Hypothermia treatment with cooling to a body temperature of 32-34°C has been shown to be an effective way of improving neurological outcome and survival in unconscious patients successfully resuscitated after cardiac arrest (CA). The method is used clinically but there are still many questions on the biological mechanisms and on how the treatment is best performed. This thesis focuses on cerebral and haemodynamic effects of hypothermia and rewarming. A porcine model of CA was used. To shorten time to reach target temperature, induction of hypothermia, by means of infusion of 4°C cold fluid, was started already during ongoing cardiopulmonary resuscitation. The temperature was satisfactorily reduced without obvious haemodynamic disturbances. Cerebral effects of hypothermia and rewarming were studied. Microdialysis monitoring showed signs of cerebral energy failure (increased lactate/pyruvate-ratio) and excitotoxicity (increased glutamate) immediately after CA. There was a risk of secondary energy failure that was reduced by hypothermia. Intracranial pressure (ICP) increased gradually after CA irrespectively of if hypothermia was used or not. There were no indications of increasing cerebral disturbances during rewarming. Haemodynamic effects of hypothermia treatment and rewarming were examined in a study of patients successfully resuscitated after CA. Hypothermia was induced by means of cold intravenous infusion. No negative effects on the cardiovascular system were revealed. There were indications of decreased intravascular volume in spite of a positive fluid balance. Cerebral microdialysis and ICP recording were performed in four patients. All patients had signs of energy failure and excitotoxicity following CA. ICP was only exceptionally above 20 mmHg. In contrast to the experimental study indications of increasing ischemia were seen during rewarming. Glycerol had a biphasic pattern, perhaps due to an overspill of metabolites from the general circulation. As most patients become extensively anti-coagulated following CA, intracranial monitoring is not suitable to be used in routine care.

Traumaskadade inkommer ofta till akutmottagningen med kort förvarning där situationen kan vara dramatisk. Omhändertagandet av den traumaskadade sker enligt speciella fastslagna principer, utfört av ett multidisciplinärt team där anestesipersonal innehar en av nyckelfunktionerna. Syftet med dennas studie var att identifiera anestesipersonalens erfarenhet och hantering av kritiska händelser i samband med traumaomhändertagande på akutmottagning. Kritisk incident teknik (CIT) har använts som metod för att identifiera avgörande händelser kring traumaomhändertagandet. Totalt utfördes och analyserades 12 intervjuer med anestesisjuksköterskor (n=8) och anestesiläkare (n=4). Analysen genomfördes med en induktiv manifest innehållsanalys. Totalt 209 kritiska incidenter samlades in där fyra teman identifierades. Anestesipersonalens erfarenheter kunde delas upp i två teman; individfokuserade och organisationsfokuserade där bland annat betydelsen av tidigare traumaerfarenhet och samarbetet i teamet belystes. Hanteringar genomfördes ur ett individuellt förhållande eller utifrån gruppförhållande. Avgörande hanteringar var till exempel förberedelse av utrustning inför patientens ankomst och utvärdering av genomfört arbete efter omhändertagandet. Förutsättningar för det multidisciplinära kliniköverskridande traumaomhändertagandet skapas genom organisatoriska förutsättningar samt individuella ageranden och förmågor. Uppkomna situationer som anses avgörande för omhändertagandet hanteras genom individuella eller teamgemensamma åtgärder.

