Significance of Early Acidosis in Predicting Early Mortality Among Flame Burned Patients in a Kenyan National Hospital

Background: Burn pathophysiology, fluid therapy and mortality have been assessed by various laboratory parameters including lactate and base deficit serum markers. This study targeted flame injured cohort with an objective to determine the significance of early acidosis, through measurement of three acid base indices at admission in predicting 5-day (early) mortality among the flame burned patients.Methodology: A cohort study. Eighty flame injured patients presenting within 24 hours of incident were assessed for arterial blood pH, lactate and base deficit (BD). Mortality was recorded until day 28. Receiver operating characteristics curves were drawn; area under curve, cut offs, sensitivities and specificities for BD, lactate and pH were determined for 5-day mortality. The cut offs were used to derive contingency tables for calculation of predictive values. Odds ratios were calculated at 95% confidence interval. 28 day survival curve was generated. Level of significance was <0.05.Results: 28-day mortality was 39%. Five-day mortality was 24%. The latter was predicted by a lactate level of 2.36 mmol/L, BD of -10.05 mmol/L and pH of 7.344 with 75%,74% and 95% sensitivities respectively. Odds of patients dying at these levels or worse were 6.3, 11.4 and 36.9 respectively all with significant p-values.Conclusion: Arterial pH, base deficit and lactate are good predictors of 5-day mortality among fire victims in the Kenyan context.

Impact of obesity on survival in COVID-19 ARDS patients receiving ECMO: results from an ambispective observational cohort

Background Since March 2020, health care systems were importantly affected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak, with some patients presenting severe acute respiratory distress syndrome (ARDS), requiring extra-corporeal membrane oxygenation (ECMO). We designed an ambispective observational cohort study including all consecutive adult patients admitted to 5 different ICUs from a university hospital. The main objective was to identify the risk factors of severe COVID-19 ARDS patients supported by ECMO associated with 90-day survival. Results Between March 1st and November 30th 2020, 76 patients with severe COVID-19 ARDS were supported by ECMO. Median (interquartile range IQR) duration of mechanical ventilation (MV) prior to ECMO was of 6 (3–10) days. At ECMO initiation, patients had a median PaO2:FiO2 of 71 mmHg (IQR 62–81), median PaCO2 of 58 mmHg (IQR 51–66) and a median arterial pH of 7.33 (IQR 7.25–7.38). Forty-five patients (59%) were weaned from ECMO. Twenty-eight day, 60-day and 90-day survival rates were, respectively, 92, 62 and 51%. In multivariate logistic regression analysis, with 2 models, one with the RESP score and one with the PRESERVE score, we found that higher BMI was associated with higher 90-day survival [odds ratio (OR): 0.775 (0.644–0.934), p = 0.007) and 0.631 (0.462–0.862), respectively]. Younger age was also associated with 90-day survival in both models [OR: 1.1354 (1.004–1.285), p = 0.044 and 1.187 (1.035–1.362), p = 0.014 respectively]. Obese patients were ventilated with higher PEEP than non-obese patients and presented slightly higher respiratory system compliance. Conclusion In this ambispective observational cohort of COVID-19 severe ARDS supported by ECMO, obesity was an independent factor associated with improved survival at 90-day.

Analysis of pH and electrolytes in blood and ruminal fluid, including kidney function tests, in sheep undergoing long-term surgical procedures

