Use of Positive Pressure Ventilation in Cold-Stunned Sea Turtles: 29 Cases (2008–2014)
Between 2008 and 2014, mechanical positive pressure ventilation (PPV) was used to manage 48 critically ill, cold-stunned sea turtles during their first week of treatment. Twenty-nine turtles had complete records for analysis and no ventilator complications, including 21 Kemp's ridley (Lepidochelys kempii; 72%), four loggerhead (Caretta caretta; 14%), and four green turtles (Chelonia mydas; 14%). Indications for PPV included poor responsiveness, bradypnea or apnea, bradycardia, and respiratory acidosis. Twenty turtles were successfully extubated, seven turtles died naturally during PPV, and two turtles were euthanized during PPV. Of the 20 turtles that were extubated, 11 survived over 24 hours after extubation and were considered successfully weaned from the ventilator, but only four turtles survived to eventual release. Throughout PPV, improvements in respiratory, cardiovascular, and clinicopathologic status were variable, likely related to the degree of illness at presentation. On average, however, ventilation resulted in expected physiologic improvements, including increasing venous pH and decreasing venous pCO2. Blood potassium concentration decreased (improved) and Mortality Prediction Index score decreased (i.e., mortality predicted to be less likely) between the beginning and end of ventilation. Among turtles that died, gross necropsy and histopathologic findings were consistent with previous observations in cold-stunned sea turtles, including fungal pneumonia and renal pathology. Results of this study indicate that mechanical PPV is effective in improving the respiratory status of some moribund cold-stunned sea turtles; however, further refinement of ventilation methods is recommended, and the prognosis remains poor to guarded for the most severely debilitated turtles.
This work was supported by an IAAAM Medway Scholarship to C. F. Spielvogel. We thank the volunteers and staff of New England Aquarium and Massachusetts Audubon Wellfleet Bay Sanctuary for recovery and care of the turtles. We thank Michelle Ceresia, Massachusetts College of Pharmacy, and Kevin O'Brien and Sean Shortall, Maquet Inc., for facilitating the loan of a Maquet ventilator; and we thank Stetson Hallowell, Hallowell EMC, for customization of a Hallowell ventilator.
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