Prospective study on long-term outcome after abdominal surgery.

BACKGROUND: Complications following major abdominal surgery are common and an important cause of morbidity and mortality. The aim of this study was to describe 1-year mortality and identify factors that influence adverse outcomes after abdominal surgery. METHODS: This prospective observational cohort study was performed in Landspitali University Hospital and included all adult patients undergoing abdominal surgery requiring > 24-h hospital admission over 13 months. The follow-up period was 60 days for complications and 24 months for mortality. RESULTS: Data were available for 1113 (99.5%) of the 1119 patients who fulfilled inclusion criteria. A total of 23% of patients had at least one underlying co-morbidity. Non-elective surgeries were 48% and 13% of the patients were admitted to ICU post-operatively. A total of 20% of patients developed complications. Mortality at 30 days, 1 and 2 years was 1.8%, 5.6%, and 8.3% respectively. One-year mortality for those admitted to ICU was 18%. The long-term survival of the individuals surviving 30 days was significantly worse than for an age- and gender-matched population control group. Independent predictors for 1-year mortality were age, pre-operative acute kidney injury and intermediate- or major surgery. CONCLUSION: Post-operative complication rates and mortality following abdominal surgery in Iceland were comparable or in the lower range of previously published outcomes, validating the utility of offering a full host of abdominal surgical services in geographically isolated region with a relatively small referral base.

Severe vitamin D deficiency is common in critically ill patients at a high northern latitude.

BACKGROUND: Critically ill patients at southern latitudes have been shown to have low vitamin D levels that were associated with prolonged hospital stay. To our knowledge no studies have been conducted on vitamin D status amongst critically ill patients at high northern latitudes. Despite the Icelandic population traditionally taking vitamin D supplements, we hypothesized that the majority of critically ill patients in Reykjavik, Iceland have low vitamin D levels. METHODS: This was a prospective observational study on 122 patients admitted to Landspitali University Hospital intensive care unit. Serum vitamin D (25(OH)D) was measured in all patients on two occasions (first and second day). The prevalence of vitamin D deficiency and its effect on hospital stay was calculated. RESULTS: Only 9% of patients had vitamin D levels recommended for good health (>75 nmol/l) and 69% were deficient (25(OH)D < 50 nmol/l). The average difference between the first and second vitamin D samples was 2.8 nmol/l. Forty-three percentage of the severely vitamin D deficient stayed in the ICU for more than 4 days compared to 19% of patients with better status (P = 0.196). DISCUSSION: Vitamin D deficiency is very common in critically ill patients at high northern latitudes and patients with severely deficient vitamin D levels had trend towards longer intensive care unit stay. Furthermore, 43% of the patients had vitamin D levels under 25 nmol/l that is associated with osteomalacia. It appears that a single vitamin D measurement gives a reasonable clue about the vitamin D status in critically ill patients.

Renal recovery and long-term survival following acute kidney injury after coronary artery surgery: a nationwide study.

BACKGROUND: Acute kidney injury (AKI) is a relatively common complication following CABG and is associated with adverse outcomes. Nonetheless, we hypothesized that the majority of patients make a good long-term recovery of their renal function. We studied the incidence and risk factors of AKI together with renal recovery and long-term survival in patients who developed AKI following CABG. METHODS: This nationwide study examined AKI among 1754 consecutive patients undergoing CABG in 2001-2013. AKI was defined according to the KDIGO criteria. RESULTS: Postoperatively 184 (11%) patients developed AKI; 121 (7%), 27 (2%), and 36 (2%) at stages 1, 2, and 3, respectively. AKI was an independent risk factor for chronic kidney disease (CKD) and AKI patients had worse post-operative outcomes. Lower pre-operative glomerular filtration rate, higher EuroSCORE and BMI, diabetes, reoperation, and units of red blood cells transfused were independent risk factors of AKI. At post-operative day 10, renal recovery rates, defined as serum creatinine ratio <1.25 of baseline, were 96 (95% CI 91-99%), 78 (95% CI 53-90%), and 94% (95% CI 77-98%) for AKI stages 1, 2, and 3, respectively. Long-term survival was predicted by AKI with 10-year survival of patients without AKI being 76% and those with AKI stages 1, 2, and 3 being 63%, 56%, and 49%, respectively (P < 0.001). CONCLUSION: Depending on the severity of the initial AKI, 78-97% of patients made good recovery of their kidney function. However, AKI was significantly linked to progression to CKD and long-term survival remained markedly affected by the severity of the initial kidney injury.

