Assessment Of Vital Signs Research Articles

Non-contact Dual Pulse Doppler System Based Real-time Relative Demodulation and Respiratory & Heart Rates Estimations for Chronic Heart Failure Patients

Long-term continuous patient monitoring is required in many health systems for monitoring and analytical diagnosing purposes. Most of monitoring systems have shortcomings related to their functionality and/or patient comfortably. Non-contact monitoring systems have been developed to address some of these shortcomings. One of such systems is non-contact physiological vital signs assessments for chronic heart failure (CHF) patients. This paper presents novel real-time demodulation technique and estimations algorithms for the non-contact physiological vital signs assessments for CHF patients based on a patented novel non-contact bio-motion sensor. A database consists of twenty CHF patients with New York Heart Association (NYHA) Heart Failure Classification Class II & III, whose underwent full Polysomnography (PSG) analysis for the diagnosis of sleep apnea, disordered sleep, or both, were selected for the study. The propose algorithms analyze the non-contact bio-motion signals and estimate the patient's respiratory and heart rates. The outputs of the algorithms are compared with gold-standard PSG recordings. Across all twenty CHF patients’ recordings, the respiratory rate estimation median accuracy achieved 91.52% with median error of ±1.31 breaths per minute. The heart rate estimation median accuracy achieved 91.29% with median error of ±6.16 beats per minute. A potential application would be home continuous sleep and circadian rhythm monitoring.

Perinatal health care in a conflict-affected setting: evaluation of health-care services and newborn outcomes at a regional medical centre in Iraq

A field-based assessment was conducted to assess maternal and newborn health-care services, perinatal and newborn outcomes and associated risk factors at Bint Al-Huda Maternal and Newborn Teaching Hospital, a large referral hospital in southern Iraq. The multi-method approach used interviews, discussions, observation and review of perinatal and newborn outcome data. There is limited assessment of maternal vital signs, labour pattern, fetal response, and complications during pregnancy and labour. Perinatal and neonatal mortality rates are 27.4/1000 births and 30.9/1000 live births respectively. Associated neonatal mortality factors were gestational age < 37 weeks, male sex, birth weight < 2.5 kg, maternal age > 35 years, rural maternal residence and vaginal delivery. Improving birth outcomes in southern Iraq requires evidence-based clinical guidelines, additional supplies and equipment, quality improvement initiatives and in-service training.

Septic patients arriving with emergency medical services

Sepsis is a serious condition with high mortality. Early treatment improves outcome and can be initiated by emergency medical services (EMS) personnel.The primary aim of our study was to investigate how many sepsis patients are transported by EMS to the internist at the emergency department (ED). The secondary aims were to compare these EMS patients with patients who arrived at the ED otherwise and to investigate how these patients were managed. We further investigated how often the diagnosis sepsis/infection was documented by EMS. We retrospectively retrieved all ED and EMS data of patients with sepsis who were assessed by the internist between March 2011 and March 2012. Half (48.0%) of 654 sepsis patients were transported by EMS. These patients were more seriously ill (more severe grades of sepsis, more admittances to the hospital/ICU) than patients who were transported otherwise. Mortality within 28 days was 19.4% compared with 6.5% in the other patients. Nevertheless, half of the EMS transports were considered not urgent, even in 34.6% of the patients with septic shock. Assessment of vital signs was not routinely performed and treatment was started in only 43.6%. The diagnosis sepsis/infection was documented in 63.4% of patients. Half of the patients with sepsis arrive at the ED by EMS. These patients are seriously ill, and although these patients are likely to benefit from early treatment, they are often transported with nonurgent rides and both assessment of vital signs and early start of treatment are not routinely performed.

