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Hu RT, Lankadeva YR, Yanase F, Osawa EA, Evans RG, Bellomo R. Continuous bladder urinary oxygen tension as a new tool to monitor medullary oxygenation in the critically ill. Crit Care 2022; 26:389. [PMID: 36527088 PMCID: PMC9758873 DOI: 10.1186/s13054-022-04230-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 11/09/2022] [Indexed: 12/23/2022] Open
Abstract
Acute kidney injury (AKI) is common in the critically ill. Inadequate renal medullary tissue oxygenation has been linked to its pathogenesis. Moreover, renal medullary tissue hypoxia can be detected before biochemical evidence of AKI in large mammalian models of critical illness. This justifies medullary hypoxia as a pathophysiological biomarker for early detection of impending AKI, thereby providing an opportunity to avert its evolution. Evidence from both animal and human studies supports the view that non-invasively measured bladder urinary oxygen tension (PuO2) can provide a reliable estimate of renal medullary tissue oxygen tension (tPO2), which can only be measured invasively. Furthermore, therapies that modify medullary tPO2 produce corresponding changes in bladder PuO2. Clinical studies have shown that bladder PuO2 correlates with cardiac output, and that it increases in response to elevated cardiopulmonary bypass (CPB) flow and mean arterial pressure. Clinical observational studies in patients undergoing cardiac surgery involving CPB have shown that bladder PuO2 has prognostic value for subsequent AKI. Thus, continuous bladder PuO2 holds promise as a new clinical tool for monitoring the adequacy of renal medullary oxygenation, with its implications for the recognition and prevention of medullary hypoxia and thus AKI.
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Affiliation(s)
- Raymond T. Hu
- grid.410678.c0000 0000 9374 3516Department of Anaesthesia, Austin Health, Heidelberg, VIC Australia ,grid.1008.90000 0001 2179 088XDepartment of Critical Care, Melbourne Medical School, The University of Melbourne, Parkville, VIC Australia
| | - Yugeesh R. Lankadeva
- grid.1008.90000 0001 2179 088XDepartment of Critical Care, Melbourne Medical School, The University of Melbourne, Parkville, VIC Australia ,grid.1008.90000 0001 2179 088XPre-Clinical Critical Care Unit, Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC Australia
| | - Fumitake Yanase
- grid.414094.c0000 0001 0162 7225Department of Intensive Care, Austin Hospital, Heidelberg, Australia
| | - Eduardo A. Osawa
- Cardiology Intensive Care Unit, DF Star Hospital, Brasília, Brazil ,grid.472984.4D’Or Institute for Research and Education (IDOR), DF Star Hospital, Brasília, Brazil
| | - Roger G. Evans
- grid.1008.90000 0001 2179 088XPre-Clinical Critical Care Unit, Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, VIC Australia ,grid.1002.30000 0004 1936 7857Cardiovascular Disease Program, Biomedicine Discovery Institute and Department of Physiology, Monash University, Clayton, VIC Australia
| | - Rinaldo Bellomo
- grid.1008.90000 0001 2179 088XDepartment of Critical Care, Melbourne Medical School, The University of Melbourne, Parkville, VIC Australia ,grid.414094.c0000 0001 0162 7225Department of Intensive Care, Austin Hospital, Heidelberg, Australia ,grid.1002.30000 0004 1936 7857Australian and New Zealand Intensive Care Research Centre, Monash University, Melbourne, Australia ,grid.416153.40000 0004 0624 1200Department of Intensive Care, Royal Melbourne Hospital, Parkville, Australia
