Virtual consultations: delivering outpatient clinics in paediatric surgery during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic has resulted in many changes to clinical practice, including the introduction of remote clinics. Those familiar with remote clinics have reported benefits to their use, such as patient satisfaction and cost benefits; however, ongoing challenges exist, including delivering optimal patient-centred care. As a tertiary paediatric surgery unit in the UK, completing remote clinics was a new experience for most of our surgical team. We completed a service evaluation early into the COVID-19 pandemic aiming to define and address issues when delivering remote clinics in paediatric surgery. Remote clinics were observed (telephone and video), with follow-up calls to families following the consultations. RESULTS: Eight paediatric surgeons were observed during their remote clinics (telephone n = 6, video n = 2). Surgeons new to remote clinics felt their consultations took longer and were reluctant to discharge patients. The calls did not always occur at the appointed time, causing some upset by parents. Prescription provision and outpatient investigations led to some uncertainty within the surgical team. Families (n = 11) were called following their child's appointment to determine how our remote clinics could be optimised. The parents all liked remote clinics, either as an intermediate until a face-to-face consultation or for continued care if appropriate.Our findings, combined by discussions with relevant managers and departments, led to the introduction of recommendations for the surgical team. An information sheet was introduced for the families attending remote clinics, which encouraged them to take notes before and during their consultations. CONCLUSIONS: There must be strong support from management and appropriate departments for successful integration of remote clinics. Surgical trainees and their training should be considered when implementing remote clinics. Our learning from the pandemic may support those considering integrating remote clinics in the future.

The multi-disciplinary management of complex congenital and acquired tracheo-oesophageal fistulae.

AIM OF THE STUDY: Complex tracheo-oesophageal fistulae (TOF) are rare congenital or acquired conditions in children. We discuss here a multidisciplinary (MDT) approach adopted over the past 5 years. METHODS: We retrospectively collected data on all patients with recurrent or acquired TOF managed at a single institution. All cases were investigated with neck and thorax CT scan. Other investigations included flexible bronchoscopy and bronchogram (B&B), microlaryngobronchoscopy (MLB) and oesophagoscopy. All cases were subsequently discussed in an MDT meeting on an emergent basis if necessary. MAIN RESULTS: 14 patients were referred during this study period of which half had a congenital aetiology and the other half were acquired. The latter included button battery ingestions (5/7) and iatrogenic injuries during oesophageal atresia (OA) repair. Surgical repair was performed on cardiac bypass in 3/7 cases of recurrent congenital fistulae and all cases of acquired fistulae. Post-operatively, 9/14 (64%) patients suffered complications including anastomotic leak (1), bilateral vocal cord paresis (1), further recurrence (1), and mortality (1). Ten patients continue to receive surgical input encompassing tracheal/oesophageal stents and dilatations. CONCLUSIONS: MDT approach to complex cases is becoming increasingly common across all specialties and is important in making decisions in these difficult cases. The benefits include shared experience of rare cases and full access to multidisciplinary expertise.

Methylomic profiling of cortex samples from completed suicide cases implicates a role for PSORS1C3 in major depression and suicide.

Major depressive disorder (MDD) represents a major social and economic health issue and constitutes a major risk factor for suicide. The molecular pathology of suicidal depression remains poorly understood, although it has been hypothesised that regulatory genomic processes are involved in the pathology of both MDD and suicidality. In this study, genome-wide patterns of DNA methylation were assessed in depressed suicide completers (n=20) and compared with non-psychiatric, sudden-death controls (n=20) using tissue from two cortical brain regions (Brodmann Area 11 (BA11) and Brodmann Area 25 (BA25)). Analyses focused on identifying differentially methylated regions (DMRs) associated with suicidal depression and epigenetic variation were explored in the context of polygenic risk scores for major depression and suicide. Weighted gene co-methylation network analysis was used to identify modules of co-methylated loci associated with depressed suicide completers and polygenic burden for MDD and suicide attempt. We identified a DMR upstream of the PSORS1C3 gene, subsequently validated using bisulfite pyrosequencing and replicated in a second set of suicide samples, which is characterised by significant hypomethylation in both cortical brain regions in MDD suicide cases. We also identified discrete modules of co-methylated loci associated with polygenic risk burden for suicide attempt, but not major depression. Suicide-associated co-methylation modules were enriched among gene networks implicating biological processes relevant to depression and suicidality, including nervous system development and mitochondria function. Our data suggest that there are coordinated changes in DNA methylation associated with suicide that may offer novel insights into the molecular pathology associated with depressed suicide completers.

