A Transfusion Regimen With Same-donor Packed Red Blood Cells Reduces Exposure to Multiple Blood Donors in Craniosynostosis Surgery.

In major craniosynostosis surgery with moderate to severe blood loss, patients may be exposed to multiple donors. We have previously reported a method for reducing donor exposure using mixed pediatric units including plasma. To further reduce donor exposure, we used plasma-free divided pediatric units. The study aimed to investigate the feasibility of the new strategy for reducing donor exposure. This prospective observational study recruited children younger than 1 year who were scheduled for nonsyndromic craniosynostosis surgery. One adult red blood cell unit was divided into 4 equal units on the day before the operation for use intra- or postoperatively. Number of donor exposures, estimated blood loss, crystalloid, colloid, and blood product volumes, and coagulation parameters were evaluated. Nineteen infants were included. The mean estimated blood loss was 19 (3) mL/kg and the transfusion volume was 17 (7) mL/kg. The median donor exposure per patient was 1 (range, 1-3). During surgery, all infants received at least one DPU. Two infants received transfusions from more than one donor during the intraoperative period. In the first 24 hours postoperatively, 14 infants received transfusion; 10 received only DPUs, whereas 4 received from multiple donors. In all, multiple donor exposure was prevented in 14 of 19 infants. Postoperative Pk-INR was 1.33 (0.16); no plasma or platelets were transfused. The plasma-free DPU transfusion protocol may be useful to reduce donor exposure in open craniosynostosis surgery in infants.

Swedish registry study showed that 50% of paediatric operations were performed in university hospitals and mortality was low.

AIM: To investigate the distribution of paediatric surgery in various hospitals and to study postoperative risk factors of mortality. METHODS: Retrospective registry-based cohort study of children aged 0-14 years undergoing surgery from 2017 to 2021. Data were extracted from the Swedish Perioperative Registry. A mixed logistic regression was applied for the all-risk mortality analysis. RESULTS: A total of 126 539 cases were identified, 50% in university, 36% in county and 14% in district hospitals. The dominating operations were appendectomy in 6667, orchidopexy in 5287, inguinal hernia repair in 4200 and gastrostomy in 1152 children. Among children under 1 year of age or American Society of Anesthesiologists Physical Status classification (ASA-PS-Class) 3-5, the majority underwent surgery in university hospitals. The 30-day mortality in university hospitals was 0.5% and in county hospitals 0%. The proportion of emergency surgery was similar in university and county hospitals. Independent risk factors of mortality were being under 1 year of age, ASA-PS-class 4-5, emergency surgery and surgery at university hospitals. CONCLUSION: Half of all operations in children were performed in university hospitals, with low postoperative mortality despite effective centralisation of high risk patients <1 year of age or ASA-PS-Class 3-5.

Effect of high-flow nasal oxygen on postoperative oxygenation in obese patients: A randomized controlled trial.

Background and Aim: Postoperative hypoxemia is common after general anesthesia in obese patients. We investigated if early application of high-flow nasal oxygen (HFNO) improved postoperative oxygenation in obese patients compared with standard oxygen therapy following general anesthesia for laparoscopic bariatric surgery. Methods: This was an open labeled randomized controlled trial conducted at a university hospital in Sweden between October 23, 2018 and February 11, 2020. The study was performed as a substudy within a previously published trial. After ethics committee approval and written informed consent, 40 obese patients (body mass index [BMI] ≥ 35 kg m-2) scheduled for laparoscopic bariatric surgery were randomized to receive oxygen using a standard low-flow nasal cannula (NC group) or HFNO at 40 L min-1 (HF group) immediately upon arrival to the post-anesthesia care unit. Flow rate (NC group) or FiO2 (HF group) was titrated to reach an initial SpO2 of 95%-98% after which settings were left unchanged. The primary outcome was PaO2 at 60 min following postoperative baseline values. Secondary outcomes included PaCO2, SpO2, hemodynamic variables, and patient self-assessed discomfort. Results: Thirty-four patients were available for analysis. PaO2 was similar between groups at postoperative baseline. After 60 min, PaO2 had increased to 12.6 ± 2.8 kPa in the NC group (n = 15) and 14.0 ± 2.7 kPa in the HF group (n = 19); (mean difference 1.4 kPa, 95% confidence interval -0.6 to 3.3; p = 0.16). There were no differences in PaCO2, hemodynamic variables, or self-assessed discomfort between groups after 60 min. Conclusion: In obese patients, HFNO did not improve postoperative short-term oxygenation compared with standard low-flow oxygen following general anesthesia for laparoscopic bariatric surgery.

The COVID-19 pandemic first wave in Sweden: A national registry study of the effects on pediatric anesthesia and surgery.

