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BACKGROUND 

Continuous positive airway pressure (CPAP) prevents peri-operative atelectasis in adults, but its effect in children has not been quantified.

OBJECTIVE 

The aim of this study was to evaluate the role of CPAP in preventing postinduction and postoperative atelectasis in children under general anaesthesia.

DESIGN 

A randomised controlled study.

SETTING 

Single-institution study, community hospital, Mar del Plata. Argentina.

PATIENTS 

We studied 42 children, aged 6 months to 7 years, American Society of Anesthesiologists physical status class I, under standardised general anaesthesia.

INTERVENTIONS 

Patients were randomised into two groups: Control group (n = 21): induction and emergence of anaesthesia without CPAP; and CPAP group (n = 21): 5 cmH₂O of CPAP during induction and emergence of anaesthesia. Lung ultrasound (LUS) imaging was performed before and 5 min after anaesthesia induction. Children without atelectasis were ventilated in the same manner as the Control group with standard ventilatory settings including 5 cmH₂O of PEEP. Children with atelectasis received a recruitment manoeuvre followed by standard ventilation with 8 cmH₂O of PEEP. Then, at the end of surgery, LUS images were repeated before tracheal extubation and 60 min after awakening.

MAIN OUTCOME MEASURES 

Lung aeration score and atelectasis assessed by LUS.

RESULTS 

Before anaesthesia, all children were free of atelectasis. After induction, 95% in the Control group developed atelectasis compared with 52% of patients in the CPAP group (P < 0.0001). LUS aeration scores were higher (impaired aeration) in the Control group than the CPAP group (8.8 ± 3.8 vs. 3.5 ± 3.3 points; P < 0.0001). At the end of surgery, before tracheal extubation, atelectasis was observed in 100% of children in the Control and 29% of the CPAP group (P < 0.0001) with a corresponding aeration score of 9.6 ± 3.2 and 1.8 ± 2.3, respectively (P < 0.0001). After surgery, 30% of children in the Control group and 10% in the CPAP group presented with residual atelectasis (P < 0.0001) also corresponding to a higher aeration score in the Control group (2.5 ± 3.1) when compared with the CPAP group (0.5 ± 1.5; P < 0.01).

CONCLUSION 

The use of 5 cmH₂O of CPAP in healthy children of the studied age span during induction and emergence of anaesthesia effectively prevents atelectasis, with benefits maintained during the first postoperative hour.

TRIAL REGISTRY 

Clinicaltrials.gov NCT03461770.

Background: Exaggerated lung strain and stress could damage lungs in anesthetized children. The authors hypothesized that the association of capnoperitoneum and lung collapse in anesthetized children increases lung strain-stress. Their primary aim was to describe the impact of capnoperitoneum on lung strain-stress and the effects of an individualized protective ventilation during laparoscopic surgery in children.

Methods: The authors performed an observational cohort study in healthy children aged 3 to 7 yr scheduled for laparoscopic surgery in a community hospital. All received standard protective ventilation with 5 cm H₂O of positive end-expiratory pressure (PEEP). Children were evaluated before capnoperitoneum, during capnoperitoneum before and after lung recruitment and optimized PEEP (PEEP adjusted to get end-expiratory transpulmonary pressure of 0), and after capnoperitoneum with optimized PEEP. The presence of lung collapse was evaluated by lung ultrasound, positive Air-Test (oxygen saturation measured by pulse oximetry 96% or less breathing 21% O₂ for 5 min), and negative end-expiratory transpulmonary pressure. Lung strain was calculated as tidal volume/end-expiratory lung volume measured by capnodynamics, and lung stress as the end-inspiratory transpulmonary pressure.

Results: The authors studied 20 children. Before capnoperitoneum, mean lung strain was 0.20 ± 0.07 (95% CI, 0.17 to 0.23), and stress was 5.68 ± 2.83 (95% CI, 4.44 to 6.92) cm H2O. During capnoperitoneum, 18 patients presented lung collapse and strain (0.29 ± 0.13; 95% CI, 0.23 to 0.35; P < 0.001) and stress (5.92 ± 3.18; 95% CI, 4.53 to 7.31 cm H₂O; P = 0.374) increased compared to before capnoperitoneum. During capnoperitoneum and optimized PEEP, children presenting lung collapse were recruited and optimized PEEP was 8.3 ± 2.2 (95% CI, 7.3 to 9.3) cm H₂O. Strain returned to values before capnoperitoneum (0.20 ± 0.07; 95% CI, 0.17 to 0.22; P = 0.318), but lung stress increased (7.29 ± 2.67; 95% CI, 6.12 to 8.46 cm H₂O; P = 0.020). After capnoperitoneum, strain decreased (0.18 ± 0.04; 95% CI, 0.16 to 0.20; P = 0.090), but stress remained higher (7.25 ± 3.01; 95% CI, 5.92 to 8.57 cm H₂O; P = 0.024) compared to before capnoperitoneum.