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Atherton J, Pendley B, Guziński M, Bissler J, Lindner E. Urinary pCO<sub>2</sub> Monitoring System with a Planar Severinghaus Type Sensor. ELECTROANAL 2022. [DOI: 10.1002/elan.202100678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Chirnoaga D, Coeckelenbergh S, Ickx B, Van Obbergh L, Lucidi V, Desebbe O, Carrier FM, Michard F, Vincent JL, Duranteau J, Van der Linden P, Joosten A. Impact of conventional vs. goal-directed fluid therapy on urethral tissue perfusion in patients undergoing liver surgery: A pilot randomised controlled trial. Eur J Anaesthesiol 2022; 39:324-332. [PMID: 34669645 DOI: 10.1097/eja.0000000000001615] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Although fluid administration is a key strategy to optimise haemodynamic status and tissue perfusion, optimal fluid administration during liver surgery remains controversial. OBJECTIVE To test the hypothesis that a goal-directed fluid therapy (GDFT) strategy, when compared with a conventional fluid strategy, would better optimise systemic blood flow and lead to improved urethral tissue perfusion (a new variable to assess peripheral blood flow), without increasing blood loss. DESIGN Single-centre prospective randomised controlled superiority study. SETTING Erasme Hospital. PATIENTS Patients undergoing liver surgery. INTERVENTION Forty patients were randomised into two groups: all received a basal crystalloid infusion (maximum 2 ml kg-1 h-1). In the conventional fluid group, the goal was to maintain central venous pressure (CVP) as low as possible during the dissection phase by giving minimal additional fluid, while in the posttransection phase, anaesthetists were free to compensate for any presumed fluid deficit. In the GDFT group, patients received in addition to the basal infusion, multiple minifluid challenges of crystalloid to maintain stroke volume (SV) variation less than 13%. Noradrenaline infusion was titrated to keep mean arterial pressure more than 65 mmHg in all patients. MAIN OUTCOME MEASURE The mean intra-operative urethral perfusion index. RESULTS The mean urethral perfusion index was significantly higher in the GDFT group than in the conventional fluid group (8.70 [5.72 to 13.10] vs. 6.05 [4.95 to 8.75], P = 0.046). SV index (ml m-2) and cardiac index (l min-1 m-2) were higher in the GDFT group (48 ± 9 vs. 33 ± 7 and 3.5 ± 0.7 vs. 2.4 ± 0.4, respectively; P < 0.001). Although CVP was higher in the GDFT group (9.3 ± 2.5 vs. 6.5 ± 2.9 mmHg; P = 0.003), intra-operative blood loss was not significantly different in the two groups. CONCLUSION In patients undergoing liver surgery, a GDFT strategy resulted in a higher mean urethral perfusion index than did a conventional fluid strategy and did not increase blood loss despite higher CVP. TRIAL REGISTRATION NCT04092608.
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Affiliation(s)
- Dragos Chirnoaga
- From the Department of Anaesthesiology, Erasme University Hospital, Université Libre de Bruxelles, Brussels (DC, SC, BI, LVO, AJ), Unit of Hepatobiliary Surgery and Liver Transplantation, Department of Digestive Surgery, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium (VL), Department of Anesthesiology, Sauvegarde Clinic, Ramsay Santé, Lyon, France (OD), Department of Anesthesiology and Pain Medicine, Université de Montréal, Centre de recherche du CHUM, Montreal, Québec, Canada (F-MC), MiCo, Denens, Switzerland (FM), Department of Intensive Care, Erasme University Hospital, Université Libre de Bruxelles, Brussels, Belgium (J-LV), Department of Anaesthesiology and Intensive Care, Assistance Publique Hôpitaux de Paris, Paris-Saclay University, Bicetre Hospital, Paris, France (JD) and Department of Anaesthesiology, Brugmann Hospital, Université Libre de Bruxelles, Brussels, Belgium (PVdL)
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Morgaz J, Espigares-Rodríguez L, Muñoz-Rascón P, Navarrete R, Fernández-Sarmiento JA, Granados Machuca MDM. Evaluation of gastric and bladder tonometry as indicators of tissue perfusion in induced hypotension in dogs. J Vet Emerg Crit Care (San Antonio) 2017; 27:532-538. [DOI: 10.1111/vec.12642] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2015] [Revised: 01/29/2016] [Accepted: 03/04/2016] [Indexed: 12/16/2022]
Affiliation(s)
- Juan Morgaz
- Department of Animal Medicine and Surgery; University of Córdoba; Córdoba Spain
| | | | - Pilar Muñoz-Rascón
- Department of Animal Medicine and Surgery; University of Córdoba; Córdoba Spain
| | - Rocío Navarrete
- Department of Animal Medicine and Surgery; University of Córdoba; Córdoba Spain