Nutritional quality of the school-day diet in Irish children (5-12 years).

BACKGROUND: The European Commission has identified schools as a priority setting for health promotion, including nutrition education and intervention. The present study examined the school-day diet of Irish primary-school children with the aim of identifying opportunities for dietary improvement. METHODS: Data from The National Children's Food Survey (2003-2004) were used to establish a dataset of school-days. Dietary intake data were collected from 594 children (5-12 years) using a 7-day weighed food-record. The nutritional quality of the diet was examined for the total school-day and for food eaten 'before school', 'at school' and 'after school'. RESULTS: Examination of dietary intake on school-days has highlighted nutritional imbalances for intakes of fat, saturated fat, added sugars, sodium and dietary fibre (DF). Mean energy (E) intake for the overall school-day was 7.1 MJ, with 16% of energy provided from food eaten 'before school', 33%E from food eaten 'at school' and 53% of energy from food eaten 'after school'. Relative to the overall school-day, food eaten 'before school' was lower in saturated fat and sodium, and higher in DF and many micronutrients. Food eaten 'at school' was relatively high in added sugars and sodium; lower in DF and micronutrients; and similar in saturated fat compared to the overall school-day. Food eaten 'after school' was relatively high in DF and vitamin A; similar in saturated fat, magnesium and sodium; and lower in added sugars and other micronutrients compared to the overall school-day. CONCLUSIONS: To improve the overall nutritional quality of the school-day diet, food eaten at school should be targeted.

Introduction to The neurosciences and music IV: learning and memory.

The conference entitled "The Neurosciences and Music-IV: Learning and Memory'' was held at the University of Edinburgh from June 9-12, 2011, jointly hosted by the Mariani Foundation and the Institute for Music in Human and Social Development, and involving nearly 500 international delegates. Two opening workshops, three large and vibrant poster sessions, and nine invited symposia introduced a diverse range of recent research findings and discussed current research directions. Here, the proceedings are introduced by the workshop and symposia leaders on topics including working with children, rhythm perception, language processing, cultural learning, memory, musical imagery, neural plasticity, stroke rehabilitation, autism, and amusia. The rich diversity of the interdisciplinary research presented suggests that the future of music neuroscience looks both exciting and promising, and that important implications for music rehabilitation and therapy are being discovered.

Finding vessels--accuracy of CT for identifying anomalous feeding vessels in patients with congenital cystic lung lesions.

INTRODUCTION: Contrast computer tomography (CT) scanning is the investigation of choice for the further assessment of suspected cystic congenital lung lesions (CCLL). Its use to identify the presence of anomalous feeding vessels supplying the lesion is well documented, but data regarding its accuracy is limited. This study compares CT results to operative and pathological findings to determine the accuracy of CT in identifying these anomalous vessels. METHODS: 51 consecutive cases of cystic congenital lung lesions managed in one hospital by a single consultant were reviewed. All cases had contrast CT scans performed preoperatively, as standard practice in this institution. We compared the results of these CT scans to the macroscopic appearance at surgery and histological findings postoperatively. We also compared the results of 2 CT protocols used in our institution between 1999-2007 and 2007-2009, respectively. RESULTS: Anomalous vessels were reported on CT in 9 cases. All but 1 had concordant operative and pathological findings. In the remaining 42 cases, no anomalous vessels were seen on CT. Of these, 9 cases were found to have an anomalous blood supply at surgery, 6 of which were hybrid lesions and 3 isolated sequestrations. The specificity of CT in identifying feeding vessels in the study was 97% (95% CI: 0.83-0.99) and the sensitivity was 47% (95% CI: 0.23-0.71). The positive predictive value was 89% (95% CI: 0.50-0.99) and negative predictive value 79% (95% CI: 0.62-0.89). The most recent protocol yielded an improved sensitivity of 75% (95% CI: 0.22-0.98) and a specificity of 100% (95% CI: 0.46-1.0) with a 100% (95% CI: 0.31-1.0) positive and 83% (95% CI: 0.36-0.99) negative predictive value. CONCLUSION: CT is a specific investigation for identifying anomalous vessels in CCLL but lacks sensitivity, leading to a relatively low negative predictive value. This emphasises the need in every case to look for anomalous vessels at surgery to avoid morbidity and potential mortality. An improved protocol for CT scans leads to improved specificity and sensitivity and predictive values.

