Oxygenation Research Articles

Evaluation of the clinical efficacy of inhaled nitric oxide synthesized from natural air in conditions of thoracic surgical intervention on the lung tissue

Introduction. Despite the significant development of an-esthetic procedures in the XX–XXI centuries the problem of optimal one-lung ventilation (OLV) of comorbid pa-tients isn’t resolved. Occasionally, there would be a situa-tion when the resectable patient is functionally inoperable or has high risk of intra- and postoperative complications. This article provides one possible solution of this problem. Purpose of the study. To analyze the use of inhaled nitric oxide (INO) on the dependent lung in order to increase the oxygenation index in the clinical practice of thoracic surgery. Materials and research methods. This is a prospec-tive study of the influence of INO on oxyge nation during thoracic operations on the organs of the respiratory sys-tem. The study participants were divided into 2 groups, each comprised of 10 individuals. Group A received INO intraoperatively as part of a combined multicomponent general anesthesia; group B received standard combined multicomponent general anesthesia. All patients under-went analysis of the gas composition of arterial blood at 2 control points: the 1st one was 10 minutes after the be-ginning of OLV; the 2nd — 40 minutes after INO entered the respiratory circuit (immediately after receiving the result of the 1st control point). Research results. In the INO group an increasing of oxygenation index was observed in 8 out of 10 cases (p=0.022). In the control group an increasing of oxygenation index occured in 2 cases out of 10 (p=0.037). Conclusions. Based on the available data a positive cor-relation was found between the raise of oxygenation in-dex and the use of INO in conditions of ALV for thoracic interventions. It could potentially help to increase the number of operable patients, reduce operative risks and intraoperative time for the borderline operability group.

PHYSIOLOGICAL CORRELATES OF ALMOST LOSS OF CONSCIOUSNESS (A-LOC) DURING DYNAMIC FLIGHT SIMULATION (DFS) ON HUMAN CENTRIFUGE: A CASE REPORT

Introduction: G-LOC is still a threat for aircrew of high performance aircrafts. It is evoked by a high level of +Gz acceleration causing a deficit of brain oxygenation. Although near-infrared spectroscopy (NIRS) was used to identify brain oxygenation decreases preceding G-LOC, it is not used regularly in aero-medicine research in Poland. Here, we report the physiological correlates of Almost Loss of Consciousness (A-LOC) that occurred during a research project. Method: During Dynamic Flight Simulation training on a human centrifuge one pilot experienced momentaneous confusion which was recorded on a camera. We post-hoc reviewed his vital signs, stroke volumes (SV), cardiac output (CO) obtained with bioimpedance rheography, and brain oxygenation (OX) measures with near-infrared spectroscopy on the forehead. Finally, we reviewed the recording of his eye movements obtained with video-oculography. Results: SV and CO measures were confounded by artefacts induced by anti-G straining manoeuvres (AGSM). However, OX measures demonstrated decreased brain oxygenation that lasted several seconds after the incident. Following the incident, the pilot’s pulse remained decreased for several seconds. Discussion: NIRS methodology seems to be resistant to artefacts created by muscles during AGSM. NIRS systems with a probing rate of 0.1 second might help detect upcoming A-LOC or G-LOC.

Association between oxygenation and ventilation indices with the time on invasive mechanical ventilation in infants

BackgroundInvasive mechanical ventilation (IMV) is a common practice in pediatric intensive care unit (PICU). However, the role of oxygenation (OI) and ventilation (VI) indices regarding the time on IMV has not been fully understood. Basic proceduresThe study was conducted with infants up to 24 months of age, hospitalized in PICU for two consecutive years. The values of ventilatory parameters, OI, VI, and blood gas of infants, collected in the first seven days in IMV, were associated with the time on IMV. IMV was classified into: short (≤seven days) and long time (>seven days). The comparison was made from the first to the seventh day. Alpha=0.05. Main findingsOf 142 infants [mean age=7.51±6.33 months], 59 (41.5%) remained on IMV for a short time and 83 (58.5%) for a long time. Differences in PaO2 values were found on the second day, and PaO2/FiO2 ratio on the second, third and fourth days, with higher values in the short-term IMV. For FiO2 from the second to the fifth day; Pinsp from the first to the seventh day; PEEP from the second to the sixth day; mechanical respiratory frequency from the second to the seventh day, PaCO2 on the second day; Paw from the first to the seventh day, OI from the second to the sixth day, and VI from the first to the seventh day, the values were higher in the long-term IMV. ConclusionsThe OI and VI can be considered as potential predictors of long-term IMV, along with other markers obtained during the IMV.

