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Byline: S. Sondergaard (1), S. Karason (2), J. Wiklund (3), S. Lundin (1), O. Stenqvist (1) Keywords: Respiratory mechanics Alveolar pressure Dynostatic algorithm Abstract: Objectives. We evaluated an algorithm for continuous on-line monitoring of alveolar pressure over time in a lung model with lower and upper inflection points and variable resistance ratios and in patients with acute lung injury. The algorithm is based on 'static' pressure/volume curves obtained from tracheal pressure measurements under dynamic conditions. Design and setting. Experimental and clinical evaluation of algorithm in a university hospital laboratory and intensive care unit. Patients. Ten patients undergoing postoperative respiratory therapy (feasibility of tracheal measurement) and ten patients with acute lung injury undergoing ventilator treatment (evaluation of algorithm). Measurements and results. Direct tracheal pressure measurements with a catheter inserted through the endotracheal tube. Comparison of measured alveolar and the dynostatic alveolar pressure vs. time in a lung model with changes in five ventilatory parameters. Examples of clinical monitoring are reported. In the model there was excellent agreement between alveolar pressures obtained by the algorithm, the dynostatic alveolar pressure, and measured alveolar pressure at all ventilator settings. For inspiratory/expiratory resistance ratios between 1:2.1--2.1:1, the dynostatic alveolar pressure was within +-1.5 cm [H.sub.2]O of measured alveolar pressure. In patients the technique for direct tracheal pressure measurement using a catheter inserted through the endotracheal tube functioned satisfactorily with intermittent air flushes for cleansing. Conclusions. Using a thin tracheal pressure catheter inserted through the endotracheal tube alveolar pressure allows continuous bedside monitoring with ease and precision using the dynostatic algorithm. The method is unaffected by tube and connector geometry or by secretions. Author Affiliation: (1) Department of Anaesthesia and Intensive Care, Sahlgrenska University Hospital, Gothenburg, Sweden (2) Department of Anaesthesia and Intensive Care, Landspitali University Hospital, Reykjavik, Iceland (3) Department of Biomedical Engineering, Sahlgrenska University Hospital, Gothenburg, Sweden Article History: Received Date: 05/02/2002 Accepted Date: 24/02/2003 Article note: Electronic Publication

Byline: S. Lethvall (1), S. Sondergaard (1), S. Karason (1), S. Lundin (1), O. Stenqvist (1) Keywords: Dead-space Tracheal pressure Carbon dioxide Hypercapnia Acute respiratory distress syndrome Double lumen tube Abstract: Abstract Objective. To evaluate the effects on CO.sub.2 washout of the coaxial double lumen tube (DLT) as compared to a standard endotracheal tube (ETT) and tracheal gas insufflation (TGI). Precision of tracheal pressure monitoring through the DLT and safety issues, including intrinsic PEEP (PEEPi) formation during DLT ventilation, were also evaluated. Design. Lung model study. Setting. University research laboratory. Measurements and results. CO.sub.2 washout was analysed in a lung model by measuring single alveolar CO.sub.2 concentration during DLT ventilation as compared to standard ETT ventilation, at different minute ventilation (6--14 l/min) and different CO.sub.2-output levels (180 ml/min, 240 ml/min, and 300 ml/min). At a CO.sub.2 output level of 240 ml/min the CO.sub.2 washout was also compared to tidal volume-adjusted continuous TGI and expiratory synchronised TGI. Precision of tracheal pressure monitoring and PEEPi formation during DLT ventilation was evaluated by comparing pressure in each limb above the tube to reference tracheal pressure, varying I:E ratios (1:2, 1:1, and 2:1), tidal volumes (300--700 ml), breathing frequencies (15--25), and compliance (20--50 ml/cm[H.sub.2]O). DLT ventilation had the same efficacy in removing CO.sub.2 as continuous and expiratory synchronised TGI, reducing single alveolar CO.sub.2 concentration by 9--21% compared to normal ventilation. Tracheal pressure could be measured through the DLT with high precision. There was only marginal formation of PEEPi at tidal volumes a$?600 ml, I:E ratio a$?1:1, and compliance a$?35 ml/cm[H.sub.2]O. Conclusions. The double lumen tube is as effective as tracheal gas insufflation in reducing CO.sub.2 tension. Tracheal pressure and formation of PEEPi can be monitored with high precision without interrupting ventilation. Author Affiliation: (1) Department of Anaesthesia and Intensive Care, Sahlgrenska University Hospital, 413 45 Goteborg, Sweden Article History: Received Date: 13/06/2001 Accepted Date: 14/04/2002 Article note: Electronic Publication

Focuses on human and robot tactile sensing. Problem for the central processor; Use of a frequency-domain approach to solve the problem of encoding and decoding mechanosensory information; What determines the optimal stress/strain components the sensors need to transduce.

Abstract Background By tradition colloid solutions have been used to obtain fast circulatory stabilisation in shock, but high molecular weight hydroxyethyl starch (HES) may cause acute kidney failure in patients with severe sepsis. Now lower molecular weight HES 130/0.4 is the preferred colloid in Scandinavian intensive care units (ICUs) and 1st choice fluid for patients with severe sepsis. However, HES 130/0.4 is largely unstudied in patients with severe sepsis. Methods/Design The 6S trial will randomise 800 patients with severe sepsis in 30 Scandinavian ICUs to masked fluid resuscitation using either 6% HES 130/0.4 in Ringer's acetate or Ringer's acetate alone. The composite endpoint of 90-day mortality or end-stage kidney failure is the primary outcome measure. The secondary outcome measures are severe bleeding or allergic reactions, organ failure, acute kidney failure, days alive without renal replacement therapy or ventilator support and 28-day and 1/2- and one-year mortality. The sample size will allow the detection of a 10% absolute difference between the two groups in the composite endpoint with a power of 80%. Discussion The 6S trial will provide important safety and efficacy data on the use of HES 130/0.4 in patients with severe sepsis. The effects on mortality, dialysis-dependency, time on ventilator, bleeding and markers of resuscitation, metabolism, kidney failure, and coagulation will be assessed. Trial Registration ClinicalTrials.gov: NCT00962156