An examination of the influence of eating location on the diets of Irish children.

OBJECTIVES: To examine the influence of eating location on the quality of the diets of Irish children and to compare intakes at home with intakes at other people's homes and intakes outside the home, and to compare intakes at various locations outside the home. DESIGN: Food intake was measured using a 7-day weighed diary in 594 children from the Republic of Ireland (aged 5-12 years). Details of where the food was prepared or obtained were also recorded. RESULTS: Eighty-nine per cent of all eating occasions occurred at home; < 6% occurred at both other people's homes and outside the home (takeaway, restaurant, shop, other). The percentage of food energy from fat was above the recommended 35% at other people's homes and outside the home, specifically at takeaways and restaurants. Fibre and micronutrient intakes (per 10 MJ) were significantly higher at home than at the other locations (P < 0.05). Within the 'out' locations, fibre and micronutrient intakes were generally higher at restaurants and lower at shops. High consumers of foods outside the home had a statistically significant, but relatively small decline in nutrient intakes compared with non- or low consumers. Chips and processed potatoes, meat products, savouries, sugars and confectionery, and savoury snacks made the greatest contribution to foods consumed outside the home. CONCLUSIONS: The main focus of nutrition policies to improve the diets of Irish children should be the home environment rather than the food service sector. However, guidelines could call for better food choices outside the home to improve nutrient intakes.

Prevalence of overweight and obesity in Irish school children, using four different definitions.

OBJECTIVE: To determine the prevalence of overweight and obesity in Irish children using four different weight-for-height methods and to examine secular trends from previous national data. DESIGN: A cross-sectional survey. Weight and height were measured according to standard procedures and used to determine the prevalence of overweight and obesity using four weight-for-height methods of assessment, actual relative weight, the Centers for Disease Control and Prevention body mass index (BMI) for age charts for boys and girls, the BMI reference curves for the UK 1990 and the International Obesity Task Force age- and sex-specific BMI cutoffs. SETTING: The survey was carried out between 2003 and 2004 in the Republic of Ireland. SUBJECTS: Random representative sample of 596 children aged 5-12 years. RESULTS: The prevalence of overweight and obesity in Irish children is high, but varies considerably with each method. The prevalence of obesity in boys ranged from 4.1 to 11.2 % and in girls from 9.3 to 16.3%. Between 1990 and 2005, depending on the method used, there was a two-to-fourfold increase in obesity in children aged 8-12 years. CONCLUSION: It is evident given the variation displayed in the prevalence of obesity when using the different methods, that there is a discernible need for a single definition to identify the obese child in Ireland. The findings show a high prevalence of overweight and obesity in Irish school children and the increase in the prevalence of obesity over the last 15 years highlights this growing public health issue.

Selenium intakes in 18-64-y-old Irish adults.

