Quantification of pelvic floor muscle strength in female urinary incontinence: A systematic review and comparison of contemporary methodologies.

AIMS: There remains no gold standard for quantification of voluntary pelvic floor muscle (PFM) strength, despite international guidelines that recommend PFM assessment in females with urinary incontinence (UI). Methods currently reported for quantification of skeletal muscle strength across disciplines are systematically reviewed and their relevance for clinical and academic use related to the pelvic floor are described. METHODS: A systematic review via Medline, PubMed, CINHAL, and the Cochrane database using key terms for pelvic floor anatomy and function were cross referenced with skeletal muscle strength quantification from 1946 to 2016. Full text peer-reviewed articles in English having female subjects with incontinence were identified. Each study was analyzed for use of controls, type of methodology as direct or indirect measures, benefits, and limitations of the technique. RESULTS: A total of 1586 articles were identified of which 50 met the inclusion criteria. Nine methodologies of determining PFM strength were described including: digital palpation, perineometer, dynamometry, EMG, vaginal cones, ultrasonography, magnetic resonance imaging, urine stream interruption test, and the Colpexin pull test. Thirty-two percent lacked a control group. CONCLUSION: Technical refinements in both direct and indirect instrumentation for PFM strength measurement are allowing for sensitivity. However, the most common methods of quantification remain digital palpation and perineometry; techniques that pose limitations and yield subjective or indirect measures of muscular strength. Dynamometry has potential as an accurate and sensitive tool, but is limited by inability to assess PFM strength during dynamic movements.

Prevalence of impaired glucose tolerance and the components of metabolic syndrome in Canadian Tsimshian Nation youth.

INTRODUCTION: Canadian Aboriginal people have been disproportionately affected by obesity and type 2 diabetes (T2D). Our objective was to determine the prevalence of obesity, glucose intolerance and the components of metabolic syndrome (MetS) in Tsimshian Nation youth living in 3 remote coastal communities. METHODS: A medical history, anthropometric measurements and an oral glucose tolerance test were performed in youth aged 6-18 years. We defined "overweight" by a body mass index (BMI) at the 85th percentile or higher and "obese" by a BMI at the 95th percentile or higher, by age and sex. We used the International Diabetes Federation criteria for MetS. RESULTS: Of the 224 eligible youth, 192 (85%) participated in the study. Nineteen percent were overweight, 26% were obese and 36% had central obesity (waist circumference > or = 90th percentile for age and sex). No new cases of T2D were identified. The prevalence of impaired fasting glucose (IFG 5.6-6.9 mmol/L) and impaired glucose tolerance (IGT 2-hr glucose 7.8-11.0 mmol/L) were 19.3% and 5.2%, respectively. Five of the 10 youth with IGT had a fasting glucose less than 5.6 mmol/L. The prevalence of MetS was 4.7% and increased to 8.3% when pediatric hypertension norms were applied. CONCLUSION: Tsimshian Nation youth have a high prevalence of central obesity, impaired glucose homeostasis and other components of MetS. The oral glucose tolerance test may be a more appropriate screening test to identify IGT in Aboriginal youth.

Near-infrared spectroscopy: validation of bladder-outlet obstruction assessment using non-invasive parameters.