Background The physiology of sheep as small ruminants is remarkably different from monogastric animals especially regarding the forestomach system. Using sheep for surgical procedures during scientific research thereby presents an exceptional setting for the anaesthetist. Long-term anaesthesia generally demands deprivation of food to reduce the risk of bloat in sheep. This might influence the energy and electrolyte balance. In horses and companion animals, close monitoring of mean arterial blood pressure, capnography and blood gas analysis are common procedures during long-term surgery. However, few data are available on reference ranges for blood gas in sheep and these cover only short periods of anaesthesia. To the authors’ knowledge, there is no study available that includes the monitoring of electrolytes and pH in ruminal fluid and kidney function tests in sheep undergoing long term anaesthesia. Thereby, the aim of the present study was to gather data on blood parameters, and data on ruminal fluid and kidney function during long-term anaesthesia in sheep. Data were obtained from eight sheep undergoing the invasive surgical procedure of left pneumonectomy and auto-transplantation or isolated left lung perfusion. After a 19-h fasting period, the animals were administered xylazine and ketamine and then intubated and maintained in general anaesthesia under artificial ventilation using isoflurane in oxygen. Blood samples were evaluated during 9 h of anaesthesia; ruminal fluid and kidney function tests were evaluated during 7 h of anaesthesia. Results Blood parameters such as electrolytes and partial pressure of carbon dioxide revealed few changes, yet blood glucose decreased and beta-hydroxybutyric acid increased significantly. All animals showed an elevated arterial pH and bicarbonate concentration despite artificial ventilation. In ruminal fluid, the pH significantly decreased and no significant changes in electrolytes occurred. Kidney function tests revealed no significant changes in any of the animals. However, fractional excretion of water and phosphate was slightly increased. One animal showed severe complications due to hypokalaemia. Conclusion Invasive surgery under long-term anaesthesia in sheep is possible without great imbalances of arterial pH and electrolytes. Nevertheless, potassium concentrations should be monitored carefully, as a deficiency can lead to life-threatening complications. The operated sheep tended not to develop metabolic acidosis and the mean kidney function could be maintained within the physiological range throughout anaesthesia. However, slight elevations in renal fractional water and phosphate excretion could suggest an early tubular reabsorption dysfunction. In ruminal fluid, acidification occurred, though no significant changes were observed in l- and d-lactate levels or in electrolyte concentrations. To our knowledge, the role of the rumen in storing fluids and balancing electrolytes in the blood has not yet been documented during anaesthesia. However, the importance of the rumen for fluid equilibrium in sheep indicates the necessity for routine monitoring and further research.

Severe portal and systemic acidosis during CO2-laparoscopy compared to helium or gasless laparoscopy and laparotomy in a rodent model: an experimental study

Background and aims This experimental study assesses the influence of different gases and insufflation pressures on the portal, central-venous and peripheral-arterial pH during experimental laparoscopy. Methods Firstly, 36 male WAG/Rij rats were randomized into six groups (n = 6) spontaneously breathing during anaesthesia: laparoscopy using carbon dioxide or helium at 6 and 12 mmHg, gasless laparoscopy and laparotomy. 45 and 90 min after setup, blood was sampled from the portal vein, vena cava and the common femoral artery with immediate blood gas analysis. Secondly, 12 animals were mechanically ventilated at physiological arterial pH during 90 min of laparotomy (n = 6) or carbon dioxide laparoscopy at 12 mmHg (n = 6) with respective blood gas analyses. Results Over time, in spontaneously breathing rats, carbon dioxide laparoscopy caused significant insufflation pressure-dependent portal acidosis (pH at 6 mmHg, 6.99 [6.95–7.04] at 45 min and 6.95 [6.94–6.96] at 90 min, pH at 12 mmHg, 6.89 [6.82–6.90] at 45 min and 6.84 [6.81–6.87] at 90 min; p < 0.05) compared to laparotomy (portal pH 7.29 [7.23–7.30] at 45 min and 7.29 [7.20–7.30] at 90 min; p > 0.05). Central-venous and peripheral-arterial acidosis was significant but less severely reduced during carbon dioxide laparoscopy. Laparotomy, helium laparoscopy and gasless laparoscopy showed no comparable acidosis in all vessels. Portal and central-venous acidosis during carbon dioxide laparoscopy at 12 mmHg was not reversible by mechanical hyperventilation maintaining a physiological arterial pH (pH portal 6.85 [6.84–6.90] (p = 0.004), central-venous 6.93 [6.90–6.99] (p = 0.004), peripheral-arterial 7.29 [7.29–7.31] (p = 0.220) at 90 min; Wilcoxon–Mann–Whitney test). Conclusion Carbon dioxide laparoscopy led to insufflation pressure-dependent severe portal and less severe central-venous acidosis not reversible by mechanical hyperventilation.

Significance of Early Acidosis In Predicting Early Mortality Among Flame Burned Patients In A Kenyan National Hospital

Introduction: Burn pathophysiology, fluid therapy and mortality have been assessed by various laboratory parameters including lactate and base deficit serum markers. This study targeted flame injured cohort with an objective to determine the significance of early acidosis, through measurement of three acid base indices at admission in predicting 5-day (early) mortality among the flame burned patients.Methodology: A cohort study. Eighty flame injured patients presenting within 24 hours of incident were assessed for arterial blood pH, lactate and base deficit (BD). Mortality was recorded until day 28. Receiver operating characteristics curves were drawn; area under curve, cut offs, sensitivities and specificities for BD, lactate and pH were determined for 5-day mortality. The cut offs were used to derive contingency tables for calculation of predictive values. Odds ratios were calculated at 95% confidence interval. 28 day survival curve was generated. Level of significance was <0.05.Results: 28-day mortality was 39%. Five-day mortality was 24%. The latter was predicted by a lactate level of 2.36 mmol/L, BD of -10.05 mmol/L and pH of 7.344 with 75%,74% and 95% sensitivities respectively. Odds of patients dying at these levels or worse were 6.3, 11.4 and 36.9 respectively all with significant p-values.Conclusion: Arterial pH, base deficit and lactate are good predictors of 5-day mortality among fire victims.