Intensive Care Unit without walls: Seeking patient safety by improving the efficiency of the system

The term “ICU without walls” refers to innovative management in Intensive Care, based on two key elements: (1) collaboration of all medical and nursing staff involved in patient care during hospitalization and (2) technological support for severity early detection protocols by identifying patients at risk of deterioration throughout the hospital, based on the assessment of vital signs and/or laboratory test values, with the clear aim of improving critical patient safety in the hospitalization process.At present, it can be affirmed that there is important work to be done in the detection of severity and early intervention in patients at risk of organ dysfunction. Such work must be adapted to the circumstances of each center and should include training in the detection of severity, multidisciplinary work in the complete patient clinical process, and the use of technological systems allowing intervention on the basis of monitored laboratory and physiological parameters, with effective and efficient use of the information generated. Not only must information be generated, but also efficient management of such information must also be achieved.It is necessary to improve our activity through innovation in management procedures that facilitate the work of the intensivist, in collaboration with other specialists, throughout the hospital environment. Innovation is furthermore required in the efficient management of the information generated in hospitals, through intelligent and directed usage of the new available technology.

A Physical Assessment Skills Module on Vital Signs

To implement and evaluate a physical assessment module for pharmacy students. A physical assessment module focusing on vital signs was incorporated into the curriculum for third-year pharmacy students. This module consisted of an online component, a practical skills workshop, and a clinical practice site. The mean score on the in-class quiz, which evaluated students' knowledge of physical assessment after completion of the online module, was 94%. During the practical skills laboratory, 48% of student-measured systolic blood pressure (BP) readings and 60% of student-measured diastolic BP readings were within 5 mmHg of the machine reading. In the assessment of blood pressure technique, areas of difficulty included detection of Korotkoff sounds; steady deflation of cuff; and hand-eye coordination. Students more frequently underestimated systolic BP than the diastolic BP when compared to the automated machine readings. Findings from this study will be used to improve existing modules and evaluation methods on the physical assessment of vital signs.

Relationship Between Nighttime Vital Sign Assessments and Acute Care Transfers in the Rehabilitation Inpatient

To investigate the role of nighttime vital sign assessment in predicting acute care transfers (ACT) from inpatient rehabilitation. Retrospective chart review. Fifty patients unexpectedly discharged to acute care underwent chart review to determine details of each ACT. Seven of 50 ACT possessed new vital sign abnormalities at the 11 pm vital sign assessment the night before ACT. None of these seven underwent ACT during the night shift the abnormalities were detected. Two of 50 ACT were transferred between 11 pm and 6:59 am; both demonstrating normal vital sign at the 11 pm assessment. During study period, an estimated 5,607 11 pm vital sign assessments were performed. Nighttime vital sign assessments do not seem to be a good screening tool for clinical instability in the rehabilitation hospital. Eliminating sleep disturbance is important to the rehabilitation inpatient as inadequate sleep hinders physical performance. Tailoring vital sign monitoring to fit patents' clinical presentation may benefit this population.

Symptoms and signs in interpreting Gamma-hydroxybutyrate (GHB) intoxication - an explorative study

BackgroundAcute poisoning with gamma-hydroxybutyrate (GHB) has been a serious medical and social problem in different parts of the world including Sweden. GHB is a drug of abuse which acts primarily as central nervous system (CNS) depressants. GHB has serious toxicity, although many young users do not recognise GHB as a dangerous drug. The aim of this pilot study was to explore how symptoms with risk of failure in vital functions would be valued among professionals that encounter GHB intoxication in the emergency phase.MethodsA web-based survey focusing on the assessment of vital clinical signs for possible GHB intoxication using a numeric scale was carried out during April and May 2011. The participants, n 105, are all professionals who encounter GHB intoxicated in the emergency phase, but have different levels of training in GHB intoxication, mainly Registered Nurses (RNs) in southwest Sweden, employed in pre-hospital or emergency departments at somatic and most psychiatric health care facilities, as well as police officers who in their work come into contact with drug users. Responses in the survey were scored according to risk of GHB intoxication with serious failure of vital functions. The score value was then referred to a so-called evidence based priority (EBP) scale and analysed using descriptive statistics and Fisher's exact test.ResultsCardiac arrest, coma, hypoxia, general convulsions, slow respiratory and heart rate and pale skin are symptoms with the highest risk of serious failure in vital physical functions and were predominantly recognised as such.ConclusionDespite the professionals' different levels of training in GHB intoxication, all of them were relatively well aware of and in accordance regarding the most risky symptoms. The interpretation score for the less risky symptoms and signs of GHB intoxication varied depending on their degree of training. The results should be viewed cautiously, as the size of the professional groups and their general knowledge of critical symptoms of GHB poisoning varied.

