing and eventual cessation of cardiac activity occur, resulting in systemic shock全身性休克.Renal function is also impaired, and sodium retenti

18、on, proteinuria, edema formation, tubular necrosis and uremia may occur.Gastrointestinal system alteration include abnormal liver function, abdominal pain and bowel infarction.Mechanisms of type II respiratory failureMechanisms that may cause type II respiratory failure (hypercapnia) are: Alveolar h

19、ypoventilation通氣不足 Ventilation-Perfusion (V/Q) mismatchMechanisms of type II respiratory failureAlveolar hypoventilation肺泡過(guò)低通氣Alveolar ventilation肺泡通氣: is the volume of gas氣體容量per breath that is available for gas exchange in functioning alveoli功能性肺泡.The PaCO2 is inversely related to the effective al

20、veolar ventilation. Therefore increase PaCO2 indicates decreased alveolar ventilation.Alveolar hypoventilation is commonly caused by diseases outside the lungs, and often the lungs are normal.Mechanisms of type II respiratory failureVentilation-Perfusion (V/Q) mismatchThis may occur in a patient who

21、 has an increased work of breathing, most likely secondary to a large increase in airway resistance. Because the patient does not have the energy or ability to overcome this increased resistance, ventilation decreases and PaCO2 increases.Pathophysiologic effects of hypercapniaSubsequent physiologic

22、effect of hypercapnia are: 2.Potassium shift (hypokalemia低鉀血癥)As the CO2 accumulates, and with it hydrogen ions (H+), the serum become more acidic H+ enters the cells and K+ move out of the cells to the plasma血漿in an attempt to achieve electorneutrality中和電解質(zhì).Initially, serum K+ may be increase, but

23、as acidemia酸血癥becomes prolonged or more pronounced, total body K+ is depleted as excess extracellular K+ is excreted by the kidneys.Pathophysiologic effects of hypercapnia3. Chloride shift (hypochloremia低氯血癥)A low serum chloride lever occurs in acute respiratory failure: as HCO3 move from the cell t

24、o the plasma to buffer H2CO3 , the chloride ions move into the cell to maintain electroneutrality電解質(zhì)平衡. Clinical manifestation臨床表現(xiàn) Hypercapia高碳酸血癥:HeadacheSomnolence嗜睡Dizziness頭暈coma昏迷Finding:HypertensionTrachycardiaDiaphoresis發(fā)汗Warm, flushed skin皮膚溫暖潮紅Bounding pulse脈沖脈Asterixis撲翼樣震顫 Papilledema視神經(jīng)乳

25、頭水腫Decreased deep tendon reflexes深腱反射降低Diagnostic studies輔助檢查Evaluation of oxygenationArterial blood gas analysis (PaO2, O2 saturation)Pulse oximetry (SpO2)Mixed venous oxygen (PvO2)Shunt equation (Qs/Qt)Alveolar-arterial oxygen difference D(A-a) O2Alterial-alveolar ratio (a/A gradient or PaO2/PAO2

26、ratio)Hypoxemia score (PaO2/FIO2 ratio)Evaluation of ventilation Arterial blood gas analysis (PaCO2)Capnography (PetCO2)Tidal volume (Vt)Forced vital capacity (FVC)Minute ventilation or volume (VE)Negative inspiratory force (NIF) or maximum inspiratory pressure (MIP)Physiologic dead space (VD/VT rat

27、io) Nursing implementation護(hù)理措施 Maintenance of adequate oxygenation維持足夠的氧合Oxygen administration to keep PaO2 60mmHg : if hypoxemia is secondary to hypoventilation, provision and maintenance of adequate ventilation usually will overcome the problem of gas exchange.Hypoxemia secondary to V/Q mismatch V

28、/Q比例失調(diào)usually responds favorably to the lowest concentration of O2 (administered by mask or cannula) necessary to maintain a PaO2 of at least 55-60 mmHg.Hypoxemia secondary to shunting 分流is usually refractory to the administration of high concentration of O2 by mask and ultimately requires mechanica

29、l ventilation Nursing implementation Maintenance of adequate oxygenation2. Maintenance of adequate Hb concentration血紅蛋白濃度and cardiac output心輸出量To ensure adequate O2 delivery to the tissues, keep the patients PaO2 equal to 60mm Hg or greater will provide adequate O2 saturation. When the PaO2 is 60mm

30、Hg or greater, the Hb is 90% saturated.BP should be maintained at the most beneficial level each patient. Usually , a systolic BP of at least 90 mmHg is adequate to maintain perfusion to vital organs.A urine output of 0.5 ml/kg per hour or more is an indication of adequate renal perfusion. Nursing i

31、mplementation Maintenance of adequate oxygenation3. Prevention and assessment of tissue hypoxia 缺氧Close observation for clinical manifestations of vital organ hypoxia is needed, including:Mental and neurologic status: clouding of sensorium感覺(jué)遲鈍, poor concentration, restlessness, stupor昏睡, lethargy嗜睡,

