| 1. |
- Rhodin, Annica, 1949-
(författare)
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Long-term Effects of Opioids in the Treatment of Chronic Pain : Investigation of Problems and Hazards on Clinical, Biochemical, Cellular and Genetic Levels
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- After two decades of liberal prescribing of opioids, there has been an increasing recognition of problems connected to the prolonged use of opioids for chronic pain. The aim of my thesis was to explore some consequences of long-term opioid treatment for chronic pain such as problematic opioid use, endocrine disorders, tolerance and genetic variations in pain and opioid response. Sixty patients with severe pain and problematic opioid use were treated with a structured methadone programme. Risk factors were musculoskeletal pain, psychiatric co-morbidity and previous addiction. Treatment resulted in good pain relief and improved quality of life, but function was impaired by side effects indicating endocrine dysregulation. The possibility of opioid-induced endocrine dysfunction was explored in the second paper, where 40 pain patients treated with strong opioids and 20 pain patients without treatment of strong opioids were investigated. The opioid-treated patients had significantly higher incidence of endocrine disturbance affecting gonadal and adrenal function and prolactin levels. The functionality of the μ-receptor after long-term treatment with morphine, saline and naloxone was explored in a cell-line expressing the μ-receptor. After one and four weeks of treatment the binding was tested with morphine, methadone, fentanyl and DAMGO and function measured by GTP γ-assay. The binding of DAMGO was significantly diminished after 4 weeks in cells treated with morphine compared with saline and naloxone. Genetic variation in three genes with functional impact on opioid response and pain sensitivity was investigated in 80 patients with chronic low-back pain and differential opioid sensitivity and in 56 healthy controls. The results indicated a higher incidence of opioid-related side effects and gender differences in patients with the minor allele of the ABCB1 gene, a correlation between increased opioid sensitivity and the major CACNA2D2 allele and a possible relationship between intrinsic protection against chronic pain and the minor allele of OPRM1.
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| 2. |
- Östberg, Erland, 1971-
(författare)
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Pulmonary Atelectasis in General Anaesthesia : Clinical Studies on the Counteracting Effects of Positive End-Expiratory Pressure
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Partial lung collapse, i.e., pulmonary atelectasis, is common during general anaesthesia. The main causal mechanism is reduced lung volume with airway closure and subsequent gas absorption from preoxygenated alveoli. Atelectasis impairs oxygenation and forms the pathophysiological basis for postoperative pulmonary complications. Positive end-expiratory pressure (PEEP) counteracts the loss in lung volume, but its role in preventing atelectasis during anaesthesia is not clear.All studies included in this thesis were prospective randomized clinical trials. In the first study, oxygenation was used as a surrogate measure of atelectasis in obese patients undergoing laparoscopic gastric bypass. The subsequent studies used single-slice computed tomography (CT) to evaluate atelectasis in healthy patients undergoing non-abdominal surgery.Paper I: We studied the use of continuous positive airway pressure (CPAP) and PEEP during induction of anaesthesia and a reduced inspired oxygen fraction (FiO2) during emergence. Oxygenation was maintained in the group that received CPAP during induction, followed by a PEEP of 10 cmH2O. Postoperative oxygenation was impaired in the group that received a high FiO2 during emergence.Paper II: An early oxygen washout manoeuvre to quickly restore nitrogen levels and thus stabilize the alveoli, had no effect on atelectasis at the end of surgery. Both study groups exhibited small atelectasis after being ventilated with a moderate PEEP of 6-8 cmH2O during anaesthesia.Paper III: The effect of PEEP versus zero PEEP on atelectasis formation and oxygenation at the end of surgery was compared. The PEEP group maintained oxygenation better and exhibited less atelectasis than the zero-PEEP group, with atelectasis involving a median 1.8% of total lung area compared with 4.6% in the zero-PEEP group (P = 0.002).Paper IV: Postoperative atelectasis was compared between a group in which PEEP was maintained during emergence preoxygenation with FiO2 1.0 and a group in which PEEP was withdrawn just before the start of emergence preoxygenation with FiO2 1.0. The two groups had small atelectasis when fully awake at 30 min after extubation, with no statistically significant difference between them. In conclusion, preserved end-expiratory lung volume is the key to avoiding atelectasis, in particular when an increased oxygen reserve is required during airway manipulation. PEEP is both necessary and sufficient to minimize atelectasis in healthy patients undergoing non-abdominal surgery.