Background and Purpose: The aim of our study was to investigate change in modifiable risk factors following preoperative optimization and whether risk of superficial surgical site infection (SSI) after total joint arthroplasty (TJA) could be reduced., Methods: This is a prospective study of implementation of a preoperative optimization pathway for patients waiting for primary TJA. Information regarding the intervention arm was collected from January 2019 to January 2021, first at decision for operation and then at preoperative assessment 1 week prior to operation. The control arm was included between August 2018 and September 2020 after receiving conventional preoperative preparation and information gathered at preoperative assessment. Follow up occurred 6 weeks postoperatively for both groups. The primary outcome was postoperative superficial SSI., Results: The optimization effort resulted in improvement of weight, anemia, HbA1c, vitamin D, and patient engagement. At preoperative assessment the baseline characteristics of the 2 groups were similar except that the intervention group had substantially more comorbidities. Regarding superficial SSI, association was found with BMI ≥ 30 and HbA1c ≥ 42 mmol/mol in the control group but not in the intervention group. When corrected for differences in ASA classification (reflecting comorbidities), age, and sex, being in the intervention group was associated with lower odds of occurrence of superficial SSI compared with the control group (OR 0.64, 95% confidence interval 0.42-0.97)., Conclusion: We showed that preoperative optimization in a structured cooperation between hospital and primary care was associated with a reduced risk of superficial SSI.

Background: Moderate or severe postoperative pain is common despite advances in surgical technique and perioperative analgesia. This study aimed to assess the prevalence and severity of postoperative pain following procedures requiring anaesthesia and identify factors associated with increased risk of postoperative pain., Methods: Surgical patients ≥18 years of age were prospectively questioned on level of current pain on a numerical rating scale (NRS) from 0 to 10 in the post-anaesthesia care unit (PACU) and on resting, active and worst pain experienced in the first 24 h postoperatively. Clinical data was obtained from medical records. Descriptive statistics were applied, and predictors of worst pain assessed as moderate/severe (NRS ≥ 5) on postoperative day one were assessed using multivariable logistic regression., Results: Of 438 included participants, moderate/severe pain occurred in 29% on the day of surgery and 70% described their worst pain as moderate/severe on postoperative day one. Procedures with the highest incidence of moderate/severe pain on the day of surgery were gynaecology-, plastic-, abdominal-, breast-, and orthopaedic procedures. On postoperative day one, patients undergoing vascular-, orthopaedic-, and abdominal operations most commonly rated their worst pain as moderate/severe. Female sex (OR = 2.15, 95% Cl 1.21-3.88, p = .010), chronic preoperative pain (OR = 4.20, 95% Cl 2.41-7.51, p < .001), undergoing a major procedure (OR = 2.07, 95% Cl 1.15-3.80, p = .017), and any intraoperative remifentanil administration (OR = 2.16, 95% Cl 1.20-3.94, p = .01) had increased odds of rating the worst pain as moderate/severe. Increased age (OR = 0.66 per 10 years (95% Cl 0.55-0.78, p < .001)) and undergoing breast-, gynaecology-, otolaryngology-, and neurosurgery (OR = 0.15-0.34, p < .038) was associated with lower odds of moderate/severe pain on postoperative day one., Discussion: In our cohort, patients rated their current pain in the PACU similarly to other studies. However, the ratio of patients rating the worst pain experienced as moderate/severe on postoperative day one was relatively high. The identified patient- and procedural-related factors associated with higher odds of postoperative pain highlight a subgroup of patients who may benefit from enhanced perioperative monitoring and pain management strategies., (© 2024 Acta Anaesthesiologica Scandinavica Foundation.)

Background: In the last decade, anaesthesia practice has changed at Landspitali, where the majority of patients now receive antiemetic prophylaxis, and the use of total intravenous anaesthesia is the dominant mode for maintenance of anaesthesia. The aim of this study was to assess the incidence of postoperative nausea and vomiting (PONV) in a prospective way, the use of PONV prophylaxis, and clinical risk factors associated with PONV during this era., Methods: A prospective cohort study using a convenience sample of 438 patients ≥18 years old admitted to the postoperative care unit (PACU) after elective or emergency operations in May-July 2022 at Landspitali University Hospital in Iceland. Patients answered questionnaires in the PACU and 24 h after discharge from PACU., Results: The incidence of self-reported moderate/severe nausea (5/10 or higher on NRS) in PACU was 4% and 3% on postoperative day 1. A total of 91% of delivered anaesthetics were with intravenous medications only, and 82% of patients received at least one prophylactic medication for PONV. When asked to rate the worst nausea experienced, this was described as moderate/severe by 7% in PACU and 17% on postoperative day 1. Risk factors associated with PONV were female gender (OR 1.90, 95% CI 1.04-3.53) and a history of motion sickness or PONV (2.74, 1.51-4.94), but increasing age was protective (0.83 per decade, 0.71-0.98). Despite a more liberal administration of antiemetics, patients with more risk factors per Apfel PONV risk classification had a higher incidence of PONV., Conclusion: The incidence of PONV is generally low in this diverse surgical population where anaesthesia is mostly maintained with total intravenous anaesthesia and PONV prophylaxis is common. PONV remains a predictable complication following anaesthesia, suggesting further improvement in its prevention is possible., (© 2024 Acta Anaesthesiologica Scandinavica Foundation.)