OBJECTIVE: To measure the intake of selenium (Se) and the contribution of different food groups to Se intake in adults aged 18-64 y in Ireland. The adequacy of Se intake in the population is also assessed. DESIGN: Food consumption was estimated using a 7 day food diary for a representative sample (n=1379; men=662, women=717) of 18-64-y-old Irish adults selected randomly from the electoral register. Se intake was estimated using updated tables of food composition. RESULTS: Mean daily Se intakes (+/-s.d.) from all sources (ie food plus supplements), and from food sources alone, for the group of Irish adults aged 18-64 y were 52 (+/-23) and 50 (+/-21) microg, respectively. Mean daily Se intake (from all sources) was significantly higher in men of all ages than women of all ages at levels of 60 and 44 microg, respectively (P<0.001). Meat/meat products (30%), bread and rolls (24%), fish/fish products (approximately 11%), and milk and yoghurt (9%) were the main contributors to mean daily Se intake. Adequacy of Se intake in population groups was estimated as the percentage of the population with mean daily Se intakes that were lower than the average requirement of 40 microg. Using this measure, 45.6% of women and 17.1% of men had inadequate Se intakes. CONCLUSION: A significant prevalence of inadequate Se intakes was observed in Irish adults. Therefore, it would seem prudent that the Se status of the Irish population be investigated at this time.

The efficacy and safety of nutritional supplement use in a representative sample of adults in the North/South Ireland Food Consumption Survey.

OBJECTIVE: To describe the current use of nutritional supplements and their contribution to micronutrient intakes in a representative sample of Irish adults, to evaluate the impact of supplement use on the adequacy of micronutrient intakes and to assess the risk to supplement users of exceeding tolerable upper intake levels (UL). STUDY DESIGN AND SUBJECTS: Food intake data were collected in 1379 (662 male and 717 female) randomly selected Irish adults aged 18 to 64 years using a 7-day food diary. The current use of nutritional supplements was assessed using a self-administered questionnaire and respondents entered each supplement as it was consumed into the food diary. RESULTS: Twenty-three per cent of respondents regularly used nutritional supplements. Twice as many women used supplements as men. The intakes of micronutrients were significantly higher (P<0.001) in supplement users than in non-users. Micronutrient intakes from food sources were similar in male users and non-users of supplements, but were significantly higher (P<0.01) in female users, by 3 to 13%, for Fe, Mg, Mn, vitamins C and E and niacin than in non-users. The percentage of female users between 18 and 50 years who had mean Fe intakes below the average requirement (AR) (10 mg) decreased from 50 to 25 when the contribution from supplements was included. The use of supplements reduced the percentage of men who had mean intakes below the AR for Zn from 19 to 13, for riboflavin from 14 to 6 and for vitamin A from 20 to 5, and reduced the percentage of women with intakes below the AR for Ca from 23 to 16 and for riboflavin from 23 to 14. Twenty-one women out of 80 aged between 18 and 50 years, who consumed supplemental folate, achieved the intake of 600 microg recommended to prevent neural tube defects. Twenty-two per cent of the women who took iron and 15% of the women who took vitamin B6 in supplemental form had mean daily intakes that exceeded that UL for these nutrients. Supplement users did not exceed the UL for the other micronutrients. CONCLUSIONS: Supplementation appears to be beneficial in promoting adequate intakes of some micronutrients, particularly Fe and folate in women aged 18-50 years and vitamin A in men. There appears to be little risk to supplement users of experiencing adverse side effects due to excessive intakes of micronutrients.

The North/South Ireland Food Consumption Survey: mineral intakes in 18-64-year-old adults.

