[Interdisciplinary position paper "Perioperative pain management"]. / Interdisziplinäres Positionspapier "Perioperatives Schmerzmanagement".

Despite many positive developments, postoperative pain and its treatment is still not always given the necessary attention. Severe pain after surgical procedures affects a significant proportion of patients. This very fact is not only detrimental to the immediate recovery process, but can also form the basis for the development of chronic pain conditions.An adequate and effective management of perioperative pain requires appropriate organizational structures. This multidisciplinary paper which was initiated by the Austrian Society for Anaesthesiology and Intensive Care and the Austrian Pain Society and developed together with numerous specialist and professional societies dealing with the subject aims at supporting the organization of perioperative pain management structures and to make best use of proven concepts. Additional recommendations describe specific interventions for selected types of intervention.

[Pain care in Austrian health care centers: Questionnaire study on the current status of Austrian pain clinics]. / Schmerztherapeutische Versorgung österreichischer Gesundheitszentren: Fragebogenstudie zum Istzustand österreichischer Schmerzambulanzen.

BACKGROUND: Pain clinics provide interdisciplinary therapy to treat chronic pain patients and to increase the return-to-work rate. In recent years and due to increased economic pressure in health care, a change in the management of pain in Austrian health care centers has been observed. For the analysis of the current situation, two surveys addressing all Austrian pain clinics were performed. MATERIALS AND METHODS: In total, 133 heads of Austrian Anesthesia Departments were interviewed online and personally. The data from the first interview were confirmed by an additional telephone survey that was performed by one anesthetist per Austrian state (n = 9). RESULTS: Currently, 44 Austrian pain clinics are active. During the last 5 years, 9 pain clinics closed. Adding the current active pain clinics together, they represent a total of 17.5 full-time-operated clinics. The most common reasons for closing the pain clinics were lack of personnel (47%), lack of time resources (26%), lack of space resources (11%), and financial difficulties (11%). A reduction of >50% of operating hours during the last 3 years was reported by 9 hospitals. The reasons for not running a pain clinic were lack of personnel (36%), lack of time (25%) and department too small (16%). Estimates between actual and required clinics indicate that 49.5 full-time-operating pain clinics are lacking in Austria, resulting in 74% of the Austrian chronic pain patients not receiving interdisciplinary pain management. CONCLUSION: Our survey confirmed the closure of 9 pain clinics during the last 5 years due to lack of personnel and time. Pain clinics appear to provide the simplest economic saving potential. This development is a major concern. Although running a pain clinic seems to be expensive at the first sight, it reduces pain, sick leave, complications, and potential legal issues against health care centers, while simultaneously increasing the hospital's competitiveness. Our results show that 74% of Austrian chronic pain patients do not have access to an interdisciplinary pain clinic. Because of plans to further economize resources, Austria may lose its ability to provide state-of-the-art pain therapy and management.

[Optimising pain therapy for neurological inpatients]. / Optimierung der Schmerztherapie an neurologischen Stationen.

BACKGROUND: The Department of Neurology at the Medical University Graz has implemented a multiprofessional pain management concept and evaluated the outcome by means of a patient survey. METHODS: Standard operating procedures for standardised pain measurement, documentation and therapy were developed. All engaged professional participants were trained before implementation. RESULTS: 88.7 % of the surveyed 63 patients reported pain during the hospitalisation. During the night and in the morning, the occurrence of severe pain was most likely. The position or activity most likely triggering severe pain was mobilisation (19 %). Patients with degenerative diseases of the spine without radiculopathy reported the highest levels of pain. CONCLUSIONS: Pain is an important problem for neurological inpatients. Nocturnal pain, pain induced by mobilisation, and pain therapy for patients with degenerative diseases of the spine without radiculopathy require particular attention.

[Austrian interdisciplinary recommendations on pediatric perioperative pain management: background, aims, methods and key messages]. / Österreichische interdisziplinäre Handlungsempfehlungen zum perioperativen Schmerzmanagement bei Kindern : Hintergrund, Ziel, Methodik und Kernaussagen.

