Postthoracotomy Pain Syndrome Following Surgery for Lung Cancer: Symptoms and Impact on Quality of Life

Postthoracotomy pain syndrome (PTPS) is a common complication following thoracic surgery. Most studies examining the influence of PTPS on patient-reported symptoms include few patients managed using a minimally invasive approach. Associated sensory changes, potentially neuropathic in origin, are not well described. We therefore examined the symptoms and quality of life (QOL) of patients with and without PTPS who underwent a standard thoracotomy (n = 43) or minimally invasive surgery (n = 54). Patients in this prospective, cross-sectional study completed questionnaires to assess pain (McGill Pain Questionnaire), neuropathic symptoms (Neuropathic Symptom Questionnaire), symptom distress (Symptom Distress Scale), anxiety and depression (Hospital Anxiety and Depression Scale), and QOL (Functional Assessment Cancer Therapy–Lung). Excepting younger age (p = .009), no demographic or surgical characteristic differentiated patients with and without PTPS. Patients with PTPS described discomfort as pain only (15.1%), neuropathic symptoms only (30.2%) or pain and neuropathic symptoms (54.7%). Scores differed between patients with and without PTPS for symptom distress (p < .001), anxiety and depression (p < .001), and QOL (p = .009), with higher distress associated with PTPS. Despite new surgical techniques, PTPS remains common and results in considerable distress. A focused assessment is needed to identify all experiencing this condition, with referral to pain management specialists if symptoms persist.

Patients in the radiology department may be at increased risk of developing critical instability

The purpose of this study was to calculate the event rate for in-patients in the Radiology Department (RD) developing instability leading to calls for Medical Emergency Team assistance (MET-RD) compared to general ward (MET-W) patients. A retrospective comparison was done of MET-RD and MET-W calls in 2009 in a U.S. tertiary hospital with a well-established MET system. MET-RD and MET-W event rates represented as MET calls/hour/1000 admissions, adjusted for length of stay (LOS); rates also calculated for RD modalities. There were 31,320 hospital ward admissions had 1,230 MET-W, and among 149,569 radiology admissions there were 56 MET-RD. When adjusted for LOS, the MET-RD event rate was 2 times higher than the MET-W rate (0.48 vs. 0.24 events/hour/1000 admissions). Event rates differed by procedure: computed tomography (CT) had 38% of MET-RDs (event rate 0.89); magnetic resonance imaging (MRI) accounted for 27% (event rate 1.56). Nuclear medicine had 1% of RD admissions but these patients accounted for 5% of MET-RD (event rate 1.53). Interventional radiology (IR) had 6% of RD admissions but 16% of MET-RD (event rate 0.61). While general x-ray comprised 63% of RD admissions, only 11% of MET-RD involved their care (event rate 0.09). In conclusion, the overall MET-RD event rate was twice the MET-W event rate; CT, MRI and IR rates were 3.7-6.5 times higher than on wards. RD patients are at increased risk for a MET call compared to ward patients when the time at risk is considered. Increased surveillance of RD patients is warranted.

Fatigue in family caregivers of adult intensive care unit survivors

CONTEXT

Family caregivers are a vital resource in the recovery of intensive care unit (ICU) survivors. Of concern, the stress associated with this role can negatively affect caregiver health. Fatigue, an important health indicator, has been identified as a predictor of various illnesses, greater use of health services, and early mortality. Examining the impact of fatigue on caregivers' physical health can assist in identifying critical time points and potential targets for intervention.

OBJECTIVES

To describe self-reported fatigue in caregivers of ICU survivors from patients' ICU admission to ≤ 2 weeks, two- and four-months post-ICU discharge.

METHODS

Patient-caregiver pairs were enrolled from a medical ICU. Caregiver fatigue was measured using the Short-Form 36 Health Survey Vitality subscale (SF-36 Vitality). Caregiver psychobehavioral stress responses included depressive symptoms, burden, health risk behaviors, and sleep quality. Patient data included self-reported physical symptoms and disposition (home vs. institution).