Procedural difficulties during successful intubation in octogenarians: A prospective observational study

Abstract Objective Octogenarians undergo anatomic and physiopathologic degradation, making airway management problematic, specific to intubation, bag mask ventilation, leading to desaturation and aspiration. Our study's aim was to examine the process of airway management regarding the steps involved in intubation and any deviations or delays in the tasks. Materials and methods An institutional review board-approved difficult airway prospective observational study in older adults was conducted. Inclusion criteria included airway features indicative of difficult airway, history of failed intubation, the planned use of specialized airway devices, and/or expected airway complications due to comorbidities. Patients 80 years and older were analyzed. Demographic data collected were age, weight, BMI, gender, ASA classification, airway indices, diagnosis, and procedures. Problems with intubation (INT) (≥3 intubation attempts), laborious assisted ventilation (VEN) (2-person and/or application of CPAP > 20 cmH2O), and complications with oxygenation (OXY) (SpO2 Results Of the 41 patients enrolled in the study, 3 (7.3%) had all 3: problematic (INT), laborious (VEN), and desaturated (OXY); 8 (19.5%) patients experienced problematic (INT), 20 (48.8%) were described as laborious (VEN), and 14 (34.1%) experienced complications with (OXY). Conclusion In octogenarians, we found a low incidence of difficulty with INT-VEN-OXY together. However, bag mask ventilation was found to be laborious with a high incidence of desaturation. Success rate of INT as a sole metric may not accurately describe the process of the intubation. We recommend alternative airway devices and techniques and the establishment of protocols for airway management in the elderly.

Dificultades de procedimiento durante la intubación exitosa en octogenarios: un estudio prospectivo observacional

ObjectiveOctogenarians undergo anatomic and physiopathologic degradation, making airway management problematic, specific to intubation, bag mask ventilation, leading to desaturation and aspiration. Our study's aim was to examine the process of airway management regarding the steps involved in intubation and any deviations or delays in the tasks. Materials and methodsAn institutional review board-approved difficult airway prospective observational study in older adults was conducted. Inclusion criteria included airway features indicative of difficult airway, history of failed intubation, the planned use of specialized airway devices, and/or expected airway complications due to comorbidities. Patients 80 years and older were analyzed. Demographic data collected were age, weight, BMI, gender, ASA classification, airway indices, diagnosis, and procedures. Problems with intubation (INT) (≥3 intubation attempts), laborious assisted ventilation (VEN) (2-person and/or application of CPAP>20cmH2O), and complications with oxygenation (OXY) (SpO2<95%) were analyzed. ResultsOf the 41 patients enrolled in the study, 3 (7.3%) had all 3: problematic (INT), laborious (VEN), and desaturated (OXY); 8 (19.5%) patients experienced problematic (INT), 20 (48.8%) were described as laborious (VEN), and 14 (34.1%) experienced complications with (OXY). ConclusionIn octogenarians, we found a low incidence of difficulty with INT-VEN-OXY together. However, bag mask ventilation was found to be laborious with a high incidence of desaturation. Success rate of INT as a sole metric may not accurately describe the process of the intubation. We recommend alternative airway devices and techniques and the establishment of protocols for airway management in the elderly.

The effect of intraoperative ventilation with recruitment maneuver on the state of pulmonary gas exchange and spirography after plastics large ventral hernias

The effect of intraoperative ventilation with recruitment maneuver (RM) 40/10 and PEEP 7-10 cm water article on the state of pulmonary gas exchange and spirography after plastics large ventral hernias. It is found that this strategy ventilation maintains an optimal level of oxygenation, reduces abnormal increase gradient P(a-et) CO 2 in the first 24 hours postoperative. However, by 48 hours after the plastic does not affect the continued decline in oxyge nation, an abnormal in crease in the gradient of P(a-et) CO 2 . In the postoperative restrictive syndrome The strategy did not affect ventilation.

Variability in Anticoagulation Management of Patients on Extracorporeal Membrane Oxygenation

The objective of this study was to determine current practices of anticoagulation in patients on extracorporeal membrane oxygenation. Internet-based cross-sectional survey distributed between November 2010 and May 2011. Extracorporeal Life Support Organization-registered extracorporeal membrane oxygenation centers internationally. : Extracorporeal membrane oxy genation medical directors and coordinators. None. There were 121 responses from extracorporeal membrane oxy genation medical directors and coordinators at 187 Extracorporeal Life Support Organization centers with access to the survey. Eighty-four of 117 (72%) respondents reported having a written institutional extracorporeal membrane oxy genation protocol for both anticoagulation and blood product management at their institutions. Sixty-nine of 117 (59%) respondents reported use of tip-to-tip or partially heparin-bonded circuits. Unfractionated heparin was used at all centers; only 8% of respondents indicated use of alternative anticoagulation medications in the six months prior to the survey. The preferred method of anticoagulation monitoring was the serial measurement of activated clotting time, as reported by 97% of respondents. In this survey, 82% of respondents reported antithrombin III testing, 65% reported anti-factor Xa testing, and 43% reported use of thromboelastography during extracorporeal membrane oxy genation. Goal ranges for these three tests and interventions triggered by out-of-range values were found to be variable. Extracorporeal membrane oxy genation anticoagulation management policies vary widely by center. The majority of extracorporeal membrane oxy genation programs employ activated clotting time as the preferred anticoagulation monitoring tool. The coagulation system is also monitored using more specific markers such as antithrombin III, anti-factor Xa, and thromboelastography by a large number of centers. Future research is needed to elucidate optimal anticoagulation management and improve outcomes.