These recommendations were originally commissioned by the"Österreichische Gesellschaft für Anästhesiologie, Reanimation und Intensivmedizin" (ÖGARI, Austrian Society for Anesthesiology, Resuscitation and Intensive Care Medicine). Against this background, Austrian experts from the disciplines anesthesiology, pain management, pediatrics and the "Berufsverband Kinderkrankenpflege" (Professional Association of Pediatric Nursing) have with legal support developed evidence-based and consensus recommendations for the clinical practice. The recommendations include key messages which cover the most important recommendations for the individual topics. The complete recommendations on pediatric perioperative pain management consist of seven separate articles which each deal with special sub-topics with comments on and explanations of the key messages. The target groups of the recommendations are all medical personnel of the individual disciplines involved in the treatment of perioperative and posttraumatic pain for neonates, infants and children up to 18 years old.

[Organization of pediatric pain management: Austrian interdisciplinary recommendations for pediatric perioperative pain management]. / Organisation des Schmerzmanagements bei Kindern : Österreichische interdisziplinäre Handlungsempfehlungen zum perioperativen Schmerzmanagement bei Kindern.

BACKGROUND: Postoperative pain management is still in need of vast improvement, especially for children. The aim of this article is to demonstrate which structures and processes must be optimized to ultimately improve patient satisfaction and safety. RESPONSIBILITIES: Basic prerequisites are among others personnel continuity and good cooperation in a multiprofessional team. A clear assignment of responsibilities is also of essential importance. PATIENT HISTORY AND INFORMED CONSENT: On admission every patient should be questioned on the currently existing pain. Patients or the parents must be informed about the pain therapy in a comprehensible manner. Possible complications, chances of success, advantages and disadvantages of the planned procedure and alternative forms of treatment must be discussed. IMPLEMENTATION: The implementation needs a great deal of consideration. The introduction of clearly defined pathways and thorough schooling contribute more to successful pain management than the establishment of pain measurement or the use of special techniques alone. EVALUATION AND DOCUMENTATION: Because pain intensity can only be described indirectly it is difficult to assess in children. Assessment is made by another person until children are 5 years old. The gold standard in pain measurement is, however, self-estimation using appropriate scales which is possible for older children. The routinely carried out representation of pain values and prompt documentation of all pain therapeutic measures are indispensible for the control and optimization of pain therapy. QUALITY OF RESULTS: Whether improvements in acute pediatric pain therapy will actually be achieved can only be realized by standardized compilation and analysis of the quality of therapy. For this purpose QUIPSInfant was developed.

[Topical pain therapy in oral mucositis: a systematic review]. / Topische Schmerztherapie bei oraler Mukositis : Eine systematische Übersicht.

BACKGROUND: The pain provoked by mucositis is often described as the most excruciating symptom of cancer treatment. It often causes reduced ingestion, malnutrition, and sometimes postponement or withdrawal of the therapy. For health care providers, adequate pain treatment is a major challenge. The aim of this article is to present an overview of studies on the topical treatment of mucositis pain. METHODS: A systematic search was performed in PubMed with the keywords "mucositis" "pain" and "topical" or "local". In addition, reference lists and relevant websites were scanned for appropriate literature. RESULTS: A total of 47 articles were included. There is only scarce evidence for the topical treatment of mucositis pain. The most convincing studies tested opioids, corticoids and benzydamine. For the other substances, too few studies were performed, the results were contradictory, or the study quality was low. CONCLUSION: Based on the information gathered in this systematic search of the literature, topical treatment of mucositis pain today is based on empiricism and not on scientific evidence.

Anatomical investigation of a new vertical obturator nerve block technique.

BACKGROUND: We evaluated a vertical obturator nerve block (VOB) using a single morphological landmark and no additional distance measurement or obligatory changes of the needle's direction. MATERIALS AND METHOD: A total of 88 cadavers (176 lower limbs), prepared using Thiel's embalming method, were examined. The index finger was placed lateral to the palpable pubic tubercle and the needle inserted laterally to the distal part of the fingernail at the tubercle's level and advanced strictly perpendicular to the table's surface. If bone contact was made, the needle was slightly turned to pass the bone distally. Colored latex (5 ml) was then injected. The injection depth was documented, then followed by dissection and nerve exposition. The real skin-nerve distance and the degree of difficulty in orientation and of palpation were measured. Additionally, the dissemination around the nerve or its branches and the intrapelvic spread were documented. RESULTS: The nerve was colored completely in 93.75%, partially in 1.71%, and not colored in 4.54% of cases. The mean injection depth was 3.9 cm (±0.7 SD) and real nerve depth was 3.8 cm (±0.69 SD). Bone contact necessitating the needle's redirection was found in 20 (11.4%) cases. Easy orientation and palpation of the tubercle was always found. In 40 cases, the latex spread via the obturator canal into the lesser pelvis. CONCLUSION: In this anatomical study, the VOB technique exhibits easy orientation without stimulation or ultrasound guidance. The nerve was located at a constant depth. The injection offered a high percentage of colored nerves.