INTRODUCTION: Near infrared spectroscopy (NIRS) is a non-invasive optical technique able to monitor changes in the concentration of oxygenated and deoxygenated hemoglobin in the bladder detrusor during bladder filling and emptying. OBJECTIVE: To evaluate the ability of a new NIRS instrument and algorithm to classify male patients with LUTS as obstructed or unobstructed based on comparison with classification via conventional invasive urodynamics (UDS). METHOD: Male patients with LUTS were recruited and underwent uroflow and urodynamic pressure flow studies with simultaneous transcutaneous NIRS monitoring following measurement of post residual volume (PVR) via ultrasound. Data analysis first classified each subject as obstructed or unobstructed using the standard pressure flow data and nomogram, then compared these results with a classification derived via a customized algorithm which analyzed the pattern of change of the NIRS data plus measurements of PVR and Qmax. RESULTS: Seventy subjects enrolled: 57 data sets had all required parameters [13 incomplete sets due to: communication error between NIRS and urodynamics instruments (9); data saving error (1); damaged fiber optic cables (3)]. Two complete data sets were excluded [subjects with hematuria (2)]. Thus data from 55 subjects was analyzed. The NIRS algorithm correctly identified those diagnosed as obstructed by conventional urodynamic classification in 24 of 28 subjects (sensitivity = 85.71%) and, and those diagnosed as unobstructed in 24 of 27 subjects (specificity = 88.89%). CONCLUSION: Scores derived from NIRS data plus PVR and Qmax are able to correctly identify > 85% of subjects classified as obstructed using UDS.

Development of a near-infrared spectroscopy instrument for applications in urology.

INTRODUCTION: Near infrared spectroscopy (NIRS) is an established technology using photons of light in the near infrared spectrum to monitor changes in tissue of naturally occurring chromophores, including oxygenated and deoxygenated hemoglobin. Technology and methodology have been validated for measurement of a range of physiologic parameters. NIRS has been applied successfully in urology research; however current instruments are designed principally for brain and muscle study. OBJECTIVE: To describe development of a NIRS instrument specifically designed for monitoring changes in chromophore concentration in the bladder detrusor in real time, to facilitate research to establish the role of this non-invasive technology in the evaluation of patients with voiding dysfunction METHOD: The portable continuous wave NIRS instrument has a 3 laser diode light source (785, 808 and 830 nanometers), fiber optic cables for light transmission, a self adhesive patient interface patch with an emitter and sensor, and software to detect the difference between the light transmitted and received by the instrument. Software incorporated auto-attenuates the optical signals and converts raw optical data into chromophore concentrations displayed graphically. RESULTS: The prototype was designed, tested, and iteratively developed to achieve optimal suprapubic transcutaneous monitoring of the detrusor in human subjects during bladder filling and emptying. Evaluation with simultaneous invasive urodynamic measurement in men and women indicates good specificity and sensitivity of NIRS chromophore concentration changes by receiver operator curve analysis, and correlation between NIRS data and urodynamic pressures. CONCLUSION: Urological monitoring with this NIRS instrument is feasible and generates data of potential diagnostic value.

Relevance of open magnetic resonance imaging position (sitting and standing) to quantify pelvic organ prolapse in women.

INTRODUCTION: In pelvic organ prolapse (POP), posture and gravity impact organ position and symptom severity. The advanced magnet configuration in open magnetic resonance imaging (MRO) allows patients to be imaged when sitting and standing, as well in a conventional supine position. This study evaluated if sitting and standing MRO images are relevant as a means of improving quantification of POP because they allow differences in organ position not seen on supine imaging to be identified. METHODS: Forty women recruited from a university urogynecology clinic had MRO imaging (0.5 T scanner) with axial and sagittal T2-weighted pelvic scans obtained when sitting, standing, and supine. Pelvic reference lines were used to quantify the degree of POP, and the relevance of imaging position on the detection of POP compared. RESULTS: Images from 40 participants were evaluated (20 with POP and 20 asymptomatic controls). Our results indicate that the maximal extent of prolapse is best evaluated in the standing position using H line, M line, mid-pubic line, and perineal line as reference lines to determine POP. CONCLUSIONS: MRO imaging of symptomatic patients in a standing position is relevant in the quantification of POP. Compared with supine images, standing imaging identifies that greater levels of downward movement in the anterior and posterior compartments occur, presumably under the influence of posture and gravity. In contrast, no appreciable benefit was afforded by imaging in the sitting position, which precluded use of some reference lines due to upward movement of the anorectal junction.

Prevalence estimates for lower urinary tract symptom severity among men in Uganda and sub-Saharan Africa based on regional prevalence data.