Point prevalence of surgical checklist use in Europe: relationship with hospital mortality.

BACKGROUND: The prevalence of use of the World Health Organization surgical checklist is unknown. The clinical effectiveness of this intervention in improving postoperative outcomes is debated. METHODS: We undertook a retrospective analysis of data describing surgical checklist use from a 7 day cohort study of surgical outcomes in 28 European nations (European Surgical Outcomes Study, EuSOS). The analysis included hospitals recruiting >10 patients and excluding outlier hospitals above the 95th centile for mortality. Multivariate logistic regression and three-level hierarchical generalized mixed models were constructed to explore the relationship between surgical checklist use and hospital mortality. Findings are presented as crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: A total of 45 591 patients from 426 hospitals were included in the analysis. A surgical checklist was used in 67.5% patients, with marked variation across countries (0-99.6% of patients). Surgical checklist exposure was associated with lower crude hospital mortality (OR 0.84, CI 0.75-0.94; P=0.002). This effect remained after adjustment for baseline risk factors in a multivariate model (adjusted OR 0.81, CI 0.70-0.94; P<0.005) and strengthened after adjusting for variations within countries and hospitals in a three-level generalized mixed model (adjusted OR 0.71, CI 0.58-0.85; P<0.001). CONCLUSIONS: The use of surgical checklists varies across European nations. Reported use of a checklist was associated with lower mortality. This observation may represent a protective effect of the surgical checklist itself, or alternatively, may be an indirect indicator of the quality of perioperative care. CLINICAL TRIAL REGISTRATION: The European Surgical Outcomes Study is registered with ClinicalTrials.gov, number NCT01203605.

Prediction of survival in patients suspected of disseminated intravascular coagulation.

BACKGROUND: Although antithrombin (AT), protein C (PC), and antiplasmin (AP) are consumed during disseminated intravascular coagulation (DIC), their association with mortality in patients initially suspected of acute DIC is unknown. We examined how these proteins associate with mortality in consecutive patients initially suspected of DIC, fulfilling or not fulfilling overt DIC criteria. METHODS: All consecutive patients clinically suspected of acute DIC during 5 years at a tertiary referral hospital were scored according to overt International Society of Thrombosis and Haemostasis (ISTH) DIC criteria. The influence of ISTH DIC score and measurements of AT, PC, and AP measured in all on mortality was assessed. RESULTS: During 1825 occurrences in 1814 patients, 91 fulfilled ISTH criteria for overt DIC (score ≥ 5). Both 28-day and 1-year mortality increased progressively as AT and in particular PC decreased. AT and PC correlated inversely with ISTH score (AT: R(2 ) = 0.14, P < 0.001, PC: R(2 ) = 0.21, P < 0.001). AP decreased when ISTH score of > 3 was reached. The 28-day mortality was 3%, 11%, 16%, 23%, 35%, and 52% and 1-year mortality 5%, 18%, 24%, 36%, 54%, and 63%, respectively for patients with an ISTH score of 0, 1, 2, 3, 4, and ≥5 (P < 0.001 for all). CONCLUSIONS: Lowered AT and in particular PC activity was predictive of mortality risk upfront in critically ill patients suspected of acute DIC. Mortality in patients suspected of acute DIC increased progressively across the spectrum of the overt ISTH score and not only in those fulfilling overt DIC criteria.