OBJECTIVE: To measure mineral intakes and the contribution of different food groups to mineral intakes in adults aged 18-64 years in Ireland. Intakes are reported for Ca, Mg, P, Fe, Cu and Zn. The adequacy of mineral intakes in the population and the risk of occurrence of excessive intakes are also assessed. DESIGN: Food consumption was estimated using a 7-day food diary for a representative sample (n=1379; 662 men, 717 women) of 18-64-year-old adults in the Republic of Ireland and Northern Ireland selected randomly from the electoral register. Mineral intakes (Ca, Mg, P, Fe, Cu and Zn) were estimated using tables of food composition. RESULTS: Mean nutrient density of intakes was higher for women than men for Ca and Fe and increased with age for all minerals, except Ca for men and Fe for women. Meat and meat products were the major contributor to mean daily intakes of Zn (38%), P (23%), Fe (18%), Cu (15%) and Mg (13%); dairy products (milk, yoghurt and cheese) to Ca (44%), P (22%), Zn (14%) and Mg (11%); bread and rolls to Fe (21%), Cu (18%), Ca and Mg (17%), Zn (13%) and P (12%); potatoes and potato products to Cu (16%), Mg (14%) and Fe (10%); and breakfast cereals to Fe (13%). In women of all ages nutritional supplements contributed 7.6%, 4.4%, 3.6% and 2.2% of mean daily intake of Fe, Zn, Cu and Ca, respectively, while in men of all ages, nutritional supplements contributed 2.7%, 2.3%, 1.7% and 0.6%, respectively, to mean daily intakes of Fe, Zn, Cu and Ca. Adequacy of minerals intakes in population groups was assessed using the average requirement (AR) as a cut-off value. A significant prevalence of intakes below the AR was observed for Ca, Fe, Cu and Zn but not P. A higher proportion of women than men had intakes below the AR for all minerals. Almost 50% of 18-50-year-old females had intakes below the AR for Fe, while 23%, 23% and 15% of women of all ages had intakes below the AR for Ca, Cu and Zn, respectively. For men of all ages, 11%, 8% and 13% had intakes below the AR for Ca, Cu and Zn, respectively. There appears to be little risk of excessive intake of Ca, Mg, P, Cu or Zn in any age/sex category. However, 2.9% of women of all ages had intakes above the tolerable upper intake level for Fe (45 mg) due to supplement use. CONCLUSION: Almost 50% of women aged 18-50 years had Fe intakes below the AR and relatively high proportions of women of all ages had intakes below the AR for Ca, Cu and Zn. With the possible exception of iron intake from supplements in women, there appears to be little risk of excessive intake of minerals in the adult population. Meat and meat products, dairy products (milk, cheese and yoghurt), bread and rolls, potatoes and potato products and breakfast cereals are important sources of minerals; nutritional supplements make only a small contribution to mineral intakes in the population as a whole but may contribute significantly to intakes among supplement users.

Effects of the stable prostacyclin analogue iloprost on mesenteric blood flow in porcine endotoxic shock.

OBJECTIVE: To determine the effects of the stable prostacyclin analog, iloprost, in a porcine model of endotoxin-induced mesenteric ischemia. DESIGN: Prospective, experimental, randomized, controlled study. SETTING: Animal research laboratory at a university medical center. INTERVENTIONS: Pigs were randomized to receive a constant infusion of iloprost (0.18 microg/kg/min) or an equivalent amount of carrier solution (normal saline) 30 mins before being infused with endotoxin (100 microg/kg over 1 hr). The infusion with iloprost or carrier solution was continued for the duration of the experiment. MEASUREMENTS AND MAIN RESULTS: Twelve pigs (six per group), weighing between 20 and 22 kg, underwent laparotomy during which a magnetic flowprobe was placed around the superior mesenteric artery and an ileal tonometer was inserted. Thirty minutes before they were infused with endotoxin, the animals were randomized to receive intravenous iloprost or normal saline. Endotoxin was infused centrally over a 60-min period. Animals received normal saline at a rate of 1.2 mL/kg/min which was begun at the start of the endotoxin infusion. Data were measured at the end of the endotoxin infusion (E60) and 1 hr later (E120). Mean arterial pressure was not affected by the dosage of iloprost used in this experiment. After resuscitation, the cardiac output returned to baseline in the iloprost-treated group but remained decreased in the control group (2.6 +/- 0.5 vs. 1.6 +/- 0.4 L/min). Superior mesenteric blood flow increased 34% above baseline levels in animals pretreated with iloprost (from 363 +/- 85 to 485 +/- 81 mL/min). The superior mesenteric PCO2 was significantly higher (53 +/- 9 vs. 40 +/- 5 torr; 7.1 +/- 1.2 vs. 5.3 +/- 0.7 kPa) and the ileal intramucosal pH was significantly lower (7.07 +/- .28 vs. 7.44 +/- .23) in the control group than in the iloprost-treated group. CONCLUSIONS: Pretreatment with intravenous iloprost effectively increased intestinal blood flow in this model of endotoxin-induced mesenteric ischemia. This action of the drug resulted in an attenuation of ileal intracellular acidosis. Since low-dose iloprost had no effect on mean arterial pressure, it may be a useful adjunct in the treatment of sepsis and septic shock.

