Mitchel B. Sosis

Which is the safest endotracheal tube for use with the CO2 laser? A comparative study.

STUDY OBJECTIVEnTo compare the efficacy of special endotracheal tubes manufactured for carbon dioxide (CO2) laser surgery with foil-wrapped and plain red rubber (RR) endotracheal tubes.nnnSETTINGnResearch laboratory of a metropolitan, university-affiliated medical center.nnnDESIGN AND INTERVENTIONSnSix types of endotracheal tubes were studied. Each had 5 L/min of oxygen passing through it and was exposed to 69 watts of continuous CO2 laser radiation for 1 minute or until combustion occurred.nnnMEASUREMENTS AND MAIN RESULTSnThe plain RR endotracheal tube burned within 15 seconds of laser impact. Aluminum foil-wrapped and copper foil-wrapped RR endotracheal tubes were not affected by the CO2 laser. The shaft of a specially manufactured stainless steel endotracheal tube was not affected by 1 minute of CO2 laser exposure. The shafts of two special endotracheal tubes made of silicone and metal burned vigorously under laser fire.nnnCONCLUSIONnCopper foil-wrapped RR tubes, aluminum foil-wrapped RR tubes, or stainless steel tubes are recommended for laser airway surgery.

Evaluation of a new laser-resistant fabric and copper foil-wrapped endotracheal tube

The risk of an endotracheal tubes combustion during laser airway surgery necessitates the use of special anesthetic techniques and equipment to prevent this complication. This study was designed to evaluate the Laser‐Trach™, a new laser‐resistant rubber endotracheal tube for use during laser airway surgery.

The effect of blood on laser‐resistant endotracheal tube combustion

The protection afforded against CO2 laser‐induced combustion by five different types of tracheal tubes or protective foil wraps was evaluated. They were compared before and after the application of human blood to their external surfaces. The tracheal tubes tested were polyvinylchloride (PVC) tubes wrapped with VentureTM copper (Cu) foil tape, 3MTM aluminum (A1) foil tape, and the Laser‐GuardTM protective coating. The Xomed Laser Shield IFTM and Mallinckrodt Laser‐FlexTM tracheal tubes were also tested. A CO2 laser set to 38 W in the continuous mode was directed at the shaft of the tracheal tube under study, which had 5 L/min of oxygen flowing through it. The laser was actuated for 90 seconds or until combustion or melting occurred.

Spinal phobia: Survey results of patient attitudes and preferences regarding anesthesia

STUDY OBJECTIVEnTo determine unbiased patient preferences for either spinal or general anesthesia for upcoming surgeries.nnnDESIGNnPrior to contact with anesthesia personnel, a simple questionnaire was completed by surgical patients to determine their demographic characteristics and previous anesthetic experiences. Their concerns regarding a list of complications of general and spinal anesthesia and their preferences for general or spinal anesthesia if either method could be used were also determined.nnnSETTINGnUniversity-affiliated suburban community hospital.nnnMEASUREMENTS AND MAIN RESULTSnThe survey was completed by 254 patients. A preference for general over spinal anesthesia was expressed by 80.2% of the patients responding. They expressed significantly more concerns regarding nausea/vomiting, sore throat, feeling sleepy, and death with general anesthesia than with spinal anesthesia. Concerns of back pain, nerve damage and paralysis were statistically related to spinal anesthesia.nnnCONCLUSIONSnThis survey shows a strong patient preference for general anesthesia and a phobia for spinal anesthesia.

Does the design of the sprotte spinal needle reduce the force needed to deform the tip

STUDY OBJECTIVEnTo determine whether the window design of pencil-point spinal needles leads to deformation under lateral or axial loading conditions.nnnDESIGNnIndependent-measure, multigroup study of the force required to deform needles.nnnSETTINGnIndependent testing laboratory.nnnMEASUREMENTS AND MAIN RESULTSnThe force necessary to bend 22- and 24-gauge Sprotte, 22- and 25-gauge Whitacre, and 22- and 25-gauge Quincke needles was measured using an Instron gauge (Instron Corp., Canton, MA) after microscopic verification of needle uniformity. Effects of lateral and axial forces were evaluated in separate experiments. The force needed to bend the Sprotte needles was less than that needed for the Whitacre and Quincke needles of similar size when lateral or axial pressure was applied. Microscopic inspection of the needles showed a marked variability in the window area placement in a single lot of Sprotte needles. Examination of the needle tips demonstrated that the Sprotte needles were most likely to bend at the needle window, while the Quincke and Whitacre needles deformed at the point of clamping.nnnCONCLUSIONSnThe Sprotte needles have an inherent design weakness to lateral and axial pressure, which may result in a greater number of needle tip deformations upon needle insertion. The nature of this deformation may result in difficulty in needle withdrawal and possibly fracture of the needle tip.

