Abstract
Pulmonary atelectasis is common following general anesthesia in dogs, often due to reduced functional residual capacity, oxygen absorption, and surfactant dysfunction. This study evaluated an ultrasound-guided alveolar recruitment maneuver (ARM) using incremental positive end-expiratory pressure (PEEP) in anesthetized client-owned dogs with ultrasound-confirmed atelectasis. Dogs were assigned to two groups: mechanically ventilated (MV) or spontaneously breathing (SB). Following anesthesia, lung ultrasound atelectasis scores (LUAS) were recorded post-procedure and during recruitment, which began at PEEP 5 cm H₂O, incrementally increasing by 3 cm H₂O every two minutes until atelectasis resolved. Hemodynamic and ventilatory parameters were recorded.
Each group included 15 dogs. SB dogs were younger and had shorter anesthesia duration than MV dogs. Heart rate increased significantly at PEEP11 (SB) and PEEP14 (MV). Et’CO₂ rose in the SB group during early recruitment. Peak inspiratory pressure and compliance were significantly lower post-recruitment (p < 0.0001). Regional LUAS was significantly higher post-procedure than during recruitment, indicating effective atelectasis resolution. Total LUAS was higher in MV dogs than SB dogs. This study demonstrates that ultrasound-guided LUAS is a reliable, non-invasive tool for detecting and monitoring pulmonary atelectasis in dogs, and effectively guides individualized ARM protocols to improve perioperative respiratory care.
Data availability
Data is available on reasonable request to the corresponding author.
Abbreviations
- ARM:
-
Alveolar recruitment maneuvers
- PEEP:
-
Positive end-expiratory pressure
- LUAS:
-
Lung ultrasound atelectasis scores
- MV:
-
Mechanically ventilated
- SB:
-
Spontaneously breathing
- FiO2 :
-
Fraction of inspired oxygen
- CO:
-
Cardiac output
- PLUS:
-
Point-of-care pleural and lung ultrasound
- Et’CO2 :
-
End tidal CO2
- HR:
-
Heart rate
- SAP, MAP:
-
Systolic and mean blood pressure
- PRAM:
-
Arterial pulse pressure recording analytical method
- CI:
-
Cardiac index
- PIP:
-
Peak inspiratory pressure
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Chiara Di Franco, Søren Boysen, Benedetta Buonamici, Flavia Evangelista, Angela Briganti all made substantial contributions in the processes of study design, data acquisition, statistical analysis and results interpretation as well as in the drafting of the article and critical revision of the manuscript.
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This prospective clinical study was approved by the local Committee for animal welfare (n° 10/2023). All methods were carried out in accordance with relevant guidelines and regulations for studies involving animals and following ARRIVE guidelines. The study did not involve humans. Owner consent was obtained for inclusion of animals in this study.
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Di Franco, C., Boysen, S., Buonamici, B. et al. Evaluation of an ultrasound-guided alveolar recruitment technique with incremental PEEP in dogs: a clinical study. Sci Rep (2026). https://doi.org/10.1038/s41598-026-35202-4
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DOI: https://doi.org/10.1038/s41598-026-35202-4