Intensive Care Unit without walls: Seeking patient safety by improving the efficiency of the system

The term “ICU without walls” refers to innovative management in Intensive Care, based on two key elements: (1) collaboration of all medical and nursing staff involved in patient care during hospitalization and (2) technological support for severity early detection protocols by identifying patients at risk of deterioration throughout the hospital, based on the assessment of vital signs and/or laboratory test values, with the clear aim of improving critical patient safety in the hospitalization process.At present, it can be affirmed that there is important work to be done in the detection of severity and early intervention in patients at risk of organ dysfunction. Such work must be adapted to the circumstances of each center and should include training in the detection of severity, multidisciplinary work in the complete patient clinical process, and the use of technological systems allowing intervention on the basis of monitored laboratory and physiological parameters, with effective and efficient use of the information generated. Not only must information be generated, but also efficient management of such information must also be achieved.It is necessary to improve our activity through innovation in management procedures that facilitate the work of the intensivist, in collaboration with other specialists, throughout the hospital environment. Innovation is furthermore required in the efficient management of the information generated in hospitals, through intelligent and directed usage of the new available technology.

Using Simulation to Expose Shortcomings in Clinical Learning Outcomes

Although our traditional baccalaureate nursing program had been in existence for a number of years and graduates had been successful as RNs in the local community, faculty began receiving reports that clinical staff and employers were concerned about the ability of nursing students to accurately assess and interpret vital signs. Noting that many students tended to rely on electronic blood pressure machines, faculty explored the issue with clinicians in local hospitals. Even experienced nurses rely heavily on technology to report vital signs. Educators made the decision to use simulation to review clinical learning outcomes among sophomore nursing students in the assessment and interpretation of vital signs. This article describes how our program assessment, undertaken in response to an identified weakness, has led to change in our nursing program and dramatic improvement in students' skills. The public views nursing as one of the most trusted professions. As educators, we owe it to the public, and to our profession, to ensure that graduates are clinically competent. USING SIMULATION TO EVALUATE LEARNING OUTCOMES While simulation cannot replace real patient care experiences, it serves as a valuable adjunct for an interactive, formative learning experience (Feingold, Calaluce, & Kallen, 2004; McCausland, Curran, & Cataldi, 2004). However, evidence of the usefulness of simulation for evaluation has been sparse. Much of the nursing education literature has explored issues of self-efficacy, confidence, and learner perceptions of simulation, but research is lacking on the use of simulation for the evaluation of learning outcomes (Kaakinen & Arwood, 2009; Nehring & Lashley, 2004; Radhakrishnan, Roche, & Cunningham, 2007). McCausland and colleagues (2004) explored the for a reduction in errors when they used high-fidelity simulation in a heart failure scenario. Seventy-two nursing students reported that participation in the simulation was a valuable learning experience, rated the simulated experience as having a high level of realism, and perceived that the simulation provided knowledge that would transfer to real clinical practice; 93 percent reported that simulation could be useful to prevent errors in their practice. Radhakrishnan and colleagues (2007) also reported safety improvements because of simulation. A systematic analysis of nursing simulation literature for the years 2000-2007 by Kaakinen and Arwood (2009) showed that many nurse educators were using simulation to teach rather than to evaluate. A few studies, however, have examined the use of simulations for evaluation. Lisko and O'Dell (2010) used Kolb's theory of experiential learning to evaluate how well learners integrated critical thinking and laboratory skill performance. They reported that students' evaluations frequently mentioned that scenario-based simulations helped them integrate theoretical knowledge with psychomotor skills used in the lab. Lasater (2007) conducted an exploratory study that provides support for simulation as an evaluation tool. Rather than evaluating psychomotor measurements to infer student understanding, she developed a clinical assessment rubric aimed at measuring what students need to know. Decker, Sportsman, Puetz, and Billings (2008) state that potential use of simulation in competency testing cannot be achieved until educators and researchers acquire the knowledge and skills needed to use this education strategy, develop realistic case scenarios, and design and validate standardized and reliable testing methods (p. 74). MEASURING CLINICAL LEARNING OUTCOMES To accomplish the task of measuring clinical learning outcomes in our program, faculty collaborated with simulation staff to develop a competency tool and scenario that objectively measures learners' ability to assess and interpret vital signs. Faculty defined competency as the ability to accurately take vital signs on the high-fidelity manikin and to interpret the meaning of those vital signs within the context of a clinical scenario. …