Preoperative pregabalin administration significantly reduces postoperative opioid consumption and mechanical hyperalgesia after transperitoneal nephrectomy.

BACKGROUND: Preoperative administration of pregabalin is proposed as a promising way of enhancing postoperative pain control. Whereas a few studies have investigated the effect of pregabalin on postoperative opioid consumption, no study has focused on the influence on postoperative hyperalgesia. In this randomized, triple-blinded, placebo-controlled study, we aimed to demonstrate that a single, preoperative dose of pregabalin reduces postoperative opioid consumption, mechanical hyperalgesia, and pain sensitivity. METHODS: Patients undergoing elective transperitoneal nephrectomy received 300 mg pregabalin or placebo 1 h before anaesthesia. After operation, patients received piritramide via a patient-controlled analgesia device. Pain levels and side-effects were documented. The area of hyperalgesia for punctuate mechanical stimuli around the incision was measured 48 h after the operation with a hand-held von Frey filament. Mechanical pain threshold was tested before and 48 h after surgery with von Frey filaments with increasing diameters. RESULTS: In each group, 13 patients were recruited. Total piritramide consumption [77 (16) vs 52 (16) mg, P=0.0004] and the normalized area of hyperalgesia [143 (87) vs 84 (54) cm(2), P=0.0497] were significantly decreased in the pregabalin group. There were no significant differences in mechanical pain threshold levels [1.20 (0.56) log(g) vs 1.05 (0.58) log(g), P=0.6738]. No case of severe sedation was reported in both groups. No other side-effects were observed. CONCLUSIONS: Our study has shown that preoperative administration of 300 mg pregabalin in patients undergoing transperitoneal nephrectomy reduces postoperative opioid consumption and decreases the area of mechanical hyperalgesia.

[Pain assessment in patients with dementia]. / Schmerzerfassung bei Demenz.

Recent literature demonstrates that pain in patients with dementia is often undertreated. This can partially be explained by a lack of training in the possibilities of assessing pain in patients with dementia. Subjective reports are the most valid approach for the assessment of the subjective experience of pain and should therefore be preferred over other methods. The assessment of the context, behavior, and physiological markers is advised if the patient is unable to provide a subjective report. Pain assessment scales are useful for documentation and monitoring.

[Quality of postoperative pain therapy in Austria: national survey of all departments of anesthesiology]. / Qualität der postoperativen Schmerztherapie in Österreich : Bundesweite Umfrage unter allen anästhesiologischen Abteilungen.

BACKGROUND: Despite increasingly sophisticated concepts of perioperative pain therapy, such as increased use of combined regional anesthesia techniques, the renaissance of ketamine and dipyrone or the use of oral opioids, no significant improvement has been achieved in postoperative pain therapy since 1995. About 300,000 of the approximately 700,000 patients undergoing major surgery each year in Austria experience moderate to severe postoperative pain. The aim of this study was therefore to assess the nationwide status of perioperative acute pain management in postoperative recovery rooms and surgical wards in order to identify potential areas for improvement. METHODS: In 2006 the directors of all Austrian anesthesiology departments (n=125, 100%) were contacted and asked to give detailed information on the status of acute pain management of each individual hospital in Austria using a standardized questionnaire. Data of each individual department were derived from quality control and self-assessment of each department. No patients were questioned. The return rate was 96% (n=120) due to intensive personal contact in cases of missing data. RESULTS: In this nationwide survey 120 anesthesiology departments participated together accounting for a total of 757,895 operations per year. Of the patients 63.6% were informed preoperatively on the available regimens of acute pain management. In 81% of patients perioperative pain therapy consisted of a multimodal therapeutic approach, 58.6% of the departments used international guidelines and 39.7% worked with international guidelines adapted to local requirements. In 88% of patients a detailed prescription for postoperative pain therapy was available when transferred to the surgical ward. Surgical wards were equipped with routine pain therapy protocols in 28% another 20% of wards had special pain therapy protocols for individual operations. In 22% of cases pain assessment was repeated 3-4 times per day and in 33.9% postoperative pain was assessed only once twice per day. Pain assessments were recorded in the patient charts in 60.7% of cases. If changes to the pain therapy regimen were required anesthesiologists were involved in only 14.3% of cases. In addition an acute pain service was available only in 39.2% of Austrian anesthesiology departments. CONCLUSIONS: Although the multimodal approach to acute pain therapy is widely used and standardized therapeutic regimens are well established in the majority of anesthesiology and surgical wards, there still remains room for improvement. Pain assessment is generally barely adequate and written documentation of pain assessment is missing almost completely. In addition, almost two thirds of hospitals in Austria are still lacking an acute pain service.