Bakgrund: Anestesisjuksköterskor i Sverige har en unik roll i och med att de har ett eget yrkesansvar som ger behörighet att utföra anestesiarbetet självständigt. Det finns många utmaningar som en anestesisjuksköterska ställs inför vid sövning av barn, både ur fysiologisk och psykologisk synvinkel. Få studier finns gjorda kring anestesisjuksköterskors erfarenheter av barninduktion. Syfte: Studiens syfte var att belysa anestesisjuksköterskors erfarenheter vid barninduktion. Metod: Studien genomfördes på ett sjukhus i mellersta Sverige under våren 2011. En kvalitativ intervjumetod användes med innehållsanalys av materialet. Sammanlagt intervjuades 14 anestesisjuksköterskor med varierande yrkeserfarenhet. Resultat: Alla studiedeltagare ansåg att det är en utmaning att söva barn. Med ökad erfarenhet upplevde anestesisjuksköterskorna att de blev tryggare i sin yrkesroll och att de lättare kunde hantera de små marginaler som barns fysiologi innebär. De betonade vikten av en god kommunikation med barnet och dess familj. Ibland uppkom situationer som ställde anestesisjuksköterskan inför etiska dilemman. Diskussion: I studien framkom hur anestesisjuksköterskor utvecklas från att vara noviser till att bli experter på sitt område. En tydlig känsla av yrkesstolthet kunde utläsas av intervjuerna. Anestesisjuksköterskorna befann sig på ett kontinuum mellan att vara uppgifts- eller relationsfokuserad.   Nyckelord: Anestesisjuksköterskor, barninduktion, erfarenheter, omvårdnad, samspel / Background: Nurse Anesthetists in Sweden have a unique role due to the responsibilities required of the profession and due to the fact that NA´s often work alone. There are many challenges a nurse anesthetist meets when performing a child induction, both from a physiological and a psychological aspect. There are only a few studies conducted concerning nurse anesthetists´ experiences of child induction. Aim: The aim of this study was to describe nurse anesthetists´ experiences of child induction. Method: The study was conducted in a hospital in Norrland in the spring of 2011. A qualitative interview method was used with a content analysis of the material. A total of 14 NA´s were interviewed, with a varied amount of years in the profession. Result: All interviewees thought that it was a challenge to perform a child induction. With increasing experience, the NA´s became more comfortable in their professional role and could cope with the small margins that a child´s physiology brings. They all emphasized the importance of a good communication with the child and its family. NA´s sometimes found themselves in situations wherein ethical dilemmas arose. Discussion: The study showed that NA´s evolved from being a novice to becoming an expert in their field. A clear sense of pride of the profession could be read between the lines during the interviews. The NA´s could be found in a continuum between being relationship-oriented and being task-oriented.   Key words: Child induction, experience, interaction,  Nurse anesthetist, Nursing

<p>Neuropathic pain of central and peripheral origin presents a substantial clinical problem as it is often resistant to pharmacological treatment.</p><p>The health related quality of life of 126 patients with peripheral neuropathic pain was studied, to provide a cross sectional description from this point of view. Two generic health-related quality of life instruments; the SF-36 and the Nottingham Health Profile were used together with pain assessments, global rating of health and verbal rating scales of pain and other symptoms, as well as patient descriptors.</p><p>The analgesic effect of ketamine, lidocaine and morphine were assessed in a double blind, placebo-controlled, randomized study design. Three groups of patients were studied: patients with peripheral neuropathic pain of traumatic origin, patients with central post-stroke pain and patients with neuropathic pain after spinal cord injury. Somatosensory function was examined to see if this could predict response to treatment and to investigate if the drugs caused changes in thermal or mechanical sensibility.</p><p>The results shows that the intense pain, limited efficacy and tolerability of available treatments, the low overall rating of health, reduced work status and troublesome symptoms constitute a substantial impact on the quality of life for patients with peripheral neuropathic pain.</p><p>The NMDA-antagonist ketamine yielded substantial pain relief to patients with peripheral neuropathic pain and patients with neuropathic pain after spinal cord injury. However, the reported side effects limit the clinical usefulness of the treatment. Lidocaine did not give significant pain relief to the patients in the three studied groups. Morphine may represent a therapeutic alternative for some patients with central post-stroke pain, although only a small group of this category of patients responded with analgesia.</p><p>Assessment of baseline somatosensory functions could not be used to identify responders to treatment with either drug, nor did ketamine, lidocaine or morphine cause any changes in thermal or mechanical sensibility.</p>

Neuropathic pain of central and peripheral origin presents a substantial clinical problem as it is often resistant to pharmacological treatment. The health related quality of life of 126 patients with peripheral neuropathic pain was studied, to provide a cross sectional description from this point of view. Two generic health-related quality of life instruments; the SF-36 and the Nottingham Health Profile were used together with pain assessments, global rating of health and verbal rating scales of pain and other symptoms, as well as patient descriptors. The analgesic effect of ketamine, lidocaine and morphine were assessed in a double blind, placebo-controlled, randomized study design. Three groups of patients were studied: patients with peripheral neuropathic pain of traumatic origin, patients with central post-stroke pain and patients with neuropathic pain after spinal cord injury. Somatosensory function was examined to see if this could predict response to treatment and to investigate if the drugs caused changes in thermal or mechanical sensibility. The results shows that the intense pain, limited efficacy and tolerability of available treatments, the low overall rating of health, reduced work status and troublesome symptoms constitute a substantial impact on the quality of life for patients with peripheral neuropathic pain. The NMDA-antagonist ketamine yielded substantial pain relief to patients with peripheral neuropathic pain and patients with neuropathic pain after spinal cord injury. However, the reported side effects limit the clinical usefulness of the treatment. Lidocaine did not give significant pain relief to the patients in the three studied groups. Morphine may represent a therapeutic alternative for some patients with central post-stroke pain, although only a small group of this category of patients responded with analgesia. Assessment of baseline somatosensory functions could not be used to identify responders to treatment with either drug, nor did ketamine, lidocaine or morphine cause any changes in thermal or mechanical sensibility.