Tdap Coverage in a Military Beneficiary Population: Room for Improvement

Pertussis has had a resurgence in recent years. Women of child-bearing age and adults with infant contact are important reservoirs of infection because of waning immunity. Recent infant deaths and outbreaks led to new tetanus, diphtheria, and acellular pertussis (Tdap) vaccine recommendations, but vaccination rates remain low. A performance improvement project was started at Walter Reed Army Medical Center to target women of child-bearing age. Women treated in Gynecology had their electronic medical record screened for Tdap during their vital signs assessment. Those eligible for vaccination were directed to the Immunization Clinic. The intervention was considered successful if the patient received the vaccine within 30 days of the visit. Data were compiled on vaccination rates 1 month before and 1 and 3 months after the start of the performance improvement project. Only 13.9% of all patients had a documented Tdap at any time. During the first month following the intervention, vaccination rates within 30 days of the appointment increased from 0.38% to 6.5% (p < 0.005). The effect waned at 3 months following intervention, with only 1.1% of patients vaccinated within 30 days of the appointment. Overall vaccination rates remain low, and future studies should focus on barriers to vaccination to prevent morbidity and mortality.

Validity of self-reported adult secondhand smoke exposure

ObjectivesExposure of adults to secondhand smoke (SHS) has immediate adverse effects on the cardiovascular system and causes coronary heart disease. The current study evaluated brief self-report screening measures for accurately...

A non-contact method based on multiple signal classification algorithm to reduce the measurement time for accurately heart rate detection

Non-contact methods for the assessment of vital signs are of great interest for specialists due to the benefits obtained in both medical and special applications, such as those for surveillance, monitoring, and search and rescue. This paper investigates the possibility of implementing a digital processing algorithm based on the MUSIC (Multiple Signal Classification) parametric spectral estimation in order to reduce the observation time needed to accurately measure the heart rate. It demonstrates that, by proper dimensioning the signal subspace, the MUSIC algorithm can be optimized in order to accurately assess the heart rate during an 8-28 s time interval. The validation of the processing algorithm performance was achieved by minimizing the mean error of the heart rate after performing simultaneous comparative measurements on several subjects. In order to calculate the error the reference value of heart rate was measured using a classic measurement system through direct contact.

Huddle for Improved Staff Productivity

A rapid improvement event (RIE) targeted to improve turnover times in the operating rooms directly impacted the practice of PACU nurses. The RIE showed inefficiencies and redundancies among team members and throughout the surgical process. Patients were connected and disconnected to blood pressure cuffs three different times during the perioperative experience. Multiple reports were given to PACU nurses from the OR nurse and anesthesia. Theobjectivesof theprojectwere todecreaseOR turnover times, find and maximize efficiencies throughout the surgical patient’s journey and eliminate redundancies in process and improve staff satisfaction. Several experimentswere implemented after reviewing the process and identifying areas to improve. Vital sign equipment was standardized and adaptors acquired so the blood pressure cuff could be placed once and remain in place for entire perioperative experience. Standardworkwas developed for team members that defined roles and reduced redundancies increasing efficiencies during patient hand offs. The handoff between the OR and PACU nurse was eliminated and anesthesia reported all pertinent information in their hand off. This enabled the PACU nurse to expedite pain management and assessment of post surgical needs 5-7 minutes sooner. Having the blood pressure cuff already in place saved 1-2 minutes leading to faster assessment of vital signs and increased quality of patient care management and increased staff satisfaction.