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Elliott RA, Tonnu A, Ghaffar N, Taylor AH, Tincello DG, Norman RI. Enhanced purinergic contractile responses and P2X1 receptor expression in detrusor muscle during cycles of hypoxia-glucopenia and reoxygenation. Exp Physiol 2013; 98:1683-95. [PMID: 23975903 DOI: 10.1113/expphysiol.2013.075010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Bladders from patients with detrusor overactivity have an increased atropine-resistant contractile response to nerve stimulation. The bladder has also been shown to be very susceptible to hypoxia-glucopenia and reperfusion injury, leading to the hypothesis that episodes of hypoxia-glucopenia and reoxygenation result in increased atropine-resistant responses to nerve stimulation in the detrusor muscle. Detrusor muscle strips were suspended in a Perspex organ bath chamber of volume 0.2 ml perfused with Krebs solution at 37°C aerated with 21% O2, 5% CO2 and the balance nitrogen. Hypoxia-glucopenia was induced by switching perfusion to Krebs solution without glucose, gassed with 95% nitrogen and 5% CO2. Atropine-resistant contractile responses increased by 40.5 ± 7.3% after four cycles of hypoxia-glucopenia (10 min) and reoxygenation (1 h), whereas α,β-methylene ATP-resistant responses did not increase. Expression of P2X1 receptors in the bladder was increased after hypoxia-glucopenia and reoxygenation cycling, and ATP release from stimulated bladder strips during cycling was also increased. Other P2X receptor-mediated mechanisms may also be involved in the augmentation of bladder contraction during hypoxia-glucopenia and reoxygenation cycling, because a non-specific P2X antagonist blocked most of the augmented response, whereas a P2X1-specific antagonist prevented only part of the augmentation of contractile response induced by hypoxia-glucopenia and reoxygenation. In conclusion, four cycles of hypoxia-glucopenia and reoxygenation increased the purinergic, but not the cholinergic, contractile responses to nerve stimulation. Increased P2X1 receptor expression and ATP release may have contributed to the augmentation of contractile response induced by hypoxia-glucopenia and reoxygenation. Purinergic antagonists may, therefore, be a useful therapeutic option for the treatment of overactive bladder with increased purinergic-mediated contractions.
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Affiliation(s)
- R A Elliott
- R. A. Elliott: University of Leicester, Cancer Studies and Molecular Medicine, Reproductive Sciences Section, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester LE2 7LX, UK.
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Seller-Pérez G, Herrera-Gutiérrez ME, Aragón-González C, Granados MM, Dominguez JM, Navarrete R, Quesada-García G, Morgaz J, Gómez-Villamandos R. Bladder mucosal CO2 compared with gastric mucosal CO2 as a marker for low perfusion states in septic shock. ScientificWorldJournal 2012; 2012:360378. [PMID: 22593678 PMCID: PMC3349138 DOI: 10.1100/2012/360378] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2011] [Accepted: 11/02/2011] [Indexed: 11/17/2022] Open
Abstract
Recent reports indicate the possible role of bladder CO(2) as a marker of low perfusion states. To test this hypothesis, shock was induced in six beagle dogs with 1 mg/kg of E. coli lipopolysaccharide, gastric CO(2) (CO(2)-G) was measured with a continuous monitor, and a pulmonary catheter was inserted in the bladder to measure CO(2) (CO(2)-B). Levels of CO(2)-B were found to be lower than those of CO(2)-G, with a mean difference of 36.8 mmHg (P < 0.001), and correlation between both measurements was poor (r(2) = 0.16). Even when the correlation between CO(2)-G and ΔCO(2)-G was narrow (r(2) = 0.86), this was not the case for the relationship between CO(2)-B and ΔCO(2)-B (r(2) = 0.29). Finally, the correlation between CO(2)-G and base deficit was good (r(2) = 0.45), which was not the case with the CO(2)-B correlation (r(2) = 0.03). In our experience, bladder CO(2) does not correlate to hemodynamic parameters and does not substitute gastric CO(2) for detection of low perfusion states.