BACKGROUND: The COVID-19 pandemic is pushing healthcare systems to their limits. Dramatic reductions in the adult elective surgery are ubiquitous, but corresponding changes in pediatric services are not well described. The Swedish Perioperative Registry contains data on all anesthetic procedures in Sweden, and therefore, provides a unique opportunity to analyze the effect of the pandemic on the pediatric anesthesia capacity on a national level. We hypothesized that there would be a significant reduction in pediatric elective procedures. The aim was to determine the effects on pediatric surgical and anesthetic services during the first wave of the COVID-19 pandemic in Sweden. METHODS: For this retrospective registry cohort study, we extracted all procedures performed on patients <18 years of age in 2020 and 2019. Weeks 12 to 26 of 2020 were defined as the first wave, and data were analyzed according to level of care, type of surgery, procedure code, and emergency or elective surgery. RESULTS: We found 7015 fewer procedures during the first wave epoch. Elective cases were reduced by 53.7% while emergency surgery was not significantly affected. During the peak of the first wave in April, there was a 72.8% reduction in elective cases; ENT/maxillofacial surgery showed the greatest reduction (86.7%). The surgical and anesthesia capacity recovered to near-normal levels by the end of June 2020. CONCLUSION: We conclude that the impact of COVID-19 on pediatric surgical procedures in Sweden during the first wave of the pandemic was dramatic, but elective services were restored a few months after the peak.

Role of Renal Sympathetic Nerve Activity in Volatile Anesthesia's Effect on Renal Excretory Function.

Regulation of fluid balance is pivotal during surgery and anesthesia and affects patient morbidity, mortality, and hospital length of stay. Retention of sodium and water is known to occur during surgery but the mechanisms are poorly defined. In this study, we explore how the volatile anesthetic sevoflurane influences renal function by affecting renal sympathetic nerve activity (RSNA). Our results demonstrate that sevoflurane induces renal sodium and water retention during pediatric anesthesia in association with elevated plasma concentration of renin but not arginine-vasopressin. The mechanisms are further explored in conscious and anesthetized ewes where we show that RSNA is increased by sevoflurane compared with when conscious. This is accompanied by renal sodium and water retention and decreased renal blood flow (RBF). Finally, we demonstrate that renal denervation normalizes renal excretory function and improves RBF during sevoflurane anesthesia in sheep. Taken together, this study describes a novel role of the renal sympathetic nerves in regulating renal function and blood flow during sevoflurane anesthesia.

Comparison of different methods for lung immobilization in an animal model.

BACKGROUND AND PURPOSE: Respiratory-induced motion introduces uncertainties in the delivery of dose in radiotherapy treatments. Various methods are used clinically, e.g. breath-holding, while there is limited experience with other methods such as apneic oxygenation and high frequency jet ventilation (HFJV). This study aims to compare the latter approaches for lung immobilization and their clinical impact on gas exchange in an animal model. MATERIALS AND METHODS: Two radiopaque tumor surrogate markers (TSM) were placed in the central (cTSM) and peripheral (dTSM) regions of the lungs in 9 anesthetized and muscle relaxed pigs undergoing 3 ventilatory interventions (1) HFJV at rates of 200 (JV200), 300 (JV300) and 400 (JV400) min-1; (2) apnea at continuous positive airway pressure (CPAP) levels of 0, 8 and 16 cmH2O; (3) conventional mechanical ventilation (CMV) as reference mode. cTSM and dTSM were visualized using fluoroscopy and their coordinates were computed. The ventilatory pattern was registered, and oxygen and carbon dioxide (pCO2) partial pressures were measured. RESULTS: The highest range of TSM motion, and ventilation was found during CMV, the lowest during apnea. During HFJV the amount of motion varied inversely with increasing frequency. The reduction of TSM motion at JV300, JV400 and all CPAP levels came at the cost of increased pCO2, however the relatively low frequency of 200 min-1 for HFJV was the only ventilatory setting that enabled adequate CO2 removal. CONCLUSION: In this model, HFJV at 200 min-1 was the best compromise between immobilization and gas exchange for sessions of 10-min duration.

The impaired diaphragmatic function after bilateral lung transplantation: A multifactorial longitudinal study.