Hemodynamic consequences of ketamine vs etomidate for endotracheal intubation in the air medical setting

ObjectiveRecent drug shortages have required the occasional replacement of etomidate for endotracheal intubation (ETI) by helicopter emergency medical services (HEMS), with ketamine. The purpose of this study was to assess whether there was an association between ketamine vs etomidate use as the main ETI drug, with hemodynamic or clinical (airway) end points. MethodsThis retrospective study used data entered into medical records at the time of HEMS transport. Subjects, 50 ketamine and 50 etomidate, were accrued from 3 US HEMS programs. The study period was from August 2011 through May 2012. Data collection included demographics, diagnostic category, ETI drugs use, ETI success, and complications. Hemodynamic parameters were assessed for up to 2 sets of vital signs before airway management and up to 5 sets of post-ETI vital signs. Significance was defined at the P < .05 level. ResultsPatients on ketamine and etomidate were similar (P > .05) with respect to age, sex, scene/interfacility mission type, trauma vs nontrauma, neuromuscular blocking agent use, and rates of coadministration of fentanyl or midazolam. All patients had successful airway placement. Peri-ETI hypoxemia was seen in 10% of etomidate and 16% of ketamine cases (P = .55). The pre-ETI and post-ETI were similar between the ketamine and etomidate groups with respect to systolic blood pressure and heart rate at every vital signs assessment after ETI. ConclusionInitial assessment of ETI success and complication rates, as well as peri-ETI hemodynamic changes, suggests no concerning complications associated with large-scale replacement of etomidate with ketamine as the major airway management drug for HEMS.

Blunt Trauma Abdomen-Fatal and Non-fatal Liver Injury

Blunt abdominal trauma is a common feature in modern day-to-day activities including RTA, falling from the height. Liver is the second most frequently injured organ and most common cause of death after abdominal trauma. Management modalities include operative and non-operative measures depending on the state of the patient, pattern of injury, and availability of surgical experts. Here we present 3 cases of blunt abdominal trauma which includes fatal and non-fatal liver injury. One of the patients managed non-operatively and two of them managed with operative techniques. Out of two patients, one died in the second post-operative day. Another patient survived and maintained healthy life after successful management. The non-operative techniques include assessment of patients, vital signs, and radiographic evaluation, volume replacement, blood transfusion, antibiotics, and analgesics. Haemodynamically stable patients are kept in this category. Operative techniques include perihepatic packing, omental packing, hepatorraphy absorbable mesh, and gel foam application. DOI: http://dx.doi.org/10.11566/cmoshmcj.v12i2.43 Chatt Maa Shi Hosp Med Coll J 2013; 12(2): 59-62

Parental presence and distraction during painful childhood procedures

To investigate the effect of parental presence and the distraction of the attention by a toy in children undergoing a painful procedure. A randomised study with two experimental groups and one control group-130 children (64 girls and 66 boys), mean age 8.3 years (range 7-10 years) were randomly assigned to one of the three groups from September 2006 to March 2007: the parent presence group, the toy group, the control group. The verbal rating scale of pain, the assessment of vital signs before and after the procedure and the State-Trait Anxiety Inventory for Children were used. Children who had their parent close to them showed a reduction in breaths (95% confidence interval (CI) for gradient of regression line): -4.20 to -2.80, p<0.001), mean blood pressure (95% CI: -4.88 to -2.99, p<0.001) and pulse (95% CI: -8.76 to -5.68, p<0.001) compared to the children whose parents were absent. They also felt less pain (95% CI: -4.40 to -2.71, p<0.001) and they were less distressed (95% confidence interval for A-State tool (CIA-State): -10.46 to -6.49, p<0.001 and 95% confidence interval for A-Trait tool (CIA-Trait): -5.71 to -2.13, p<0.001). Parental presence is considered to be important in decreasing children's pain, stress and their negative behaviour in general during invasive procedures.

