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Reversible endotracheal tube obstruction caused by meconium acting as a check valve.

Hwang W, Hwang J, Jeon J - Korean J Anesthesiol (2014)

View Article: PubMed Central - PubMed

Affiliation: Department of Anesthesiology and Pain Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.

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We herein describe a case of a reversible ETT obstruction caused by meconium acting as a check valve, which was mistaken initially to be leakage from the anesthetic machine... He was born by cesarean delivery at gestational age 34 weeks due to an omphalocele... The ruptured sac of the omphalocele (approximately 5 cm in diameter) was found at birth, and the emergency operation was planned... The ventilator leakage alarm sounded during venous cut-down... The tidal volume decreased from 20 to 5-7 ml, and ETCO2 decreased to < 10 mmHg... Inspection of the removed ETT revealed thick meconium approximately 2 cm long plugging the distal lumen of the ETT... Additionally, an approximately 0.3 cm-long inspissated meconium was dangling from the superior portion of the inner wall of the ETT (Fig. 1)... ETT obstruction due to bronchial secretions is usually suspected by abnormally high peak inspiratory pressures, a significant difference between the measured inhaled and exhaled tidal volumes, decreased lung compliance, increased resistance to inflation, and an obstructive pattern on capnography... After the termination of inspiration, the dangling meconium might have obstructed the lumen of the ETT and acted as a one-way check valve, preventing minimal gas egress... As a result, the expiratory tidal volume might have decreased, and a flow sensor in the expiratory limb must have detected this change as a leak in the anesthetic machine... We used a heated breathing circuit with a humidifier in this case... However, the humidified inspiratory gas did not entirely prevent accumulation of meconium in the ETT, despite the fact that it may have induced slow accumulation... Moreover, the suction catheter may not have been inserted to a sufficient depth to reach the meconium, or the suction catheter that fit the small lumen of the ETT was too thin to remove the thick meconium.

No MeSH data available.


Related in: MedlinePlus

Side view of the removed endotracheal tube showing obstruction of the distal lumen by meconium. The arrow indicates the dangling meconium, which acted as a check valve.
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Figure 1: Side view of the removed endotracheal tube showing obstruction of the distal lumen by meconium. The arrow indicates the dangling meconium, which acted as a check valve.

Mentions: Upon completion of the abdominal closure, the surgeon decided to place an internal jugular venous catheter for postoperative care. The ventilator leakage alarm sounded during venous cut-down. The tidal volume decreased from 20 to 5-7 ml, and ETCO2 decreased to < 10 mmHg. The capnography curve exhibited a blunt concave slope during the expiratory phase. The ETT was confirmed to be positioned correctly, and there was little gas leakage around the ETT. A full examination of the anesthetic machine and breathing circuit, including capnography, revealed no abnormalities, but the SpO2 had decreased to 88%. Upon switching to manual ventilation during examination, we encountered resistance during the inspiratory phase. Chest auscultation revealed inspiratory rales and faint expiratory wheezing in both lung fields. The ETT suction was repeated, but no secretion was seen. The ETT was removed, and we reintubated with another 3.0 mm uncuffed ETT under direct laryngoscopy. The tidal volume was 20-25 ml at an inspiratory pressure of 15 cmH2O, and capnography showed a normal plot. The ETCO2 measured immediately after reintubation was 58 mmHg and decreased to 33-35 mmHg after hyperventilation for 3 minutes. Inspection of the removed ETT revealed thick meconium approximately 2 cm long plugging the distal lumen of the ETT. Additionally, an approximately 0.3 cm-long inspissated meconium was dangling from the superior portion of the inner wall of the ETT (Fig. 1).


Reversible endotracheal tube obstruction caused by meconium acting as a check valve.

Hwang W, Hwang J, Jeon J - Korean J Anesthesiol (2014)

Side view of the removed endotracheal tube showing obstruction of the distal lumen by meconium. The arrow indicates the dangling meconium, which acted as a check valve.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4295967&req=5

Figure 1: Side view of the removed endotracheal tube showing obstruction of the distal lumen by meconium. The arrow indicates the dangling meconium, which acted as a check valve.
Mentions: Upon completion of the abdominal closure, the surgeon decided to place an internal jugular venous catheter for postoperative care. The ventilator leakage alarm sounded during venous cut-down. The tidal volume decreased from 20 to 5-7 ml, and ETCO2 decreased to < 10 mmHg. The capnography curve exhibited a blunt concave slope during the expiratory phase. The ETT was confirmed to be positioned correctly, and there was little gas leakage around the ETT. A full examination of the anesthetic machine and breathing circuit, including capnography, revealed no abnormalities, but the SpO2 had decreased to 88%. Upon switching to manual ventilation during examination, we encountered resistance during the inspiratory phase. Chest auscultation revealed inspiratory rales and faint expiratory wheezing in both lung fields. The ETT suction was repeated, but no secretion was seen. The ETT was removed, and we reintubated with another 3.0 mm uncuffed ETT under direct laryngoscopy. The tidal volume was 20-25 ml at an inspiratory pressure of 15 cmH2O, and capnography showed a normal plot. The ETCO2 measured immediately after reintubation was 58 mmHg and decreased to 33-35 mmHg after hyperventilation for 3 minutes. Inspection of the removed ETT revealed thick meconium approximately 2 cm long plugging the distal lumen of the ETT. Additionally, an approximately 0.3 cm-long inspissated meconium was dangling from the superior portion of the inner wall of the ETT (Fig. 1).

View Article: PubMed Central - PubMed

Affiliation: Department of Anesthesiology and Pain Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.

AUTOMATICALLY GENERATED EXCERPT
Please rate it.

We herein describe a case of a reversible ETT obstruction caused by meconium acting as a check valve, which was mistaken initially to be leakage from the anesthetic machine... He was born by cesarean delivery at gestational age 34 weeks due to an omphalocele... The ruptured sac of the omphalocele (approximately 5 cm in diameter) was found at birth, and the emergency operation was planned... The ventilator leakage alarm sounded during venous cut-down... The tidal volume decreased from 20 to 5-7 ml, and ETCO2 decreased to < 10 mmHg... Inspection of the removed ETT revealed thick meconium approximately 2 cm long plugging the distal lumen of the ETT... Additionally, an approximately 0.3 cm-long inspissated meconium was dangling from the superior portion of the inner wall of the ETT (Fig. 1)... ETT obstruction due to bronchial secretions is usually suspected by abnormally high peak inspiratory pressures, a significant difference between the measured inhaled and exhaled tidal volumes, decreased lung compliance, increased resistance to inflation, and an obstructive pattern on capnography... After the termination of inspiration, the dangling meconium might have obstructed the lumen of the ETT and acted as a one-way check valve, preventing minimal gas egress... As a result, the expiratory tidal volume might have decreased, and a flow sensor in the expiratory limb must have detected this change as a leak in the anesthetic machine... We used a heated breathing circuit with a humidifier in this case... However, the humidified inspiratory gas did not entirely prevent accumulation of meconium in the ETT, despite the fact that it may have induced slow accumulation... Moreover, the suction catheter may not have been inserted to a sufficient depth to reach the meconium, or the suction catheter that fit the small lumen of the ETT was too thin to remove the thick meconium.

No MeSH data available.


Related in: MedlinePlus