[Postoperative pain assessment in special patient groups: part I: children without cognitive impairment]. / Postoperative Schmerzmessung bei speziellen Patientengruppen: Teil I: Das kognitiv unbeeinträchtigte Kind.

The intensity of pain cannot be measured directly but can only be described subjectively. This obviously complicates the assessment especially in the younger age group. Pain evaluation and documentation are essential for good results in pain therapy. Pain can be measured by pain scales which should fulfill the requirements of practicability, reliability and validity. In neonates and children up to 4 years of age, standardized scales have been developed for observation of their activities. Children in the age group 4-6 years old are able to communicate about pain. At this age self-report scales can be used to assess pain sensations."Quality Improvement in Postoperative Pain Management in Infants" (QUIPSInfant) represents a new tool for pediatric outcome evaluation, consisting of standardized data acquisition of outcome and process quality indicators.

[Postoperative pain assessment in special patient groups: part II. Children with cognitive impairment]. / Postoperative Schmerzmessung bei speziellen Patientengruppen: Teil II: Das kognitiv beeinträchtigte Kind.

Postoperative pain assessment in children with cognitive impairment poses major challenges to healthcare professionals.Children with moderate to severe cognitive impairment are generally unable to communicate effectively and to self-report the level of pain. Difficulties assessing pain have led to their exclusion from clinical trials and rendered them vulnerable to insufficient treatment of pain.The realization of pain is a particularly important step forward for a better care of children with cognitive impairment.Scales based on a child's own perception of pain and its severity play a limited role in this vulnerable population and pain assessment tools which rely on observing pain behavior are essential. The r-FLACC, which is reliable and valid, includes specific behavioral descriptors and can be used simply and effectively postoperatively in clinical practice. Our task has to be assessing pain as a routine procedure in cognitively impaired children as a keystone for an improved and successful pain management in this very sensitive patient population.

[Pregabalin and postoperative hyperalgesia. A review]. / Pregabalin und postoperative Hyperalgesie. Ein Review.

Numerous studies support the theory that pregabalin causes an antihyperalgesic effect, which could be potentially beneficial in a perioperative setting. By binding to calcium channels pregabalin reduces the release of excitatory neurotransmitters and therefore inhibits central sensitization. Animal studies clearly demonstrated the antihyperalgesic potency of pregabalin but human experiments are, however, inconclusive. Clinical studies with quantitative sensory testing have not yet been published. Although strongly supported by theoretical considerations the routine preoperative application of pregabalin for the prevention of hyperalgesia cannot be recommended due to the lack of clinical studies. Future studies should incorporate secondary hyperalgesia and allodynia as primary parameters.

Implementation of a standardized pain management in a pediatric surgery unit.

Postoperative pain is still a major complication causing discomfort and significant suffering, especially for children. Therefore, every effort should be made to prevent pain and treat it effectively once it arises. Under-treatment of pediatric pain is often due to a lack of both knowledge about age-specific aspects of physiology and pharmacology and routine pain assessment. Factors for long term success require regularly assessing pain, as routinely as the other vital signs together with documentation of side effects. The fear of side effects mostly prevents the adequate usage of analgesics. Essential is selecting and establishing a simple concept for clinical routine involving a combination of non-pharmacological treatment strategies, non-opioid drugs, opioids and regional anesthesia.

Long-term efficacy and safety of combined prolonged-release oxycodone and naloxone in the management of non-cancer chronic pain.