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Affiliation(s)
- Gemma Seller-Pérez
- Intensive Care Medicine, University Hospital Carlos Haya, 29010 Málaga, Spain
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Dubin A, Pozo MO, Edul VSK, Murias G, Canales HS, Barán M, Maskin B, Ferrara G, Laporte M, Estenssoro E. Urinary bladder partial carbon dioxide tension during hemorrhagic shock and reperfusion: an observational study. CRITICAL CARE : THE OFFICIAL JOURNAL OF THE CRITICAL CARE FORUM 2005; 9:R556-61. [PMID: 16277718 PMCID: PMC1297623 DOI: 10.1186/cc3797] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2005] [Revised: 07/20/2005] [Accepted: 07/25/2005] [Indexed: 11/24/2022]
Abstract
Introduction Continuous monitoring of bladder partial carbon dioxide tension (PCO2) using fibreoptic sensor technology may represent a useful means by which tissue perfusion may be monitored. In addition, its changes might parallel tonometric gut PCO2. Our hypothesis was that bladder PCO2, measured using saline tonometry, will be similar to ileal PCO2 during ischaemia and reperfusion. Method Six anaesthetized and mechanically ventilated sheep were bled to a mean arterial blood pressure of 40 mmHg for 30 min (ischaemia). Then, blood was reinfused and measurements were repeated at 30 and 60 min (reperfusion). We measured systemic and gut oxygen delivery and consumption, lactate and various PCO2 gradients (urinary bladder–arterial, ileal–arterial, mixed venous–arterial and mesenteric venous–arterial). Both bladder and ileal PCO2 were measured using saline tonometry. Results After bleeding systemic and intestinal oxygen supply dependency and lactic acidosis ensued, along with elevations in PCO2 gradients when compared with baseline values (all values in mmHg; bladder ΔPCO2 3 ± 3 versus 12 ± 5, ileal ΔPCO2 9 ± 5 versus 29 ± 16, mixed venous–arterial PCO2 5 ± 1 versus 13 ± 4, and mesenteric venous–arterial PCO2 4 ± 2 versus 14 ± 4; P < 0.05 versus basal for all). After blood reinfusion, PCO2 gradients returned to basal values except for bladder ΔPCO2, which remained at ischaemic levels (13 ± 7 mmHg). Conclusion Tissue and venous hypercapnia are ubiquitous events during low flow states. Tonometric bladder PCO2 might be a useful indicator of tissue hypoperfusion. In addition, the observed persistence of bladder hypercapnia after blood reinfusion may identify a territory that is more susceptible to reperfusion injury. The greatest increase in PCO2 gradients occurred in gut mucosa. Moreover, the fact that ileal ΔPCO2 was greater than the mesenteric venous–arterial PCO2 suggests that tonometrically measured PCO2 reflects mucosal rather than transmural PCO2. Ileal ΔPCO2 appears to be the more sensitive marker of ischaemia.