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.

Atelektaser uppstår inom tio minuter hos 90 % av alla patienter som sövs och leder till försämrad syresättning men kan även leda till postoperativa lungkomplikationer. Syftet med studien var att beskriva hur anestesisjuksköterskan med olika ventilationsstrategier kan förebygga atelektasbildning under generell anestesi. Studien genomfördes som en litteraturstudie där 19 vetenskapliga artiklar granskades och analyserades. Resultatet visar att när 100 % syrgas ges under induktionen av anestesi ökar uppkomsten av atelektaser. Om positive end-expiratory pressure (PEEP) 6-10 cmH2O används tillsammans med 100 % syrgas motverkas detta. Det är mer oklart vilken effekt PEEP har efter induktionen av anestesi. PEEP bör kombineras med rekryteringsmanöver för att effektivt motverka atelektasbildning. Olika metoder för att genomföra rekryteringsmanöver finns beskrivna men gemensamt är att topptrycket ska nå upp till cirka 40 cmH2O. Efter induktionen kan anestesisjuksköterskan även förebygga uppkomst av atelektaser genom använda 40 % syrgas. I den kliniska verksamheten saknas ofta riktlinjer för vilken ventilationsstrategi som ska användas. För att kunna arbeta preventivt med att förebygga atelektasbildning måste anestesisjuksköterskan diskutera ventilationsstrategi med anestesiläkaren innan problem med syresättningen uppstår. För framtida forskning skulle det kunna vara av intresse att undersöka hur olika ventilationsinställningar påverkar patientens upplevelse under preoxygenering.

<p>Transesophageal echocardiography (TEE) has become a useful tool in monitoring the heart in patients during open-heart surgery. This study was undertaken to evaluate whether it is feasible to use TEE to assess left ventricular myocardial viability in anesthetized patients scheduled for coronary artery bypass grafting (CABG).</p><p>A total of 84 patients were studied. To test myocardial viability, TEE and a low-dose dobutamine stress regimen were used. Echocardiographic data were analyzed off-line using a visual or semiautomatic analysis of segmental left ventricular wall motion (LVWM). Visual assessment was performed by readers blinded to the sequence of events. The agreement between readers in visual analysis of segmental LVWM in the transgastric short-axis view was 73% or higher. Segmental LVWM assessed by TEE was compared to hemodynamic data obtained by thermodilution pulmonary artery catheter (PAC) and coronary angiographic data. Also, using the same low-dose dobutamine stress regimen, TEE findings in the anesthetized patient perioperatively were compared with preoperative transthoracic echocardiography (TTE) findings in the awake patient.</p><p>TEE was found to be feasible and adequate for testing left segmental ventricular viability. A concomitant increase in stroke volume assessed by PAC and decrease in LVWM-score assessed by TEE was found with dobutamine stimulation. Abnormal segmental LVWM corresponded to angiographically stenosed supplying coronary artery vessels. During dobutamine stimulation, 69% of the corresponding segments responded which is a sign of viability. The LVWM response to preoperative TTE and perioperative TEE dobutamine stress was comparable except for a significant difference in the apical segments.</p><p>This study showed that perioperative TEE dobutamine stress could be used to test left ventricular viability and was also a valuable supplement to PAC, angiography and TTE. The acquired knowledge is important and suggest that further development of transesophageal ultrasound technology is warranted.</p>