RESULTS

Forty-seven patient-caregiver pairs were initially enrolled. Clinically significant fatigue (SF-36 Vitality ≤ 45) was reported by 43%-53% of caregivers across the time points, and these caregivers reported worse scores in measures of depressive symptoms, burden, health risk behaviors and sleep quality, and patients' symptom burden. In 26 caregivers with data for all time points (55% of the total sample), SF-36 Vitality scores showed trends of improvement when the patient returned home and greater impairment when institutionalization continued.

CONCLUSION

In caregivers of ICU survivors, fatigue is common and potentially linked with poor psychobehavioral responses. Worsening fatigue was associated with greater symptom distress and long-term patient institutionalization.

Nurse and patient interaction behaviors' effects on nursing care quality for mechanically ventilated older adults in the ICU

The study purposes were to (a) describe interaction behaviors and factors that may effect communication and (b) explore associations between interaction behaviors and nursing care quality indicators among 38 mechanically ventilated patients (age ≥60 years) and their intensive care unit nurses (n = 24). Behaviors were measured by rating videorecorded observations from the Study of Patient-Nurse Effectiveness with Communication Strategies (SPEACS). Characteristics and quality indicators were obtained from the SPEACS dataset and medical chart abstraction. All positive behaviors occurred at least once. Significant (p < 0.05) associations were observed between (a) positive nurse and positive patient behaviors, (b) patient unaided augmentative and alternative communication (AAC) strategies and positive nurse behaviors, (c) individual patient unaided AAC strategies and individual nurse positive behaviors, (d) positive nurse behaviors and pain management, and (e) positive patient behaviors and sedation level. Findings provide evidence that nurse and patient behaviors effect communication and may be associated with nursing care quality.

Self-reported physical symptoms in intensive care unit (ICU) survivors: pilot exploration over four months post-ICU discharge

CONTEXT

Survivors of critical illness must overcome persistent physical and psychological challenges. Few studies have longitudinally examined self-reported physical symptoms in intensive care unit (ICU) survivors.

OBJECTIVES

To describe prevalence and severity of self-reported symptoms in 28 adult medical ICU survivors during the first four months post-ICU discharge and their associations with family caregiver responses.

METHODS

Patients completed the Modified Given Symptom Assessment Scale. Caregivers completed the Shortened 10-item Center for Epidemiologic Studies Depression Scale, Brief Zarit Burden Score, Pittsburgh Sleep Quality Index, and the Caregiver Health Behavior form. Data at ICU discharge (two weeks or less), and two and four months post-ICU discharge were analyzed.

RESULTS

Across the time points, most patients reported one or more symptoms (88.5-97%), with sleep disturbance, fatigue, weakness, and pain the most prevalent. For these four symptoms with the highest prevalence, there were: 1) moderate correlations among symptom severity at two and four months post-ICU discharge; and 2) no difference in prevalence or severity by patients' disposition (home vs. institution), except worse fatigue in patients at home at two weeks or less post-ICU discharge. Patients' overall symptom burden showed significant correlation with caregivers' depressive symptoms two weeks or less post-ICU discharge. There were trends of moderate correlations between patients' overall symptom burden and caregivers' health risk behaviors and sleep quality at two and four months post-ICU discharge.

CONCLUSION

In our sample, sleep disturbance, fatigue, weakness, and pain were the four key symptoms during first four months post-ICU discharge. Future studies focusing on these four symptoms are necessary to promote quality in post-ICU symptom management.

Adherence to hemodialysis dietary sodium recommendations: influence of patient characteristics, self-efficacy, and perceived barriers

OBJECTIVE

To identify characteristics of hemodialysis patients most likely to experience difficulty adhering to sodium restrictions associated with their dietary regimen.

DESIGN

Secondary analysis using baseline data from an ongoing randomized clinical trial examining the effects of a technology-supported behavioral intervention on dietary sodium intake in hemodialysis patients.

SETTING

Thirteen dialysis centers in southwestern Pennsylvania.

SUBJECTS

We included 122 participants (61% women; 48% African American) aged 61 ± 14 years undergoing maintenance, intermittent hemodialysis for end-stage renal disease.

MAIN OUTCOME MEASURES

Normalized dietary sodium intake, adjusted interdialytic weight gain, perceived problems, and self-efficacy for restricting dietary sodium.