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Affiliation(s)
- Arnaldo Dubin
- Medical Director, Intensive Care Unit, Sanatorio Otamendi y Miroli, Buenos Aires, Argentina
| | - Mario O Pozo
- Staff physician, Intensive Care Unit, Clínicas Bazterrica y Santa Isabel, Buenos Aires, Argentina
| | - Vanina S Kanoore Edul
- Research Fellow, Cátedra de Farmacología, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, La Plata, Argentina
| | - Gastón Murias
- Staff physician, Intensive Care Unit, Clínicas Bazterrica y Santa Isabel, Buenos Aires, Argentina
| | - Héctor S Canales
- Staff physician, Intensive Care Unit, Hospital San Martín de La Plata, Argentina
| | - Marcelo Barán
- Medical Director, Renal Transplantation Unit, CRAI Sur, CUCAIBA, Argentina
| | - Bernardo Maskin
- Medical Director, Intensive Care Unit, Hospital Posadas, Buenos Aires, Argentina
| | - Gonzalo Ferrara
- Resident, Intensive Care Unit, Hospital San Martín de La Plata, Argentina
| | - Mercedes Laporte
- Medical Director, Clinical Chemistry Laboratory, Hospital San Martín de La Plata, Argentina
| | - Elisa Estenssoro
- Medical Director, Intensive Care Unit, Hospital San Martín de La Plata, Argentina
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Clavijo-Alvarez JA, Sims CA, Menconi M, Shim I, Ochoa C, Puyana JC. Bladder Mucosa pH and Pco2 as a Minimally Invasive Monitor of Hemorrhagic Shock and Resuscitation. ACTA ACUST UNITED AC 2004; 57:1199-209; discussion 1209-10. [PMID: 15625450 DOI: 10.1097/01.ta.0000145484.40534.3b] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Continuous monitoring of pH, Pco2, and Po2 using fiberoptic sensor technology has been proposed recently as a clinical monitor of the severity of shock and impaired tissue perfusion. Surrogates of gut tissue perfusion such as gastric tonometry, although cumbersome, have been used to indirectly quantify the degree of gut ischemia. The purpose of this study was to demonstrate the feasibility of monitoring bladder mucosa (BM) and to compare urinary bladder mucosa and proximal jejunum mucosa interstitial pH and Pco2 during hemorrhagic shock and resuscitation. METHODS Eleven male miniature swine (25-35 kg) (control, n = 4; shock, n = 7) underwent jejunal tonometry and cystostomy. A multisensor probe was placed adjacent to the BM. Urine was diverted. Normocarbia was maintained. Animals were hemorrhaged and kept at a mean arterial pressure of 40 mm Hg. When a constant infusion was required to maintain the mean arterial pressure at 40 mm Hg (decompensation), animals were resuscitated with shed blood plus two times the shed volume in lactated Ringer's solution (20 minutes) and observed for 2 hours. RESULTS During decompensation, BM pH values decreased significantly from 7.33 +/- 0.08 to 7.01 +/- 0.2 (p < 0.01) and recovered to 7.11 +/- 0.19 at 120 minutes after completion of resuscitation. During decompensation, BM Pco2 values increased significantly compared with baseline (from 49 +/- 6 mm Hg to 71 +/- 19 mm Hg, p < 0.05) and returned to baseline with resuscitation. Jejunum mucosa and BM interstitial Pco2 correlated throughout shock and resuscitation (r = 0.49). Bland-Altman analysis demonstrated significant differences between jejunum mucosa (intramucosal pH) and BM interstitial pH. CONCLUSION Shock-induced changes in the Pco2 of the BM are comparable to tonometric changes in the gut. These data suggest that continuous fiberoptic multisensor probe monitoring of the BM could potentially provide a minimally invasive method for the assessment of impaired tissue perfusion of the splanchnic circulation during shock and resuscitation.
