Biological research for nursing
-
Randomized Controlled Trial Clinical Trial
Tissue and wound healing effects of short duration postoperative oxygen therapy.
The purpose of this study was to determine the effects of 28% oxygen given in the first 36 hours after surgery on tissue oxygen, collagen deposition, and clinical healing outcomes. Twenty-four subjects having cervical spine surgical procedures participated in a randomized, repeated-measures pilot study of tissue and healing effects of postoperative supplemental oxygen. The treatment group (n = 13) received 28% oxygen for the first 36 postoperative hours, whereas the control group (n = 11) was maintained on room air. ⋯ Significant differences were not found in hydroxyproline levels or clinical wound outcome measures. Low level, short duration, supplemental oxygen increased and sustained wound tissue oxygen and was well tolerated by subjects. Larger studies of populations at risk for wound complications are needed to investigate variables of dose and duration of oxygen therapy in relation to clinical and cellular wound healing outcomes.
-
The purpose of this study was to examine the relationship between Czosnyka and others' Pressure Reactivity Index (PRx) and neurologic outcome in patients with acute brain injury, including traumatic brain injury (TBI) and cerebrovascular pathology. PRx measures the correlation between arterial blood pressure and intracranial pressure waves and may reflect cerebral autoregulation in response to blood pressure changes. A negative PRx reflects intact cerebrovascular response, whereas a positive PRx reflects impaired response. ⋯ For those with cerebrovascular pathology, the effect was not significant (P = 0.10) and was in the opposite direction. For individuals with TBI, PRx may provide useful information related to cerebral autoregulation that is predictive of outcome. The meaning of PRx in individuals with cerebrovascular pathology is unclear, and further study is needed to examine the paradoxical findings observed.
-
Variations in intrathoracic pressure generated by different ventilator weaning modes may significantly affect intrathoracic hemodynamics and cardiovascular stability. Although several investigators have attributed cardiovascular alterations during ventilator weaning to augmented sympathetic tone, there is limited investigation of changes in autonomic tone during ventilator weaning. Heart rate variability (HRV), the analysis of beat-to-beat changes in heart rate, is a noninvasive indicator of autonomic tone that might be useful in the identification of patients who are at risk for weaning difficulty due to underlying cardiac dysfunction. ⋯ The increase in intrathoracic pressure reduced right ventricular end-diastolic volume (preload). This hemodynamic alteration generated a change in autonomic tone, so that cardiac output could be maintained. Individuals with autonomic and/or cardiovascular dysfunction may not be capable of this type of response and may fail to successfully wean from mechanical ventilation.