The primary objective of this study was to characterize the autonomic responses to common therapeutic procedures in DOC patients, specifically changes in heart rate variability (HRV), skin conductance response (SCR), and heart rate (HR). Additionally, the LF/HF ratio of HRV was analyzed separately as an indicator of sympathetic activity, providing insight into the balance between sympathetic and parasympathetic responses. The aim was to determine the extent to which these interventions elicit stress-related physiological alterations and contribute to raising awareness about the impact of physiotherapy procedures on these patients, whose condition often leads to their responses being neglected.
A descriptive study was conducted involving 15 adult patients with DOC who were monitored at a long-term care facility. Physiological variables were recorded during a 5-minute baseline period, followed by distinct phases of the respiratory physiotherapy procedure: (1) suction pump activation without suction, (2) thoracic maneuvers by the physiotherapist, (3) tracheal suctioning, and (4) a 5-minute post-procedure recovery period. Data were collected using continuous monitoring of HR and SCR, and a repeated measures analysis was performed to describe the changes in these variables across the different phases, identifying percentage changes relative to baseline values.
The results showed that all physiological variables changed significantly during respiratory physiotherapy, indicating marked autonomic responses. Skin conductance response (SCR) increased by 700-800% during thoracic maneuvers and tracheal suctioning compared to baseline (F(4,14) = 15, p =1.8e-08), suggesting a strong sympathetic activation due to the interventions. LF/HF ratio, showed a significant increase of 400-1200% during the same phases (F(4,14) = 9.2, p =8.5e-06), emphasizing the imbalance between the autonomic branches. A smaller yet significant variation of 5-10% displayed the HR (F(4,14) = 2.8, p=0.03)) and HRV (F(4,14) = 3.4, p= 0.01) suggesting that are less sensitive than SCR and LF/HF in detecting stress responses in this population. These findings indicate that routine clinical procedures, even when performed with the utmost care, elicit substantial autonomic stress responses in DOC patients.
The study concludes that DOC patients experience significant autonomic stress during respiratory physiotherapy procedures, as evidenced by marked increases in SCR and HRV. These autonomic changes occur even in the absence of overt behavioral responses, highlighting the importance of autonomic monitoring in this population.
The results emphasize the need to incorporate autonomic monitoring into routine clinical care for DOC patients. Clinicians should be aware of the stress induced by therapeutic procedures and modify interventions to reduce negative autonomic responses. Future research should identify specific procedural adaptations that mitigate stress while maintaining efficacy.
Stress
Autonomic response