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Affiliation(s)
- Julio A Clavijo-Alvarez
- Harvard Center for Minimally Invasive Surgery, Center of Integration of Medicine and Innovative Technology, Boston, Massachusetts, USA
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Maciel AT, Creteur J, Vincent JL. Tissue capnometry: does the answer lie under the tongue? Intensive Care Med 2004; 30:2157-65. [PMID: 15650865 DOI: 10.1007/s00134-004-2416-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2003] [Accepted: 07/26/2004] [Indexed: 10/26/2022]
Abstract
Increases in tissue partial pressure of carbon dioxide (PCO(2)) can reflect an abnormal oxygen supply to the cells, so that monitoring tissue PCO(2) may help identify circulatory abnormalities and guide their correction. Gastric tonometry aims at monitoring regional PCO(2) in the stomach, an easily accessible organ that becomes ischemic quite early when the circulatory status is jeopardized. Despite substantial initial enthusiasm, this technique has never been widely implemented due to various technical problems and artifacts during measurement. Experimental studies have suggested that sublingual PCO(2 )(P(sl)CO(2)) is a reliable marker of tissue perfusion. Clinical studies have demonstrated that high P(sl)CO(2) values and, especially, high gradients between P(sl)CO(2) and arterial PCO(2) (DeltaP(sl-a)CO(2)) are associated with impaired microcirculatory blood flow and a worse prognosis in critically ill patients. Although some questions remain to be answered about sublingual capnometry and its utility, this technique could offer new hope for tissue PCO(2) monitoring in clinical practice.
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Affiliation(s)
- Alexandre Toledo Maciel
- Department of Intensive Care, Erasme University Hospital, Free University of Brussels, Route de Lennik 808, 1070 Brussels, Belgium
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Tao W, Mathru M. Gut mucosal blood flow: regional regulation or systemic pressure dependence? Chest 2003; 124:427-8. [PMID: 12907524 DOI: 10.1378/chest.124.2.427] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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Sims C, Seigne P, Menconi M, Monarca J, Barlow C, Pettit J, Puyana JC. Skeletal muscle acidosis correlates with the severity of blood volume loss during shock and resuscitation. THE JOURNAL OF TRAUMA 2001; 51:1137-45; discussion 1145-6. [PMID: 11740266 DOI: 10.1097/00005373-200112000-00020] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
BACKGROUND Continuous assessment of tissue perfusion and oxygen utilization may allow for early recognition and correction of hemorrhagic shock. We hypothesized that continuously monitoring skeletal muscle (SM) PO2, PCO2, and pH during shock would provide an easily accessible method for assessing the severity of blood loss and the efficacy of resuscitation. METHODS Thirteen anesthetized pigs (25-35 kg) underwent laparotomy and femoral vessel cannulation. Multiparameter fiberoptic sensors were placed in the deltoid (SM) and femoral artery. Ventilation was maintained at a PaCO2 of 40-45 mm Hg. Total blood volume (TBV) was measured using an Evans blue dye technique. Animals were bled for 15 minutes, maintained at a mean arterial pressure (MAP) of 40 mm Hg for 1 hour, resuscitated (shed blood + 2 times shed volume in normal saline) and observed for 1 hour. Four animals served as controls (sham hemorrhage). Blood and tissue samples were taken at each time point. RESULTS Blood loss ranged from 28.5-56% of TBV. SM pH and SM PO2 levels fell rapidly with shock. SM PO2 returned to normal with resuscitation; however, SM pH did not return to baseline. SM PCO2 significantly rose with shock, but returned to baseline promptly with resuscitation. There was a significant correlation between SM pH and blood volume loss at end shock (r2 = 0.73, p < 0.001) and recovery (r2 = 0.84, p < 0.001). Animals (n = 2) whose SM pH did not recover to 7.2 were found to have ongoing blood loss from biopsy sites and persistent tissue hypercarbia despite normal MAP. CONCLUSION Continuous multiparameter monitoring of SM provides a minimally invasive method for assessing severity of shock and efficacy of resuscitation. Both PCO2 and PO2 levels change rapidly with shock and resuscitation. SM pH is directly proportional to lost blood volume. Persistent SM acidosis (pH < 7.2) and elevated PCO2 levels suggest incomplete resuscitation despite normalized hemodynamics.
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Affiliation(s)
- C Sims
- Harvard Center for Minimally Invasive Surgery, Brigham and Women's Hospital, Boston, Massachusetts, USA
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