In vitro evaluation of negative pressure generated during application of negative suction volumes by use of various syringes with and without thoracostomy tubes

Abstract

OBJECTIVE To determine the amount of negative pressure generated by syringes of various sizes with and without an attached thoracostomy tube and whether composition of thoracostomy tubes altered the negative pressure generated. SAMPLE Syringes ranging from 1 to 60 mL and 4 thoracostomy tubes of various compositions (1 red rubber catheter, 1 polyvinyl tube, and 2 silicone tubes). PROCEDURES A syringe or syringe with attached thoracostomy tube was connected to a pneumatic transducer. Each syringe was used to aspirate a volume of air 10 times. Negative pressure generated was measured and compared among the various syringe sizes and various thoracostomy tubes. RESULTS The negative pressure generated decreased as size of the syringe increased for a fixed volume across syringes. Addition of a thoracostomy tube further decreased the amount of negative pressure. The red rubber catheter resulted in the least amount of negative pressure, followed by the polyvinyl tube and then the silicone tubes. There was no significant difference in negative pressure between the 2 silicone tubes. The smallest amount of negative pressure generated was −74 to −83 mm Hg. CONCLUSIONS AND CLINICAL RELEVANCE Limited data are available on the negative pressure generated during intermittent evacuation of the thoracic cavity. For the present study, use of a syringe of ≥ 20 mL and application of 1 mL of negative suction volume resulted in in vitro pressures much more negative than the currently recommended pressure of −14.71 mm Hg for continuous suction. Additional in vitro or cadaveric studies are needed.

Microliposuction and radiofrequency combined with the thread technique as a new method used in lower face lifting

“…The face is an anatomically complex area that requires gentle liposuction to reduce damage to the SMAS, blood vessels and nerves. Hence, we used a bullet head, four‐hole liposuction cannula with a diameter of 1.6 mm and smooth side holes of 1 × 2 mm connected to a 5‐ml or 10‐ml syringe for liposuction, and the negative pressure of withdrawal aspiration was set at 1–2 ml, which is approximately 100–200 mmHg 9 . This microliposuction method can reduce the possible accumulation of negative pressure and damage to the vasculature or branches of the facial nerve.…”