Upper extremity ischemia is superior to lower extremity ischemia for remote ischemic conditioning of antero-lateral thigh cutaneous blood flow.

Remote ischemic conditioning (RIC) is known to improve microcirculation in various settings, but little is known about the impact of the amount of ischemic tissue mass or the limb itself. Since ischemia and subsequent necrosis of flaps is one of the most dreaded complications in reconstructive surgery, adjuvant methods to improve microcirculation are desirable. We therefore performed a randomized trial to compare the effect of arm versus leg ischemia for RIC of the cutaneous microcirculation of the antero-lateral thigh. Forty healthy volunteers were randomized to undergo 5 min of ischemia of either the upper or lower extremity, followed by 10 min of reperfusion.Ischemia was induced by a surgical tourniquet applied to the proximal limb, which was inflated to 250 mmHg for the upper and 300 mgHg for the lower extremity. This cycle was repeated a total of three times. Cutaneous microcirculation was assessed by combined laser doppler spectrophotometry on the antero-lateral aspect of the thigh to measure cutaneous blood flow (BF), relative hemoglobin content (rHb), and oxygen saturation (StO2). Baseline measurements were performed for 10 min, after which the ischemia/reperfusion cycles were begun. Measurements were performed continuously and were afterwards pooled to obtain a mean value per minute. Both groups showed significant increases in all three measured parameters of cutaneous microcirculation after three cycles of ischemia/reperfusion when compared to baseline (BF: 95.1% (P < 0.001) and 27.9% (P = 0.002); rHb: 9.4% (P < 0.001) and 5.9% (P < 0.001), StO2: 8.4% (P = 0.045) and 9.4% (P < 0.001). When comparing both groups, BF was significantly higher in the arm group (P = 0.019 after 11 min., P = 0.009 after 45 min). In conclusions, both ischemic conditioning of the upper and lower extremity is able to improve cutaneous BF on the ALT donor site. However, RIC of the upper extremity seems to be a superior trigger for improvement of cutaneous BF.

[Postoperative pain management after ambulatory surgery. A survey of anaesthesiologists]. / Postoperative Schmerztherapie nach ambulanten Operationen. Eine Befragung der behandelnden Anästhesisten.

BACKGROUND: Data on practice and quality of postoperative pain treatment by anaesthesiologists after ambulatory surgery are sparse. The current survey enrolled anaesthesiologists in private practice who were responsible for pain therapy after ambulatory surgery. The aim of this investigation was to evaluate the implementation of the German S3 guidelines for acute and postoperative pain therapy in the outpatient setting. PATIENTS AND METHODS: A total of 2,156 anaesthesiologists in private practice received a postal questionnaire which was limited to those anaesthesiologists who were responsible for postoperative pain therapy. The questionnaire included items such as types of surgery, techniques of anaesthesia and analgesic drugs used for pain management during the immediate postoperative phase and for the treatment at home as well as details of pain measurement. RESULTS: Out of 116 responses 108 could be analyzed covering a total of 86,616 patients receiving postoperative pain therapy, 80% of the operations were performed using general anaesthesia and local anaesthesia was additionally used in 9% of the institutions. In the perioperative period 66% of the respondents administered non-steroidal-antiinflammatory drugs (NSAIDs), 62% metamizol (dipyrone), 41% paracetamol (acetaminophen) and 73% opioids. After discharge 81% of the responding anaesthesiologists prescribed NSAIDs, 55% metamizol and 47% opioids for pain relief at home. Only 40% of the respondents measured and documented pain intensity. Nearly all respondents (93%) were satisfied with their pain management after outpatient surgery. CONCLUSIONS: Pain therapy after ambulatory surgery significantly varied with respect to the methods, drugs and measures of quality assurance used by anaesthesiologists in private praxis. This survey demonstrated that the national guidelines of acute pain therapy have only been partially implemented.

[Postoperative pain after ambulatory surgery]. / Postoperative Schmerztherapie nach ambulanten Operationen.

BACKGROUND: Outpatient surgeons were surveyed about the quality of postoperative pain therapy after outpatient interventions. PATIENTS AND METHODS: Of 2,317 outpatient surgeons who received a questionnaire by mail, 419 responded. The return rate was 18.1%. The questionnaire collected data on the operative procedures and methods of anesthesia from 2004 and the analgesics, which were applied in the immediate postoperative period and at home. Methods and contents of quality control were registered. RESULTS: The respondents indicated that the person responsible for the pain therapy was the surgeon in 74% of the practices, the anesthesiologist in 16%, and both in 10%. The drugs used in the practice were: novaminsulfone (34%), NSAIDs (28%), and opioids (36%). The drugs used for at-home care were: NSAIDs (58%), opioids (43%), novaminsulfone (32%), and mixed analgesics (28%). No analgesics were given by 6%, and 21% prescribed a supplementary antiemetic. Routine pain measurement was performed with pain scales in only 11% of the practices; among the certified practices, 48% performed pain measurement for quality control. Ninety-five percent of the surgeons were satisfied with the pain therapy. CONCLUSION: This survey shows that the guidelines for acute pain therapy (http://www.awmf.de ) are only partially implemented.

[Delayed negative pressure pulmonary edema]. / Verzögert auftretendes, postobstruktives Lungenödem.

A young athletic male adult (smoker) developed a pulmonary edema 30 min after the end of anaesthesia. Extubation was complicated by a laryngospasm. After artificial ventilation for 12 h the patient recovered completely.A negative pressure pulmonary edema (NPPE) develops after deep inspiratory efforts with an occluded airway. Such a maneuver leads to negative intrapleural pressures of -50 to -100 mmHg. This pressure gradient causes damage to the pulmonary capillaries, a transcapillary volume shift into the interstitium,and hemodynamic changes that increase the intrapulmonary blood volume. As a NPPE may occur with a delay of up to 1 h it is crucial to provide adequate monitoring for patients at risk. Symptomatic therapy usually leads to complete recovery within several hours.

