ABSTRACT
Context: Bioelectrical impedance analysis (BIA) detects changes in tissue electrical properties and has been seen as a prognostic tool in several chronic conditions, including cancer. AIMS: The study was conducted to investigate whether there are any tissue electrical differences in patients with head and neck cancer (H and NC) before and after surgery treatment. Settings and Design: The observational study was performed at the Otolaryngology Department, Head and Neck Oncology. Materials and Methods : Tissue electrical properties were assessed in 31 patients with H and NC before and 2 weeks after surgery treatment. Direct bioimpedance measures [resistance, reactance, phase angle (PA)] were determined by BIA. Statistical Analysis Used: The Shapiro-Wilk test was used to assess the distribution conformity of examined parameters with a normal distribution; the Fisher (F) test was used to assess variance homogeneity. For group comparisons of metric data we used the Mann-Whitney U test. P value < 0.05 was considered as statistically significant. The statistical analysis for this study was performed using the computer software STATISTICA v. 8.0 (StatSoft). Results: PA at 50 kHz was found to be significantly (P = 0.000009) lower after surgery in patients with H and NC than before treatment (4.69° ±0.71 vs. 4.22 ± 0.83, respectively). Resistance was significantly (P = 0.0005) greater after surgery in patients with H and NC than before (596.24 ± 96.31 ohm vs 647.64 ± 276.11 ohm, respectively). Conclusions: There are tissue electrical differences before and after surgery in patients diagnosed with H and NC. Further observations would be useful to feedback in support therapy planning of individual patients.
Subject(s)
Adult , Aged , Electric Impedance/diagnosis , Humans , Head and Neck Neoplasms/physiology , Head and Neck Neoplasms/surgery , Male , Tissues/physiologyABSTRACT
Transthoracic electrical bioimpedance (TEB) has been proposed as a non-invasive, continuous, and cost-effective method of cardiac output (CO) measurement. In this prospective, non-randomized, clinical study, we measured CO with NICOMON (Larsen and Toubro Ltd., Mysore, India) and compared it with thermodilution (TD) method in patients after off-pump coronary artery bypass (OPCAB) graft surgery. We also evaluated the effect of ventilation (mechanical and spontaneous) on the measurement of CO by the two methods. Forty-six post-OPCAB patients were studied at five predefined time points during controlled ventilation and at five time points when breathing spontaneously. A total of 230 data pairs of CO were obtained. During controlled ventilation, TD CO values ranged from 2.29 to 6.74 L/min (mean 4.45 ± 0.85 L/min), while TEB CO values ranged from 1.70 to 6.90 L/min (mean 4.43 ± 0.94 L/min). The average correlation (r) was 0.548 (P = 0.0002), accompanied by a bias of 0.015 L/min and precision of 0.859 L/min. In spontaneously breathing patients, TD CO values ranged from 2.66 to 6.92 L/min (mean 4.66 ± 0.76 L/min), while TEB CO values ranged from 3.08 to 6.90 L/min (mean 4.72 ± 0.82 L/min). Their average correlation was relatively poor (r = 0.469, P= 0.002), accompanied by a bias of −0.059 L/min and precision of 0.818 L/min. The overall percent errors between TD CO and TEB CO were 19.3% (during controlled ventilation) and 17.4% (during spontaneous breathing), respectively. To conclude, a fair correlation was found between TD CO and TEB CO measurements among post-OPCAB patients during controlled ventilation. However, the correlation was weak in spontaneously breathing patients.