Background: Pre-operative anaemia is common and associated with adverse outcomes. We hypothesised that pre-operative anaemia would be evident more than 1 month pre-operatively, and that peri-operative changes in haemoglobin and post-operative outcomes differed between red cell size-based subsets of anaemia., Methods: A retrospective single-centre cohort study, including all patients 18 years and older undergoing their first surgery at Landspitali between January 2006 and December 2018 with available measurement of haemoglobin (Hb) within 30 days preceding surgery. Clinical data were compared between patients with subgroups of anaemia classified by mean corpuscular volume (MCV) into microcytic (MCV < 80 fl), normocytic (MCV 80-100 fl), and macrocytic (MCV > 100 fl) anaemia. The development of haemoglobin measurements from a nationwide database was plotted from 1 year pre-operatively to 2 years post-operatively., Results: Of 40,979 patients, 10,505 (25.6%) had pre-operative anaemia, of which 1089 (10.4%) had microcytic anaemia, 9243 (88.0%) had normocytic anaemia, and 173 (1.6%) had macrocytic anaemia. Patients within all subgroups of pre-operative anaemia had a higher degree of comorbidity and frailty burden and a low haemoglobin evident for more than 100 days pre-operatively and similar changes post-operatively. Post-operative prolonged recovery of haemoglobin was slower for macrocytic anaemia than other types of anaemia. All groups of patients with anaemia had a higher incidence of 30-day mortality, acute kidney injury, and rate of readmission compared with patients without anaemia., Conclusions: Pre-operative anaemia is evident long prior to the procedure and its association with worse outcomes is similar regardless of red cell size., (© 2023 Acta Anaesthesiologica Scandinavica Foundation.)

Background: Prolonged corrected QT interval (QTc) has been linked to risk of arrhythmias and mortality in the general population. Pre-operative electrocardiography is often obtained for patient-and procedural cardiovascular risk assessment. The aim of this study was to investigate the association of pre-operative QTc and all-cause mortality in a non-cardiac surgical cohort., Methods: A retrospective study of all patients over 18 years undergoing non-cardiac surgery at Landspitali-the National University Hospital in Iceland between 2 January 2005 to 31 December 2015, with follow-up through 20 May 2016. Patients were separated into five categories according to their pre-operative QTc interval ≤ 379, 380-439 (reference group), 440-479, 480-519 and ≥520 ms. Primary outcome was long-term mortality and secondary outcome was 30-day mortality., Results: A total of 10,209 surgeries for 10,209 individuals were included. The median follow-up for mortality was 2691 days (interquartile range [IQR] 1620-3705 days). Patients with longer QTc interval had a higher comorbidity burden, were more likely to undergo emergency surgery and were often prescribed cardiac medications. After adjustment for confounding variables, the hazard ratio (HR) for long-term mortality compared with reference (QTc 380-439 ms) was 0.85 [CI: 0.66-1.09] for QTc ≤379, 1.08 [CI: 0.99-1.17] for QTc 440-479 ms, 1.26 [CI: 1.10-1.43] for QTc between 480 and 519 ms and 0.97 [CI: 0.78-1.21] for QTc ≥520 ms. When compared with reference, only patients with QTc interval between 480 and 519 ms had higher odds ratio for 30-day mortality as odds ratio for other groups were following; 1.12 [CI: 0.18-3.8] for ≤379 ms, 1.03 [CI: 0.70-1.51] for QTc 440-479 ms, 1.64 [CI: 1.02-2.60] for QTc 480-519 ms and 0.98 [0.44-2.06] for QTc ≥520 ms., Conclusion: Pre-operative QTc between 480 and 519 ms is associated with both higher long-term and 30-day mortality after non-cardiac surgery. The results suggest that this could reflect an underlying cardiovascular risk., (© 2022 Acta Anaesthesiologica Scandinavica Foundation.)

Background and Purpose: The aim of this study was to identify the prevalence of modifiable risk factors of surgical site infections (SSI) in patients undergoing primary elective total joint arthroplasty (TJA) receiving conventional preoperative preparation, and to explore their association with infectious outcomes., Patients and Methods: Information regarding modifiable risk factors (anemia, diabetes, obesity, nutritional status, smoking, physical activity) was prospectively gathered in patients undergoing primary TJA of hip or knee in 2018-2020 at a single institution with 6 weeks' follow-up time., Results: 738 patients (median age 68 years [IQR 61-73], women 57%) underwent TJA (knee 64%, hip 36%). Anemia was detected in 8%, diabetes was present in 9%, an additional 2% had undiagnosed diabetes (HbA1c > 47 mmol/mol), and 8% dysglycemia (HbA1c 42-47 mmol/mol). Obesity (BMI ≥ 30) was observed in 52%. Serum albumin, total lymphocyte count, and vitamin D below normal limits was identified in 0.1%, 18%, and 16%, respectively. Current smokers were 7%. Surgical site complications occurred in 116 (16%), superficial SSI in 57 (8%), progressing to periprosthetic joint infection in 7 cases. Univariate analysis identified higher odds of superficial SSI for BMI ≥ 30 (OR 2.1, 95%CI 1.2-3.8) and HbA1c ≥ 42 mmol/mol (OR 2.2, CI 1.1-4.2), but no association was found with other factors., Conclusion: In a general population undergoing primary TJA an association was found between obesity (52%) and dysglycemia/diabetes (19%) and superficial SSI (8%), which progressed to PJI in 12% of cases, generating a 1% total rate of PJI. Modification of these risk factors might mitigate infectious adverse outcomes.