INTRODUCTION: In the absence of specific regional data, the prevalence of urinary symptoms in the developing world is currently estimated. Regional prevalence data and estimates based on them have relevance for accurate planning/provision of future healthcare. We sought to extrapolate prevalence estimates for lower urinary tract symptom (LUTS) severity and associated sexual dysfunction for Uganda as a whole and sub-Saharan Africa (SSA) using newly available regional data from a community-based cohort of men in Uganda. METHODS: Global Burden of Disease Study (GBDS) population statistics were applied to a regional dataset to provide prevalence estimates for Uganda and SSA; 415 men >55 years from five rural Ugandan communities had completed the International Prostate Symptom Scale (IPSS) and Epstein inventory to grade their LUTS severity and satisfaction with sexual function. RESULTS: Prevalence rates for moderate and severe LUTS were 40.5% and 20%, respectively, in men >55 in the Ugandan regional data; associated scores for all four Epstein sexual satisfaction measures were low. GBDS population figures (2016) for men >55 years are 942 115 (Uganda) and 33.9 million (SSA); hence, scaling up from regional prevalence data suggests 381 557 and 188 423 men >55 years in Uganda, and 13 729 500 and 6 780 000 in SSA have moderate and severe LUTS, respectively, and the majority will have compromise of elements of their sexual function. CONCLUSIONS: Extrapolation from a small regional dataset (for which we have no guarantee of national or SSA representability) provides the first prevalence estimates for LUTS severity based on African data, and suggests a large proportion of men >55 years are troubled with LUTS and associated sexual dysfunction.

Associations between the severity of obstructive lower urinary tract symptoms and care-seeking behavior in rural Africa: A cross-sectional survey from Uganda.

STUDY TYPE: A cross sectional survey. BACKGROUND: Global estimates indicate that by 2018 2.3 billion individuals worldwide will suffer from lower urinary tract symptoms (LUTS), with 1.1 billion having LUTS related to bladder outlet obstruction (BOO). Left untreated BOO in men causes irreversible changes to the urinary tract leading to urinary retention, the need for catheterization, renal failure and even death. Estimates suggest that Africa will be one of the continents with the greatest increase in (LUTS) by 2018 however direct measures in Africa are lacking. The objectives were to: (1) measure of prevalence of LUTS/BOO in a community-based sample of men in Africa, (2) compare community-based LUTS/BOO frequency to those seeking care for LUTS in a local clinic (3) quantify bother, interference with daily living, worry and quality of life related to LUTS/BOO between community and clinic settings and (4) examine relationships between socioeconomic and demographics related to LUTS/BOO. METHODS AND FINDINGS: 473 men from a rural Ugandan community (238 residents living with their symptoms and 177 presenting at a clinic for care) completed the International Prostate Symptom Scale (IPSS) and a 53-item validated LUTS symptom, bother and quality of life index. Severity of symptoms was categorized based on reference ranges for mild, moderate and severe levels of the IPSS, comparing those in the community versus those seeking care for symptoms. IPSS indicated that 55.9% of men in the community versus 17.5% of those at the clinic had mild symptoms, 31.5% in the community versus 52.5% of those at the clinic had moderate symptoms and 12.6% of those in the community versus 29.9% of those at the clinic had severe symptoms (p<0.001). Men seeking care for LUTS/BOO had a lower quality of life (p<0.05), were more bothered by their urinary symptoms (p<0.05), had more interference with daily activity and worry (p<0.05) but this did not have an impact on their general sense of wellbeing. CONCLUSIONS: The burden of disease of LUTS/BOO in this rural African cohort is high and significantly higher among those seeking care due to the bother of their symptoms. One in 4 men will spend money for transport to clinic due to LUTS/BOO despite low economic resources. Educational tools for patients structured to the level of literacy are justified.

Brighter Smiles: Service learning, inter-professional collaboration and health promotion in a First Nations community.

