A new neurosurgical adjustable pressure suction apparatus with a mechanically controlled air inlet: the study of precise regulation and atraumatic suction.

Background: An essential surgical tool in neurosurgery is the suction tube. The skillful and accurate use of a suction tube facilitates the neurosurgical operation. Objective: This study is to verify the practicality of an adjustable pressure suction tube (APS tube) and to explore the ideal APS tube diameter and tip negative pressure for different intracranial structures. Methods: APS tubes were used to aspirate brain tissues and carotid arteries of rats. Laser speckle contrast imaging (LSCI) was used to record the blood flow velocity (BFV). We measured APS tube diameter, air inlet size, tip negative pressure and central negative pressure and calculated the correlation between them. In our department, intraoperative real-time parameters including APS tube diameter, length, air inlet size, and central negative pressure were recorded, and the tube tip negative pressure suitable for different intracranial structures and parts was calculated. Results: All experiments were carried out using APS tubes. Experiments on rats objectively reflected a severe structural damage to the brain and blood vessels by the suction tube, which might even result in an irreversible reduction in blood flow., Rat carotid arteries and brain tissue suffered severe damage when the tip negative pressure exceeded 33.4 ± 1.8 and 29.2 ± 2.0 kPa, respectively. BFV failed to return to the preoperative level 3 min after the operation (p < 0.05), and this decrease was more pronounced when the suction tube diameter was large (p < 0.05). The tip negative pressure was positively and negatively correlated with central negative pressure and the air inlet size, and was independent of APS tube diameter. A total of 50 operations including 39 tumor resection operations and 11 moyamoya disease bypass operations were recorded. Large-diameter APS tubes (3.5 mm) with an closed air inlet were frequently used to maintain a greater tip negative pressure before the incision of dura mater. When important structures such as motor cortex and brainstem were involved, 1.5- or 2.0-mm-diameter APS tubes were mostly used, and an air inlet was opened up to 0.7-2.1 mm to maintain a safe tip negative pressure (7.4-27.9 kPa). Conclusion: APS tubes with a mechanical knob provide stable and precise adjustment of the tip negative pressure, avoiding excessive negative pressure that causes serious damage to the intracranial structure. And, this allows the surgeon to hold the suction tube more freely and operate at any angle with an appropriate fulcrum near the incision to achieve efficient atraumatic suction and enhance surgical safety.

Development and validation of the family management scale for children with asthma (FMSCA).

Objective: This study aims to develop and validate the Family Management Scale for Children with Asthma (FMSCA) in China context. Methods: Based on the Family Management Style Framework (FMSF) model, an original 89 items were generated from literature review and interviews with 15 caregivers of children with asthma. The preliminary scale was refined to 82 items through two rounds of experts' evaluation and a pilot study, then administered to 329 caregivers of children with asthma for testing between April and July 2013. Item analysis and exploratory factor analysis were performed to screen the items, reliability and validity analysis were tested using psychometric techniques (internal consistency, split-half reliability, test-retest reliability, content validity, and construct validity). Confirmatory factor analysis was adopted to further evaluate the construct validity of the scale in an additional 600 children with asthma and their parents from August 2014 to December 2015. Results: A final 57-item FMSCA from 8 subscales (children identity, view of condition, management mindset, parental mutuality, parenting philosophy, management approach, family focus, and future expectation) were generated. The excellent internal consistency (Cronbach's α = 0.918), very good split-half reliability (r = 0.802, p < 0.01) and test-retest reliability (r = 0.857, p < 0.01) indicate a satisfactory reliability of the FMSCA. The Item Content Validity Index (I-CVI) of the scale ranged 0.8 3 ～1.00, Scale Content Validity Index (S-CVI) was 0.807, indicating a good content validity. Construct validity was established by accepted correlation coefficient of item-to-subscale (r range = 0.513-0.865, P < 0.01), intersubscale (r range = 0.195-0.604, p < 0.01), and subscale-to-total (r range = 0.408-0.876, p < 0.01), respectively. Additionally, the factors accounted for 51.586%∼74.063% of the variance in each subscale, confirmatory factor analysis indicated the confirmatory model fitted data well and the scale had adequate construct validity. Conclusions: The study demonstrates FMSCA can serve as a valid and reliable measure of family management level for Chinese children with asthma.