Task shifting an inpatient triage, assessment and treatment programme improves the quality of care for hospitalised Malawian children

We aimed to improve paediatric inpatient surveillance at a busy referral hospital in Malawi with two new programmes: (i) the provision of vital sign equipment and implementation of an inpatient triage programme (ITAT) that includes a simplified paediatric severity-of-illness score, and (ii) task shifting ITAT to a new cadre of healthcare workers called 'vital sign assistants' (VSAs). This study, conducted on the paediatric inpatient ward of a large referral hospital in Malawi, was divided into three phases, each lasting 4weeks. In Phase A, we collected baseline data. In Phase B, we provided three new automated vital sign poles and implemented ITAT with current hospital staff. In Phase C, VSAs were introduced and performed ITAT. Our primary outcome measures were the number of vital sign assessments performed and clinician notifications to reassess patients with high ITAT scores. We enrolled 3994 patients who received 5155 vital sign assessments. Assessment frequency was equal between Phases A (0.67 assessments/patient) and B (0.61 assessments/patient), but increased 3.6-fold in Phase C (2.44 assessments/patient, P<0.001). Clinician notifications increased from Phases A (84) and B (113) to Phase C (161, P=0.002). Inpatient mortality fell from Phase A (9.3%) to Phases B (5.7) and C (6.9%). ITAT with VSAs improved vital sign assessments and nearly doubled clinician notifications of patients needing further assessment due to high ITAT scores, while equipment alone made no difference. Task shifting ITAT to VSAs may improve outcomes in paediatric hospitals in the developing world.

493P - Pharmacokinetic Profile of MGCD265, an Oral Tyrosine Kinase Inhibitor, with or Without Food in Healthy Volunteers

ABSTRACT Background MGCD265 is a novel targeted cancer therapeutic, currently in phase I/II clinical trials, that inhibits Met and VEGF receptor tyrosine kinases. The abnormal activation of Met is involved in tumor development and metastasis, and VEGF kinase is responsible for inappropriate angiogenesis that nourishes the tumor. MGCD265 has demonstrated a favorable safety profile in patients with advanced malignancies and can safely be combined with other cancer therapeutics such as docetaxel and erlotinib. The objective of this Phase I study was to assess the bioavailability of MGCD265 under fasting and fed conditions in healthy volunteers. Methods This was a randomized, laboratory-blinded, 2-period, crossover study. MGCD265 was administered as a single dose (100 mg) after a 10-hr overnight fast. For the fasting condition, fasting was continued for at least 4 hrs following drug administration. For the fed condition, subjects received a standardized meal 30 mins before drug administration. Blood samplings for the pharmacokinetic (PK) evaluation were done from pre-dose to up to 96 hrs post-dose. Safety was evaluated through the assessment of adverse events (AEs), laboratory tests, vital signs and 12-lead ECG. Results Fourteen subjects were recruited [M/F: 8/6; median age: 51 years old (range 41-65); median BMI: 25 kg/m2 (range: 19-29)]. One female subject discontinued early due to a fall (unrelated to MGCD265). Using nominal timepoints, on average, the fed condition was associated with an ∼3 fold increase in Cmax, AUCT, and AUCinf. The half-life of MGCD265 was found to be ∼34 hrs. Tmax was calculated to be 7 hrs and 10 hrs under fasting and fed conditions, respectively. MGCD265 related AEs were mostly mild and included dry mouth in 3 subjects, somnolence in 1 subject and moderate diarrhea in 1 subject. There were no clinically significant changes in vital signs, ECG or laboratory values. Conclusions Exposure of MGCD265 increased significantly in the presence of a meal, with no added toxicity. The prolonged sampling time used in this study provided a more accurate estimation of MGCD265 half-life (∼34 hrs) compared to the estimate found in patients with advanced malignancies (∼23 hrs). Disclosure E. Sicard: Research funding from Methylgene, Inc. M. Juretic: Employee of Methylgene, Inc. M. Drouin: Employee of Methylgene, Inc. G. Reid: Employee of Methylgene, Inc. J. Wang: Employee of Methylgene, Inc. W. Hunt: Employee of Methylgene, Inc. C. Maroun: Employee of Methylgene, Inc. J. Besterman: Employee of Methylgene, Inc.