OBJECTIVE: The goal of Brighter Smiles was to improve children's dental health in a remote First Nations community in British Columbia in the context of a service-learning experience for pediatrics residents. SETTING AND PARTICIPANTS: The provincial Ministry of Health had competitive funds available for collaborations between remote communities and medical educators. Hartley Bay (Gitga'at), a tribe of the Tsimshian Nation, responded by declaring children's dental health to be a primary health concern. This northern community has an on-reserve population fluctuating around 200 people and is accessible only by air or water. INTERVENTION: A convenience sample of children had a baseline dental exam; parents also completed a questionnaire about dental health behaviours. Only 31% (4/13) of pre-kindergarten and 8% (2/26) of kindergarten to Grade 12 children had no dental caries. Planning of the Brighter Smiles intervention involved community leaders, teachers, parents, Elders, health care staff, pediatrics residents, and dental and medical faculty from the University of British Columbia (UBC). Brighter Smiles includes school-based brush-ins, fluoride programs, classroom presentations, and regular visits by UBC pediatrics residents to Hartley Bay to provide well-child care that includes age-appropriate dental counselling to parents at the clinic visits. OUTCOMES: An early success indicator was a significantly increased proportion of dental service provider's time scheduled for preventive maintenance services rather than dental rehabilitation (restorations and extractions). CONCLUSIONS: The goal of providing a service-learning experience for trainee pediatricians in a remote community has been achieved. In addition, early indicators demonstrate improvements in child oral health.

Paramedic evaluation of adult Intraosseous Infusion System.

INTRODUCTION: The First Access for Shock and Trauma (FAST 1) Sternal Intraosseous (IO) System is a vascular access device designed as an alternative to peripheral or central intravenous (IV) cannulation for the treatment of critically ill and injured adults. During the development of the device, key objectives included safety, speed of insertion, and ease of use with minimal training. This study evaluated these characteristics. METHODS: Ten experienced paramedics participated in a 90-minute training program for the use of the FAST 1 System at the Paramedic Academy of the Justice Institute of British Columbia. Then, the paramedics used the system in three simulated prehospital scenarios and evaluated the ease of use and compatibility of the training method with current practice using a 10-centimeter (cm) (3.94 inches (in)), visual analog scale. RESULTS: The duration of the procedure from opening the package to initiation of fluid flow ranged 52-127 seconds (mean = 92 +/- 32 seconds). Placement accuracy was excellent, with a mean displacement of 2 mm (0.08 in) and 1 mm (0.04 in) in the vertical and horizontal planes, respectively. The paramedics rated the system highly in all areas. They considered the training "straight-forward" and "comprehensive". The possibility for interference between the IO system and cervical collars was reported, and several suggestions to remedy this and achieve other improvements were made. CONCLUSIONS: Placement of the FAST 1 is fast, accurate, and easy to use. Paramedics had useful input concerning the design of the product.

Cadaver testing to validate design criteria of an adult intraosseous infusion system.

INTRODUCTION: The FAST 1 intraosseous (IO) infusion system was designed to deliver fluids and medications into the adult sternum in the prehospital and battlefield environments. OBJECTIVE: To test the prototype in 106 cadavers and excised sterna and compare it with other IO devices. RESULTS: The insertion force was similar to that of other IO devices (mean, 8.5 kg; range, 2.3-19.6 kg). In 39 of 39 trials, the depth-control mechanism inserted the portal within 1.0 mm of a predetermined distance below the anterior surface of the cortical bone. If misplaced, underpenetration was more likely than overpenetration (mean displacement, -0.3 mm; SD, 0.5 mm). After release, the portal could not be advanced further into the manubrium. Marrow was accessed in 75 of 77 trials. Mean flow rates were 109 mL/min for normal saline solution and 102 mL/min for hypertonic saline/dextran, similar to the Cook Sur-Fast device. CONCLUSION: The cadaver and bench tests demonstrated the reliability and safety of the FAST 1 system at the design/prototype stage.