RESULTS

Younger participants were more likely to report problems managing their hemodialysis diet and low self-efficacy for restricting sodium intake. Consistent with these findings, younger participants had a higher median sodium intake and higher average adjusted interdialytic weight gain. Females reported more problems managing their diet. Race, time on dialysis, and perceived income adequacy did not seem to influence outcome measures.

CONCLUSION

Our findings suggest that patients who are younger and female encounter more difficulty adhering to the hemodialysis regimen. Hence, there may be a need to individualize counseling and interventions for these individuals. Further investigation is needed to understand the independent effects of age and gender on adherence to hemodialysis dietary recommendations and perceived self-efficacy.

Teaching self-management skills in persons with chronic lower limb swelling and limited mobility: evidence for usability of telerehabilitation

The purpose of this study was to evaluate the usability of telerehabilitation as a method of teaching self-management for chronic swelling of the lower limbs in persons with limited mobility. An in-home telerehabilitation self-management education protocol for chronic swelling of the lower limbs, termed Telerehabilitation to Empower You to Manage and Prevent Swelling (TR-PUMPS), was implemented using the Versatile and Integrated System for Telerehabilitation (VISYTER) software platform. Participants (n=11) were 36–79 years old, predominately female (72.7%) and diagnosed with a variety of health conditions. Participants’ perceived usability scores of the remote delivery of TR-PUMPS was high with a median score of 6.67 (range 4.90 – 7.00) on a Likert scale: 1= disagree to 7= agree. There was no correlation between participants’ familiarity with information technology and their perception of telerehabilitation usability. These results support telerehabilitation as a viable method for teaching a home-based, self-management protocol for chronic swelling.

Exercise intensity self-regulation using the OMNI scale in children with cystic fibrosis

Prescribing exercise at intensities that improve fitness is difficult in children with cystic fibrosis (CF) due to ventilatory limitations and fluctuating health status. Our aim was to determine if children with CF could regulate the intensity of cycle ergometer and treadmill exercise using target ratings of perceived exertion (RPE) derived from the Children's OMNI Scale. We examined prescription congruence (similar oxygen consumption [VO₂] and heart rate [HR] for target RPE) and intensity discrimination (different VO₂ and HR for different RPEs), from cycle to cycle and cycle to treadmill. Subjects were 24 children (12 male, 12 female), aged 10-17 years with varying disease severity. Each child participated in one orientation, one estimation trial (graded maximal exercise test), and two production trials (cycle and treadmill, alternating between RPE 4 and 7). At RPE 4, congruence was evident for both VO₂ and HR on the treadmill. On the cycle at RPE 4, VO₂ was significantly higher only in the first production trial, although HRs tended to be higher in the production trials than the estimation trial. Prescription congruence was also supported at RPE 7, with no significant differences in VO₂ or HR between estimation and production trials on cycle or treadmill. Results fully supported intensity discrimination, with significant differences between VO₂ and HR at RPE 4 and 7 (P < 0.0001). Children with CF appear capable of using the OMNI Scale to regulate cycle and treadmill exercise intensity. Training using this methodology has the potential to promote fitness in children with CF of varying severity.

Effect of pressure support vs unassisted breathing through a tracheostomy collar on weaning duration in patients requiring prolonged mechanical ventilation: a randomized trial

IMPORTANCE

Patients requiring prolonged mechanical ventilation (>21 days) are commonly weaned at long-term acute care hospitals (LTACHs). The most effective method of weaning such patients has not been investigated.

OBJECTIVE

To compare weaning duration with pressure support vs unassisted breathing through a tracheostomy collar in patients transferred to an LTACH for weaning from prolonged ventilation.

DESIGN, SETTING, AND PARTICIPANTS

Between 2000 and 2010, a randomized study was conducted in tracheotomized patients transferred to a single LTACH for weaning from prolonged ventilation. Of 500 patients who underwent a 5-day screening procedure, 316 did not tolerate the procedure and were randomly assigned to receive weaning with pressure support (n = 155) or a tracheostomy collar (n = 161). Survival at 6- and 12-month time points was also determined.

MAIN OUTCOME MEASURE

Primary outcome was weaning duration. Secondary outcome was survival at 6 and 12 months after enrollment.