OBJECTIVE: The aim of this study was to assess safety and efficacy of fixed combination oxycodone prolonged release (PR)/naloxone PR in terms of both analgesia and improving opioid-induced bowel dysfunction (OIBD) and associated symptoms, such as opioid-induced constipation (OIC), in adults with chronic non-cancer pain. STUDY DESIGN: These were open-label extension studies in which patients who had previously completed a 12-week, double-blind study received oxycodone PR/naloxone PR for up to 52 weeks. The analgesia study assessed pain using the modified Brief Pain Inventory-Short Form (BPI-SF). The bowel function study assessed improvements in constipation using the Bowel Function Index (BFI). RESULTS: At open-label baseline in the analgesia study (n = 379), mean score [+/- standard deviation (SD)] for the BPI-SF item 'average pain over the last 24 h' was 3.9 +/- 1.52, and this remained low at 6 months (3.7 +/- 1.59) and 12 months (3.8 +/- 1.72). Mean scores for BPI-SF item 'sleep interference', and the BPI-SF 'pain' and 'interference with activities' subscales also remained low throughout the 52-week study. In the bowel function study (n = 258), mean BFI score (+/- SD) decreased from 35.6 +/- 27.74 at the start of the extension study to 20.6 +/- 24.01 after 12 months of treatment with oxycodone PR/naloxone PR. Pain scores also remained low and stable during this study. Adverse events in both extension phases were consistent with those associated with opioid therapy; no additional safety concerns were observed. CONCLUSION: Results from these two open-label extension studies demonstrate the long-term efficacy and tolerability of fixed combination oxycodone PR/naloxone PR in the treatment of chronic pain. Patients experienced clinically relevant improvements in OIBD while receiving effective analgesic therapy.

[Anesthesia related physiologic and pharmacologic changes in the elderly]. / Anästhesierelevante physiologische und pharmakologische Veränderungen im Alter.

The importance of geriatric patients is growing with the increasing number of people over the age of 65 and with the higher percentage of surgical interventions. Multiple physiological changes in the cerebrovascular, cardiovascular, respiratory, renal and hepatic system, and pharmacological changes such as a reduction in hydrophilic distribution and metabolism cause increased drug sensitivity, a reduced elimination rate and prolonged duration of action. Pre-existing diseases correlate with an increased rate of complications such as hypoxia, hypothermia and cardiovascular, pulmonary, cerebral or renal complications, the highest incidence of which occurs on the first and between the third and fifth postoperative days. To reduce the incidence of these complications, a thorough pre-anaesthetic examination and optimization of the patient's condition is recommended. Hypovolaemia or too intense premedication should be avoided. In cardiac-risk patients, a beta-adrenergic blockade is necessary. Purely regional anaesthesiological techniques should be used as they reduce one-month mortality by a third and morbidity by up to 59%. For general anaesthesia, preoxygenation and careful titration of the drugs used help to achieve cardiovascular stability. Institutionalized postanaesthetic standards help to avoid an aggravation of the patient's condition due to shivering, hypothermia or postoperative pain.

Lamotrigine monotherapy for control of neuralgia after nerve section.

BACKGROUND: We present six patients treated only with the new-generation anticonvulsant lamotrigine to define its sole effect on neuralgia after nerve section. METHODS: Previous surgical or pharmacological attempts failed to relieve this neuropathic pain in our patients. Before initiation of lamotrigine therapy, patients reported spontaneous and touch-evoked shooting pain followed by periods of burning pain. No breakthrough medication was needed during the maintenance phase of 1-23 months. Data were acquired by a pain diary on a weekly basis. RESULTS: With 75-300 mg of lamotrigine per day, the burning and shooting pain intensity was relieved by 33-100%. Most obviously, the attack frequency of the shooting pain was reduced by 80-100%. No adverse effects were observed. CONCLUSION: We conclude that lamotrigine may be beneficial in the treatment of neuralgia after nerve section following the failure of previous pharmacological or surgical attempts.

Morphine-induced spinal release of adenosine is reduced in neuropathic rats.