Background: There is a need for a feasible tool to assess the risk of frailty prior to surgery. We aimed to identify the ratio of abnormal results for three clinically applicable screening tools to assess the risk of frailty, and their association with adverse outcomes in a cohort of elderly surgical patients., Methods: In this prospective pilot study, patients ≥65 years undergoing preoperative evaluation for elective surgery were included and subjected to three frailty screening tests; Program of Research to Integrate Services for the Maintenance of Autonomy 7-item questionnaire (PRISMA7), Timed Up and Go (TUG), and Clock Drawing Test (CDT). The primary outcome was the incidence of abnormal testing, and secondary outcomes were the association between abnormal tests and mortality, readmission, delirium, surgical complications and non-home discharge., Results: Out of 99 patients, 41%, 37%, and 43% had abnormal PRISMA7, TUG, and CDT screening, respectively. Postoperative delirium was more likely to occur in patients with abnormal TUG screening (19% vs. 3%, p = .011) and CDT (17% vs. 2%, p = .019). When analyzing screening tool combinations, patients with abnormal PRISMA7 and TUG had a higher rate of non-home discharge (38% vs. 17%, p = .029); and patients with abnormal TUG and CDT had a higher rate of postoperative delirium (25% vs. 3%, p = .006) and any surgical complication (58% vs. 38%, p = .037); and patients with abnormal results from all three tools had a higher rate of postoperative delirium (21% vs. 5%, p = .045) and non-home discharge (42% vs. 18%, p = .034)., Conclusion: Approximately 40% of elderly surgical patients have abnormal PRISMA7, TUG, and CDT screening tests for frailty, and they are associated individually or in combination with increased risk of adverse postoperative outcomes. The results will aid in designing studies to further risk-stratify patients at risk of frailty and attempt to modify associated outcomes., (© 2022 Acta Anaesthesiologica Scandinavica Foundation.)

Background: Despite multiple studies suggesting that low 25(OH)D-vitamin levels are associated with worse outcomes in critically ill individuals, attempts to mitigate the outcomes by fixed dose enteral supplementation unguided by baseline or target blood levels have been unsuccessful. Since a single measurement of 25(OH)D may not optimally reflect an individual's vitamin D status, we studied the plasma concentration of different vitamin D metabolites and their recovery during and following resolution of acute critical illness., Methods: A prospective observational study including patients 18 years and older admitted to a mixed medical-surgical ICU in Reykjavik, Iceland, located at a high-northern altitude (64° N). Vitamin D metabolites were measured at three timepoints; On admission (S1), 3-5 days following admission (S2) and after recovery from acute illness (median 178 days) (S3). Concentrations of total 25(OH)D-vitamin, cholecalciferol (D 3 ), total 24,25(OH)D-vitamin, vitamin D binding protein (VDBP) were measured with LC-tandem mass spectrometry (LC-MS/MS) and free 25-(OH)D was measured with enzyme-linked immunosorbent assay., Results: Most individuals were vitamin D deficient when assessed during critical illness, with 25(OH)D-vitamin levels under 30 ng/ml for 37/40 individuals at timepoint S1 and 34/38 at S2. After recovery, 18/30 patients were deficient at S3. Levels of all vitamin D metabolites measured were low during critical illness but rose substantially following resolution of acute illness. No strong correlation was found between markers of acute illness severity or duration and resolution of vitamin D metabolites in the interval between acute illness and recovery., Conclusions: In critically ill patients, levels of multiple vitamin D metabolites are low but substantial recovery occurs following resolution of acute illness. It is unclear whether a single metabolite is sufficient to assess vitamin D status of critically ill patients and guide potential supplementation., (© 2022 Acta Anaesthesiologica Scandinavica Foundation.)

Background: Tracheostomies are commonly utilized in ICU patients due to prolonged mechanical ventilation, upper airway obstruction, or surgery in the face/neck region. However, practices regarding the timing of placement and utilization vary. This study provides a nationwide overview of tracheostomy utilization and outcomes in the ICU over a 14-year period., Methods: A retrospective study including all patients that received a tracheostomy during their ICU stay in Iceland between 2007 and 2020. Data were retrieved from hospital records on admission cause, comorbidities, indication for tracheostomy insertion, duration of mechanical ventilation before and after tracheostomy placement, extubation attempts, complications, length of ICU and hospital stay and survival. Descriptive statistics were provided, and survival analysis was performed using Cox regression., Results: A total of 336 patients (median age 64 years, 33% females) received a tracheostomy during the study period. The most common indication for tracheostomy insertion was respiratory failure, followed by neurological disorders. The median duration of mechanical ventilation prior to tracheostomy insertion was 9 days and at least one extubation had been attempted in 35% of the cases. Percutaneous tracheostomies were 32%. The overall rate of complications was 25% and the most common short-term complication was bleeding (5%). In-hospital mortality was 33%. The one- and five-year survival rate was 60% and 44%, respectively., Conclusions: We describe a whole-nation practice of tracheostomies. A notable finding is the relatively low rate of extubation attempts prior to tracheostomy insertion. Future work should focus on standardization of assessing the need for tracheostomy and the role of extubation attempts prior to tracheostomy placement., (© 2022 Acta Anaesthesiologica Scandinavica Foundation.)

Background: Sepsis is the leading cause of admission to the intensive care unit (ICU) for cancer patients and survival rates have historically been low. The aims of this nationwide cohort study were to describe the characteristics and outcomes of cancer patients admitted to the ICU with sepsis compared with other sepsis patients requiring ICU admission., Material and Methods: This was a retrospective, observational study. All adult admissions to Icelandic ICUs during years 2006, 2008, 2010, 2012, 2014 and 2016 were screened for severe sepsis or septic shock by ACCP/SCCM criteria. Clinical characteristics and outcomes of sepsis patients with cancer were compared to those without cancer., Results: In the study period, 235 of 971 (24%) patients admitted to Icelandic ICUs because of sepsis had cancer, most often a solid tumour (100), followed by metastatic tumours (69) and haematological malignancies (66). Infections were more often hospital-acquired in cancer patients (52%) than other sepsis patients (18%, p  < 0.001) and sites of infections differed, with abdominal infections being most common in patients with solid and metastatic tumours but lungs and bloodstream infections in haematological malignancies. The length of stay in the ICU was shorter for sepsis patients with metastatic disease than other sepsis patients (2 vs. 4 days, p  < 0.001) and they were more likely to have treatment limitations (52 vs. 19%, p  < 0.05). Median survival of patients with metastatic disease was 19 days from ICU admission. The 28-day mortality (25%) of solid tumour patients was comparable to that of sepsis patients without cancer (20%, p  < 0.001)., Conclusions: Cancer is a common comorbidity in patients admitted to the ICU with sepsis. The clinical presentation and outcome differs between cancer types. Individuals with metastatic cancer were unlikely to receive prolonged invasive ICU care treatment. Comparable short-term outcome was found for patients with solid tumours and no cancer.