Impact of umbilical cord arterial pH, gestational age, and birth weight on neurodevelopmental outcomes for preterm neonates

Background The aim of this study was to determine the impact of umbilical cord arterial pH, gestational age, and birth weight on neurodevelopmental outcomes for preterm neonates. Methods We examined 112 neonates. Inclusion criteria were: Saturations greater than 88%, and heart rates between 100–205 beats per minute. Measurements We assessed several neurodevelopmental factors as part of the Brazelton Neonatal Behavioral Assessment Scale (NBAS), 4th edition, such as asymmetric tonic neck reflex (ATNR), motor maturity, response to sensory stimuli, habituation, and state regulation. Initial assessment parameters such as APGAR score and umbilical cord arterial pH were used to assess neonates. Results We found a strong correlation between the presence of the sucking reflex and umbilical cord arterial pH (r = 0.32; p = 0.018981). Umbilical cord arterial pH was also correlated with the presence of asymmetric tonic neck reflex (r = 0.27; p = 0.047124), cost of attention (r = 0.31; p = 0.025381) and general motor maturity (r = 0.34; p = 0.011741). Conclusions We found that the sucking reflex may be affected in infants with low umbilical cord arterial pH values. Practitioners and parents can use the NBAS to help determine neurodevelopmental factors and outcomes in preterm infants, possibly leading to safer and more effective feeding practices and interventions.

Predictors of acute kidney injury in patients with acute decompensated heart failure in emergency departments in China

Objective This retrospective multicentre observational study was performed to assess the predictors of acute kidney injury (AKI) in patients with acute decompensated heart failure (ADHF) in emergency departments in China. Methods In total, 1743 consecutive patients with ADHF were recruited from August 2017 to January 2018. Clinical characteristics and outcomes were compared between patients with and without AKI. Predictors of AKI occurrence and underdiagnosis were assessed in multivariate regression analyses. Results Of the 1743 patients, 593 (34.0%) had AKI. AKI was partly associated with short-term all-cause mortality and cost. Cardiovascular comorbidities such as coronary heart disease, diabetes mellitus, and hypertension remained significant predictors of AKI in the univariate analysis. AKI was significantly more likely to occur in patients with a lower arterial pH, lower albumin concentration, higher creatinine concentration, and higher N-terminal pro-brain natriuretic peptide (NT-proBNP) concentration. Patients treated with inotropic agents were significantly more likely to develop AKI during their hospital stay. Conclusion This study suggests that cardiovascular comorbidities, arterial pH, the albumin concentration, the creatinine concentration, the NT-proBNP concentration, and use of inotropic agents are predictors of AKI in patients with ADHF.

Acute Effects of the Wim Hof Breathing Method on Repeated Sprint Ability: A Pilot Study

The Wim Hof breathing method (WHBM) combines periods of hyperventilation (HV) followed by voluntary breath-holds (BH) at low lung volume. It has been increasingly adopted by coaches and their athletes to improve performance, but there was no published research on its effects. We determined the feasibility of implementing a single WHBM session before repeated sprinting performance and evaluated any acute ergogenic effects. Fifteen amateur runners performed a single WHBM session prior to a Repeated Ability Sprint Test (RAST) in comparison to voluntary HV or spontaneous breathing (SB) (control) in a randomized cross-over design. Gas exchange, heart rate, and finger pulse oxygen saturation (SpO2) were monitored. Despite large physiological effects in the SpO2 and expired carbon dioxide (VCO2) levels of both HV and WHBM, no significant positive or negative condition effects were found on RAST peak power, average power, or fatigue index. Finger SpO2 dropped to 60 ± 12% at the end of the BHs. Upon the last HV in the WHBM and HV conditions, end-tidal CO2 partial pressure (PETCO2) values were 19 ± 3 and 17 ± 3 mmHg, indicative of respiratory alkalosis with estimated arterial pH increases of +0.171 and of +0.181, respectively. Upon completion of RAST, 8 min cumulated expired carbon dioxide volumes in the WHBM and HV were greater than in SB, suggesting lingering carbon dioxide stores depletion. These findings indicate that despite large physiological effects, a single WHBM session does not improve anaerobic performance in repeated sprinting exercise.

