Quantifying postoperative recovery using wearable activity monitors following abdominal wall surgery: The AbTech trial.

PURPOSE: This work aimed to investigate the validity of wearable activity monitors (WAMs) as an objective tool to measure the return toward normal functional mobility following abdominal wall surgery. This was achieved by quantifying and comparing pre- and postoperative physical activity (PA). METHODS: A multicenter, prospective, observational cohort study was designed. Patients undergoing abdominal wall surgery were assessed for eligibility and consent for study participation was obtained. Participants were asked to wear a WAM (AX3, Axivity) on the wrist of their dominant hand at least 48 hours pre-operatively, for up to 2 weeks postop, and again after 6 months postop for 48 hours. RESULTS: A cohort of 20 patients were recruited in this validation study with a mean age of 47.3 ± 13.0 years. Postoperation, the percentage median PA (±IQR) dropped to 32.6% (20.1), whereas on day 14, PA had reached 64.6% (22.7) of the preoperative value providing construct validity. Activity levels at >6 months postop increased by 16.4% on an average when compared to baseline preoperative PA (p = 0.046). CONCLUSION: This study demonstrates that WAMs are valid markers of postoperative recovery following abdominal wall surgery. This was achieved by quantifying the reduction in PA postoperation, which has not been previously shown. In addition, this study suggests that abdominal wall surgery may improve the patient's quality of life via increased functional mobility at 6 months postop. In the future, this technology could be used to identify the patient and surgical factors that are predictors of outcome following abdominal wall surgery.

Pulse oximetry for the diagnosis of vascular injury following limb trauma.

Prompt diagnosis and intervention are essential for acute limb ischaemia after trauma. Guidelines for diagnosis are changing with new evidence. Pulse oximetry may be a useful adjunct. We aim to assess the value of pulse oximetry and other common tests for diagnosing vascular injury. Electronic medical records of patients with limb injuries were identified. Patient demographics, the mechanism of injury, comorbidities, the results of diagnostic tests or examinations, and the end outcome were extracted. Receiver Operator Characteristics (ROC) curves were used to calculate cut-offs with optimum sensitivity and specificity for pulse oximetry. Performance characteristics to predict vascular injury for all documented tests were calculated and compared. SpO2 values were significantly different in the group with and without vascular disruption (p = 0.034). Using a cut-off of 96% calculated from ROC curve analysis, SpO2 had a sensitivity of 78% and a specificity of 90%. For the other techniques, abnormal pulse oximetry waveform, absent distal pulses, and capillary refill over 2 s were significantly different between the two groups. Abnormal pulse oximetry waveform had the highest specificity (100%) while SpO2 was the most sensitive (78%). We suggest that pulse oximetry is a useful adjunct for patients with limb trauma, an abnormal waveform or SpO2 value below 96% suggests vascular disruption is present. Capillary refill over 2 s and absent distal pulses can also be used; if either are positive, this suggests vascular disruption. No test or examination was shown to be able to exclude vascular injury.

Enhanced recovery after surgery: Current research insights and future direction.

Since the concept of enhanced recovery after surgery (ERAS) was introduced in the late 1990s the idea of implementing specific interventions throughout the peri-operative period to improve patient recovery has been proven to be beneficial. Minimally invasive surgery is an integral component to ERAS and has dramatically improved post-operative outcomes. ERAS can be applicable to all surgical specialties with the core generic principles used together with added specialty specific interventions to allow for a comprehensive protocol, leading to improved clinical outcomes. Diffusion of ERAS into mainstream practice has been hindered due to minimal evidence to support individual facets and lack of method for monitoring and encouraging compliance. No single outcome measure fully captures recovery after surgery, rather multiple measures are necessary at each stage. More recently the pre-operative period has been the target of a number of strategies to improve clinical outcomes, described as prehabilitation. Innovation of technology in the surgical setting is also providing opportunities to overcome the challenges within ERAS, e.g., the use of wearable activity monitors to record information and provide feedback and motivation to patients peri-operatively. Both modernising ERAS and providing evidence for key strategies across specialties will ultimately lead to better, more reliable patient outcomes.

Predicting free-living energy expenditure using a miniaturized ear-worn sensor: an evaluation against doubly labeled water.

Accurate estimation of daily total energy expenditure (EE)is a prerequisite for assisted weight management and assessing certain health conditions. The use of wearable sensors for predicting free-living EE is challenged by consistent sensor placement, user compliance, and estimation methods used. This paper examines whether a single ear-worn accelerometer can be used for EE estimation under free-living conditions.An EE prediction model as first derived and validated in a controlled setting using healthy subjects involving different physical activities. Ten different activities were assessed showing a tenfold cross validation error of 0.24. Furthermore, the EE prediction model shows a mean absolute deviation(MAD) below 1.2 metabolic equivalent of tasks. The same model was applied to a free-living setting with a different population for further validation. The results were compared against those derived from doubly labeled water. In free-living settings, the predicted daily EE has a correlation of 0.74, p 0.008, and a MAD of 272 kcal day. These results demonstrate that laboratory-derived prediction models can be used to predict EE under free-living conditions [corrected].

Gait parameter estimation from a miniaturized ear-worn sensor using singular spectrum analysis and longest common subsequence.

This paper presents a new approach to gait analysis and parameter estimation from a single miniaturized ear-worn sensor embedded with a triaxial accelerometer. Singular spectrum analysis combined with the longest common subsequence algorithm has been used as a basis for gait parameter estimation. It incorporates information from all axes of the accelerometer to estimate parameters including swing, stance, and stride times. Rather than only using local features of the raw signals, the periodicity of the signals is also taken into account. The hypotheses tested by this study include: 1) how accurate is the ear-worn sensor in terms of gait parameter extraction compared to the use of an instrumented treadmill; 2) does the ear-worn sensor provide a feasible option for assessment and quantification of gait pattern changes. Key gait events for normal subjects such as heel contact and toe off are validated with a high-speed camera, as well as a force-plate instrumented treadmill. Ten healthy adults walked for 20 min on a treadmill with an increasing incline of 2% every 2 min. The upper and lower limits of the absolute errors using 95% confidence intervals for swing, stance, and stride times were obtained as 35.5 ±3.99 ms, 36.9 ±3.84 ms, and 17.9 ±2.29 ms, respectively.

An unusual metastasis of a transglottic squamous cell carcinoma to the forearm.

Introduction. Each year around 2,200 people in the UK are diagnosed with laryngeal SCC (Office of National Statistics 2009). Compared to pharyngeal carcinoma, it is a highly curable disease with a survival rate of around 60% for all stages and all forms of treatment. Case Presentation. We present the case of a 60-year-old man with a previously treated T4 N2c transglottic squamous cell carcinoma (SCC), who developed an isolated swelling in the extensor compartment of his right forearm at 6 months after radical laryngectomy with bilateral neck dissection. Fine needle aspiration of the forearm lesion revealed SCC consistent with a metastasis from the laryngeal primary. MRI revealed that the lesion was confined to the muscle. Initial staging CT showed no distant metastases or signs of advanced disease, including no evidence of axillary nodal involvement. Conclusion. This case is therefore unusual, as one of only 2 cases reported in the scientific literature of isolated distant muscular metastasis from a laryngeal squamous cell carcinoma. We conclude that any muscular swelling, in the setting of previous head and neck malignancy, should be treated with a high degree of suspicion for metastasis and investigated promptly.