BACKGROUND: Lung transplantation is a complex but effective treatment of end-stage pulmonary disease. Among the post-operative complications, phrenic nerve injury, and consequent diaphragmatic dysfunction are known to occur but are hitherto poorly described. We aimed to investigate the effect of lung transplantation on diaphragmatic function with a multimodal approach. METHODS: A total of 30 patients were studied at 4 time points: pre-operatively, at discharge after surgery, and after approximately 6 and subsequently 12 months post surgery. The diaphragmatic function was studied in terms of geometry (assessed by the radius of the diaphragmatic curvature delineated on chest X-ray), weakness (considering changes in forced vital capacity when the patient shifted from upright to supine position), force (maximal pressure during sniff), mobility (excursion of the dome of the diaphragm delineated by ultrasound), contractility (thickening fraction assessed by ultrasound), electrical activity (latency and area of compound muscle action potential during electrical stimulation of phrenic nerve), and kinematics (relative contribution of the abdominal compartment to tidal volume). RESULTS: Despite good clinical recovery (indicated by spirometry and 6 minutes walking test), a reduction of the diaphragmatic function was detected at discharge; it persisted 6 months later to recover fully 1 year after transplantation. Diaphragmatic dysfunction was demonstrated in terms of force, weakness, electrical activity, and kinematics. Our data suggest that the dysfunction was caused by phrenic nerve neurapraxia or moderate axonotmesis, potentially as a consequence of the surgical procedure (i.e., the use of ice and pericardium manipulation). CONCLUSIONS: The occurrence of diaphragmatic dysfunction in patients with a good clinical recovery indicates that the evaluation of diaphragmatic function should be included in the post-operative assessment after lung transplantation.

An evaluation of the mixed pediatric unit for blood loss replacement in pediatric craniofacial surgery.

BACKGROUND: Surgical correction for craniosynostosis is often associated with significant perioperative hemorrhage. We implemented a transfusion strategy with a strict protocol including transfusion triggers, frequent assessment of coagulation tests, and the use of a novel transfusion unit, the mixed pediatric unit. AIM: The aim of the study was to evaluate if the applied transfusion strategy could reduce total blood loss and number of blood donors. METHODS: Children <1 year old admitted for craniosynostosis surgery were included for the study. On the day before surgery, an adult red blood cell unit was mixed with plasma and split into two mixed pediatric units-one intended for intraoperative use and the other saved for the postoperative period. A series of blood samples were obtained for standard coagulation parameters as well as thromboelastography to evaluate potential coagulopathy. Estimated blood loss, the number of additional standard packed red cell units opened in the first 24 h after surgery, the volume of fluid administered, and the total transfusion volumes were compared to a historical control group with similar age and characteristics. RESULTS: Nineteen infants were included in the study group, and were compared to 21 historical controls. There was a significant reduction of intraoperative transfusion volume. Twelve patients were transfused postoperatively, but in 8 of these additional exposure to packed red cell donor blood was avoided by using the saved mixed pediatric unit. In the historical controls, a total of 10 packed red cell units were used in nine patients postoperatively. No additional transfusions of plasma, platelets, fibrinogen, or tranexamic acid were needed in either group, and the coagulation parameters including thromboelastography remained within their respective normal ranges in the study group. CONCLUSION: For craniofacial surgery in infants, moderate perioperative blood loss and avoidance of coagulopathy is possible when a multifactorial approach is implemented. In this setting, intraoperative, but not total perioperative blood loss was reduced with the studied protocol. The study indicates that there may be a role for mixed pediatric units to reduce exposure to multiple donors although the reduction in total donor exposure was not significant.

Influence of Tracheal Obstruction on the Efficacy of Superimposed High-frequency Jet Ventilation and Single-frequency Jet Ventilation.

BACKGROUND: Both superimposed high-frequency jet ventilation (SHFJV) and single-frequency (high-frequency) jet ventilation (HFJV) have been used with success for airway surgery, but SHFJV has been found to provide higher lung volumes and better gas exchange than HFJV in unobstructed airways. The authors systematically compared the ventilation efficacy of SHFJV and HFJV at different ventilation frequencies in a model of tracheal obstruction and describe the frequency and obstruction dependence of SHFJV efficacy. METHODS: Ten anesthetized animals (weight 25 to 31.5 kg) were alternately ventilated with SHFJV and HFJV at a set of different fHF from 50 to 600 min. Obstruction was created by insertion of interchangeable stents with ID 2 to 8 mm into the trachea. Chest wall volume was measured using optoelectronic plethysmography, airway pressures were recorded, and blood gases were analyzed repeatedly. RESULTS: SHFJV provided greater than 1.6 times higher end-expiratory chest wall volume than HFJV, and tidal volume (VT) was always greater than 200 ml with SHFJV. Increase of fHF from 50 to 600 min during HFJV resulted in a more than 30-fold VT decrease from 112 ml (97 to 130 ml) to negligible values and resulted in severe hypoxia and hypercapnia. During SHFJV, stent ID reduction from 8 to 2 mm increased end-expiratory chest wall volume by up to 3 times from approximately 100 to 300 ml and decreased VT by up to 4.2 times from approximately 470 to 110 ml. Oxygenation and ventilation were acceptable for 4 mm ID or more, but hypercapnia occurred with the 2 mm stent. CONCLUSION: In this in vivo porcine model of variable severe tracheal stenosis, SHFJV effectively increased lung volumes and maintained gas exchange and may be advantageous in severe airway obstruction.