Liquid light guides versus fiber light guides in clinical near-infrared spectroscopy.

New commercial liquid light guides have an advantage over fiberoptic bundles regarding breakage during clinical handling. We investigate the quality of clinical data collection using liquid versus fiber bundles as receivers. A four-wavelength NIRO-500 near-IR spectrophotometer is used with single-terminal fiber bundles, multiterminal fiber bundles, or a single-terminal liquid light guide as receivers. Repeated 3-min trials are done using a stable phantom, an unstable phantom, and the human forearm. A least-squares linear best-fit line and its root mean square error (RMSE), a measure of signal noise, are derived for each wavelength of each trial. The mean and standard deviations for the RMSEs of the single-terminal fiber optic receiving cable are derived for comparison standards. The liquid light guides have 51 to 174% greater signal noise with RMSEs 2 to 12 standard deviations above the mean of the single-terminal fiber bundle. The multiterminal fiber bundles have 49% less to 32% greater signal noise and had RMSEs within 1 to 4 standard deviations above the mean of the single-terminal fiber bundle. These comparisons suggest fiber optic bundles are preferable for clinical near-IR spectroscopy (NIRS) applications requiring low signal noise.

Evaluation of a semi-quantitative CO2 monitor with pulse oximetry for prehospital endotracheal tube placement and management.

OBJECTIVE: To evaluate three prototype versions of semi-quantitative end-tidal CO2 monitors with different alarm features during prehospital or interfacility use. METHODS: Subjects were 43 adult, non-pregnant patients requiring intubation, or who already were intubated and required transport. Teams at one AirEvac and seven Advanced Life Support (ALS) paramedic stations were trained in the use of the monitors. Team members at each station evaluated each model for eight days. Participants completed questionnaires following each use. RESULTS: The monitors performed properly in all cases, but in one case, vomit in the airway adapter tube prevented obtaining a readout. The monitors aided management in 40 of 43 cases (93%); in one, the monitor reading was reported as variable (between 20 and 30 mmHg) although the teams knew the monitors were semi-quantitative; in another, the monitor was not required, but performed properly; and the third was the one in which vomit in the tube prevented a reading. In 26 of 43 cases (60.4%), the monitor was used to confirm endotracheal tube placement (there were no instances of incorrect placement). In all cases, the devices were used to monitor respiration and oxygen saturation. Alarms were audible in the environment, but only preferred in the AirEvac situation. The "breath beep" feature was useful, particularly in patients in whom chest movements during respiration were difficult to observe. CONCLUSIONS: "Breath beeps" were clearly audible and were a useful feature in all prehospital and transport environments, while audible alarms were desired only in the AirEvac situation. Semi-quantitative CO2 detection is valuable in the ALS/AirEvac environment, even for teams with high intubation success rates.

Cost: benefit of point-of-care blood gas analysis vs. laboratory measurement during stabilization prior to transport.

INTRODUCTION: This study was conducted to determine whether point-of-care testing, using the iSTAT Portable Clinical Analyzer, would reduce time at the referring hospital required to stabilize ventilated pediatric patients prior to interfacility, air-medical transport. METHODS: The following data were collected prospectively: (1) When a blood gas analysis was ordered; (2) If it was necessary to call in a technician; (3) Waiting time for blood to be drawn; and (4) Waiting time for results. The cost-efficacy of point-of-care testing was calculated based on: (1) Three minutes for a transport team member to draw a sample and obtain a result using the iSTAT (unit cost 8,000 CDN dollars); (2) Lab technician call-back (minimum two hours at 90 dollars); (3) Paramedic overtime (by the minute at 49 dollars/hour); and (4) Cost of charter aircraft wait time (200 dollars per hour) for every hour beyond four hours. RESULTS: Data were collected on 46 ventilated patients over a three month period. A blood gas analysis was ordered on 35 patients. Laboratory technicians were called in for 17 (49%). For 12 (34%) patients, there was a wait for the sample to be drawn, and for 23 (66%), there was a wait for results to become available. Total time waiting to obtain laboratory gases was 526 minutes compared with a calculated 105 minutes using point-of-care testing. An iSTAT cartridge cost of 420 dollars would not have been different from laboratory costs. Cost-saving on technician callback (1,530 dollars), paramedic overtime (690 dollars) and aircraft time waiting charges (2,000 dollars) would have totaled (4,220 dollars). From this study, the cost of point-of-care equipment could be recouped in 101 patients if aircraft charges apply or 192 patients if no aircraft costs are involved. For 11 cases, ventilator adjustments were made subsequently during transport, and for six patients, point-of-care testing, if in place, would have been used to optimize transport care. CONCLUSION: The data from the present study indicate significant cost-efficacy from use of this technology to reduce stabilization times, and support the potential to improve quality of care during air medical interfacility transport.