Conclusions: Capnoperitoneum increased lung strain in healthy children undergoing laparoscopy. Lung recruitment and optimized PEEP during capnoperitoneum decreased lung strain but slightly increased lung stress. This little rise in pulmonary stress was maintained within safe, lung-protective, and clinically acceptable limits.

Background: Doppler images of pulmonary vessels in pulmonary diseases associated with subpleural consolidations have been described. Color Doppler easily identifies such vessels within consolidations while spectral Doppler analysis allows the differentiation between pulmonary and bronchial arteries. Thus, Doppler helps in diagnosing the nature of consolidations. To our knowledge, Doppler analysis of pulmonary vessels within anesthesia-induced atelectasis has never been described before. The aim of this case series is to demonstrate the ability of lung ultrasound to detect the shunting of blood within atelectatic lung areas in anesthetized children.

Findings: Three anesthetized and mechanically ventilated children were scanned in the supine position using a high-resolution linear probe of 6-12 MHz. Once subpleural consolidations were detected in the most dependent posterior lung regions, the probe was rotated such that its long axis followed the intercostal space. In this oblique position, color Doppler mapping was performed to detect blood flow within the consolidation. Thereafter, pulsed waved spectral Doppler was applied in the previously identified vessels during a short expiratory pause, which prevented interferences from respiratory motion. Different flow patterns were identified which corresponded to both, pulmonary and bronchial vessels. Finally, a lung recruitment maneuver was performed which leads to the complete resolution of the aforementioned consolidation thereby confirming the pathophysiological entity of anesthesia-induced atelectasis.

Conclusions: Lung ultrasound is a non-invasive imaging tool that not only enables the diagnosis of anesthesia-induced atelectasis in pediatric patients but also analysis of shunting blood within this consolidation.

Background: Several studies have recently addressed factors associated with severe Coronavirus disease 2019 (COVID-19); however, some medications and comorbidities have yet to be evaluated in a large matched cohort. We therefore explored the role of relevant comorbidities and medications in relation to the risk of intensive care unit (ICU) admission and mortality.

Methods: All ICU COVID-19 patients in Sweden until 27 May 2020 were matched to population controls on age and gender to assess the risk of ICU admission. Cases were identified, comorbidities and medications were retrieved from high-quality registries. Three conditional logistic regression models were used for risk of ICU admission and three Cox proportional hazards models for risk of ICU mortality, one with comorbidities, one with medications and finally with both models combined, respectively.

Results: We included 1981 patients and 7924 controls. Hypertension, type 2 diabetes mellitus, chronic renal failure, asthma, obesity, being a solid organ transplant recipient and immunosuppressant medications were independent risk factors of ICU admission and oral anticoagulants were protective. Stroke, asthma, chronic obstructive pulmonary disease and treatment with renin-angiotensin-aldosterone inhibitors (RAASi) were independent risk factors of ICU mortality in the pre-specified primary analyses; treatment with statins was protective. However, after adjusting for the use of continuous renal replacement therapy, RAASi were no longer an independent risk factor.

Conclusion: In our cohort oral anticoagulants were protective of ICU admission and statins was protective of ICU death. Several comorbidities and ongoing RAASi treatment were independent risk factors of ICU admission and ICU mortality.

Severe Coronavirus disease 2019 (COVID-19) is associated with several pre-existing comorbidities and demographic factors. Similar factors are linked to critical sepsis and acute respiratory distress syndrome (ARDS). We hypothesized that age and comorbidities are more generically linked to critical illness mortality than a specific disease state. We used national databases to identify ICU patients and to retrieve comorbidities. The relative importance of risk factors for 60-day mortality was evaluated using the interaction with disease group (Sepsis, ARDS or COVID-19) in logistic regression models. We included 32,501 adult ICU patients. In the model on 60-day mortality in sepsis and COVID-19 there were significant interactions with disease group for age, sex and asthma. In the model on 60-day mortality in ARDS and COVID-19 significant interactions with cohort were found for acute disease severity, age and chronic renal failure. In conclusion, age and sex play particular roles in COVID-19 mortality during intensive care but the burden of comorbidity was similar between sepsis and COVID-19 and ARDS and COVID-19.

