Determination of changes in the intrathoracic blood volume in man

Short-term effects of mobilization on oxygenation in patients after open surgery for pancreatic cancer: a randomized controlled trial

Background

Despite the unequivocal role of progressive mobilization in post-surgical patient management, its specific effects and timing, particularly after abdominal surgery, remain debated. This study’s aim was to examine the short-term effects of mobilization on oxygenation in hemodynamically stable patients after open surgery for pancreatic cancer.

Methods

A randomized controlled clinical trial was conducted in which patients (n = 83) after open pancreatic surgery were randomized to either the same-day mobilization group (mobilized when hemodynamically stable within four hours after surgery) or the next-day mobilization group (mobilized first time in the morning of the first post-operative day). Mobilization was prescribed and modified based on hemodynamic and subjective responses with the goal of achieving maximal benefit with minimal risk. Blood gas samples were taken three times the evening after surgery; and before and after mobilization on the first post-operative day. Spirometry was conducted pre-operatively and on the first post-operative day. Adverse events and length of stay in postoperative intensive care were also recorded.

Results

With three dropouts, 80 patients participated (40 per group). All patients in the same-day mobilization group, minimally sat over the edge of the bed on the day of surgery and all patients (both groups) minimally sat over the edge of the bed the day after surgery. Compared with patients in the next-day mobilization group, patients in the same-day mobilization group required lower FiO₂ and had higher SaO₂/FiO₂ at 1800 h on the day of surgery (p < .05). On the day after surgery, FiO_2, SaO₂/FiO_2, PaO₂/FiO₂, and alveolar-arterial oxygen gradient, before and after mobilization, were superior in the same-day mobilization group (p < 0.05). No differences were observed between groups in PCO₂, pH, spirometry or length stay in postoperative intensive care.

Conclusions

Compared with patients after open pancreatic surgery in the next-day mobilization group, those in the same-day mobilization group, once hemodynamically stable, improved oxygenation to a greater extent after mobilization. Our findings support prescribed progressive mobilization in patients after pancreatic surgery (when hemodynamically stable and titrated to their individual responses and safety considerations), on the same day of surgery to augment oxygenation, potentially helping to reduce complications and hasten functional recovery.

Trial registration: This prospective RCT was carried out at the Sahlgrenska University Hospital, Sweden. The study was approved by the Regional Ethical Review Board in Gothenburg (Registration number: 437-17). Trial registration: “FoU in Sweden” (Research and Development in Sweden, URL: https://www.researchweb.org/is/vgr) id: 238701 Registered 13 December 2017 and Clinical Trials (URL:clinicaltrials.gov) NCT03466593. Registered 15 March 2018.

Effect of Different Positions on FVC and FEV1 Measurements of Asthmatic Patients

[Purpose] The purpose of our study was to investigate the effect of different positions on pulmonary function test (PFT) values such as forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) of asthmatic patients .[Subjects and Methods] Thirty subjects with severe asthma aged between 20-39 years were enrolled after they had signed a written consent. Subjects were selected using the inclusion criteria, and PFT were randomly administered. Spirometer measurements (FVC, FEV1) were taken in the supine, side lying on right, side lying on left, sitting and standing positions. Each measurement was taken three times, and the average values were analyzed. [Results] One- way analysis of variance (ANOVA) and Tukey's Test (post hoc) for pair- wise comparison indicated that there was a significant difference in the FEV1 values of the asthmatic patients however a significant difference was obtained between standing and supine positions. There was also a significant difference in the FVC values between the standing and supine lying position in the pair -wise comparison. [Conclusion] This study showed standing is the best position for measuring FEV1 and FVC of asthmatic subjects. The more upright the position, the higher the FEV1 and FVC will be.

Mobility criteria for upright sitting with patients in the neuro/trauma intensive care unit: an analysis of length of stay and functional outcomes

BACKGROUND AND PURPOSE

Few studies have explored optimal advancement and variation in mobility and length of stay (LOS) data with critically ill patients in the intensive care unit (ICU). The purpose of this study was to analyze the outcomes and LOS of critically ill patients in the neurotrauma ICU involved in rehabilitation.

METHODS

A bidirectional case-control study of a total of 30 patients admitted to a level 1 trauma hospital in the metropolitan Chicago area with Glasgow Coma Score (GCS) of ≤12 (3-12) were studied. Functional outcomes of a structured mobility group were compared at first upright sitting and at ICU discharge using the functional independence measure (FIM). Retrospective LOS review of a group (n = 15) with unstructured activity advancement was compared.

RESULTS

The main outcome measures were FIM scores and LOS in number of days. In the structured mobility group, a significant increase in functional performance between first upright sitting and ICU discharge was found (P < .005). Length of stay was shorter in the structured mobility groups but the difference was not statistically significant.

CONCLUSIONS

Results from this study revealed favorable functional outcomes for patients involved in a structured mobility program with physical therapy in the neuro/trauma ICU.

Time courses of pulmonary gas exchange and heart rate changes in supine exercise

The time courses of ventilation (VE), O2 uptake (VO2), CO2 elimination (VCO2), respiratory exchange ratio (R), end-tidal PO2 and PCO2 and heart rate (HR) were studied in seven subjects performing light dynamic leg exercise in the supine position. Individual and group mean time courses in response to step changes in work load were computed and displayed graphically. A computer-based method was also used to fit mono- or bi-exponential mathematical functions to the recorded responses. The over-all rate of HR change in response to the transition from 0-load pedalling to exercise (on-response) was faster (mean response time, MRT = 31 s) than the corresponding VO2 response (MRT = 45 s) while VE responded considerably slower (MRT = 86 s). During the reverse transition (off-response), VO2 and VE changed with the same rate as in the on-response, while the HR-change was slower than during the on-response (MRT = 50 s). During the initial 15-sec period, VO2 changed only slightly, which contrasts to previous results in the sitting position, where 50% of the final change in VO2 has been reported to occur within the first 15-sec period, and where changes in blood distribution and stroke volume are known to be more pronounced than in the supine position. Our results emphasize the importance of central circulatory changes for the time course of VO2 at the start and end of exercise.