Background: Mechanical ventilation is a life-saving therapy for critically ill patients, providing rest to the respiratory muscles and facilitating gas exchange in the lungs. Ventilator-induced lung injury (VILI) is an unfortunate side effect of mechanical ventilation that may lead to serious consequences for the patient and increase mortality. The four main injury mechanisms associated with VILI are: baro/volutrauma caused by overstretching the lung tissues; atelectrauma, caused by repeated opening and closing of the alveoli resulting in shear stress; oxygen toxicity due to use of high ratio of oxygen in inspired air, causing formation of free radicals; and biotrauma, the resulting biological response to tissue injury, that leads to a cascade of events due to excessive inflammatory reactions and may cause multi-organ failure. An often-overlooked part of the inflammatory reaction is oxidative stress. In this research, a mouse model of VILI was set up with three tidal volume settings (10, 20 and 30 mL/kg) at atmospheric oxygen level. Airway pressures and heart rate were monitored and bronchoalveolar lavage fluid (BALF) and lung tissue samples were taken., Results: We show a correlation between increased inflammation and barrier failure, and higher tidal volumes, evidenced by increased IL-6 expression, high concentration of proteins in BALF along with changes in expression of adhesion molecules. Furthermore, swelling of mitochondria in alveolar type II cells was seen indicating their dysfunction and senescence-like state. RNA sequencing data present clear increases in inflammation, mitochondrial biogenesis and oxidative stress as tidal volume is increased, supported by degradation of Keap1, a redox-regulated substrate adaptor protein., Conclusions: Oxidative stress seems to be a more prominent mechanism of VILI than previously considered, indicating that possible treatment methods against VILI might be identified by impeding oxidative pathways., (© 2022. The Author(s).)

Background: Registry-based studies have shown increasing incidence of sepsis and declining mortality rates in recent years, but are inherently at risk of bias. The objectives of this study were to describe 11-year trends in the incidence, treatment and outcome of sepsis using clinical criteria with chart review., Methods: This was a retrospective, observational study. All adult admissions to Icelandic ICUs during years 2006, 2008, 2010, 2012, 2014, and 2016 were screened for severe sepsis or septic shock by ACCP/SCCM criteria (sepsis-2). Incidence, patient characteristics, treatment and outcome were compared across the study years., Results: During the six study years, 9166 patients were admitted to Icelandic ICUs, 971 (10.6%) because of severe sepsis or septic shock. The crude incidence of sepsis requiring admission to ICU remained stable between 0.55 and 0.75 per 1000 inhabitants. No statistically significant trends were observed over time in median patient age (67 years), APACHE II score (21), SOFA score (8) or Charlson Comorbidity Index (4). The time to antibiotic administration (median 1.8 h) in the emergency departments was stable over the study period but the time to lactate measurements decreased from 4.1 h in 2006 to 1.2 h in 2016, p < .001. The 28-day mortality was 25% and 1-year mortality 41%, both with no observed change with time., Conclusions: In a nationwide cohort, diagnosed with clinical criteria, the incidence of sepsis requiring intensive care did not change over an 11-year period. Mortality remained stable and only minimal changes were observed in initial resuscitation in the emergency departments., (© 2022 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Ventilator-induced lung injury (VILI) is a serious acute injury to the lung tissue that can develop during mechanical ventilation of patients. Due to the mechanical strain of ventilation, damage can occur in the bronchiolar and alveolar epithelium resulting in a cascade of events that may be fatal to the patients. Patients requiring mechanical ventilation are often critically ill, which limits the possibility of obtaining patient samples, making VILI research challenging. In vitro models are very important for VILI research, but the complexity of the cellular interactions in multi-organ animals, necessitates in vivo studies where the mouse model is a common choice. However, the settings and duration of ventilation used to create VILI in mice vary greatly, causing uncertainty in interpretation and comparison of results. This review examines approaches to induce VILI in mouse models for the last 10 years, to our best knowledge, summarizing methods and key parameters presented across the studies. The results imply that a more standardized approach is warranted., (© 2021. The Author(s).)

Background: There is a need for standardized and cost-effective identification of frailty risk. The objective was to validate the Hospital Frailty Risk Score which utilizes International Classification Diagnoses in a cohort of older surgical patients, assess the score as an independent risk factor for adverse outcomes and compare discrimination properties of the frailty risk score with other risk stratification scores., Methods: Data were analysed from all patients ≥65 years undergoing primary surgical procedures from 2006-2018. Patients were categorized based on the frailty risk score. The primary outcomes were 30-day mortality and 180-day risk of readmission., Results: Of 16 793 patients evaluated, 7480 (45%), 7605 (45%) and 1708 (10%) had a low, intermediate and high risk of frailty. There was a higher incidence of 30-day mortality for individuals with intermediate (2.9%) and high (8.3%) compared with low (1.4%) risk of frailty (P < .001 for both comparisons). Similarly, the hazard of readmission within the first 180 days was higher for intermediate (HR 1.25; 95% CI: 1.16-1.34) and high (HR 1.84; 95% CI: 1.66-2.03) compared with low (HR 1.00, P < .001 for both comparisons) risk of frailty. The hazard of long-term mortality was higher for intermediate (HR 1.70; 95% CI: 1.61-1.80) and high (HR 4.16; 95% CI: 3.84-4.49) compared with low (HR 1.00, P < .001 for both comparisons) risk of frailty. Finally, long length of primary hospitalization occurred for 9.3%, 15.0% and 27.3% of individuals with low, intermediate and high frailty risk (P < .001 for all comparisons). A model including age and ASA classification had the best discrimination for 30-day mortality (AUC 0.862; 95% CI: 0.847-0.877)., Conclusion: Our findings suggest that the Hospital Frailty Risk Score might be used to screen older surgical patients for risk of frailty. While only slightly improving prediction of 30-day mortality using the ASA classification, the Hospital Frailty Risk Score can be used to independently classify older patients for the risk of important outcomes using pre-existing readily available electronic data., (© 2021 Acta Anaesthesiologica Scandinavica Foundation.)