BACKGROUND: Comorbidities are similarly associated with short-term mortality for COVID-19, acute respiratory distress syndrome (ARDS) and sepsis in intensive care unit (ICU) patients, but their adjusted frequencies at admission are unknown. Thus, we aimed to evaluate the adjusted distribution, reported as odds ratios, of known risk factors (i.e., age, sex and comorbidities) for ICU admission between COVID-19, sepsis and ARDS patients in this nationwide registry-based study.

METHODS: In this cohort study, we included adult patients admitted to Swedish ICUs with COVID-19 (n = 7382) during the pandemic and compared them to patients admitted to ICU with sepsis (n = 22,354) or ARDS (n = 2776) during a pre-COVID-19 period. The main outcomes were the adjusted odds for comorbidities, sex, and age in multivariable logistic regression on diagnostic categories in patients admitted to ICU, COVID-19 or sepsis and COVID-19 or ARDS.

RESULTS: We found that most comorbidities, as well as age, had a stronger association with sepsis admission than COVID-19 admission with the exception of male sex, type 2 diabetes mellitus, and asthma that were more strongly associated with COVID-19 admission, while no difference was seen for chronic renal failure and obesity. For COVID-19 and ARDS admission most risk factors were more strongly associated with ARDS admission except for male sex, type 2 diabetes mellitus, chronic renal failure, and obesity which were more strongly associated with COVID-19 admission, whereas hypertension, chronic obstructive pulmonary disease and asthma were not different.

CONCLUSIONS: Patients admitted to ICU with sepsis or ARDS carry a heavier burden of comorbidity and high age than patients admitted with COVID-19. This is likely caused by a combination of: (1) respiratory failure in COVID-19 being less dependent on comorbidities than in other forms of ARDS, and the cause of critical illness in other infections causing sepsis and (2) COVID-19 patients being deferred admission in situations where patients with the other syndromes were admitted.

BackgroundDeveloping dementia is feared by many for its detrimental effects on cognition and independence. Experimental and clinical evidence suggests that sepsis is a risk factor for the later development of dementia. We aimed to investigate whether intensive care-treated sepsis is an independent risk factor for a later diagnosis of dementia in a large cohort of intensive care unit (ICU) patients.MethodsWe identified adult patients admitted to an ICU in 2005 to 2015 and who survived without a dementia diagnosis 1year after intensive care admission using the Swedish Intensive Care Registry, collecting data from all Swedish general ICUs. Comorbidity, the diagnosis of dementia and mortality, was retrieved from the Swedish National Patient Registry, the Swedish Dementia Registry, and the Cause of Death Registry. Sepsis during intensive care served as a covariate in an extended Cox model together with age, sex, and variables describing comorbidities and acute disease severity.ResultsOne year after ICU admission 210,334 patients were alive and without a diagnosis of dementia; of these, 16,115 (7.7%) had a diagnosis of sepsis during intensive care. The median age of the cohort was 61years (interquartile range, IQR 43-72). The patients were followed for up to 11years (median 3.9years, IQR 1.7-6.6). During the follow-up, 6312 (3%) patients were diagnosed with dementia. Dementia was more common in individuals diagnosed with sepsis during their ICU stay (log-rank p<0.001), however diagnosis of sepsis during critical care was not an independent risk factor for a later dementia diagnosis in an extended Cox model: hazard ratio (HR) 1.01 (95% confidence interval 0.91-1.11, p=0.873). Renal replacement therapy and ventilator therapy during the ICU stay were protective. High age was a strong risk factor for later dementia, as was increasing severity of acute illness, although to a lesser extent. However, the severity of comorbidities and the length of ICU and hospital stay were not independent risk factors in the model.ConclusionAlthough dementia is more common among patients treated with sepsis in the ICU, sepsis was not an independent risk factor for later dementia in the Swedish national critical care cohort.Trial registrationThis study was registered a priori with the Australian and New Zeeland Clinical Trials Registry (registration no. ACTRN12618000533291).