An Exercise Therapy Program Can Increase Oxygenation and Blood Volume of the Erector Spinae Muscle During Exercise in Chronic Low Back Pain Patients

ObjectiveTo determine whether erector spinae muscle oxygenation (OXY) and blood volume during a progressive isoinertial lifting evaluation (PILE) are modified by an exercise therapy program. DesignPre- (t1) and post- (t2) exercise therapy experimental design. SettingHospital. ParticipantsSubjects with chronic low back pain (LBP group) (n=24) and healthy subjects (control group) (n=24) were evaluated. InterventionExercise program. Main Outcome MeasuresThe control group was evaluated once, and the LBP group was evaluated before (t1) the exercise therapy program and 28 days thereafter (t2). The maximal load lifted, total work, and total power were determined using the PILE test. Continuous-wave near-infrared spectroscopy was used to measure OXY and blood volume during the PILE test. ResultsThe maximal load lifted, total power, and total work were significantly lower in the LBP group (−42%±5%, −46%±6%, and −67%±6% at t1, respectively; P<.05) than the control group. In the LBP subjects, these parameters improved significantly after the exercise therapy program (+20%±3%, +56%±4%, and +61%±5%; P<.05). At each submaximal power (ie, 25, 50, 75, and 100% of maximal load lifted at t1), OXY and blood volume were significantly higher at t2 than t1. One-half recovery time for OXY was significantly higher in the LBP group (at t1 and t2) than in control subjects. ConclusionsThe findings in this study suggest that LBP subjects present an impairment in their capacity to deliver oxygen at the level of the erector spinae muscle, which can be partly restored by an exercise therapy program.

Airway management outside the operating theatre

This review is intended to assist anesthesiologists in assessment and intubation of patients in venues other than the operating room (OR). Rapid assessment to identify patients at risk of failed intubation and oxy genation is essential to avoid a potentially disastrous emergency “Can’t Intubate, Can’t Ventilate” scenario. The equipment and drugs required for intubation may need to be taken to the venue where intubation is required as they may not be as freely available as in the OR. Extubation of the previously difficult airway needs to take place in a similar venue and with similar drugs and equipment available as when intubation was performed.

Monitoring individual erector spinae fatigue responses using electromyography and near infrared spectroscopy.

This study examined the utility of electromyography and near-infrared spectroscopy (NIRS) in assessing m. erector spinae activity during the Biering-Sorensen Back Muscle Endurance (BSME) test. Six men and four women (27.0 +/- 7.1 years of age) performed the BSME test (time = 131.5 +/- 43.5 s). EMG was used to quantify neuromuscular activity of the right and left side at the L3 level, and root mean square was scaled for maximum value at the start of the exercise. NIRS was used to evaluate blood volume (BV) and oxygenation (OX) simultaneous with EMG bilaterally at the L3 level. There was a decrease to 49+/- 8% of initial median frequency (mean= 83 Hz) on both right and left sides when the exercise was 90% complete, and the slope of the median frequency/time relationship was significantly related to BSME time (r = 0.82). Group means for BV increased during back exercise while OX decreased and was significantly different between right and left sides of the lower back. However, large OX response differences among individuals and between right and left sides were noted. OX and median frequency were moderately related (r = 0.27-0.38). It appears that NIRS combined with EMG is a promising tool for assessing localized metabolic and neuromuscular activity during static contractions of the lower back.

SIMULTANEOUS MEASUREMENT OF CEREBRAL AND MUSCLE TISSUE OXYGENATION USING NIRS.