Optimizing positive end-expiratory pressure by oscillatory mechanics minimizes tidal recruitment and distension: an experimental study in a lavage model of lung injury.

INTRODUCTION: It is well established that during mechanical ventilation of patients with acute respiratory distress syndrome cyclic recruitment/derecruitment and overdistension are potentially injurious for lung tissues. We evaluated whether the forced oscillation technique (FOT) could be used to guide the ventilator settings in order to minimize cyclic lung recruitment/derecruitment and cyclic mechanical stress in an experimental model of acute lung injury. METHODS: We studied six pigs in which lung injury was induced by bronchoalveolar lavage. The animals were ventilated with a tidal volume of 6 ml/kg. Forced oscillations at 5 Hz were superimposed on the ventilation waveform. Pressure and flow were measured at the tip and at the inlet of the endotracheal tube respectively. Respiratory system reactance (Xrs) was computed from the pressure and flow signals and expressed in terms of oscillatory elastance (EX5). Positive end-expiratory pressure (PEEP) was increased from 0 to 24 cm H2O in steps of 4 cm H2O and subsequently decreased from 24 to 0 in steps of 2 cm H2O. At each PEEP step CT scans and EX5 were assessed at end-expiration and end-inspiration. RESULTS: During deflation the relationship between both end-expiratory and end-inspiratory EX5 and PEEP was a U-shaped curve with minimum values at PEEP = 13.4 ± 1.0 cm H2O (mean ± SD) and 13.0 ± 1.0 cm H2O respectively. EX5 was always higher at end-inspiration than at end-expiration, the difference between the average curves being minimal at 12 cm H2O. At this PEEP level, CT did not show any substantial sign of intra-tidal recruitment/derecruitment or expiratory lung collapse. CONCLUSIONS: Using FOT it was possible to measure EX5 both at end-expiration and at end-inspiration. The optimal PEEP strategy based on end-expiratory EX5 minimized intra-tidal recruitment/derecruitment as assessed by CT, and the concurrent attenuation of intra-tidal variations of EX5 suggests that it may also minimize tidal mechanical stress.

Early release of interalveolar synechiae under general anesthesia through fiberscopic nasal intubation.

This article presents a treatment strategy for early release of interalveolar synechiae, aiming to facilitate early oral feeding and prevent temporomandibular joint ankylosis.The treatment results of 2 patients with van der Woude syndrome were retrospectively studied. Both patients underwent early surgical release of interalveolar synechiae under general anesthesia through fiberscopic nasal intubation. The 2 patients were treated at the ages of 6 and 14 days, respectively. The interincisival distances increased from 5 and 6 mm preoperatively to 11 and 10 mm immediately after surgery. This was increased further to 25 and 20 mm at long-term follow-up (6 and 24 months).In conclusion, synechiae between the upper and lower jaws can be safely treated at a very early age under general anesthesia with fiberscopic nasotracheal intubation. The purpose of early intervention in these cases is to facilitate oral feeding and prevent temporomandibular joint ankylosis.

Low-dose oral midazolam reduces fear and distress during needle procedures in children with cancer.

BACKGROUND: Children with cancer often mention needle procedures as the most frightening, distressing, and sometimes painful aspect of the disease and treatment. The aim was to investigate whether children experience less fear, distress, and/or pain according to parents, nurses, and children >or=7 years of age when they receive oral midazolam versus placebo before a needle is inserted in a subcutaneously implanted intravenous port. PROCEDURE: Fifty children 1-18 years of age who were being treated in a pediatric oncology and hematology setting were included consecutively when undergoing routine needle insertion into an intravenous port. All children were subjected to one needle insertion in this randomized, triple-blind, placebo-controlled study in which orally administered midazolam (n = 24) 0.3 mg/kg body weight (maximum 10 mg) was compared with placebo (n = 26). Parents, nurses, and children >or=7 years reported the patients' fear, distress, and pain on 0-100 mm Visual Analogue Scales. RESULTS: Fear was lower in the midazolam group according to parents (P = 0.001), nurses (P = 0.001), and children (P = 0.015). Parents and nurses also reported lower distress (P = 0.020 and 0.007, respectively). Post hoc analyses indicated that the effects were more pronounced in younger children (<7 years of age). CONCLUSION: Low-dose oral midazolam was effective in reducing fear and distress in pediatric oncology patients, especially in younger children, undergoing subcutaneous port needle insertion.