Vitamin D deficiency in anesthesia department caregivers at the end of winter.

BACKGROUND: To test whether the vitamin D status of anesthesia department caregivers practicing at high Northern latitudes is compatible with current recommendations, the 25-hydroxyvitamin D (25(OH)D) levels of caregivers at hospitals in Iceland (64°08' N) and in Wisconsin (43°07' N) were compared at the end of winter. METHODS: Anesthesia department faculty and resident physicians, non-physician anesthetists, and critical care nurses completed a questionnaire, and provided blood samples for analysis of 25(OH)D by reverse-phase high performance liquid chromatography. RESULTS: One hundred and six participants in Iceland and 124 participants in Wisconsin were enrolled. No difference in mean serum 25(OH)D levels between Iceland [70.53 nmol/l, standard deviation (SD) 30.87 nmol/l] and Wisconsin (70.0 nmol/l, SD 30.0 nmol/l) was observed. In Iceland and Wisconsin, 25(OH)D levels below 25 nmol/l were observed in 4.7% and 4.0%, below 50 nmol/l in 34.9% and 25.0%, and below 75 nmol/l in 56.6% and 61.3% of caregivers, respectively. CONCLUSIONS: 25(OH)D levels below the 50 nmol/l (20 ng/ml) threshold recommended by the Institute of Medicine and the European Society for Clinical and Economic Aspects of Osteoporosis and Osteoarthritis, and below the 75 nmol/l (30 ng/ml) threshold recommended by The Endocrine Society, are highly prevalent among anesthesia caregivers working at two Northern hospitals at the end of winter who may otherwise not meet criteria to be tested. Anesthesia and critical care providers may wish to determine their 25(OH)D levels and use effective, safe, and low cost supplementation to target a 25(OH)D level compatible with optimal health.

Current use of nitrous oxide in public hospitals in Scandinavian countries.

BACKGROUND: The use of nitrous oxide in modern anaesthesia has been questioned. We surveyed changes in use of nitrous oxide in Scandinavia and its justifications during the last two decades. METHODS: All 191 departments of anaesthesia in the Scandinavian countries were requested by email to answer an electronic survey in SurveyMonkey. RESULTS: One hundred and twenty-five (64%) of the departments responded; four were excluded. The 121 departments provided 807.520 general anaesthetics annually. The usage of nitrous oxide was reported in 11.9% of cases, ranging from 0.6% in Denmark to 38.6% in Iceland while volatile anaesthetics were employed in 48.9%, lowest in Denmark (22.6%) and highest in Iceland (91.9%). Nitrous oxide was co-administered with volatile anaesthetics in 21.5% of general anaesthetics [2.4% (Denmark) -34.5% (Iceland)]. Use of nitrous oxide was unchanged in five departments (4%), decreasing in 75 (62%) and stopped in 41 (34%). Reasons for decreasing or stopping use of nitrous oxide were fairly uniform in the five countries, the most important being that other agents were 'better', whereas few put weight on its potential risk for increasing morbidity. Decision to stop using nitrous oxide was made by the departments except in four cases. Of 87 maternity wards, nitrous oxide was used in 72, whereas this was the case in 42 of 111 day-surgery units. CONCLUSION: The use of nitrous oxide has decreased in the Scandinavian countries, apparently because many now prefer other agents. Difference in practices between the five countries were unexpected and apparently not justified on anticipated evidence only.

Acute respiratory distress syndrome: nationwide changes in incidence, treatment and mortality over 23 years.

