Management of Intra-Operative Pulmonary Atelectasis

Abstract

P ulmonary complications are relatively frequent after surgery, but some patient groups are considered more susceptible than others. Those groups include: obese patients, pediatric patients, while some types of surgeries render the patient more susceptible to lung atelectasis as in cardiothoracic and laparoscopic surgeries. Recruitment is a dynamic physiological process that refers to the reopening of previously gasless lung units. General anesthesia, even in the lung-healthy subject, causes an increase in intrapulmonary shunt, which may impair oxygenation. The magnitude of shunt is correlated with the formation of pulmonary atelectasis. Atelectasis appears within minutes after the induction of anesthesia in 85%–90% of all patients. The effects of atelectasis include: Decreased compliance, impaired oxygenation, increase in pulmonary vascular resistance, and lung injury.The impact of atelectasis can extend beyond the operating room if persisted post operatively in the form of postoperative hypoxemia, pneumonia. Several types of Recruitment maneuvers have been described, including The sustained inflation technique, Incrementally increased PEEP limiting the maximum inspiratory pressure, The prolonged recruitment maneuver (PRM), Maximal recruitment strategy (MRS), Intermittent sighs to reach a specific plateau pressure in volume or pressure control mode. Other maneuvers that can be employed that can assist in the alveolar recruitment as positioning and Variable Ventilation as recruitment maneuver. For monitoring of the success of the maneuver and its efficacy several tools have been described. They include: Pulse Oximetry, Bronchoalveolar lavage Fluid Sampling, Inductive plethysmography (IP), Ultrasonography, Computed Tomography (CT). Possible side effects of alveolar recruitment include hypotension, desaturation, barotrauma, and decrease in cardiac output, hypo-ventilation and acidosis.