The simultaneous measurement of cerebral and muscle oxygenation (OX) and blood volume (BV) has not been studied during exercise using non-invasive near infrared spectroscopy (NIRS) when additional muscle mass is added to ongoing steady state exercise. This could provide some indication on how blood flow is redistributed when performing multi-exercise tasks. PURPOSE To examine the simultaneous measurement of OX and BV changes in the forearm flexor digitorum (OXf; BVf), vastus lateralis (OXv; BVv), and cerebral-frontal lobe (OXc; BVc) tissue using NIRS. METHODS Nine well-trained male cyclists (VO2max =69.2 ± 9.5 mL×kg−1×min−1) performed steady state cycle ergometry for 5 min below (BVT) and above (AVT) the ventilation threshold. Maximal rhythmical hand-grip exercise was performed for one min with the right hand during the last minute at each exercise intensity. Cardiorespiratory measurements were also recorded simultaneously. RESULTS The results indicated that OXc and BVc increased systematically during cycling exercise (r=0.975) and demonstrated an additional increase during maximal hand-grip exercise. However, BVT there was an increased OXv (10%; i.e. reduced deoxygenation) and a levelling-off of BVv in relation to the steady state exercise, while OXf [91%; (i.e. greater deoxygenation)] and BVf (35%) decreased. Similar trends were noted AVT but to a lesser degree. Whole body VO2 was significantly correlated to OX and BV changes BVT and AVT in all tissues monitored (r=0.64–0.98). CONCLUSION These results indicate that: (1) addition of maximal hand-grip exercise during submaximal cycling increases cerebral hemodynamcis, most likely due to increased cortical activation, and (2) OX and BV can be compromised in the vastus lateralis muscle during cycling exercise at intensities below and above the ventilatory threshold. Support by Faculty Research Fund, VP Research, UNB.

Use of Percutaneous Transtracheal Jet Ventilation (PTJV) during Difficult Airway Management

A life threatening situation can occur if tracheal intubation and bag-mask-valv e ventilation are unable to be performed in restoring adequate gas exchange dur ing acute respiratory failure. Under these circumstances, percutaneous transtra cheal jet ventilation (PTJV) using a large bore needle provides immediate oxyge nation and ventilation. In the present case, PTJV proved to be a life saving pr ocedure by providing adequate gas-exchange and ensuring the patency of the airw ay until a definitive procedure such as oral intubation with bronchoscopy follo wed by surgical tracheostomy was performed. Therapeutic indications and complic ations of PTJV are discussed.

Analytic Reviews : Red Cell Transfusion in a Critical Care Unit

The acquired immunodeficiency syndrome epidemic and recognition of human immunodeficiency virus transmission by blood products have increased concern over the risks of blood transfusion and generated discus sion on proper indications. To assess current practice with respect to red blood cell transfusion, we examined transfusion practices in a medical-surgical intensive care unit. The extensive clinical and physiological moni toring in this setting allowed us to examine indices of oxygen carrying capacity, oxygen delivery, tissue oxy genation, and their associations with subsequent trans fusion. We were unable to detect changes in hemody namic or tissue oxygenation measurements associated with transfusions. Tissue oxygenation measures were in frequently documented even in the presence of an in dwelling pulmonary artery catheter. Hemoglobin and hematocrit levels showed statistically significant de creases prior to initial and subsequent transfusions. He modynamic and tissue oxygenation indices available in intensive care settings merit further evaluation for use in the assessment of transfusion need.

Observations on the foetal development of the reindeer

The offsprings of different species show a wide range of stages of maturi ty at b i r th . The y o u n g may be almost completely unable to move and require perfect protect ion and rather thorough nurs ing , o r may have an excellent insulatory hair coat and be able to walk almost immediately after b i r th . Regardless of the degree of matur i ty at b i r th a prerequisite of extrauterine life exists c o m m o n among all mammal ian species. A l l y o u n g must have developed c irculat ion and lungs capable of mainta ining independent life. T h e foetal systemic and p u l m o n a r y c irculat i ons are coupled parallely and the p u l m o n a r y circuit comprises a high-pressure system. The foetal shunts and high p o u l m o n a r y vascular resistance guarantee a larger f l ow i n the systemic c i rculat ion than in the p u l m o n a r y c irculat ion. Af ter b i r th placental oxygenat ion of the b lood is completely abolished and replaced by the lungs. T h e c i rculatory rearrangements occurr ing after b i r th consist not on ly of the closure of the shunts, but also recoupl ing of the t w o circuits in series as seen dur ing extra-uterine life. The p u l m o n a r y c i rculat ion n o w becomes a lowpressure system whi le systemic arterial pressures gradually rise towards the adult levels. D u r i n g the first breath the airways open. The requirements the per ior neonatal cardiorespiratory system is facing to is comprised , not on ly of the maintainance of life under basal condit ions , but also the demands raised by thermoregulat ion, the alimentary canal after feeding or by l o c o m o t i o n or excretory organs. R u m i n a n t calves are able to wa lk and run soon after b i r th . T h i s is because of a well-developed l o c o m o t o r system at b i r t h . Th i s system c o m p r i ses not on ly the muscles and lever systems, but also the coordinative functions served by the central nervous system. T h e n e w b o r n reindeer calf shows h igh ly advanced adaptation to hostile environment b y having a good insulating coat