Transthoracic bioimpedance can measure extravascular lung water in acute lung injury.

We used a porcine endotoxemic model of acute lung injury to compare extravascular lung water (EVLW) measured by right transthoracic bioimpedance to postmortem gravimetric EVLW measurements. Adult pigs were randomized into control (N = 5) or endotoxin groups [150 microgram/kg Escherichia coli lipopolysaccharide B for 1 hr followed by 3 hr of resuscitation for a thermodilution cardiac output less than 90% of baseline using either isotonic saline (N = 5) or isooncotic albumin (N = 5)]. Right lung resistance was measured using a novel electrode array and a highly sensitive analyzer and was used to calculate right lung resistivity. At the end of the experiment, animals in the endotoxin-albumin group had higher gravimetric EVLWs than those in the endotoxin-saline or control groups (P < 0.05). Right lung resistivity corrected for body weight significantly correlated with gravimetric EVLW (r2 = 0.49; SEE = 0.96; P = 0.0038). Using multiple regression analysis, a predictive equation for EVLW based on right lung resistivity, body weight, and mean pulmonary artery pressure was generated (r2 = 0.81; SEE = 0.60; P < 0.0001). These results demonstrate that right lung resistivity measurements can provide a noninvasive estimate of EVLW. In addition, crystalloid may be preferable to colloid for fluid resuscitation in noncardiogenic pulmonary edema.

Continuous fiberoptic arterial and venous blood gas monitoring in hemorrhagic shock.

STUDY OBJECTIVE: To compare the performance of continuous fiberoptic blood gas monitoring with standard, intermittent blood gas sampling in the measurement of arterial and central venous blood gases during marked hemodynamic changes. DESIGN: Prospective, consecutive, enrollment, experimental study. SETTING: Research laboratory at a university medical center. PARTICIPANTS: Seven anesthetized, mechanically ventilated pigs. INTERVENTIONS: Severe shock was induced by hemorrhage in pigs monitored by a pulmonary artery catheter, an arterial line, and two fiberoptic blood gas sensors: one intra-arterial, and the other inserted into the superior vena cava via right internal jugular vein cutdown. Fiberoptic blood gas monitor measurements were compared with standard intermittent blood gas sampling. MEASUREMENTS AND RESULTS: A total of 184 blood gas samples were compared in seven animals at baseline, during shock, and after resuscitation. The baseline mean (+/- 1 SD) cardiac output decreased from 4.0 +/- 0.9 to 1.2 +/- 0.6 L/min during shock and returned to baseline after retransfusion (3.9 +/- 1.3 L/min). The comparison of continuous fiberoptic blood gas monitoring with intermittent blood gas sampling showed a bias+/-precision of 0.035 +/- 0.047 for arterial pH, 0.021 +/- 0.031 for central venous pH, -4.09 +/- 2.96 mm Hg (-0.55 +/- 0.39 kPa) for arterial Pco2, -3.67 +/- 2.44 mm Hg (-0.49 +/- 0.3 3 kPa) for central venous Pco2, -5.79 +/- 9.64 mm Hg (-0.77 +/- 1.29 kPa) for arterial Po2, and -7.85 +/- 8.52 mm Hg (-1.05 +/- 1.14 kPa) for central venous Po2. CONCLUSIONS: Continuous fiberoptic blood gas monitoring agrees closely with standard intermittent blood gas sampling during severe hemodynamic shifts and has a comparable accuracy for both arterial and venous blood gas measurements. Changes in venous Pco2 have recently been shown to correlate with changes in global tissue perfusion (eg, changes in cardiac output). Such data, available immediately via continuous venous blood gas monitoring, may be useful for monitoring shock and the response to resuscitation.