Transesophageal echocardiography (TEE) has become a useful tool in monitoring the heart in patients during open-heart surgery. This study was undertaken to evaluate whether it is feasible to use TEE to assess left ventricular myocardial viability in anesthetized patients scheduled for coronary artery bypass grafting (CABG). A total of 84 patients were studied. To test myocardial viability, TEE and a low-dose dobutamine stress regimen were used. Echocardiographic data were analyzed off-line using a visual or semiautomatic analysis of segmental left ventricular wall motion (LVWM). Visual assessment was performed by readers blinded to the sequence of events. The agreement between readers in visual analysis of segmental LVWM in the transgastric short-axis view was 73% or higher. Segmental LVWM assessed by TEE was compared to hemodynamic data obtained by thermodilution pulmonary artery catheter (PAC) and coronary angiographic data. Also, using the same low-dose dobutamine stress regimen, TEE findings in the anesthetized patient perioperatively were compared with preoperative transthoracic echocardiography (TTE) findings in the awake patient. TEE was found to be feasible and adequate for testing left segmental ventricular viability. A concomitant increase in stroke volume assessed by PAC and decrease in LVWM-score assessed by TEE was found with dobutamine stimulation. Abnormal segmental LVWM corresponded to angiographically stenosed supplying coronary artery vessels. During dobutamine stimulation, 69% of the corresponding segments responded which is a sign of viability. The LVWM response to preoperative TTE and perioperative TEE dobutamine stress was comparable except for a significant difference in the apical segments. This study showed that perioperative TEE dobutamine stress could be used to test left ventricular viability and was also a valuable supplement to PAC, angiography and TTE. The acquired knowledge is important and suggest that further development of transesophageal ultrasound technology is warranted.

Introduction. Multiple clinical methods for detecting myocardial ischemia are utilised in the hospital setting each day, but there is uncertainty about their diagnostic accuracy. In the operating room, multiple methods may be employed, while in the CCU advanced electrophysiological (ECG) techniques for myocardial ischemia detection, and in particular, ST segment analysis, are common. Vectorcardiography (VCG) is one form of ECG. Several conditions other than ischemia may cause marked ST changes, which can impair the process of diagnosis of clinical ischemia. Elevated HR is one of these factors, which is studied here. The hypotheses were about concordance of different methods to detect ischemia, and relation of ECG ST levels to HR with and without myocardial ischemia. Methods. Study I. Anesthetised vascular surgical patients with coronary artery disease were studied during the start of anesthesia and surgery: ECG, hemodynamic, mechanical, and metabolic parameters were measured and categorised as positive or negative with reference to a specific definition of myocardial ischemia. Study II. Awake patients with no ischemic heart disease were paced in graded steps, and VCG ST analyses were performed. Study III. Anesthetised pigs were studied for local metabolic and VCG ST changes related to controlled HR levels and transient coronary occlusion. Study IV. Thirty five anesthetised coronary artery disease (CAD) patients and ten non-CAD patients were paced at controlled levels, and great coronary artery vein (GCV) lactate measurement was used to determine presence or absence of myocardial ischemia. The CAD patients were paced up to HR levels where myocardial ischemia could be confirmed. The relation of HR-related VCG ST levels to presence or absence of ischemia was analysed. In Studies II,, III, and IV the ST vector magnitude (ST-VM), the change from baseline in ST-VM (STC-VM), and the vector angle change from baseline (STC-VA) were analysed for each step. Results. Study I. Poor concordance was demonstrated for positive events (presumed myocardial ischemia) between the hemodynamic, ECG, mechanical, and metabolic detection methods. Study II. STC-VM but not ST-VM levels demonstrated HR-related increases in the presumed absence of myocardial ischemia in 18 awake subjects. J point time to ST measurement did not affect the response of VCG ST to HR. Study III. STC-VM levels showed HR-related increases in the absence of ischemia (tested by local metabolic observations). VCG ST parameters responded positively to transient regional ischemia. Study IV. CAD patients, which demonstrated a clear pattern of onset and progress of ischemia during pacing, were further analysed for the relation of VCG ST level to ischemia. Sensitivity and specificity of STC-VM levels were described by ROC analysis for a range of STC-VM levels. Conclusions. Concordance of different measures for detection of onset of myocardial ischemia is difficult to assess in the absence of a very reliable reference method. The contribution of HR and ischemia to VCG ST levels were estimated in study subjects. HR-related increases in STC-VM occur in the absence of ischemia. HR levels need to be considered when interpreting STC-VM as a diagnostic test for ischemia. Further study is needed to establish criteria that take into account multiple clinical factors in order to improve the predictive value of our tests for myocardial ischemia.