Incidence, predictors, and prognosis of thrombocytopenia among patients undergoing intra-aortic balloon pumping in the intensive care unit: a propensity score analysis.

OBJECTIVE: To explore the incidence, predictors, and prognosis of intra-aortic balloon pumping (IABP)-related thrombocytopenia in critically ill patients. METHODS: This multi-center study used the eICU Collaborative Research Database V1.2, comprising data on > 130,000 patients from multiple intensive care units (ICUs) in America between 2014 and 2015. A total of 710 patients undergoing IABP were included. Thrombocytopenia was defined as a drop in platelet count > 50% from baseline. From the cohort, 167 patients who developed thrombocytopenia were matched 1:1 with 167 patients who did not, after propensity score (PS) matching. The associations between IABP-related thrombocytopenia and clinical outcomes were examined by multivariable logistic regression. RESULTS: Among 710 patients undergoing IABP, 249 patients (35.07%) developed thrombocytopenia. The APACHE IVa score was a predictor of thrombocytopenia [adjusted odds ratio (OR) = 1.09, 95% confidence interval (CI): 1.02-1.15]. After 1:1 PS matching, in-hospital mortality (adjusted OR = 0.76, 95% CI: 0.37-1.56) and in-ICU mortality (adjusted OR = 0.74, 95% CI: 0.34-1.63) were similar between the thrombocytopenia and non-thrombocytopenia groups. However, major bleeding occurred more frequently in the thrombocytopenia group (adjusted OR = 2.54, 95% CI: 1.54-4.17). In-hospital length of stay (LOS) and in-ICU LOS were significantly longer in patients who developed thrombocytopenia than in those who did not (9.71vs. 7.36, P < 0.001; 5.13 vs. 2.83, P < 0.001). CONCLUSIONS: Among patients undergoing IABP in the ICUs, thrombocytopenia was not associated with a difference in in-hospital mortality or in-ICU mortality; however, thrombocytopenia was significantly associated with a greater risk of major bleeding and increased in-ICU and in-hospital LOS.

Development of adaptive pneumatic tourniquet systems based on minimal inflation pressure for upper limb surgeries.

BACKGROUND: Pneumatic tourniquets are medical devices that occlude blood flow to distal part of extremities and are commonly used in upper limb surgeries to provide a dry, clean and bloodless field. To decrease pressure-related injuries and potential risk of complications subjected to the high inflation pressure of pneumatic tourniquet, minimal inflation pressures are recommended. METHODS: A new occlusion pressure mathematical model for the upper limb was established based on the correlation analysis between several possible influencing parameters and the minimal pneumatic tourniquet pressure at which the peripheral pulse disappeared was recorded using a digital plethysmograph. A prototype of an adaptive pneumatic tourniquet which automatically varies the pressure in the tourniquet cuff according to the above prediction model was developed for the upper limb which used the lowest possible inflation pressure to achieve occlusion. The prototype comprises a blood pressure monitoring module, an inflatable tourniquet cuff, and a pressure relief mechanism to maintain an optimal cuff inflation pressure. Simulation experiments were conducted to verify the function and stability of the designed adaptive pneumatic tourniquet and clinical experiments using volunteers were undertaken to evaluate the performance of the prototype design in achieving adequate haemostasis in the upper limb. RESULTS: Results demonstrated that the mean arterial occlusion pressure was 152.3 ± 16.7 mmHg, obviously below the 250 to 300 mmHg previously recommended (J Bone Joint Surg Br 68:625-628, 1986 and Arthroscopy 11:307-311, 1995). CONCLUSIONS: In conclusion, this adaptive method and apparatus which can provide minimal inflation pressure may be a clinically practical alternative for upper limb surgery performed with pneumatic tourniquets.

[Interactive guided breathing technology].

OBJECT: Scientific guided breathing technology is to be studied based on the cardiopulmonary interaction. METHODS: Heart rate variability was used as the target function to study the smoothly respiratory relaxation procedure in order to acquire the common pattern of regular and slow breathing. RESULTS: Music based on the acquired common pattern was created and a musical pattern temporally-related to the breathing movement monitored by a sensor could be chosen to guide the breathing interactively.

[Design of a digital respiratory inductive plethysmography system].

A new type of respiratory inductive plethysmography (RIP) has keen designed based on digital demodulation technique with equal relative error. Compared with former amplitude demodulation, digital modulation RIP can obtain more accurate measurements of respiration and reduce the signal interference and distortion. But the system's power consumption is still a problem which needs to be solved in the future design.