RESULTS

Of 316 patients, 4 were withdrawn and not included in analysis. Of 152 patients in the pressure-support group, 68 (44.7%) were weaned; 22 (14.5%) died. Of 160 patients in the tracheostomy collar group, 85 (53.1%) were weaned; 16 (10.0%) died. Median weaning time was shorter with tracheostomy collar use (15 days; interquartile range [IQR], 8-25) than with pressure support (19 days; IQR, 12-31), P = .004. The hazard ratio (HR) for successful weaning rate was higher with tracheostomy collar use than with pressure support (HR, 1.43; 95% CI, 1.03-1.98; P = .033) after adjusting for baseline clinical covariates. Use of the tracheostomy collar achieved faster weaning than did pressure support among patients who did not tolerate the screening procedure between 12 and 120 hours (HR, 3.33; 95% CI, 1.44-7.70; P = .005), whereas weaning time was equivalent with the 2 methods in patients who did not tolerate the screening procedure within 0 to 12 hours. Mortality was equivalent in the pressure-support and tracheostomy collar groups at 6 months (55.92% vs 51.25%; 4.67% difference, 95% CI, -6.4% to 15.7%) and at 12 months (66.45% vs 60.00%; 6.45% difference, 95% CI, -4.2% to 17.1%).

CONCLUSION AND RELEVANCE

Among patients requiring prolonged mechanical ventilation and treated at a single long-term care facility, unassisted breathing through a tracheostomy, compared with pressure support, resulted in shorter median weaning time, although weaning mode had no effect on survival at 6 and 12 months.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01541462.

Health risk behaviors in family caregivers during patients' stay in intensive care units: a pilot analysis

BACKGROUND

Studies of family caregivers of the critically ill have mainly focused on the psychological impact of the patients' stay in the intensive care unit and related stress. Despite known associations between stress and physical health, limited attention has been paid to the need to promote and maintain physical health in these caregivers.

OBJECTIVE

To explore how family caregivers' health risk behaviors are associated with patients' preexisting care needs and the caregivers' depressive symptoms and burden.

METHODS

During the intensive-care-unit stay of critically ill patients (who required mechanical ventilation for ≥4 days), 50 family caregivers were surveyed to determine the caregivers' depressive symptoms, burden, and health risk behaviors. Data were also collected on patients' care needs before admission to the intensive care unit.

RESULTS

One or more health risk behaviors were reported by 94% of family caregivers. More than 90% of caregivers reported depressive symptoms above the score indicating risk for clinical depression. A high level of burden was reported by 36% of caregivers. More health risk behaviors were associated with higher scores of depressive symptoms and burden (P < .001 for both). Caregivers' responses did not differ according to patients' preexisting care needs.

CONCLUSION

Health risk behaviors of family caregivers are associated with greater perceptions of burden and/or depressive symptoms but not with patients' care needs before admission to the intensive care unit.

Design and development of a telerehabilitation self-management program for persons with chronic lower limb swelling and mobility limitations: preliminary evidence

This paper describes design and development of a self-management program, delivered by telerehabilitation (TR), to address the problem of chronic lower limb swelling in persons with limited mobility. The 18.6 million persons with limited mobility in the USA are at increased risk for chronic lower limb swelling and related secondary complications, including cellulitis and skin ulcers. Over time, chronic swelling often progresses to lymphedema, an incurable condition requiring lifelong care. Without successful self-management, lymphedema and its related complications inevitably worsen. Access and adherence to appropriate treatment are challenging for persons with limited mobility. Program development involved a structured process to establish content validity (videos and manuals), readability, suitability, and selection of a TR platform to deliver the educational program. Our goal was to develop a program that would engage patients in self-management skills. The TR software platform chosen, Versatile and Integrated System for Telerehabilitation (VISYTER) was designed to facilitate face-to-face delivery of an interactive home-based self-management program via the internet in real time. Results demonstrated validity of the educational program and ease of use with TR. Future plans are to evaluate ability of this approach to promote self-management skills, home monitoring, and improved management of persons with lymphedema and limited mobility.

Medical emergency team calls in the radiology department: patient characteristics and outcomes

OBJECTIVE

We sought to identify the characteristics of patients who experience medical emergency team calls in the radiology department (MET-RD) and the relationship between these characteristics and patient outcomes.