Background: Sepsis requiring admission to intensive care (ICU) is a rare complication of elective surgery, but is associated with high morbidity and mortality. The aim of this study was to describe the incidence and outcome of sepsis following elective surgery., Methods: This was a retrospective, observational study where all admissions to Icelandic ICUs during calendar years 2006, 2008, 2010, 2012, 2014 and 2016 were screened, identifing patients with sepsis following elective surgery (ACCP/SCCM criteria). The number of elective operations performed at the largest center (Landspitali) during the study years were collected. Descriptive statistics were used to assess the incidence and outcome of patients with sepsis after elective surgery., Results: During the study years, 88 patients were admitted to Icelandic ICUs with sepsis following elective surgery. Of those, 80 were operated at Landspitali, where the incidence of sepsis was 0.19% per elective procedure, highest following pancreaticoduodenectomies (14%, CI 6-25) and esophagectomies (13%, CI 4-27), but the greatest number of patients (30% (26/88)) developed sepsis after a colorectal procedure. The most common infection sources were the abdomen (65% (57/88)) and lungs/mediastinum (22% (19/88)), frequently polymicrobial (58% (36/62) of patients with cultures). The incidence of insufficient empirical antibiotics was high (50% (30/60)). The median ICU and hospital length-of-stay were 5.5 and 26 days and the 28-day and 1-year mortality rates were 16% (14/88) and 41% (36/87), respectively., Conclusions: Incidence of sepsis following elective surgery is low in Iceland but mortality is high. Initial antimicrobial therapy needs careful consideration in these hospital-acquired, often polymicrobial infections., (© 2020 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Objectives: To determine the nationwide demographics and hospital mortality of patients with severe acute respiratory syndrome coronavirus 2 infection requiring admission to the ICU for coronavirus disease 2019 in Iceland., Design: Prospective observational study., Setting: All ICUs in Iceland (Landspitali University Hospital and Akureyri Regional Hospital)., Patients: All patients admitted to the ICU for management of coronavirus disease 2019 between March 14, 2020, and April 13, 2020, with follow-up through May 5, 2020., Interventions: None., Measurements and Main Results: A total of 27 patients were admitted to the ICU for coronavirus disease 2019 out of 1,788 severe acute respiratory syndrome coronavirus 2 positive cases, rendering an overall admission ratio of 1.5% (95% CI, 1.0-2.2%). The population rate of ICU admission for coronavirus disease 2019 was 7.4 (95% CI, 4.9-10.8) admissions per 100,000 individuals. The hospital mortality of patients admitted to the ICU was 15% (95% CI, 4-34%), and the mortality of patients receiving mechanical ventilation was 19% (95% CI, 4-46%)., Conclusions: We report a lower overall ratio of ICU admissions for coronavirus disease 2019 among severe acute respiratory syndrome coronavirus 2 positive patients and a lower hospital mortality for patients treated in the ICU for coronavirus disease 2019 compared with initial reports from Italy and China. Our results could be explained by the early adoption of widespread testing and a successful national response to the pandemic.

Background: Elevated red cell distribution width (RDW) has been associated with worse outcomes in several medical patient populations. The aim of this study was to investigate the association of increased preoperative RDW and short- and long-term mortality after noncardiac surgery., Methods: This investigation was a retrospective cohort study including all patients undergoing noncardiac surgery between 2005 and 2015 at Landspitali-the National University Hospital in Iceland. Patients were separated into five predefined groups based on preoperative RDW (≤13.3%, 13.4-14.0%, 14.1-14.7%, 14.8-15.8%, and >15.8%). The primary outcome was all-cause long-term mortality and secondary outcomes included 30-day mortality, length of stay, and readmissions within 30 days, compared with propensity score matched (PSM) cohort from patients with RDW ≤13.3%., Results: There was a higher hazard of long-term mortality for patients with RDW between 14.8% and 15.8% (hazard ratio=1.33; 95% confidence interval, 1.15-1.59; P<0.001) and above 15.8% (hazard ratio=1.66; 95% confidence interval, 1.41-1.95; P<0.001), compared with matched controls with RDW ≤13.3%. This association held in multiple patient subgroups. For secondary outcomes, there was no difference in 30-day mortality, length of stay, or risk of readmission within 30 days., Conclusions: Increased preoperative RDW is associated with increased long-term mortality after noncardiac surgery. RDW could be a composite biomarker of pre-existing chronic inflammation and poor nutritional status. Future studies should clarify if this is a modifiable risk factor for improved surgical outcomes., (Copyright © 2020 British Journal of Anaesthesia. Published by Elsevier Ltd. All rights reserved.)