Prediction of non-reassuring fetal status and umbilical artery acidosis by the maternal characteristic and ultrasound prior to induction of labor

Objective To investigate the predictive value of pre-induction digital examination, sonographic measurements and parity for the prediction of non-reassuring fetal status and cord arterial pH < 7.2 prior to the induction of labor (IOL). Method This was a prospective observational study, including 384 term pregnancies undergoing IOL. Before the IOL, the Bishop score (BS) by digital examination, sonographic Doppler parameters and the estimated fetal weight (EFW) was assessed. The fetal cord arterial was sampled to measure the pH at delivery. Multivariate logistic regression analysis was performed to identify independent predictors of non-reassuring fetal status and low cord arterial pH. Results Forty four cases (11.5%) had non-reassuring fetal status, and 76 cases (19.8%) had fetal cord arterial pH < 7.2. In the non-reassuring fetal status group, the incidence of cord arterial pH < 7.2 was significantly higher than that in the normal fetal heart rate group (χ2 = 6.401, p = 0.011). Multivariate analysis indicated that significant independent predictors of non-reassuring fetal status were nulliparity (adjusted odds ratio [AOR]: 3.746, p = 0.003), EFW < 10th percentile (AOR: 3.764, p = 0.003) and cerebroplacental ratio (CPR) < 10th centile (AOR:4.755, p < 0.001). In the prediction of non-reassuring fetal status, the performance of the combination of nulliparity and EFW < 10th percentile was improved by the addition of CPR < 10th percentile (AUC: 0.681, (95%CI: 0.636 to 0.742) vs 0.756, (95%CI:0.713 to 0.795)), but the difference was not significant (DeLong test: z = 1.039, p = 0.053).. None of the above variables were predictors of cord arterial pH < 7.2. Conclusion The risk of fetal acidosis has increased in cases of non-reassuring fetal status. Nulliparity, small for gestational age and CPR < 10th centile are independent predictors for non-reassuring fetal status in term fetuses, though the addition of CPR < 10th centile could not significantly improve the screening accuracy.

Characteristics and Clinical Course of Adult in Patients with SARS-CoV-2 Pneumonia at High Altitude

Background. SARS-CoV-2 has spread worldwide with different dynamics in each region. We aimed to describe the clinical characteristics and to explore risk factors of death, critical care admission, and use of invasive mechanical ventilation in hospitalized patients with SARS-CoV-2 pneumonia in a high-altitude population living in Bogotá, Colombia. Methods. We conducted a concurrent cohort study of adult patients with laboratory-confirmed SARS-CoV-2 pneumonia. Demographic, clinical, and treatment data were extracted from electronic records. Univariate and multivariable methods were performed to investigate the relationship between each variable and outcomes at 28 days of follow-up. Results. 377 adults (56.8% male) were included in the study, of whom 85 (22.6%) died. Nonsurvivors were older on average than survivors (mean age, 56.7 years [SD 15.8] vs. 70.1 years [SD 13.9]; p ≤ 0.001 ) and more likely male (28 [32.9%] vs. 57 [67.1%]; p = 0.029 ). Most patients had at least one underlying disease (333 [88.3%]), including arterial hypertension (149 [39.5%]), overweight (145 [38.5%]), obesity (114 [30.2%]), and diabetes mellitus (82 [21.8%]). Frequency of critical care admission (158 [41.9%]) and invasive mechanical ventilation (123 [32.6%]) was high. Age over 65 years (OR 9.26, 95% CI 3.29–26.01; p ≤ 0.001 ), ICU admission (OR 12.37, 95% CI 6.08–25.18; p ≤ 0.001 ), and arterial pH higher than 7.47 (OR 0.25, 95% CI 0.08–0.74; p = 0.01 ) were independently associated with in-hospital mortality. Conclusions. In this study of in-hospital patients with SARS-CoV-2 pneumonia living at high altitude, frequency of death was similar to what has been reported. ICU admission and use of invasive mechanical ventilation were high. Risk factors as older age, ICU admission, and arterial pH were associated with mortality.