Standard cricothyrotomy technique uses a tracheal hook cephalad to the opening to stabilize the trachea during endotracheal (ET) tube passage. A newly described Rapid Four-Step Technique (RFST) uses the tracheal hook caudal to the opening to stabilize the trachea during ET tube passage. This experimental crossover trial compared standard cephalad tracheal hook traction to caudad traction as recommended by RFST in a cadaver model of cricothyrotomy. Outcome measures included the incidence of complications and the size of ET tube able to be passed with each technique. The anterior necks of 30 formalin-fixed cadavers were dissected to completely reveal the cricothyroid membranes and surrounding structures. Two emergency medicine residents performed all cricothyrotomies. Each cadaver was randomly assigned to undergo either standard open technique followed by RFST, or RFST followed by standard open technique. Standard open technique was performed using a #11 scalpel blade, a Trousseau dilator for widening the opening, and a tracheal hook held cephalad through the thyroid cartilage. RFST was performed using a #11 scalpel blade and a tracheal hook held caudad through the cricoid cartilage. Cuffed ET tubes without stylettes were passed in progressively larger sizes until significant resistance was met as determined independently by two physicians. The size of the largest ET tube passed for each technique was recorded. After each attempt the trachea was inspected for evidence of structural damage and the balloon cuff was checked to assess for cuff rupture. There were no complications with standard technique; five cadavers (16.7%) had complications with RFST including one (3.3 %) with balloon cuff rupture and four (13.3 %) with cricoid cartilage fractures. Tracheal damage prevented standard technique performance on three of the cadavers. There was no significant difference between maximal ET tube sizes for standard technique (median size 7.0, mean 6.95 mm internal diameter) versus RFST (median size 7.0, mean 6.82 mm internal diameter). We conclude that RFST may be associated with a higher incidence of complications than standard technique as demonstrated by our cadaver model of cricothyrotomy. We were unable to demonstrate a difference between the two techniques with regards to size of ET tube able to be passed.

Aged↗

PubMedDate not supplied

Use of the Trousseau dilator in cricothyrotomy.

When performing cricothyrotomy, once the initial incision has been created, the scalpel handle may be inserted into the incision and rotated, or a Trousseau dilator may be used to widen the opening. During endotracheal (ET) tube passage, the Trousseau dilator may be left in place or a tracheal hook may be inserted for tracheal stabilization. This experimental crossover trial of cricothyrotomy in a cadaver model compared: 1) scalpel handle rotation to the use of a Trousseau dilator in widening the initial incision, and 2) the use of a tracheal hook to a Trousseau dilator during ET tube passage. Part 1: Cricothyrotomy incisions were made in 30 formalin-fixed cadavers using a #11 scalpel blade. The opening was initially widened using a Trousseau dilator or a scalpel handle rotated through 360 degrees. Progressively larger ET tubes were passed using a tracheal hook for stabilization at the thyroid cartilage, and the size of the largest ET tube passed without significant resistance was recorded. Each opening was then widened using the other technique and ET tubes again passed as above. The dimensions of the opening after initial dilatation and after final ET tube passage were also recorded. Part 2: A tracheal hook inserted cephalad at the thyroid cartilage or a Trousseau dilator was used to stabilize the trachea during passage of progressively larger ET tubes, and the size of the largest ET tube passed without significant resistance was recorded. The insertion techniques were then reversed and ET tubes again passed as above. The trachea was inspected for damage and the balloon cuff checked for rupture after each attempt. Descriptive statistics were applied using a paired t-test and a chi-square analysis. We found no significant difference between the two techniques with regard to initial opening dimensions, final opening dimensions, or maximal ET tube size. There was no damage to local tissue and no balloon cuff ruptures. We found that the average size of the largest ET tube passed was significantly greater with the use of a tracheal hook (internal diameter mean 7.0 mm, median 7.0 mm) than with a Trousseau dilator (internal diameter mean 5.7 mm, median 5.5 mm). There was no damage to local tissue and no cuff ruptures. We conclude that the scalpel handle rotation technique is equal to the use of the Trousseau dilator with regard to opening size and maximal ET tube size but that use of a tracheal hook rather than a Trousseau dilator allows for passage of a larger ET tube in a cadaver model of cricothyrotomy.

Airway Obstruction↗

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Inactive cathepsin B-like enzyme in human melanoma culture medium.

An inactive cathepsin B-like enzyme with a molecular mass of 40 kD was found in a human melanoma culture medium. The inactive form of this enzyme was converted into an active form with a molecular mass of 28 kD by pepsin treatment. This activated cathepsin B-like enzyme had almost the same characteristics regarding molecular size, substrate specificity, dependence on chemical reagents, and Km values as intracellular cathepsin B. Sodium dodecylsulphate polyacrylamide gel electrophoresis followed by electroblotting with an antiserum against cathepsin B yielded inactive cathepsin B-like enzyme fractions which showed two immunoreactive bands with molecular masses of 40 and 28 kD, respectively. On the other hand, alkali treatment of the inactive cathepsin B-like enzyme fractions released a cysteine proteinase inhibitor with a molecular mass of 12 kD. These data suggest that these inactive cathepsin B-like enzymes in melanoma culture medium are present not only in the precursor form, but that they are also present as enzyme-inhibitor complexes, both of which can be activated enzymatically in vitro.

Cathepsin B↗

PubMedDate not supplied

Celiac sprue and ulcerative colitis in three South Asian women.

The association of celiac disease and inflammatory bowel disease has not been described in females of South Asian descent. We report three women, aged 33, 43 and 46 years, of South Asian origin, with both ulcerative colitis and celiac disease.

Adult↗