DESIGN/PARTICIPANTS

Retrospective review of 111 inpatient MET-RD calls (May 2008-April 2010).

SETTING

Academic medical centre with a well established MET system.

MEASUREMENTS

The characteristics of patients before, during and after transport to radiology were extracted from medical records and administrative databases. These characteristics were compared between patients with good and poor outcomes.

MAIN RESULTS

The majority of patients who experience MET-RD calls had a Charlson Comorbidity Index ≥4 and were from non-intensive care units (60%). Almost half (43%) of MET-RD calls occurred during patients' first day in hospital. Patients commonly arrived with nasal cannula oxygen (38%), recent tachypnoea (28%) and tachycardia (34%). A minority (16%) fulfilled MET call criteria in the 12 h before the MET-RD. MET-RD etiologies were cardiac (41%), respiratory (29%) or neurological (25%), and occurred most frequently during CT (44%) and MRI (22%) testing. Post MET-RD, the majority of patients (70%) required a higher level of care. Death before discharge (25%) was associated with need for cardiovascular support prior to RD transport (p=0.02), need for RD monitoring (p=0.02) and need for heightened RD surveillance (p=0.04).

CONCLUSIONS

The majority of patients who experienced MET-RD calls came from non-intensive care units, with comorbidities and vital sign alterations prior to arrival at the RD. Risk appeared to be increased for those requiring CT and MRI. These findings suggest that prior identification of a subset of patients at risk of instability in the RD may be possible.

Anxiety and agitation in mechanically ventilated patients

During an ethnography conducted in an intensive care unit (ICU), we found that anxiety and agitation occurred frequently and were important considerations in the care of 30 patients weaning from prolonged mechanical ventilation. We conducted a secondary analysis to (a) describe characteristics of anxiety and agitation experienced by mechanically ventilated patients, (b) explore how clinicians recognized and interpreted anxiety and agitation, and (c) describe strategies and interventions used to manage anxiety and agitation with mechanically ventilated patients. We constructed the Anxiety/Agitation in Mechanical Ventilation Model to illustrate the multidimensional features of symptom recognition and management. Patients' ability to interact with the environment served as a basis for identification and management of anxiety or agitation. Clinicians' attributions about anxiety or agitation, and "knowing the patient," contributed to their assessment of patient responses. Clinicians chose strategies to overcome either the stimulus or the patient's appraisal of risk of the stimulus. This article contributes to the body of knowledge about symptom recognition and management in the ICU by providing a comprehensive model to guide future research and practice.

Role of endothelin-1 in human aneurysmal subarachnoid hemorrhage: associations with vasospasm and delayed cerebral ischemia

BACKGROUND

Endothelin-1 (ET-1) is a potent vasoconstrictor implicated in the pathogenesis of vasospasm and delayed cerebral ischemia (DCI) in aneurysmal subarachnoid hemorrhage (aSAH) patients. The aim of this study was to investigate the relationship between cerebrospinal fluid (CSF) ET-1 levels and angiographic vasospasm and DCI.

METHODS

Patients with aSAH were consented (n = 106). Cerebral vasospasm was determined by angiography. DCI was determined by transcranial Doppler (TCD) results and/or angiogram results with corresponding clinical deterioration. CSF ET-1 levels over 14 days after the initial insult was quantified by ELISA. ET-1 analysis included a group-based trajectory analysis and ET-1 exposure rate during 24, 48, and 72 h prior to, as well as 72 h post angiography, or clinical deterioration.

RESULTS

Trajectory analysis revealed two distinct groups of subjects with 56% of patients in the low ET-1 trajectory group (mean at day 1 = 0.31 pg/ml; SE = 0.04; mean at day 14 = 0.41 pg/ml; SE = 0.15) and 44% of patients in the high ET-1 trajectory group (mean at day 1 = 0.65 pg/ml; SE = 0.08; mean at day 14 = 0.61 pg/ml; SE = 0.06). Furthermore, we observed that ET-1 exposure rate 72 h before angiography and clinical spasm was a significant predictor of both angiographic vasospasm and DCI, whereas, ET-1 exposure after angiography and clinical spasm was not associated with either angiographic vasospasm or DCI.