Quantitation of the renal clearance of interleukin-2 using nephrectomized and ureter-ligated rats.

The objective of this work was to determine the role of the kidneys in the systemic clearance rate (CL) of interleukin-2 (IL-2). Rats received IL-2 by i.v. bolus and the pharmacokinetic data were found to be well described by a two-compartment, first-order elimination model. With administration of 0.2, 0.5 or 1.0 mg/kg of IL-2 (n = 3 per treatment), the median alpha and beta half-lives (T1/2 alpha, 2.3 min; T1/2 beta, 13.2 min, respectively), initial volume of distribution (V1, 93 ml/kg), volume of distribution at steady state (Vss, 198 ml/kg) and CL (16.8 ml min-1 kg-1) did not vary with the dose (P = .05). This demonstration of first-order kinetics suggested that renal CL remains constant over a range of doses. The pharmacokinetic properties of 1.0 mg/kg of IL-2 were examined after either single or double nephrectomy (n = 3 and 4, respectively), sham operation (n = 4) or no renal operation (n = 4; the "controls"). No difference in median T1/2 alpha, T1/2 beta, V1, Vss or CL was detected between control and sham-operated rats nor between single nephrectomy and sham operation. Compared with sham operation, double nephrectomy showed no significant change in V1 or Vss but the T1/2 alpha and T1/2 beta approximately doubled and CL was reduced by 75%. In a separate experiment, ureter-ligated rats were compared with sham-operated rats. With ureter ligation, T1/2 alpha, T1/2 beta, V1 and Vss were unchanged but CL was reduced by 36%.

Effects of acid-base correction on hemodynamics, oxygen dynamics, and resuscitability in severe canine hemorrhagic shock.

OBJECTIVE: To compare the effects of hypertonic saline, sodium bicarbonate, and Carbicarb resuscitation on acid-base balance, hemodynamics, and oxygen dynamics in a reperfused, canine hemorrhagic shock model. DESIGN: Prospective, randomized trial. SETTING: Laboratory at a university medical center. SUBJECTS: Thirty-five anesthetized, mongrel dogs. INTERVENTIONS: After the administration of anesthesia, the dogs were intubated and mechanically ventilated. Vascular catheters were inserted into each femoral artery, for continuous blood pressure monitoring, intermittent blood sampling, and for establishing controlled hemorrhage. A pulmonary artery catheter was inserted via the right jugular vein. Inhaled and exhaled gases were continuously analyzed using a metabolic gas monitor. The animals were subjected to 90 mins of controlled hemorrhagic shock. They were then randomly given a 2.5-mL/kg equimolar injection of 8.4% sodium bicarbonate, Carbicarb, or 5.84% hypertonic saline. The sodium load per kilogram of body weight was identical in all three groups. Thirty minutes later, the animals were retransfused with the shed blood over 15 mins and further observed for 120 mins. MEASUREMENTS AND MAIN RESULTS: Carbicarb and sodium bicarbonate both significantly increased bicarbonate concentrations compared with saline. Arterial and venous blood pH increased more with Carbicarb than with bicarbonate but this increase was not statistically significant. After shock but before retransfusion, all three treatments moderately increased blood pressure, cardiac index, oxygen delivery index, and oxygen consumption index to a similar extent. After retransfusion, blood pressure, cardiac index, and oxygen dynamics temporarily improved in all groups, without significant improvement in the bicarbonate and Carbicarb-treated animals, despite their excellent acid-base status. CONCLUSIONS: In severe canine hemorrhagic shock, Carbicarb, bicarbonate, and hypertonic saline appear to possess similar hemodynamic properties despite the buffering properties of bicarbonate and Carbicarb. The similar responses may be due to their identical sodium content. Arterial pH correction does not appear to further improve the responses to blood retransfusion.