Noninvasive Optical Monitoring of Bladder Filling to Capacity Using a Wireless Near Infrared Spectroscopy Device.

Lack of bladder fullness sensation is an issue that arises in different neurogenic conditions and in addition to influencing patients' quality of life, can result in serious kidney damage. We describe a wireless wearable sensor for detecting bladder fullness using near infrared spectroscopy (NIRS). The sensor has been tested in vitro and in vivo to verify its feasibility and is shown to be capable of detecting changes in bladder content noninvasively.

Monitoring Detrusor Oxygenation and Hemodynamics Noninvasively during Dysfunctional Voiding.

The current literature indicates that lower urinary tract symptoms (LUTSs) related to benign prostatic hyperplasia (BPH) have a heterogeneous pathophysiology. Pressure flow studies (UDSs) remain the gold standard evaluation methodology for such patients. However, as the function of the detrusor muscle depends on its vasculature and perfusion, the underlying causes of LUTS likely include abnormalities of detrusor oxygenation and hemodynamics, and available treatment options include agents thought to act on the detrusor smooth muscle and/or vasculature. Hence, near infrared spectroscopy (NIRS), an established optical methodology for monitoring changes in tissue oxygenation and hemodynamics, has relevance as a means of expanding knowledge related to the pathophysiology of BPH and potential treatment options. This methodological report describes how to conduct simultaneous NIRS monitoring of detrusor oxygenation and hemodynamics during UDS, outlines the clinical implications and practical applications of NIRS, explains the principles of physiologic interpretation of NIRS voiding data, and proposes an exploratory hypothesis that the pathophysiological causes underlying LUTS include detrusor dysfunction due to an abnormal hemodynamic response or the onset of oxygen debt during voiding.

Hantavirus cardiopulmonary syndrome: implications for transport management and care.

INTRODUCTION: A 14-year-old boy with cardiorespiratory failure was referred for air medical transport. The complexity of care during air medical transport and subsequent diagnosis of hantavirus warranted a post hoc review of the literature to establish optimal transport management criteria. METHODS: This is a case report and literature review, defining epidemiology, presentation, cause of pulmonary edema and cardiac failure, management, and outcome. RESULTS: Hantavirus cardiopulmonary syndrome is rare in children. Severe cases have manifestations similar to those seen in adults: atypical pneumonia progresses to respiratory failure with severe pulmonary edema and associated circulatory compromise. Mechanical ventilation, judicious fluid replacement, and early inotropic therapy are central to transport management. Critical care may require extracorporeal membrane oxygenation (ECMO). Mortality remains high, although it appears to be lower in children younger than 14 years. CONCLUSION: Hantavirus infection commonly progresses to a cardiopulmonary syndrome, in which mortality is high. Optimal management includes: early suspicion/recognition based on characteristic clinical course and history; provision of oxygen and comprehensive ventilatory support; judicious fluid replacement; early and intensive inotropic therapy; prompt referral to an appropriate level of care; skillful interfacility transport. Definitive care can involve ECMO.

Aortic arch reconstruction: safety of moderate hypothermia and antegrade cerebral perfusion during systemic circulatory arrest.