INTRODUCTION: The aim of this study was to assess population-based changes in incidence, treatment, and in short- and long-term survival of patients with acute respiratory distress syndrome (ARDS) over 23 years. MATERIALS AND METHODS: Analysis of all patients in Iceland who fulfilled the consensus criteria for ARDS in 1988-2010. Demographic variables, Acute Physiology and Chronic Health Evaluation II (APACHE II) scores and ventilation parameters were collected from hospital charts. RESULTS: The age-standardised incidence of ARDS during the study period was 7.2 cases per 100,000 person-years and was increased by 0.2 cases per year (P < 0.001). The most common causes of ARDS were pneumonia (29%) and sepsis (29%). The use of pressure-controlled ventilation became almost dominant from 1993. The peak inspiratory pressure (PIP) has significantly decreased (-0.5 cmH(2) O/year), but the peak end-expiratory pressure (PEEP) has increased (0.1 cmH(2) O/year) during the study period. The hospital mortality decreased by 1% per year (P = 0.03) during the study period, from 50% in 1988-1992 to 33% in 2006-2010. A multivariable logistic regression model revealed that higher age and APACHE II score increased the odds of hospital mortality, while a higher calendar year of diagnosis reduced the odds of mortality. This was unchanged when dominant respiratory treatment, PIP and PEEP were added to the model. The 10-year survival of ARDS survivors was 68% compared with 90% survival of a reference population (P < 0.001). CONCLUSION: The incidence of ARDS has almost doubled, but hospital mortality has decreased during the 23 years of observation. The 10-year survival of ARDS survivors is poor compared with the reference population.

Acute kidney injury in intensive care units according to RIFLE classification: a population-based study.

INTRODUCTION: Recent studies of the incidence of acute kidney injury (AKI) are largely based on estimated baseline serum creatinine values. The aim of this study was to more accurately determine the incidence of AKI using the RIFLE criteria for intensive care unit (ICU) patients of a whole population. MATERIALS AND METHODS: All adult patients admitted to the ICUs of Landspitali - The National University Hospital of Iceland in 2007 (n = 1026) were studied with meticulous search for baseline creatinine. The underlying risk factors and contributing causes for AKI were defined, and survival and ratio of end-stage renal failure evaluated. RESULTS: A measured baseline creatinine value was found for all but two patients with AKI. The incidence of AKI according to RIFLE criteria was 21.7% [95% confidence interval (CI): 19.0-24.1%], with 7.1% (95 CI: 5.6-8.9%), 6.8% (95 CI: 5.3-8.5%) and 7.8% (95 CI: 6.2-9.6%) in the risk, injury and failure subgroups. Using estimated baseline creatinine overestimated the incidence of AKI by 3.5%. The sensitivity and specificity of the RIFLE criteria using estimated baseline creatinine were 76% and 95%. Renal replacement therapy was required for 17% of the AKI patients. One year survival of AKI patients was 51%, but only 2.5% of patients surviving 90 days required chronic renal replacement therapy. CONCLUSIONS: The incidence of AKI in the ICU was lower than previously published, perhaps due to overestimation of AKI using estimated baseline creatinine or bias from tertiary referrals. AKI patients have high mortality, but the survivors have a low incidence of end-stage renal failure.

Recombinant factor VIIa as last-resort treatment of desperate haemorrhage.

INTRODUCTION: Studies are inconclusive regarding clinical outcomes after administration of recombinant activated coagulation factor VII (rFVIIa) during severe haemorrhage. The circumstances encountered during desperate haemorrhage make it difficult to include the most critically ill patients that could possibly benefit the most from such treatment into randomized controlled trials. We report our experience with rFVIIa as last-resort treatment of desperate haemorrhage when all standard treatment has failed. MATERIALS AND METHODS: Hospital charts of all consecutive patients treated with rFVIIa for desperate non-haemophilic bleeding over a 10-year period at the single institution administering rFVIIa were surveyed for treatment indications, clinical outcome, transfusion need and coagulation profiles. RESULTS: Fifty-five rFVIIa treatment occasions of desperate bleeding were identified in 54 patients (median age 54 years). A single rFVIIa dose was used in 86%, and haemorrhage was considered effectively contained by immediate clinical response on 81% of occasions. Overall, 38 patients (71%) survived for over 30 days. Two thromboembolic events occurred (3.6%). The 24-h mortality in 45 rFVIIa immediate clinical responders and 10 non-responders was 2% and 50%, respectively (P = 0.0004), and the 30-day mortality was 25% and 60%, respectively (P = 0.05). Blood product use decreased with rFVIIa (P < 0.01) as did the prothrombin time (20.0-13.3 s, P < 0.0001). CONCLUSIONS: The majority of unselected consecutive patients receiving rFVIIa as last-resort treatment for desperate haemorrhage were considered to have immediate clinical response as well as reduced transfusion requirements and correction of coagulation parameters. An immediate clinical response to rFVIIa may possibly be predictive of survival.