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| 3. |
- Burström, Lena
(författare)
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Patient Safety in the Emergency Department : Culture, Waiting, and Outcomes of Efficiency and Quality
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The overall aim of this thesis was to investigate patient safety in the emergency department (ED) and to determine whether this varies according to patient safety culture, waiting, and outcomes of efficiency and quality variables.I: Patient safety culture was described in the EDs of two different hospitals before and after a quality improvement project. The questionnaire “Hospital Survey on Patient Safety Culture” was used to investigate the patient safety culture. The main finding was that the staff at both hospitals scored more positively in the dimension Team-work within hospital after implementing a new work model aimed at improving patient flow and patient safety in the ED. Otherwise, we found only modest improvements.II: Grounded theory was used to explore what happens in the ED from the staff perspective. Their main concern was reducing patients’ non-acceptable waiting time. Management of waiting was improved either by increasing the throughput of patient flow by structure pushing and by shuffling patients, or by changing the experience of waiting by calming patients and by feinting to cover up.III: Three Swedish EDs with different triage models were compared in terms of efficiency and quality. The median length of stay was 158 minutes for physician-led team triage compared with 243 and 197 minutes for nurse–emergency physician and nurse–junior physician triage, respectively. Quality indicators (i.e., patients leaving before treatment was completed, the rate of unscheduled return within 24 and 72 hours, and mortality rate within 7 and 30 days) improved under the physician-led team triage.IV: Efficiency and quality variables were compared from before (2008) to after (2012) a reorganization with a shift of triage model at a single ED. Time from registration to physician decreased by 47 minutes, and the length of stay decreased by 34 minutes. Several quality measures differed between the two years, in favour of 2012. Patients leaving before treatment was completed, unscheduled return within 24 and 72 hours, and mortality rate within 7 and 30 days all improved despite the reduced admission rate.In conclusion, the studies underscore the need to improve patient safety in the ED. It is important to the patient safety culture to reduce patient waiting because it dynamically affects both patients and staff. Physician-led team triage may be a suitable model for reducing patient waiting time and increasing patient safety.
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| 4. |
- Edmark, Lennart, 1954-
(författare)
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Reducing Atelectasis during General Anaesthesia – the Importance of Oxygen Concentration, End-Expiratory Pressure and Patient Factors : A Clinical Study Exploring the Prevention of Atelectasis in Adults
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: The use of pure oxygen during preoxygenation and induction of general anaesthesia is a major cause of atelectasis. The interaction between reduced lung volume, resulting in airway closure, and varying inspiratory fractions of oxygen (FIO2) in determining the risk of developing atelectasis is still obscure.Methods: In this thesis, computed tomography (in studies I and II during anaesthesia, in studies III and IV postoperatively) was used to investigate the area of atelectasis in relation to FIO2 and varying levels of continuous positive airway pressure (CPAP) or positive end-expiratory pressure (PEEP).Study I investigated the short-term influence of reducing FIO2 during preoxygenation and induction of general anaesthesia, and the time to hypoxia during apnoea.Study II focused on the long-term effect of an FIO2 of 0.8 for preoxygenation.Study III applied CPAP/PEEP with an FIO2 of 1.0 or 0.8 for pre- and postoxygenation until extubation. After extubation, CPAP with an FIO2 of 0.3 was applied before the end of mask ventilation.Study IV compared two groups given CPAP/PEEP during anaesthesia and an FIO2 of 1.0 or 0.3 during postoxygenation, but without CPAP after extubation.Results: Study I showed a reduction in atelectasis with an FIO2 of 0.8 or 0.6, compared with 1.0, but the time to hypoxia decreased. In study II, atelectasis evolved gradually after preoxygenation. In study III, atelectasis was reduced with an FIO2 of 1.0 and CPAP/PEEP compared with an FIO2 of 1.0 without CPAP/PEEP. The intervention failed in the group given an FIO2 of 0.8, this group had more smokers. Atelectasis and age were correlated. In study IV, no difference was found between the groups. Post hoc analysis showed that smoking and ASA class increased the risk for atelectasis.Conclusion, the effect of reducing FIO2 during preoxygenation to prevent atelectasis might be short-lived. A lower FIO2 shortened the time to the appearance of hypoxia. Increasing lung volume by using CPAP/PEEP also decreased the risk of atelectasis, but the method might fail; for example in patients who are heavy smokers. In older patients care must be taken to reduce a high FIO2 before ending CPAP.
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| 5. |
- Kuchalik, Jan, 1965-
(författare)
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Postoperative pain, inflammation and functional recovery after total hip arthroplasty : Prospective, randomized, clinical studies
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Total hip arthroplasty (THA) is performed in patients with osteoarthritis of the hip joint. Pain following THA is often moderate but no gold stand-ard exists for pain management. Good postoperative pain management may lead to a better quality of life and hip function. In study I, we inves-tigated whether intrathecal morphine (ITM) or local infiltration analgesia (LIA) is better for pain management. Eighty patients were randomized to one of two groups, ITM or LIA in this randomized double-blind study. Lower pain intensity was recorded early after surgery (< 8 h) in ITM group but subsequently (> 24 h), analgesic consumption, pain intensity on mo-bilization, and side-effects were lower in patients receiving LIA. In study II, in a randomized, double blind study, we compared LIA with femoral nerve block (FNB) for pain management following THA in 56 patients. We found that LIA significantly reduces pain intensity on standing and mobilization at 24 -48 h, as well as rescue analgesic consumption (0 – 24 h) compared to FNB without causing significant side effects. In study III, the same patients were included as in study II to determine the role of inflammation on postoperative pain by analyzing a battery of cytokines in the plasma before and at fixed time points after surgery. We found that LIA has a modest but short-lasting effect (≈4 h) on postoperative inflam-mation, specifically IL-6. This is likely to be due to local infiltration of ketorolac and/or local anesthetics.Study IV was a long-term follow-up of patients included in study I. We found no differences in quality of life or hip function up to 6 months after surgery when comparing LIA with ITM. Additionally, the incidence of persistent post-surgical pain and postoperative complications was similar between the groups and LIA had no long-term negative effects.In conclusion, LIA is a good alternative to intrathecal morphine or fem-oral nerve block in patients undergoing THA. The analgesic effect may be due to anti-inflammatory effect of ketorolac injected locally or local anes-thetics. No negative long-term effects of LIA were found. The technique is efficacious, simple to apply and offers a good alternative to intrathecal morphine or femoral nerve block without negative effects during THA.