BACKGROUND AND AIM: The ideal strategy for cerebral protection during aortic arch (AA) reconstructive surgery remains undefined. Antegrade cerebral perfusion (ACP) during systemic circulatory arrest (SCA) may provide superior results; however, optimal systemic temperature is undetermined. Our objective was to determine whether "deep" hypothermia is necessary during ACP with SCA, and whether the degree of hypothermia is associated with neurologic outcomes postoperatively. METHODS: Retrospective series of 72 consecutive patients (aged 65.9 +/- 3.2 years) who underwent AA reconstructive surgery at Vancouver General Hospital using a cerebral protection strategy of ACP with SCA between December 1995 and December 2002. Patients were divided into two groups according to lowest systemic temperature: <22 degrees C (n = 52) and > or =22 degrees C (n = 20). RESULTS: ACP was via right axillary or innominate artery, +/- left common carotid cannulation. Median SCA time with ACP was not different between groups. There were four hospital deaths (5.6%) (three from the <22 degrees C group). Eight patients (11.2%) had major neurologic injuries (seven from the <22 degrees C group): 4 (5.6%) permanent (1 fatal) and 4 (5.6%) temporary. There was a trend toward a significantly higher incidence of delirium in the <22 degrees C group than the > or =22 degrees C group (30.8 vs 10.0%, respectively, p = 0.07). CONCLUSIONS: In our experience, SCA with ACP was a safe technique for AA reconstructive surgery. The observation of a larger number of major neurologic injuries, and a trend toward a higher incidence of delirium in the <22 degrees C group, suggests that systemic temperatures below 22 degrees C may not be necessary and may be associated with a higher incidence of neurologic injury when using ACP during SCA.

Correlation of near-infrared spectroscopy with perfusion parameters at the hepatic and systemic levels in an endotoxemic shock model.

BACKGROUND: To determine the correlation of near-infrared spectrophotometry (NIRS) readings from the liver surface with invasive measurements of blood flow and tissue perfusion parameters in an animal model of endotoxemic shock. MATERIAL/METHODS: Laparotomy was performed in 12 Yorkshire piglets, and ultrasound blood flow probes were placed on the hepatic artery and portal vein. Hepatic vein, portal vein, and femoral artery catheters were inserted for intermittent blood sampling, and a pulmonary artery catheter was inserted via the jugular vein for cardiac output measurements. Near-infrared spectrophotometry optodes were placed across the right hepatic lobe. Endotoxemic shock was induced by continuous infusion of Escherichia coli lipopolysaccharide 055: B5. Pearson correlations were calculated between the perfusion parameters and the near-infrared spectrophotometry (NIRS) readings. RESULTS: After endotoxemic shock induction, liver blood flow decreased from 144 +/- 36 to 62 +/- 24 ml*min(-1)*100 g(-1) and oxygen delivery to the liver decreased from 20 +/- 6 to 7 +/- 4 ml*min(-1)*100 g(-1). Near-infrared spectrophotometry readings of oxyhemoglobin concentration decreased by 11.7+/-15.1 micromol*L(-1), and readings of deoxyhemoglobin concentration increased by 12.3 +/- micromol*L(-1). There were significant correlations (p < 0.05 for r2 > 0.11) between the oxyhemoglobin readings and liver oxygen delivery (r2 = 0.58), liver blood flow (r2 = 0.73) and cardiac output (r2 = 0.80). Deoxyhemoglobin readings highly correlated (p < 0.05 for r2 > 0.11) with mixed venous lactate (r2 = 0.87) and with hepatic vein lactate (r2 = 0.82). CONCLUSIONS: Noninvasive near-infrared spectrophotometry measurements of hepatic oxyhemoglobin and deoxyhemoglobin correlate with liver hemodynamics as well as with global and specific organ perfusion parameters and may serve, in the future, as a useful tool to monitor tissue perfusion in septic patients.