Severe sepsis and septic shock: a prospective population-based study in Icelandic intensive care units.

BACKGROUND: The aims of our study were to describe the nationwide epidemiology of sepsis requiring intensive care during an entire year and to evaluate compliance with treatment guidelines. METHODS: This was a prospective, observational study of all adult patients admitted to Icelandic intensive care units (ICUs), who were screened for the ACCP/SCCM criteria for severe sepsis or septic shock on admission. Data were collected from 1 April 2008 to 31 March 2009. RESULTS: One thousand five hundred and twenty-four patients were admitted to the ICUs during the study year, 115 of them because of severe sepsis or septic shock. The incidence in Iceland was 0.48/1000 inhabitants ≥18 years per year [95% confidence intervals (CI) 0.42-0.55]. The mean APACHE II score was 20.7. Mortality was 24.6% (95% CI 17.5-33.3) at 28 days and 40.4% (95% CI 31.8-49.5) at 1 year. The main sources of infections were pulmonary (37%), abdominal (28%) and urinary tract (8%). Pathogens were gram-positive (39%), gram-negative (30%) and mixed (28%). No patient had sepsis caused by methicillin-resistant Staphylococcus aureus or a monomicrobial fungal infection. Pulmonary infections were an independent predictor of death. Compliance to the resuscitation goals of the Surviving Sepsis Campaign ranged from 60% to 72% and the 6-hour Sepsis Bundle was completed in 35% of patients. CONCLUSIONS: This nationwide study showed an incidence of 0.48/1000 inhabitants for severe sepsis and septic shock requiring intensive care therapy. The 28-day mortality rate of 25 % was in the lower range of previous reports but the compliance to resuscitation goals and sepsis bundles was similar.

Induced hypothermia in comatose survivors of asphyxia: a case series of 14 consecutive cases.

BACKGROUND: Induced hypothermia is widely used for comatose survivors of cardiac arrest. Other causes of hypoxic brain injury carry a poor prognosis when treated using traditional methods. At our hospital, hypothermia has also been used for the management of all comatose survivors of asphyxiation. The aim of the present study was to report the results of the management of these patients. METHODS: Hospital charts of all patients admitted unconscious after asphyxiation during a 7-year period were reviewed. This included patients after hanging, drowning, carbon monoxide intoxication and other gas intoxications. In all patients, hypothermia with a target temperature of 32-34 degrees C was induced with external or intravascular cooling for 24 h. The primary outcome was neurologic function at discharge. RESULTS: Fourteen male patients were treated with hypothermia, eight after hanging, three after drowning, two after carbon monoxide intoxication and one after methane intoxication. All were deeply comatose (Glasgow Coma Score 3-5) on arrival to hospital. Nine had been resuscitated from cardiac arrest. There were nine survivors (65%), all with good neurological recovery (Cerebral Performance Category 1-2). Four out of five non-survivors showed cerebral edema already on arrival computed tomographic (CT) scan while none of the nine survivors did. CONCLUSIONS: The results of this study suggest that an early abnormal CT scan of the brain in patients resuscitated after asphyxiation carries an adverse prognosis. The favorable outcome of the patients in the present study suggests that a randomized clinical trial on the use of induced hypothermia in patients exposed to severe asphyxia might be warranted.