32、 somnolence tremors, slurred speech, depressed tendon reflexes跟鍵反射減弱, and asterixis撲翼樣震顫.Cardiovascular status: direct or indirect BP monitoring, cardiac rate and rhythm心律和心率, symptoms of right-sided and left-sided heart failure.Fluid and electrolyte levels: continuous or serial monitoring of oxygen

33、ation status is essential; serial evaluations of serum electrolytes are made to determine excesses or deficiencies.Nursing implementation Maintenance of adequate oxygenation4. Measures to decrease stress and promote comfortThe patient should be maintained in an atmosphere as quite and relaxed as pos

34、sible.Positioning the patient for comfort and for the most efficient ventilation is important.Frequent rest periods needed to be provided and efficient scheduling (pacing) of care, treatments, assessments and diagnostic studies are important to help with conserving the patients energy.It is helpful

35、to explain to the patient the possible sensation that may be encountered with each new experience (e.g., suctioning, drawing ABGs) so that coping strategies can be purposefully selected.Measures to increase physical comfort are also important: mouth care, removing perspiration-soaked gown, sponging

36、the upper torso軀干上部酒精擦浴. Nursing implementation Improvement of alveolar ventilation Maintenance of patent airway維持氣道的開(kāi)放Effective coughingAugmented coughing增加咳嗽may be useful in the patient with neuromuscular weakness or in an exhausted patient.If the patients cough is ineffective in removing secretio

37、ns, nasopharyneal or nasotracheal suctioning is indicated.Coughing at the end of expiration呼氣末is helpful in the patient with sever airway obstruction because it can cause compression of the more distal or peripheral airways and may help “milk” or move secretions into the proximal airway.Nursing impl

38、ementation Maintenance of patent airwayPositioning體位Positioning the patient either by elevating the head of the bed to at least 45 degree (if tolerated) or by using a reclining chair bed may maximize thoracic expansion.A patient with only one functioning lung should be positioned with the unaffected

39、 lung健側(cè)in the dependent position. This position is important in preventing hypoxemia because the “down” lung gets more perfusion. If the diseased lung was “down”, more V/Q mismatch would occur.The patient should be lying on the side if there is any possibility that the tongue will obstruct the airwa

40、y or that aspiration may occur.Nursing implementation Maintenance of patent airway3.Suctioning吸引 Adequate oxygenation and monitoring of the patient are essential during suctioning procedures.Although rarely indicated, bronchoscopy may be used to remove secretions, especially if they are extremely th

41、ick and tenacious.Nursing implementation Improvement of alveolar ventilation4.Measures to liquefy and mobilize secretionsHumidification加濕Adequate hydration Chest physiotherapy (if indicated)Aerosol and untrasonic nebulization霧化If suctioning or other measures to mobilize secretions are ineffective, i

42、t may become necessary to insert endotracheal or tracheostomy tube to facilitate suctioning of secretions.Improvement of alveolar ventilation5. Relief of bronchospasm減輕支氣管痙攣Bronchodilators支氣管擴(kuò)張劑Relief of bronchospasm (if present) will aid in maximal bronchodilatation and increase effective alveolar

43、ventilation.Administration of an O2-riched gas mixture simultaneously with the bronchodilator may help to alleviate the subsequently hypoxemia.Corticosteroids (when indicated)Corticosteroids are used in conjunction with bronchodilating agents when bronchospasm and inflammation are present.Nursing im

44、plementation Improvement of alveolar ventilationVentilation assistanceIf intensive measures fail to improve alveolar ventilation and the patient continues to deteriorate clinically, mechanical ventilation may be instituted to assist or control ventilation;Continuous positive pressure breathing (CPPB

45、)連續(xù)正壓呼吸Noninvasive positive pressure breathing (NIPPV)無(wú)創(chuàng)正壓呼吸Nursing implementation Treatment of underlying cause of failureIn a patient with absolute hypoventilation, the primary problem usually can be diagnosed rapidly, and appropriate therapy initiated.Continuous monitoring of the effects of treat

46、mentAccurate, clear documentation of subjective and objective assessments on the patients flowchart is an important aspect of care.A flowchart that shows the patients ABG measurement, vital signs, pulmonary artery pressure, weights, intake and output, medications and dosages, electrolytes, respirato

47、ry parameters is extremely helpful.Nursing intervention and rationalesIneffective airway clearance related to accumulation of secretion, exudate, sputum in airways, decreased level of consciousness, thoracic and/or abdominal neuromuscular dysfunction, pain and expiratory airflow obstruction Evaluate

48、 patients ability to cough to determine the need for assistance in removing secretion.Perform chest physiotherapy to enhance removal of secretions.Perform tracheobronchial suctioning if coughing is effective.Humidify inspired air if upper airway is bypassed or O2 is being used at 3L/min to prevent d

49、rying of mucosa.Splint chest abdominal incision with pillow or hand to reduce pain and allow deeper, more effective breathing and coughing.Turn q2hr to prevent stasis of secretions and promote optimal ventilationStabilizer artificial airway to prevent accidental extubation.Ensure adequate fluid intake of 2-3L/24hr to liquefy secretions and prevent dehydrationAdminister prescribed bronchodilator and mucolytic medication.Nursing intervention and rationalesIneffective breathing pattern related to neuromuscular impairment,