BACKGROUND: Spinally administered opioids show decreased potency and efficacy in the treatment of neuropathic pain. As reported previously, morphine stimulates spinal opioid receptors to effect adenosine release, which acts at adenosine receptors to produce analgesia. The authors hypothesized that morphine induces less adenosine release in neuropathic compared with normal rats, explaining its reduced potency and efficacy. METHODS: Sprague-Dawley rats (200-250 g) were divided into three groups: no surgery (n = 52), sham surgery (n = 20), or left L5 and L6 spinal nerve ligation (n = 64). Two weeks after surgery, mechanical hypersensitivity of the left hind paw was verified. For each experiment, a crude synaptosomal P2 suspension was prepared by homogenizing cervical and lumbar dorsal spinal cord halves from four rats, followed by differential centrifugation, and aliquots incubated with morphine sulfate from 10(-8) to 10(-4) m alone or in presence of 10(-5) m dipyridamole. Extrasynaptosomal concentrations of adenosine were analyzed by high-pressure liquid chromatography. RESULTS: Synaptosomal release of adenosine in the absence of morphine was similar between groups. Morphine produced a concentration-dependent adenosine release, which was less in synaptosomes from dorsal lumbar spinal cord in spinal nerve ligation compared with normal or sham animals. This reduction was removed by adding dipyridamole. CONCLUSION: Morphine normally stimulates spinal release of adenosine, a potent antihypersensitivity compound. Because this effect of morphine is diminished in spinal nerve ligation animals, one explanation for decreased efficacy and potency of opioids in the treatment of neuropathic pain may be a dipyridamole-sensitive disruption in the opioid-adenosine link in the spinal cord.

Laser doppler flowmetry in combined needle acupuncture and moxibustion: a pilot study in healthy adults.

Laser Doppler flowmetry (LDF) (DRT 4/Moor Instruments Ltd, Devon, UK) was used in this pilot study for monitoring the effects of an invariable acupuncture pattern on microcirculation of the skin before, during, and after combined needle acupuncture and moxibustion in 12 healthy volunteers (mean age 35.2 +/- 4.4 years, range 26-41 years, four female and eight male). According to the standards of traditional Chinese medicine (TCM), this acupuncture pattern is assumed to be unspecific and non-therapeutic. Flux decreased during the treatment period (p<0.05) compared to the control phase before combined needle acupuncture and moxibustion. After the removal of the needles, flux did not return to the initial control value. No significant differences between mean arterial blood pressure, heart rate, skin temperature or gender were detected. A prediction of individual incidences and kinds of acupuncture effects in our healthy volunteers was not possible. Modern monitoring techniques like LDF could be a method to separate responders from non-responders to acupuncture in peripheral microcirculatory disorders. Further studies on patients with peripheral microcirculatory disorders are necessary in order to demonstrate the value of LDF in detecting responders/non-responders in combination with therapeutic acupuncture patterns according to TCM.

Pressor and mesenteric arterial hyporesponsiveness to angiotensin II is an early event in haemorrhagic hypotension in anaesthetised rats.

OBJECTIVE: Vascular responsiveness to vasoconstrictors is known to be attenuated in haemorrhagic shock. In this study we assessed the temporal development and the underlying mechanisms of haemorrhage-induced vascular hyporeactivity to pressor agents. METHODS: In phenobarbital-anaesthetised rats hypotension was induced by graded haemorrhage (8 ml blood total). Sham-manipulated rats served as controls. Blood flow (BF) was recorded with ultrasonic transit time flow probes. RESULTS: Following haemorrhage mean arterial pressure (MAP) fell by 25-45 mm Hg and was accompanied by a reduction in mesenteric BF without any alteration of mesenteric vascular conductance (VC). While pressor responses to arginine vasopressin remained unaltered, hyporesponsiveness to phenylephrine (10 nmol kg-1) developed 120-180 min after hypotension had been induced. Pressor and mesenteric constrictor responses to angiotensin II (30 pmol kg-1) became significantly blunted as early as 60 min post haemorrhage. The hypotensive effect of an angiotensin1 receptor antagonist, telmisartan (1 mg kg-1), was likewise blunted 3 h after haemorrhage. Pretreatment with the cyclooxygenase inhibitor indomethacin (10 mg kg-1) exaggerated the hypotensive reaction to haemorrhage but did not prevent the development of angiotensin II hyporesponsiveness. In contrast, the nitric oxide (NO) synthase inhibitor NG-nitro-L-arginine methyl ester (10 mg kg-1), as investigated 3 h post haemorrhage, restored the systemic pressor responses to angiotensin II and phenylephrine as well as the mesenteric constrictor responses to phenylephrine to normal level and diminished the mesenteric hyporesponsiveness to angiotensin II. Glibenclamide (20 mg kg-1), an inhibitor of ATP-sensitive K- channels given 180 min post haemorrhage, partially reversed haemorrhage-induced hypotension but did not modify angiotensin II hyporesponsiveness. CONCLUSION: Systemic pressor responsiveness and mesenteric arterial reactivity to endogenous and exogenous angiotensin II is selectively impaired at an early stage of haemorrhagic hypotension. This phenomenon partially involves NO and is not related to ATP-sensitive K+ channels.