Effects of fibrinogen concentrate administration during severe hemorrhage.

BACKGROUND: Fibrinogen concentrate has been shown to improve coagulation in dilutional coagulopathy in experimental studies, but clinical experience is still scarce. The aim of this study was to evaluate laboratory data and the clinical outcome of fibrinogen administration in patients suffering from severe hemorrhage. MATERIALS AND METHODS: A retrospective study over a 3-year observation period of consecutive patients who received a single dose of fibrinogen concentrate but not recombinant factor VIIa as part of their treatment of severe hemorrhage, defined as >6 U of packed red blood cells (PRBCs). RESULTS: Thirty-seven patients were included, most of them suffering from severe hemorrhage following open heart surgery (68%). After a median fibrinogen dose of 2 g (range 1-6 g), an absolute increase in the plasma fibrinogen concentration of 0.6 g/l was observed (P<0.001). The activated partial thromboplastin time (APTT) decreased significantly (P<0.001), from 52 to 43 s and the prothrombin time (PT) decreased from 20 to 17 s, respectively. The transfusion requirement for PRBCs decreased from 6 to 3 U (P<0.01) in the 24 h after fibrinogen administration, but fresh-frozen plasma and platelet concentrate transfusions did not change significantly. Eight patients (22%) died in intensive care unit and the pre-operative fibrinogen concentration was not significantly different in these patients. CONCLUSION: Administration of fibrinogen for severe hemorrhage was associated with an increased fibrinogen concentration and a significant decrease in APTT, PT and the requirement for PRBCs.

Plasma levels of high-energy compounds compared with severity of illness in critically ill patients in the intensive care unit.

BACKGROUND: Plasma metabolic changes have been shown to reflect deterioration of the energy state of tissue in studies in animals. This study evaluates whether high-energy compounds and their metabolites in plasma reflect the clinical condition and predict outcome in critically ill patients. METHODS: Thirteen critically ill patients with major trauma, severe septic shock, or cardiogenic shock (initial Acute Physiology and Chronic Health Evaluation [APACHE] II score > or = 16) were studied. The APACHE II score was recorded daily until discharge from the intensive care unit or death. The plasma contents of adenosine triphosphate, adenosine diphosphate, adenosine, inosine, hypoxanthine, creatine phosphate, creatine, uric acid, and lactic acid were determined daily. Fifteen healthy volunteers were used as control subjects. RESULTS: All patients with an APACHE II score of 12 or less at some time during their stay in the intensive care unit survived (n = 4); all patients with a score of 26 or higher died (n = 5). The initial APACHE II median score for survivors was 21 (range 16 to 25; n = 7) and for nonsurvivors 24 (range 17 to 28; n = 6) (difference not significant). The final APACHE II score for the survivors was 11 (range 3 to 16) and for nonsurvivors 29 (range 20 to 47) (p < 0.01). The plasma metabolites were grouped according to the patients' APACHE II score of the day. There was a positive correlation between the severity of metabolic derangement and the APACHE II score. The plasma contents of adenosine triphosphate and creatine phosphate were depleted with higher APACHE II scores (p < 0.01), whereas creatine and uric acid levels increased progressively (p < 0.001). The levels of adenosine, inosine, hypoxanthine, and lactic acid were elevated significantly in critically ill patients. CONCLUSIONS: Grouping patients with successively higher APACHE II scores revealed specific patterns of altered plasma metabolism, possible reflecting different levels of tissue adenylate energy charge. However, neither the initial individual APACHE II score nor any initial plasma metabolic level had any prognostic value in this group of critically ill patients, although the deterioration of the physiologic parameters was coexistent with specific metabolic changes.

Effects of ketoprofen on respiratory and circulatory changes in endotoxic shock.

