Comparison of weight-based and pinna size method for ProSeal laryngeal mask airway size selection in children receiving general anesthesia: A randomized clinical study

Background and Aims

Several methods are in use for LMA ProSeal™ size selection in pediatric patients. Weight-based method is most commonly used. Pinna size-based method is a promising new technique for accurate size selection.

Material and Methods

A total of 146 children aged between 6 months and 12 years undergoing surgery under general surgery were included. They were randomized into either pinna-based group (group X) or weight-based group (group Y). Both groups were compared for accurate placement of ProSeal™ laryngeal mask airway (PLMA), ease of insertion, number of attempts needed, and peak airway pressures.

Results

A Comparable number of patients had a Brimacombe score of 3 and above, indicating correct placement in both groups (P = 0.407). PLMA was easily inserted in 79.5% and 87.7% of patients of groups X and Y, respectively (P = 0.180). Insertion was found to be difficult in 20.5% of patients in group X, whereas it was difficult in only 12.3% of patients of group Y (P = 0.180). The two groups were comparable as per the number of attempts needed for insertion (P = 0.161). Mean peak airway pressures too were comparable between both groups. Ease of insertion too, was statistically insignificant between both groups.

Conclusions

Pinna size-based estimation of LMA size is an effective alternative method to weight-based selection.

Neural crest cells give rise to non-myogenic mesenchymal tissue in the adult murid ear pinna

Despite being a major target of reconstructive surgery, development of the external ear pinna remains poorly studied. As a craniofacial organ highly accessible to manipulation and highly conserved among mammals, the ear pinna represents a valuable model for the study of appendage development and wound healing in the craniofacial complex. Here we provide a cellular characterization of late gestational and postnatal ear pinna development in Mus musculus and Acomys cahirinus and demonstrate that ear pinna development is largely conserved between these species. Using Wnt1-cre;ROSAmT/mG mice we find that connective tissue fibroblasts, elastic cartilage, dermal papilla cells, dermal sheath cells, vasculature, and adipocytes in the adult pinna are derived from cranial crest. In contrast, we find that skeletal muscle and hair follicles are not derived from neural crest cells. Cellular analysis using the naturally occurring short ear mouse mutant shows that elastic cartilage does not develop properly in distal pinna due to impaired chondroprogenitor proliferation. Interestingly, while chondroprogenitors develop in a mostly continuous sheet, the boundaries of cartilage loss in the short ear mutant strongly correlate with locations of vasculature-conveying foramen. Concomitant with loss of elastic cartilage we report increased numbers of adipocytes, but this seems to be a state acquired in adulthood rather than a developmental abnormality. In addition, chondrogenesis remains impaired in the adult mid-distal ear pinna of these mutants. Together these data establish a developmental basis for the study of the ear pinna with intriguing insights into the development of elastic cartilage.

Management of pinna haematoma study (MaPHaeS): A multicentre retrospective observational study

OBJECTIVES

To assess current variation in the management of pinna haematoma (PH) and its effect on outcomes.

DESIGN

Multicentre retrospective observational record-based study.

SETTING

Eleven hospitals around the UK.

PARTICIPANTS

Eighty-three patients above the age of 16 with PH.

OUTCOME MEASURES

The primary outcome measure was recurrence rate of PH over a 6-month period post-treatment, assessed by treatment type (scalpel incision vs needle aspiration). Secondary outcome measures assessed the impact of other factors on recurrence, infection and cosmetic complications of PH over a period of 6 months.

RESULTS

After adjusting for confounding factors, involvement of the whole ear, and management within an operating theatre were associated with a lower rate of recurrence of pinna haematoma. The drainage technique, suspected aetiology, choice of post-drainage management, grade and specialty of practitioner performing drainage, the use of antibiotic cover and hospital admission did not affect the rate of haematoma recurrence, infection or cosmetic complications.

CONCLUSIONS

Where possible PH should be drained in an operating theatre. Multicentre randomized controlled trials are required to further investigate the impact of drainage technique and post-drainage management on outcome.