Saline soaked pledgets prevent carbon dioxide laser-induced endotracheal tube cuff ignition

STUDY OBJECTIVEnTo determine whether saline soaked pledgets would protect the cuffs of polyvinylchloride (PVC) endotracheal tubes from carbon dioxide (CO2) laser-induced combustion.nnnDESIGNn12 PVC endotracheal tubes were studied. The cuffed end of each was placed in a graduated cylinder and flushed with 5 L/min of oxygen for 5 minutes. The endotracheal tubes cuff was then inflated with air and the system pressure set to 20 cm H2O.nnnSETTINGnResearch laboratory of a university hospital.nnnINTERVENTIONSnSix of the endotracheal tube cuffs were protected with 1 inch by 3 inch saline soaked pledgets and six were left unprotected. A CO2 laser set to 40 watts was then fired at the cuffs.nnnMEASUREMENTS AND MAIN RESULTSnAll six unprotected cuffs were ignited in less than 1 second. No significant combustion occurred at the six pledget protected endotracheal tube cuffs after 1 minute of laser fire.nnnCONCLUSIONSnUnder the conditions of this experiment, saline soaked pledgets protected PVC endotracheal tube cuffs from the CO2 laser.

Metal anesthesia circuit components stop the progression of laser fires

STUDY OBJECTIVEnTo determine whether metallic Y-pieces and elbows would halt the progression of a laser-induced endotracheal tube fire.nnnDESIGNnA segment of polyvinyl chloride endotracheal tube was attached to either an all-plastic anesthesia circle breathing system (n = 5) or a circuit consisting of a metal Y-piece and elbow with plastic hoses (n = 5). In each case, an Nd-YAG laser was used to ignite the endotracheal tube segment and attached anesthesia circuit as 5 L/min of oxygen was flowing through them.nnnSETTINGnResearch laboratory of a university-affiliated metropolitan medical center.nnnMEASUREMENTS AND MAIN RESULTSnThe flames from the endotracheal tubes burned through the 22 mm hoses that were part of the all-plastic circuits in 49.5 +/- 8.8 seconds (mean +/- SD). In none of the trials with the metal components did the fire advance beyond the endotracheal tubes 15 mm adapter.nnnCONCLUSIONSnMetal circuit components halt the progression of laser-induced endotracheal tube fires toward the anesthesia machine.

Evaluation of a technique of nitrogen insufflation to decrease plastic endotracheal tube cuff flammability during carbon dioxide laser surgery

STUDY OBJECTIVEnTo determine whether nitrogen insufflation reduces the laser-induced combustibility of polyvinyl chloride (PVC) endotracheal tube cuffs.nnnSETTINGnResearch laboratory of a metropolitan, university-affiliated medical center.nnnDESIGN AND INTERVENTIONSnA plastic catheter was fastened along the shafts of 10 PVC endotracheal tubes with self-adhesive copper foil tape down to a level just above the cuff. The modified endotracheal tubes were inserted into graduated cylinders and flushed with oxygen. The cuffs were then inflated with air, and a carbon dioxide (CO2) laser was aimed at them. Five of the modified endotracheal tubes had 10 L/min of nitrogen insufflated via the plastic tube.nnnMEASUREMENTS AND MAIN RESULTSnThe laser ignited only 1 of the cuffs insufflated with nitrogen; however, all 5 of the modified endotracheal tubes that were not insufflated burned (p < 0.05).nnnCONCLUSIONnNitrogen insufflation decreases CO2 laser-induced PVC endotracheal tube cuff combustibility. However, clinical applications of this technique should be undertaken with caution, as the administration of a hypoxic mixture may be possible.