OBJECTIVE: To study the effects of ketoprofen, a dual inhibitor of the arachidonic acid metabolism, on hemodynamic and respiratory changes during endotoxic shock. DESIGN: Prospective, randomised, controlled study using an established intact animal model of endotoxic shock in sheep. SETTING: An animal laboratory in a university hospital. INTERVENTIONS: 4 groups were studied (n = 7 in each). Group K received ketoprofen and group A received aspirin 30 min before start of endotoxin infusion. Group E received endotoxin, but no drug treatment. Group C received neither endotoxin nor drug treatment. All the animals were anaesthetised with ketamine, had controlled ventilation with FiO2 = 0.5 and received Ringer's lactate at an infusion rate that would keep the pulmonary capillary wedge pressure constant. RESULTS: Both ketoprofen and aspirin prevented the early rise in pulmonary arterial pressure that occurred in group E a few minutes after start of i.v. infusion of endotoxin. Furthermore, ketoprofen prevented any significant changes in arterial blood pressure, arterial oxygen tension, oxygen delivery index, oxygen extraction ratio, respiratory compliance, intrapulmonary shunt fraction, and platelet counts that occurred in group E. Aspirin, on the other hand, provided only partial and time limited (1-2 h) protection against these changes. Wet-to-dry weight ratios of the lungs were significantly lower in the ketoprofen treated than in the untreated shock controls and the aspirin treated animals. CONCLUSION: Ketoprofen completely prevented the changes in hemodynamics and respiratory function observed in control-endotoxin-treated animals.

Effects of extradural anesthesia on microcirculatory blood flow in free latissimus dorsi musculocutaneous flaps in pigs.

Free musculocutaneous flaps are used frequently in plastic surgery to reconstruct soft-tissue defects after radical cancer surgery and trauma. Despite improved surgical techniques, some of these flaps fail due to insufficient blood supply. Extradural anesthesia causes both sensory (pain relief) and sympathetic (vasodilatation) block that may be advantageous in free-flap surgery. This hypothesis, however, has not yet been studied. An experimental model in pigs was developed in which clinical conditions for anesthesia and microvascular surgery on the lower extremity were simulated as closely as possible. The effects of extradural anesthesia as well as phenylephrine infusion, combined with general anesthesia, on central hemodynamics and on microcirculatory blood flow in skin and muscle of the latissimus dorsi free flap were studied. After surgery, seven animals received extradural anesthesia during stable normovolemic conditions and another seven during mild hypovolemia (10 percent blood loss). The extradural block was objectively evaluated using the temporal summation test. Thirty minutes after induction of extradural anesthesia, the animals received an intravenous infusion of phenylephrine 1 microgram/kg per minute over a period of 15 minutes. Multichannel laser-Doppler flowmetry was used to measure microcirculatory blood flow in skin and muscle of the free flap as well as in control skin and muscle on the same extremity simultaneously. In normovolemic animals, extradural block caused a 10 percent decrease in mean arterial pressure and cardiac output and an approximately 20 percent decrease in microcirculatory blood flow in both the skin and muscle of the flap (all changes were nonsignificant). In slightly hypovolemic animals, however, extradural anesthesia caused a significant decrease in cardiac output (31 percent, p < 0.01), mean arterial pressure (24 percent, p < 0.01), and in mean blood flow in the flap muscle (22 percent, p < 0.05) and skin (20 percent, p < 0.05). During phenylephrine infusion, mean arterial pressure increased significantly (p < 0.05) in both hypovolemic and normovolemic animals, while cardiac output and microcirculatory blood flow in the flap remained almost unchanged. Extradural anesthesia does not improve microcirculatory blood flow in free musculocutaneous flaps in pigs. It causes a significant decrease in cardiac output, mean arterial pressure, and microcirculatory blood flow in slightly hypovolemic animals. During phenylephrine infusion, the microcirculatory blood flow in free flaps slightly improves due to the increase in mean arterial pressure. We suggest that extradural anesthesia for microvascular surgery should be used with great caution until human data are available.