Background: The deceased organ donation rate in Iceland has been low compared with other Western countries. The aim of this study was to explore the potential for organ donation after brain death in Iceland., Methods: Observational cohort study of patients with catastrophic brain injury who died in intensive care units (ICUs) at hospitals in Iceland in 2003-2016. Medical records were retrospectively reviewed to identify potential donors (PDs), using the WHO Critical Pathway for Deceased Donation. Trends in annual incidence of PDs, conversion to actual donors, and family refusals were assessed., Results: Among 1537 patients who died in the ICU, 125 (8.1%) were identified as PDs. Of 103 PDs who were declared brain dead, consent for organ donation was pursued in 84 cases and granted in 63. Fifty-six became actual donors. The annual donation rate averaged 13 per million population (pmp), but rose abruptly in the final 2 years to 36 and 27 pmp, respectively. This was paralleled by an increase in annual incidence of PDs from an average of 28 pmp to 54 and 42 pmp, respectively. The donor conversion rate increased during the study period (P = .026). Twenty-three PDs (18%) were not pursued without an apparent reason., Conclusions: The donation rate increased markedly in the last 2 years of the study period after remaining low for more than a decade. This change can largely be explained by a high incidence of PDs and a low family refusal rate. Missed donation opportunities suggest a potential to maintain a high donation rate in the future., (© 2020 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Background: The Basic life support (BLS) and Advanced life support (ALS) are known prediction rules for termination of resuscitation (TOR) in out-of-hospital cardiac arrest (OHCA). Recently, a new rule was developed by Jabre et al. We aimed to independently validate and compare the predictive accuracy of these rules., Methods: OHCA cases in Iceland from 2008 to 2017 from a population-based, prospectively registered database. Primary outcome was survival to discharge among patients that met all conditions of abovementioned rules: BLS (not witnessed by EMS personnel, no defibrillation nor ROSC before transport), ALS (BLS criteria plus not witnessed nor CPR by bystander) and Jabre (not witnessed by EMS personnel, initial rhythm non-shockable, no sustainable ROSC before third dose of adrenaline)., Results: Overall, 568 OHCA patients were included in validation of TOR rules. Mean age 67, males 74%, witnessed by EMS 11%, by bystander 66% that attempted CPR in 50%, transported to hospital 60%, overall survival 20%. All rules had high specificity for mortality, 99.6-100% (95%CI 95-100). The Jabre and BLS rules had similar sensitivity 47% (43-52) vs. 44% (40-49), respectively, the sensitivity of ALS was lower, 8% (5-11). Combined use of positive BLS and Jabre rules performed the best, identifying 88/226 (39%) of futile cases transported to hospital, specificity 100% (97-100) and sensitivity 59% (55-64)., Conclusions: The accuracy of the BLS and Jabre TOR rules to predict mortality after OHCA is very good and their combined use may be superior to the use of either one., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Azithromycin (AZM) is a broad-spectrum antibiotic widely used to treat infections. AZM also has been shown to have anti-inflammatory and immunomodulatory functions unrelated to its antibacterial activity that contribute to the effectiveness of this drug in chronic respiratory diseases. The mechanisms behind these beneficial effects are not yet fully elucidated. We have previously shown that AZM enhances barrier integrity of bronchial epithelial cells and directs them towards epidermal differentiation. In this study, we analyzed the effect of AZM pre-treatment of human bronchial and alveolar derived cell lines on mechanical stress in a cyclical pressure air-liquid interface device (CPAD) that models the disruption of the epithelial barrier with increased inflammatory response in lung tissue, which is associated with ventilator-induced lung injury (VILI). Immunostaining and electron microscopy showed that barrier integrity of the epithelium was compromised by cyclically stressing the cells but maintained when cells had been pre-treated with AZM. Lamellar body formation was revealed in AZM pre-treated cells, possibly further supporting the barrier-enhancing effects. RNA sequencing showed that the inflammatory response was attenuated by AZM treatment before cyclical stress. YKL-40, an emerging inflammatory marker, increased both due to cyclical stress and upon AZM treatment. These data confirm the usefulness of the CPAD to model ventilator-induced lung injury and suggest that AZM has barrier protective and immunomodulatory effects, attenuating the inflammatory response during mechanical stress, and might therefore be lung protective during mechanical ventilation. The model could be used to assess further drug candidates that influence barrier integrity and modulate inflammatory response.

Background Limited data exist on long-term survival of patients requiring admission to intensive care units (ICUs). The aim of this study was to investigate long-term survival of ICU patients in Iceland and assess changes over a 15-year period. Methods Data were collected on age, gender, admission cause, length of stay, comorbidities, mechanical ventilation and survival of patients 18 years and older admitted to the ICUs in Landspitali during 2002-2016. Long-term survival of patients surviving more than 30 days from admission was estimated and its predictors assessed with Cox regression analysis. Long-term survival was compared to the survival of an age- and gender-matched reference group from the general population. Results Of 15 832 ICU admissions, 55% was medical, 38% was surgical and 7% was due to trauma. The 5-year survival of medical, surgical and trauma patients was 66%, 76% and 92% respectively. Significant survival differences were found between admission subgroups. Higher age and comorbidity burden was related to decreased survival in all patient groups. After correcting for age, gender, comorbidities, length of ICU stay and mechanical ventilation, patient survival improved during the study period only for patients admitted for infections. There was a high variability in the estimated time point where the ICU admission had no residual effect on survival. Conclusions Long-term survival of ICU patients is substantially decreased compared to the general population, but varies based on admission causes. Improved long-term survival of patients admitted with infections could be explained by earlier detection and improved treatment of septic shock., (© 2019 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.)

Background: Infections are a frequent complication of cardiac surgery. The intraoperative use of transesophageal echocardiography (TEE) may be an underrecognized risk factor for post-operative infections. The aim of this study was to investigate infection rates and outcomes after cardiac surgery in a nationwide cohort, especially in relation to periods where surface damaged TEE probes were used., Methods: This was a retrospective, observational study at Landspitali University Hospital. All consecutive cardiac surgery patients from 1 January 2013 to 31 December 2017 were included. Patients' charts were reviewed for evidence of infection, post-operative complications or death., Results: During the study period, 973 patients underwent cardiac surgery at Landspitali and 198 (20.3%) developed a post-operative infection. The most common infections were: Pneumonia (9.1%), superficial surgical site (5.7%), bloodstream (2.8%) and deep sternal wound (1.7%). Risk factors for developing an infection included: The duration of procedure, age, insulin-dependent diabetes, EuroScore II, reoperation for bleeding and an operation in a period with a surface damaged TEE probe in use. Twenty-two patients were infected with a multidrug resistant strain of Klebsiella oxytoca, 10 patients with Pseudomonas aeruginosa and two patients developed endocarditis with Enterococcus faecalis. All three pathogens were cultured from the TEE probe in use at respective time, after decontamination. The 30-day mortality rate in the patient cohort was 3.2%., Conclusions: The intraoperative use of surface damaged TEE probes caused two serious infection outbreaks in patients after cardiac surgery. TEE probes need careful visual inspection during decontamination and probe sheaths are recommended., (© 2019 The Authors. Acta Anaesthesiologica Scandinavica published by John Wiley & Sons Ltd on behalf of Acta Anaesthesiologica Scandinavica Foundation.)