CONCLUSION

Based on these results we conclude that ET-1 concentrations are elevated in a sub-group of patients and that the acute (72 h prior to angiography and clinical neurological deterioration), but not chronic, elevations in CSF ET-1 concentrations are indicative of the pathogenic alterations of vasospasm and DCI in aSAH patients.

Intrahospital Transport to the Radiology Department: Risk for Adverse Events, Nursing Surveillance, Utilization of a MET and Practice Implications

Nurses providing care in the Radiology Department (RD) are challenged by the broad scope of conditions and varied acuity of patients served by this unit. Nurses must facilitate the required diagnostic testing and simultaneously provide the surveillance necessary to detect physiologic changes signaling the need for rescue interventions. When instability occurs, one method of rescue involves activation of a Medical Emergency Team (MET) to bring an experienced cadre of critical care providers to the unstable patient. Despite recognition that the RD can be a high risk area, there is little in the literature specific to the surveillance of RD patients, risk for and prevention of adverse events, MET activation or the management of patient instability specific to the RD. The purpose of this paper is to examine what is known regarding risk for adverse events during intrahospital transport, utilization of a MET as a rescue intervention, and practice implications.

Caregivers of the chronically critically ill after discharge from the intensive care unit: six months' experience

BACKGROUND

Chronically critically ill patients typically undergo an extended recovery after discharge from the intensive care unit, making involvement of family caregivers essential. Prior studies provide limited detail about specific ways this experience affects caregivers.

OBJECTIVES

To (1) describe lifestyle restrictions and distress among caregivers of chronically critically ill patients 1 and 6 months after discharge and (2) explore how caregivers' lifestyle restrictions and distress differ according to patients' and caregivers' characteristics.

METHODS

Sixty-nine chronically critically ill patients and their family caregivers completed follow-up at 1 and 6 months after discharge from the intensive care unit. Data were collected from medical records and survey via telephone or mail.

RESULTS

Caregivers' perceived lifestyle restrictions (Changes in Role Function) decreased from 1 month (mean [SD], 23.0 [8.3]) to 6 months (19.4 [8.6]) after discharge (P = .003), although patients' problem behaviors and caregivers' distress (8.9 [9.3] vs 7.9 [9.6], respectively; P = .32) did not change. Change in caregivers' lifestyle restrictions differed by patients' disposition (P = .02) and functional status (Health Assessment Questionnaire; P = .007). Caregiver's lifestyle restrictions remained high when patients never returned home or never recovered their preadmission functional status. Caregivers reported the most restrictions in social life and personal recreation. Patients' negative emotions and pain caused the most caregiver distress.

CONCLUSIONS

Caregivers of chronically critically ill patients perceived fewer lifestyle restrictions over time but reported no change in patients' problem behaviors or distress. Lifestyle restrictions and distress remained high when patients never returned home or regained their preadmission functional status.

Critical thinking skills in nursing students: comparison of simulation-based performance with metrics

AIM

This paper is a report of an examination of the relationship between metrics of critical thinking skills and performance in simulated clinical scenarios.

BACKGROUND

Paper and pencil assessments are commonly used to assess critical thinking but may not reflect simulated performance.

METHODS

In 2007, a convenience sample of 36 nursing students participated in measurement of critical thinking skills and simulation-based performance using videotaped vignettes, high-fidelity human simulation, the California Critical Thinking Disposition Inventory and California Critical Thinking Skills Test. Simulation-based performance was rated as 'meeting' or 'not meeting' overall expectations. Test scores were categorized as strong, average, or weak.

RESULTS

Most (75.0%) students did not meet overall performance expectations using videotaped vignettes or high-fidelity human simulation; most difficulty related to problem recognition and reporting findings to the physician. There was no difference between overall performance based on method of assessment (P = 0.277). More students met subcategory expectations for initiating nursing interventions (P ≤ 0.001) using high-fidelity human simulation. The relationship between videotaped vignette performance and critical thinking disposition or skills scores was not statistically significant, except for problem recognition and overall critical thinking skills scores (Cramer's V = 0.444, P = 0.029). There was a statistically significant relationship between overall high-fidelity human simulation performance and overall critical thinking disposition scores (Cramer's V = 0.413, P = 0.047).