AimIn acute respiratory distress syndrome (ARDS) damaged alveolar epithelium, leakage of plasma proteins into the alveolar space and inactivation of pulmonary surfactant lead to respiratory dysfunction. Lung function could potentially be restored with exogenous surfactant therapy, but clinical trials have so far been disappointing. These negative results may be explained by inactivation and/or too low doses of the administered surfactant. Surfactant based on a recombinant surfactant protein C analogue (rSP-C33Leu) is easy to produce and in this study we compared its effects on lung function and inflammation with a commercial surfactant preparation in an adult rabbit model of ARDS.MethodsARDS was induced in adult New Zealand rabbits by mild lung-lavages followed by injurious ventilation (V-T 20m/kg body weight) until P/F ratio<26.7kPa. The animals were treated with two intratracheal boluses of 2.5mL/kg of 2% rSP-C33Leu in DPPC/egg PC/POPG, 50:40:10 or poractant alfa (Curosurf (R)), both surfactants containing 80mg phospholipids/mL, or air as control. The animals were subsequently ventilated (V-T 8-9m/kg body weight) for an additional 3h and lung function parameters were recorded. Histological appearance of the lungs, degree of lung oedema and levels of the cytokines TNF alpha IL-6 and IL-8 in lung homogenates were evaluated.ResultsBoth surfactant preparations improved lung function vs. the control group and also reduced inflammation scores, production of pro-inflammatory cytokines, and formation of lung oedema to similar degrees. Poractant alfa improved compliance at 1h, P/F ratio and PaO2 at 1.5h compared to rSP-C33Leu surfactant.ConclusionThis study indicates that treatment of experimental ARDS with synthetic lung surfactant based on rSP-C33Leu improves lung function and attenuates inflammation.

Background

New paediatric fasting guidelines allow free clear fluids up until one hour prior to surgery. At the paediatric anaesthesia department of Uppsala University Hospital, children are fasted six hours for solids, four hours for breast milk and are allowed free clear fluids up until called to theatre. Preoperative fasting is necessary to avoid perioperative pulmonary aspiration. However, extended fasting times have detrimental effects for fluid homeostasis and may cause hypoglycaemia and ketone bodies.

Aim

The aim of the current study was to investigate if preoperative weight loss, glucose level and ketone bodies were related to preoperative fasting times.

Methods

Paediatric patients aged 0-72 months were included in this prospective, observational study. All children included were instructed to fast from midnight for solids, four hours for breast milk or semi-solids and from when they are called to theatre for clear fluids. Fasting times were registered, and patient weight was measured in the evening prior to surgery, and before induction. Blood glucose and ketone body levels were measured before induction. Multiple regression was used to determine how fasting time affected the outcomes weight change, blood glucose level and ketone bodies, respectively.

Results

43 patients were enrolled. Three children had a weight loss of more than 5 %, five children presented with blood glucose level < 3.3 mmol l^-1, and 11 children presented with ketone bodies > 0.6 mmol l^-1. There was no correlation between fasting time and the respective outcomes.

Conclusion

Even with a lenient preoperative fasting regimen, mild dehydration or hypoglycaemia may occur. This methodology may be used in further studies of the effects of preoperative fasting in settings where dehydration may be more significant.

We performed a systematic review to investigate the effects of vasopressor-induced hemodynamic changes in adults with shock. We applied a physiological approach using the interacting domains of intravascular volume, heart pump performance, and vascular resistance to structure the interpretation of responses to vasopressors. We hypothesized that incorporating changes in determinants of cardiac output and vascular resistance better reflect the vasopressor responsiveness beyond mean arterial pressure alone. We identified 28 studies including 678 subjects in Pubmed, EMBASE, and CENTRAL databases. All studies demonstrated significant increases in mean arterial pressure (MAP) and systemic vascular resistance during vasopressor infusion. The calculated mean systemic filling pressure analogue increased (16 +/- 3.3 mmHg to 18 +/- 3.4 mmHg; P = 0.02) by vasopressors with variable effects on central venous pressure and the pump efficiency of the heart leading to heterogenous changes in cardiac output. Changes in the pressure gradient for venous return and cardiac output, scaled by the change in MAP, were positively correlated (r (2) = 0.88, P < 0.001). Changes in the mean systemic filling pressure analogue and heart pump efficiency were negatively correlated (r (2) = 0.57, P < 0.001) while no correlation was found between changes in MAP and heart pump efficiency. We conclude that hemodynamic changes induced by vasopressor therapy are inadequately represented by the change in MAP alone despite its common use as a clinical endpoint. The more comprehensive analysis applied in this review illustrates how vasopressor administration may be optimized.