Preoperative Management of Hypoxic Patients

Classification of Hypoxia Pathophysiologic Category Clinical Example Hypoxic hypoxia Decreased Pbarom or FiO2 Altitude, O2 equipment error Alveolar hypoventilation Drug overdose, COPD exacerbation Pulmonary diffusion defect Emphysema, pulmonary fibrosis V/Q mismatch Asthma, pulmonary emboli R-->L shunt Atelectasis, cyanotic congenital heart disease Circulatory hypoxia Reduced cardiac output CHF, MI, dehydration

Classification of Hypoxia Pathophysiologic Category Clinical Example Hemic hypoxia Reduced Hb content Anemia Reduced Hb function Carboxyhemoglobinemia, methemoglobinemia Demand hypoxia Increased oxygen consumption Fever, seizures Histotoxic hypoxia Inability of cells to utilize oxygen Cyanide toxicity

Atelectasis and pulmonary embolism are most likely causes of the desaturation.

Atelectasis

Preoperative Evaluation for Postoperative Pulmonary Complications Postoperative Pulmonary Complications (PPC) Atelectasis Pneumonia Respiratory failure ARDS Pleural effusion Med Clin N Am 87(2003) 153-173

Med Clin N Am 87(2003) 153-173

Med Clin N Am 87(2003) 153-173

Preoperative Evaluation for Postoperative Pulmonary Complications Risk Reduction Strategies Preoperative smoking cessation Abstinence for at least 8 weeks probably decreases PPC risk Med Clin N Am 87(2003) 153-173

Preoperative Evaluation for Postoperative Pulmonary Complications Risk Reduction Strategies Perioperative lung expansion maneuvers Incentive spirometry Chest physical therapy deep breathing exercise postural drainage percussion and vibration cough suctioning mobilization Med Clin N Am 87(2003) 153-173

Preoperative Evaluation for Postoperative Pulmonary Complications Risk Reduction Strategies Perioperative lung expansion maneuvers Intermittent positive pressure breathing CPAP Patient education in lung maneuvers initiated preoperatively is more effective in reducing PPC versus education initiated postoperatively Med Clin N Am 87(2003) 153-173

Preoperative Evaluation for Postoperative Pulmonary Complications Risk Reduction Strategies Postoperative analgesia Optimizing pulmonary function in patients with COPD and asthma Delaying surgery for patients with acute exacerbations of chronic lung disease or URI. No clear role for prophylactic antibiotic use. Med Clin N Am 87(2003) 153-173

Pulmonary Embolism

Venous Thromboembolism (VTE) The cornerstone of VTE diagnosis is clinical suspicion. Because the first manifestation of VTE may be fatal pulmonary embolism (PE), patients with suspected VTE should be anticoagulated until the diagnosis is excluded. Med Clin N Am 86(2002) 731-748

Diagnosis of VTE Duplex ultrasonography Contrast venography or MR venography Patient with suspected PE: Lung ventilation and perfusion scan Helical CT Med Clin N Am 86(2002) 731-748

Prevention of Venous Thromboembolism The Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy Chest 2004; 126:338S-400S

Recommendations: Trauma Factors with increased risk of VTE: Spinal cord injury Lower extremity or pelvic fracture Need for a surgical procedure Increasing age femoral venous line insertion or major venous repais Prolonged immobility longer duration of hospital stay

Recommendations: Trauma We recommend that all trauma patients with at least one risk fector for VTE receive thromboprophylaxis, if possible In the absence of major contraindication (intracranial bleeding, ongoing and uncontrolled bleeding, uncorrected major coagulopathy, incomplete SCI with suspected or proven perispinal hematoma...), we recommend that clinicians use LMWH prophylaxis starting as soon as it is considered safe to do so.

Recommendations: Trauma We recommend that mechanical prophylaxis with intermittent pneumatic compression (IPC), or possibly with graduated compression stocking (GCS) alone, be used if LMWH prophylaxis is delayed or if it is currently contraindicated due to active bleeding or a high risk for hemorrhage

Recommendations: Trauma We recommend DUS screening in patients at high risk for VTE and who have received suboptimal prophylaxis or no prophylaxis We recommed against the use of inferior vena cava filters (IVCFs) as primary prophylaxis in trauma patients.

Recommendations: Trauma We recommend the continuation of thromboprophylaxis until hospital discharge, including the period of inpatient rehabilitation. We suggest continuing prophylaxis after hospital discharge with LMWH or a VKA (target INR, 2.5; INR range, 2.0 to 3.0) in patients with impaired mobility.

As for this patient... Atelectasis Perioperative lung expansion maneuvers Pulmonary embolism undergo further examination to exclude or confirm this diagnosis Thromboprophylaxis with anticoaulant or mechanical prophylaxis