CONCLUSION

Students' performance reflected difficulty meeting expectations in simulated clinical scenarios. High-fidelity human simulation performance appeared to approximate scores on metrics of critical thinking best. Further research is needed to determine if simulation-based performance correlates with critical thinking skills in the clinical setting.

Effect of short periods of normobaric hyperoxia on local brain tissue oxygenation and cerebrospinal fluid oxidative stress markers in severe traumatic brain injury

Preliminary evidence suggests local brain tissue oxygenation (PbtO(2)) values of <or=15 mm Hg following severe traumatic brain injury (TBI) represent brain tissue hypoxia. Accordingly, many neurotrauma units attempt to maintain PbtO(2) >or=20 mm Hg to avoid hypoxia. This study tested the impact of a short (2 h) trial of normobaric hyperoxia on measures of oxidative stress. We hypothesized this treatment would positively affect cerebral oxygenation but negatively affect the cellular environment via oxidative stress mechanisms. Cerebrospinal fluid (CSF) was serially assessed in 11 adults (9 male, 2 female), aged 26 +/- 1.8 years with severe TBI (Glasgow Coma Scale score, 6 +/- 1.4) before, during, and after a FiO(2) = 1.0 challenge for markers of oxidative stress, including lipid peroxidation (F(2)-isoprostane [ELISA]), protein oxidation (protein sulfhydryl [fluorescence]), and antioxidant defenses (total antioxidant reserve (AOR) [chemiluminescence] and glutathione [fluorescence]). Physiological parameters [PbtO(2), arterial oxygen content (PaO(2)), intracranial pressure (ICP), mean arterial pressure (MAP), and cerebral perfusion pressure (CPP)] were assessed at the same time points. Mean (+/-SD) PbtO(2) and PaO(2) levels significantly changed for each time point. Oxidative stress markers, antioxidant reserve defenses, and ICP, MAP, and CPP did not significantly change for any time period. These preliminary findings suggest that brief periods of normobaric hyperoxia do not produce oxidative stress and/or change antioxidant reserves in CSF. Additional studies are required to examine extended periods of normobaric hyperoxia in a larger sample.

Post-traumatic stress disorder after weaning from prolonged mechanical ventilation

PURPOSE

Weaning from prolonged mechanical ventilation may be associated with mental discomfort. It is not known whether such discomfort is linked with the development of post-traumatic stress disorder (PTSD). Accordingly, we investigated whether PTSD occurs in patients after weaning from prolonged ventilation. We also determined whether administering a questionnaire would identify patients at risk for developing PTSD.

METHODS

A prospective longitudinal study of patients transferred to a long-term acute-care hospital for weaning from prolonged ventilation was undertaken: 72 patients were studied 1 week after weaning, and 41 patients were studied again 3 months later. An experienced psychologist conducted a structured clinical interview 3 months after weaning to establish a diagnosis of PTSD. To assess for the presence of PTSD-related symptoms, the post-traumatic stress syndrome (PTSS-10) questionnaire was administered 1 week after weaning and 3 months later.

RESULTS

The psychologist diagnosed PTSD in 12% of patients 3 months after ventilator weaning. Patients who developed PTSD were more likely to have a previous history of psychiatric disorders (P < 0.02). A PTSS-10 score >20 one week after weaning reliably identified patients who were diagnosed with PTSD 3 months later: sensitivity 1.0; specificity 0.76; area under the receiver-operating characteristic curve 0.91.

CONCLUSION

PTSD was diagnosed in 12% of patients who were weaned from prolonged ventilation. A PTSS-10 score >20 one week after weaning identified patients diagnosed with PTSD 3 months later. This finding suggests that a simple questionnaire administered before hospital discharge can identify patients at risk for developing PTSD.

