Mucosal fluid evaporation is not the method of heat dissipation from fourth-degree laryngopharyngeal burns

Temperature processing and distribution in larynx thermal inhalation injury with analogy to human airway cells: a mechanism of protection

OBJECTIVE

Inhalation injuries, especially laryngeal injuries, threaten the lives of burn patients. Unlike studies on temperature distribution in the upper airway, studies on temperature development in different laryngeal layers, including the mucosa, lamina propria, cartilage, muscle, and subcutaneous layer, are lacking.

METHOD

For the in-vivo study, 16 healthy adult male beagles were divided into four groups: control, low-, medium-, and high-heat groups, inhaling dry air at 26, 80, 160, and 320°C for 20 min, with temperature probes punctured through skin into layers as mentioned, and heat energy was calculated. For the in-vitro study, we heated human lung fibroblasts and bronchial epithelial cells using a similar heating profile with heat energy of 15-90 J/g to investigate cell survival and viability for clinical comparison.

RESULTS

No statistical difference emerged between the temperatures of different laryngeal layers at each timepoint. The temperatures decreased significantly and shortly before increasing unevenly in the low- and medium-heat groups. The survival rates and viability of the two cell lines correlated negatively with heat energy. The heat energy absorbed in the low-, medium-, and high-heat groups of beagles were 12, 29, and 44 J/g, with calculated in-vitro human cell survival rates of 114%, 90%, and 69%, respectively, for the corresponding energy levels.

CONCLUSIONS

The abnormal temperature processing and lack of a difference between layers indicate an effective self-protective mechanism of heat conduction in larynx. The in-vitro results demonstrate a high survival rate of lung cells at comparable heat energy levels to those measured in the larynx.

Application of intraoperative hypothermic saline to relieve postoperative pain for pediatric coblation tonsillectomy

OBJECTIVES

To evaluate the effect of hypothermic saline application for pediatric coblation tonsillectomy on postoperative pain.

METHODS

Forty-eight children with adenotonsillar hyperplasia underwent tonsillectomy ± adenoidectomy. 24 children were in the HTS group (which used hypothermic saline as the coblation medium in operation), the other 24 children with the same age were in the control NTS group (who use normothermic saline as the coblation medium). All children and their parents were asked to complete a daily questionnaire for 7 days following their surgery.

RESULTS

Significant differences were observed when comparing the two outlet water temperatures of the coblation wand both at ablation power and at coagulation power (p = 0.000). Children in HTS group got lower scores than those in the NTS group (p < 0.05). No side effects were observed.

CONCLUSIONS

Using hypothermic normal saline as the media of coblation wand is potential for reduce postoperative pain in pediatric patients while also having no detrimental financial or medical effects on said patients.