Hypoxemia During One-Lung Ventilation: Does It Really Matter?

Abstract

Purpose of Review Hypoxemia during one-lung ventilation, while decreasing in frequency, persists as an intraoperative challenge for anesthesiologists. Discerning when desaturation and resultant hypoxemia correlates to tissue hypoxia is challenging in the perioperative setting and requires a thorough understanding of the physiology of oxygen delivery and tissue utilization. Recent Findings Oxygen delivery is not directly correlated with peripheral oxygen saturation in patients undergoing one-lung ventilation, emphasizing the importance of hemoglobin concentration and cardiac output in avoiding tissue hypoxia. While healthy humans can tolerate acute hypoxemia without long-term consequences, there is a paucity of evidence from patients undergoing thoracic surgery. Increasingly recognized is the potential harm of hyperoxic states, particularly in the setting of complex patients with comorbid diseases. Summary Anesthesiologists are left to determine an acceptable oxygen saturation nadir that is individualized to the patient and procedure based on an understanding of oxygen supply, demand, and the consequences of interventions.

Effect of the VivaSight double-lumen tube on the incidence of hypoxaemia during one-lung ventilation in patients undergoing thoracoscopic surgery: a study protocol for a prospective randomised controlled trial

“…5 The second is the imbalance of the ventilation/perfusion ratio caused by onelung ventilation, and ventilated lungs cannot tolerate one-lung ventilation. 6 V-DLT is a video double-lumen tube with an embedded camera and light source between the bifurcation of the trachea and bronchus. 7 Therefore, continuous airway visualisation can be realised during catheter positioning, and the placement process is simpler and…”

Flurbiprofen used in one-lung ventilation improves intraoperative regional cerebral oxygen saturation and reduces the incidence of postoperative delirium

“…There are several limitations. First, oxygen delivery is not solely dependent on saturation but rather must be considered in concert with hemoglobin level and, more importantly, cardiac output ( 8 ). Thus, whether hypoxemia reflected through peripheral oxygen saturation results in hypoxia is patient-dependent.…”

“…Exclusion criteria were as follows: ( 1 ) severe impairment of respiratory function (forced expiratory volume in 1 s of <50% of the predicted values); ( 2 ) presence of contraindications for using flurbiprofen or intralipid; ( 3 ) treatment with NSAIDs drugs within 1 month before surgery; ( 4 ) scored<24 on the Mini-mental State Examination (MMSE) or who were unable to complete baseline cognitive assessment; ( 5 ) history of smoking, alcohol or drug abuse; ( 6 ) difficulty to maintain oxygenation with one-lung ventilation intraoperatively; ( 7 ) duration of one-lung ventilation was smaller than 60 min; ( 8 ) unable to collect data due to the cerebral oximeter machine malfunction; ( 9 ) researchers believe that other situations do not meet the conditions of this study. For example, VATS was intraoperatively converted to an open thoracotomy procedure.…”

“…Figure 1 shows the flow diagram of participant recruitment. The inclusion criteria were as follows: (1) Mini-mental State Examination (MMSE) or who were unable to complete baseline cognitive assessment; (5) history of smoking, alcohol or drug abuse; (6) difficulty to maintain oxygenation with one-lung ventilation intraoperatively; (7) duration of one-lung ventilation was smaller than 60 min; (8) unable to collect data due to the cerebral oximeter machine malfunction; (9) researchers believe that other situations do not meet the conditions of this study. For example, VATS was intraoperatively converted to an open thoracotomy procedure.…”

“…It is thought that hypoxemia during OLV is related to ventilation/perfusion disturbance due to intrapulmonary shunts ( 5 , 6 ). Although hypoxic pulmonary vasoconstriction (HPV) allows redirection of blood flow into the ventilated lung, approximately 4–10% of patients still experience an oxygen saturation of <90% ( 1 , 7 , 8 ).…”