THE CATALYTIC EFFECT OF DYES ON THE OXYGEN CONSUMPTION OF LIVING CELLS

From the experiments described in this paper and in those previously published it can be concluded that dyes which can be reversibly oxidized and reduced, act as catalysts for some oxidative processes taking place in the living cells, as is manifested by an increase in their oxygen consumption. It has been found that the catalytic power of the dyes on the oxygen consumption of starfish eggs (mature, unfertilized) is conditioned by two factors: the reduction potential of the dye and the permeability of the cell surface. Dyes whose E'_o is towards the positive side of the aerobic reduction potential of the starfish eggs have a maximum catalytic effect. This catalytic power decreases as the E'_o becomes more negative than the reduction potential of the cell and becomes nil beyond certain limits. When a dye cannot penetrate into the cell, its effect is greatly diminished as in this case only those oxidative processes taking place at the outer surface of the cell can be activated. Whether a dye can act as a catalyst or not is dependent on whether the normal consumption of oxygen by the cell is slower or quicker than the oxidation activated by the dye. The speed of this activation is correlated to (1) the speed at which the dye is reduced by the cell, and (2) the speed at which the leuco-dye is oxidized by the atmospheric oxygen. If one of these two processes is slower than the normal respiration, the dye cannot increase the rate of oxygen consumption (phenol indophenol at low concentrations which is kept reduced by the cell is very slowly reoxidized by atmospheric oxygen, on the other hand safranin and neutral red which are not reduced by the cell or at least too slowly reduced, though rapidly reoxidized by air). It will depend on these two reactions velocities whether a dye will act as catalyst (methylene blue and dyes with similar E'_o which are quickly reduced by the cell and the leuco-dyes of which are relatively quickly reoxidized). Though this relationship between the reduction potential of the dyes and its catalytic power would seem in contradiction with the well known thermodynamic assumption that there is in general no distinct relationship between the potential and velocity of the reaction, we have pointed out from the literature some of the various experiments where one does recognize this connection.

The association between bathing and weaning trial duration

OBJECTIVE

To describe patterns of bath care for patients who are weaning from prolonged mechanical ventilation (PMV) and to explore the association between bathing and weaning trial duration.

METHODS

Descriptive correlational study. Clinical records from 439 weaning trial days for 30 patients who required PMV were abstracted for bathing occurrences during weaning trials, within 1 hour before a trial, and nocturnally.

RESULTS

Most baths occurred during weaning trials (30.8%) or at night (35.3%), and less frequently (16%) within 1 hour before a trial. No significant effects were found on trial duration for nocturnal bathing or bathing within 1 hour before a trial. By using random coefficient modeling, weaning duration was shown to be longer when bathing occurred during a weaning trial (P < .05), even when controlling for age, severity of illness, and days on bedrest.

CONCLUSION

Bathing occurred during approximately one third of PMV weaning trials. Baths during PMV weaning trials were associated with longer weaning trial duration.

Multiple flow rates measurement of exhaled nitric oxide in patients with sarcoidosis: a pilot feasibility study

Fraction of end tidal exhaled nitric oxide (FeNO) has been introduced as a non-invasive marker of airway inflammation in patients with asthma and may have value in monitoring disease activity in patients with sarcoidosis. This pilot study explored: 1) feasibility of the multiple flow rates maneuver to estimate alveolar (C(AlV)NO) and airway wall (J(AW)NO) NO in patients with sarcoidosis; and 2) utility of exhaled NO (FeNO, C(Alv)NO and J(AW)NO) measurements to detect and monitor treatment response in patients with active pulmonary sarcoidosis. Patients with sarcoidosis (n = 42) and healthy non-smokers (n = 20) underwent FeNO measurement at 7 flow-rates (50 to 400 ml/s). Using the Tsoukias and George (1998) model, C(Alv)NO and J(AW)NO were estimated. Both patients and healthy non-smokers were able to perform the multiple flow rates maneuver without discomfort, with first measurement success rate of 57% and 65%, respectively. No significant difference was found between patients with sarcoidosis and healthy non-smokers in exhaled NO. None were correlated with pulmonary function tests, except a significant negative correlation between C(Alv)NO and FVC% (p = 0.001) and DLCO% (p = 0.012). In 8 patients with active sarcoidosis, FeNO, C(Alv)NO or J(AW)NO were not different from those of patients with inactive sarcoidosis. Treatment of active sarcoidosis using oral prednisone and methotrexate did not show any consistent pattern of changes in C(Alv)NO or J(AW)NO. Due to a large inter-subject variability and difficulty controlling use of the inhaled corticosteroids, exhaled NO measurement did not appear to be a clinically useful method of monitoring disease progression in sarcoidosis.