Mechanical ventilation (MV) is a life-saving therapy for critically ill patients, alleviating the work of breathing and supporting adequate gas exchange. However, MV can cause ventilator induced lung injury (VILI) by baro/volu- and atelectrauma, even lead to acute respiratory distress syndrome (ARDS), and substantially augment mortality. There is a need for specific biomarkers and novel research platforms for VILI/ARDS research to study these detrimental disorders and seek ways to avoid or prevent them. Previous in vitro studies on bronchial epithelium, cultured in air-liquid interface (ALI) conditions, have generally utilized static or constant pressure.  We have developed a Cyclical Pressure ALI Device (CPAD) that enables cyclical stress on ALI cultured human bronchial cells, with the aim of mimicking the effects of MV. Using CPAD we were able to analyze differentially expressed VILI/ARDS and innate immunity associated genes along with increased expression of associated proteins. CPAD provides an easy and accessible way to analyze functional and phenotypic changes that occur during VILI and may provide a platform for future drug testing.

Arterial cannulation is a common procedure in critically ill patients, as it facilitates continuous monitoring of blood pressure, titration of inotropes, vasopressors and fluids and is also used for blood sampling. Serious complications from arterial lines are very rare, permanent ischemic damage occurs in less than 0,1% of patients. We report the case of a 60-year-old woman in septic shock caused by a perforated duodenal ulcer which was treated with emergent laparoscopic repair. She required high doses of vasopressors and received several arterial lines, including lines in both the ulnar and the radial arteries of the left arm. After two weeks in the intensive care unit she developed ischemia in all fingers of her left hand. She received anticoagulative therapy which was complicated by serious gastrointestinal bleeding and the therapy had to be discontinued. Eight weeks later she had demarcated necrosis in all fingers of her left hand and underwent partial amputation of fingers II-V, the thumb recovered without surgery. The cause of the necrosis was believed to be arterial embolism or ischemia secondary to arte- rial cannulations in combination with her underlying critical septic condition.

Objective: High prevalence of hypopituitarism (HP) has been reported after traumatic brain injury (TBI) and subarachnoid haemorrhage (SAH). The aim of the study was to prospectively evaluate the prevalence and progression of HP in patients after TBI and SAH in Icelandic population., Design: A 12 month prospective single-centre study., Methods and Procedures: A total of 27 patients were included, 15 patients with TBI and 12 patients with SAH. Pituitary function was evaluated with baseline hormone measurements and diagnostic tests. An insulin tolerance test was used unless contraindicated, then the GHRH-arginine test and Synachten test were used., Results: At three months, 16.7% (2/12) of the patients had HP after TBI and 33.3% (4/12) after SAH. At 12 months, 21.4% (3/14) of patients had HP after TBI and 9.1% (1/11) after SAH. Gonadotropin deficiency was the most common deficiency at 3 months and GH and gonadotropin deficiency at 12 months., Conclusions: There is a considerable risk of HP after TBI and reason to study pituitary function further in patients with SAH. We believe that neuroendocrine evaluation is important in these patients. Since recovery commonly occurs 12 months after the event, evaluation should be performed after that time if not clinically indicated earlier.

Introduction: Hip fractures are common amongst the elderly, often with serious consequences and increased mortality. The aim of this study was to describe treatment and outcome of patients with hip fractures., Material and Methods: Retrospective study on all hip fracture patients ≥60 years of age operated at Landspitali University Hospital in the year 2011., Results: The study group was made up of 255 patients (mean age 82 ± 8 years, women 65%). Mean delay to operation was 22 ± 14 hours. Mean length of hospital stay for those living at a nursing home before hip fracture was 4 ± 2 days but if they had lived at home 14 ± 10 days (p<0.001). Before the fracture 68% of the patients lived at home but 54% at the end of follow-up (p<0.001). Mortality one year after hip fracture was 27% and on average eightfold compared to the general population ≥60 years. A multivariate analysis showed that age, time from fracture to arrival at hospital, ASA-classification and living in a nursing home before fracture were linked to an increased risk of death., Conclusion: The mean delay to surgery was within recommended guidelines, but one- third waited longer than 24 hours. Resources outside hospital seemed to decide hospital length of stay. Mortality of hip fracture patients was manifold compared to the general population of the same age and within higher range compared to other countries. Significantly fewer lived in their own home after the fracture. Hip fractures cause serious debilitation and are demanding for society.

Mechanical ventilation (MV) of patients can cause damage to bronchoalveolar epithelium, leading to a sterile inflammatory response, infection and in severe cases sepsis. Limited knowledge is available on the effects of MV on the innate immune defense system in the human lung. In this study, we demonstrate that cyclic stretch of the human bronchial epithelial cell lines VA10 and BCi NS 1.1 leads to down-regulation of cathelicidin antimicrobial peptide (CAMP) gene expression. We show that treatment of VA10 cells with vitamin D3 and/or 4-phenyl butyric acid counteracted cyclic stretch mediated down-regulation of CAMP mRNA and protein expression (LL-37). Further, we observed an increase in pro-inflammatory responses in the VA10 cell line subjected to cyclic stretch. The mRNA expression of the genes encoding pro-inflammatory cytokines IL-8 and IL-1β was increased after cyclic stretching, where as a decrease in gene expression of chemokines IP-10 and RANTES was observed. Cyclic stretch enhanced oxidative stress in the VA10 cells. The mRNA expression of toll-like receptor (TLR) 3, TLR5 and TLR8 was reduced, while the gene expression of TLR2 was increased in VA10 cells after cyclic stretch. In conclusion, our in vitro results indicate that cyclic stretch may differentially modulate innate immunity by down-regulation of antimicrobial peptide expression and increase in pro-inflammatory responses.