Emergency Nursing Resource: Orthostatic Vital Signs

Summary of Literature Review Summary of Definitions The definition of orthostatic vital signs warrants further research despite its common use in clinical practice, textbooks, guidelines and research studies. A review of definitions from the literature indicates that the assessment parameter labeled as orthostatic vital signs can be summarized by its: physiological variables, measurement method, and purpose. The physiological variables include blood pressure, heart rate, and stroke index (Durukan et al., 2009; Fuchs & Jaffe, 1987; Horam & Roscelli, 1992; Koziol-McLain et al., 1991; Levitt et al., 1992; Witting & Gallagher, 2003), as well as symptoms of dizziness or lightheadedness (Lance et al., 2009; Sarasin et al., 2002). Stated purposes of orthostatic vital signs assessment include identification of hypovolemia (both dehydration and blood loss) and treatment efficacy of pharmacological agents for neurological conditions. Assessment for hypovolemia is the purpose of orthostatic vital signs for this review. The most common variables measured to assess orthostatic vital signs in potentially hypovolemic patients include blood pressure and heart rate, measured with the patient in different positions (supine, sitting, standing). Equipment used to obtain orthostatic vital signs, as well as the feasibility of obtaining orthostatic vital signs in the clinical setting will be described. For the purposes of this document, orthostatic vital signs are defined as a change in blood pressure, heart rate, or onset of symptoms after a change in position in individuals (adult, child, and adolescent) with a decrease in intravascular volume (Durukan et al., 2009; Fuchs & Jaffe, 1987; Horam & Roscelli, 1992; Koziol-McLain et al., 1991; Levitt et al., 1992; Witting & Gallagher, 2003).

Continuous measurement of cerebral oxygen saturation (rSO2) for assessment of cardiovascular status during hemorrhagic shock in a swine model

Early trauma care is dependent on subjective assessments and sporadic vital sign assessments. We hypothesized that near-infrared spectroscopy-measured cerebral oxygenation (regional oxygen saturation [rSO₂]) would provide a tool to detect cardiovascular compromise during active hemorrhage. We compared rSO₂ with invasively measured mixed venous oxygen saturation (SvO₂), mean arterial pressure (MAP), cardiac output, heart rate, and calculated pulse pressure. Six propofol-anesthetized instrumented swine were subjected to a fixed-rate hemorrhage until cardiovascular collapse. rSO₂ was monitored with noninvasively measured cerebral oximetry; SvO₂ was measured with a fiber optic pulmonary arterial catheter. As an assessment of the time responsiveness of each variable, we recorded minutes from start of the hemorrhage for each variable achieving a 5%, 10%, 15%, and 20% change compared with baseline. Mean time to cardiovascular collapse was 35 minutes ± 11 minutes (54 ± 17% total blood volume). Cerebral rSO₂ began a steady decline at an average MAP of 78 mm Hg ± 17 mm Hg, well above the expected autoregulatory threshold of cerebral blood flow. The 5%, 10%, and 15% decreases in rSO₂ during hemorrhage occurred at a similar times to SvO₂, but rSO₂ lagged 6 minutes behind the equivalent percentage decreases in MAP. There was a higher correlation between rSO₂ versus MAP (R² =0.72) than SvO₂ versus MAP (R² =0.55). Near-infrared spectroscopy-measured rSO₂ provided reproducible decreases during hemorrhage that were similar in time course to invasively measured cardiac output and SvO₂ but delayed 5 to 9 minutes compared with MAP and pulse pressure. rSO₂ may provide an earlier warning of worsening hemorrhagic shock for prompt interventions in patients with trauma when continuous arterial BP measurements are unavailable.