Postoperative respiratory problems

Common in those with pre-existing respiratory disease, especially with a reduced vital capacity or peak flow rate. Problems include:

• Exacerbation of chronic chest disease

• Retained secretions

• Basal atelectasis

• Upper airway problems, e.g. laryngeal oedema

Anaesthesia and surgery (especially upper abdominal surgery) reduce functional residual capacity, thoracic compliance and cough. There is reduced macrophage function and systemic inflammatory activation with infection and acute lung injury as possible consequences.

Therapeutic aims

Pre-operative preparation may help avoid some of the problems:

• Cessation of smoking for >1 week

• Bronchodilatation

• Respiratory muscle training

• Chest physiotherapy

• Avoidance of hypovolaemia in the nil-by-mouth period

Post-operative clearance of secretions and maintenance of basal lung expansion are very important. These require effective analgesia and chest physiotherapy. Consider early use of non-invasive ventilation if spontaneously breathing but requiring high FIO2. Mechanical ventilation assists basal expansion and secretion clearance where anaesthetic recovery is expected to be prolonged or where surgery ± pre-existing disease increase the risk of secretion retention and atelectasis. Ensure a patent airway prior to extubation where intubation was difficult or after upper airway surgery.

Post-operative circulatory problems

• Prevention of hypovolaemia is crucial in avoiding inflammatory activation and, therefore, many post-operative complications.

• Haemorrhage is usually obvious and managed by resuscitation, correction of coagulation disturbance and surgery.

• Subclinical hypovolaemia is common postoperatively. Hypothermia and high catecholamine levels help to maintain CVP and BP despite continuing hypovolaemia. Avoiding reduced stroke volume or metabolic acidosis are the best indicators of adequate resuscitation.

• Post-operative fluid management requires a high degree of suspicion of hypovolaemia; fluid challenges with colloid should be used to confirm and treat hypovolaemia where there is any circulatory disturbance, metabolic acidosis or oliguria.

Reasons for elective ICU admission

• Airway monitoring: e.g. major oral, head and neck surgery

• Respiratory monitoring: e.g. cardiothoracic surgery, upper abdominal surgery, prolonged anaesthesia, previous respiratory disease

• Cardiovascular monitoring: e.g. cardiac surgery, vascular surgery, major abdominal surgery, prolonged anaesthesia, previous cardiovascular disease

• Neurological monitoring: e.g. neurosurgery, cardiac surgery with circulatory arrest

• Elective ventilation: e.g. cardiac surgery, major abdominal surgery, prolonged anaesthesia, previous respiratory disease

See also:

Ventilatory support—indications, p4; Endotracheal intubation, p36; Non-invasive respiratory support, p32; Chest physiotherapy, p48; Pulse oximetry, p90; Blood gas analysis, p100; ECG monitoring, p108; Blood pressure monitoring, p110; Central venous catheter—use, p114; Central venous catheter—insertion, p116; Cardiac output—thermodilution, p122; Cardiac output—other invasive, p124; Cardiac output—non-invasive (1), p126; Cardiac output—non-invasive (2), p128; Electrolytes

, p146; Full blood count, p154; Coagulation monitoring, p156; Colloids, p180; Blood transfusion, p182; Bronchodilators, p186; Respiratory stimulants, p188; Opioid analgesics, p234; Non-opioid analgesics, p236; Sedatives, p238; Muscle relaxants, p240; Anticoagulants, p248; Coagulants and antifibrinolytics, p254; Fluid challenge, p274; Respiratory failure, p282; Atelectasis and pulmonary collapse, p284; Chronic airflow limitation, p286; Hypotension, p312; Oliguria, p330; Metabolic acidosis, p434; Hypothermia, p516; Pain, p532

P.535

Ovid: Oxford Handbook of Critical Care

Editors: Singer, Mervyn; Webb, Andrew R.

Title: Oxford Handbook of Critical Care, 2nd Edition

Copyright ©1997,2005 M. Singer and A. R. Webb, 1997, 2005. Published in the United States by Oxford University Press Inc

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