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| 6. |
- Pösö, Tomi, 1972-
(författare)
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Assessment and management of bariatric surgery patients
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background: In morbidly obese individuals (MO) cardiorespiratory comorbidities and body habitus challenge the perioperative management of anesthesia. To implement safe and reproducible routines for anesthesia and fluid therapy is the cornerstone in order to minimize anesthesia-related complications and to meet individual variability in rehydration needs. Methods: Paper I: Impact of rapid-weight-loss preparation prior to bariatric surgery was investigated. Prevalence of preoperative dehydration and cardiac function were assessed with transthoracic echocardiography (TTE). Paper II: The anesthetic technique for rapid sequence induction (RSI) in MO based on a combination of volatile and i.v. anesthetics was developed. Pre- and post-induction oxygenation, blood pressure levels and feasibility of the method was evaluated. Paper III: The preoperative ideal body weight based rehydration regime was evaluated by TTE. Paper IV: Need of rehydration during bariatric surgery was evaluated by comparing conventional monitoring to a more advanced approach (i.e. preoperative TTE and arterial pulse wave analysis).Results: Rapid-weight-loss preparation prior to bariatric surgery may expose MO to dehydration. TTE was shown to be a robust modality for preoperative screening of the level of venous return, assessment of filling pressures and biventricular function of the heart in MO. The combination of sevoflurane, propofol, alfentanil and suxamethonium was demonstrated to be a safe method for RSI regardless of BMI. The preoperative rehydration regime implemented by colloids 6 ml/kg IBW was an adequate treatment to obtain euvolemia. In addition, preoperative rehydration seems to increase hemodynamic stability during intravenous induction of anesthesia and even intraoperatively. Conclusion: This thesis describes a safe and comprehensive perioperative management of morbidly obese individuals scheduled for bariatric surgery. Hemodynamic and respiratory stability can be achieved by implementation of strict and proven methods of anesthesia and fluid therapy. Much focus should be placed on feasible monitoring and preoperative optimization in morbidly obese individuals for increased perioperative safety.
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| 7. |
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| 8. |
- Södersved Källestedt, Marie-Louise, 1976-
(författare)
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In-Hospital Cardiac Arrest : A Study of Education in Cardiopulmonary Resuscitation and its Effects on Knowledge, Skills and Attitudes among Healthcare Professionals and Survival of In-Hospital Cardiac Arrest Patients
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis investigated whether outcome after in-hospital cardiac arrest patients could be improved by a cardiopulmonary resuscitation (CPR) educational intervention focusing on all hospital healthcare professionals.Annually in Sweden, approximately 3000 in-hospital patients suffer a cardiac arrest in which CPR is attempted, and which 900 will survive.The thesis is based on five papers:Paper I was a methodological study concluding in a reliable multiple choice questionnaire (MCQ) aimed at measuring CPR knowledge.Paper II was an intervention study. The intervention consisted of educating 3144 healthcare professionals in CPR. The MCQ from Paper I was answered by the healthcare professionals both before (82% response rate) and after (98% response rate) education. Theoretical knowledge improved in all the different groups of healthcare professionals after the intervention.Paper III was an observational laboratory study investigating the practical CPR skills of 74 healthcare professionals’. Willingness to use an automated external defibrillator (AED) improved generally after education, and there were no major differences in CPR skills between the different healthcare professions.Paper IV investigated, by use of a questionnaire, the attitudes to CPR of 2152 healthcare professionals (82% response rate). A majority of healthcare professionals reported a positive attitude to resuscitation.Paper V was a register study of patients suffering from cardiac arrest. The intervention tended not to reduce the delay to start of treatment or to increase overall survival. However, our results suggested indirect signs of an improved cerebral function among survivors.In conclusion, CPR education and the introduction of AEDs in-hospital– improved healthcare professionals knowledge, skills, and attitudes– did not improve patients’ survival to hospital discharge, but the functional status among survivors improved.
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