[The extracorporeal circulation in the treatment of pulmonary diseases]. / Die extrakorporale Kreislaufzirkulation bei der Behandlung von Lungenkrankheiten.

The extracorporeal circulation is seldom used in pulmonary surgery. In this paper, we present some clinical cases and discuss the different indications for extracorporeal circulation in pulmonary diseases. Pulmonary embolectomy and lung transplantation are the main indications for the use of heart-lung-machine. Less frequent indications are oxygen support during whole lung lavage in pulmonary alveolar proteinosis. Lung cancer surgery and other indications for extracorporeal circulation are also discussed.

[Prevention of "post-sevoflurane delirium" with midazolam]. / Prophylaxe des "Postsevoflurandelirs" mit Midazolam.

In a randomized double-blind placebo-controlled trial in children 2-7 years of age, we investigated the effect of a single prophylactic midazolam bolus (0.1 mg/kg b.w.) prior to the termination of anaesthesia, on the incidence and severity of agitation occurring after sevoflurane administration. Compared to the placebo group, midazolam prophylaxis significantly decreased the incidence of postanaesthetic delirium. However, the incidence of severe agitation requiring treatment was not different between the groups (placebo: n = 6; midazolam: n = 4). The mean severity of agitation was significantly lower in patients with midazolam prophylaxis. When midazolam was administered for the treatment of severe agitation it reduced the severity but did not abolish agitation. All patients were discharged from the recovery room after the 2 h observation period. From our study we conclude that a small prophylactic midazolam bolus is able to reduce the incidence and severity of agitation after sevoflurane anesthesia in some patients but is insufficiently effective in patients with severe agitation. Thus, the prophylactic administration of midazolam extenuates but does not solve the problem of post-sevoflurane agitation.

[Myocardial infarction during pregnancy]. / Myokardinfarkte in der Schwangerschaft.

Up to now 136 cases of myocardial infarction during pregnancy have been reported, and angiography revealed normal findings in 47%. In these cases coronary spasms have been discussed as the major mechanism of the disease. In isolated cases coronary artery dissection may also present with a normal coronary angiography. The case of a 31-year-old pregnant women who developed myocardial infarction during a caesarean section under spinal anaesthesia gives rise to the assumption that an early stage of coronary artery disease may be the third cause that has to be considered. Probably as a consequence of phases of tachycardia and hypertension during the course of anaesthesia, the patient developed a myocardial infarction that she survived without sequelae. While coronary angiography showed normal coronary vessels, an intravascular ultrasound study (IVUS) demonstrated an atheroma in the left main coronary artery with a ruptured fibrous cap. Laboratory screening for risk factors of coronary artery disease (CAD) showed hypercholesterinemia, increased factor VII activity and hyperfibrinogenemia. Platelet aggregation was not inhibited by acetylsalicylic acid. It was pointed out recently that even in asymptomatic patients, plaques may be present in coronary vessels indicating an early stage of CAD that cannot be diagnosed by angiography. Plaque rupture is often triggered by hypertension and may lead to myocardial infarction, instable angina pectoris, or sudden ischemic death. As IVUS is a new diagnostic tool that allows diagnoses of even early stages of CAD we believe that myocardial infarction during pregnancy is more often caused by plaque rupture than may be expected according to the current literature.

Pain management in children: assessment and documentation in burn units.

Burns are considered to be among the most painful types of trauma. Especially the pain of children is often unsatisfactorily treated. This study investigates the assessment and documentation of pain by physicians and nurses in children suffering from burns. Pain management was considered sufficient in 80% of ventilated patients and in 60% of non-ventilated patients. The minority of the staff regarded pain management as sufficient during dressing changes after the acute phase and during nursing care. Thirty-eight per cent of the physicians and 58% of the nurses documented the pain. Standardized documentation was used by fewer than 20% of the staff. Pain documentation was not considered relevant for further therapy by 48% of the physicians. More than half of all participants believed that an improvement of the pain therapy performed in their hospital was necessary. Standardized documentation, an algorithm for the application of analgesics, and more training in pain management were desired by many staff members.

[Treatment of low back pain--significance, principles and danger]. / Medikamentöse Therapie bei Rückenschmerzen - Bedeutung, Prinzipien und Gefahren.

Today, a wide range of efficient analgesic and non-analgesic drugs for the treatment of back pain are available. However, drugs should never be the only mainstay of a back pain treatment program. Non-steroidal antiinflammatory drugs (NSAID) are widely used in acute back pain. NSAIDs prescribed at regular intervals are effective to reduce simple back pain. The different NSAIDs are effective for the reduction of this pain. They have serious adverse effects, particularly at high doses, in the elderly, and on long-term administration. The new cyclooxygenase II-inhibitors have less gastrointestinal complications. But the long-term experiences are limited up to now. Considerable controversy exists about the use of opioid analgesics in chronic noncancer pain. Many physicians are concerned about the effectiveness and adverse effects of opioids. Other clinicians argue that there is a role for opioid therapy in chronic noncancer pain, e. g. especially in chronic low back pain. There is a low incidence of organ toxicity in patients who respond to opioids. The incidence of abuse and addiction is likewise relatively low. The potential for increased function and improved quality of life seems to outweigh the risks. However, there is a lack of randomised controlled trials (RCT) on opioid therapy in a multimodal pain treatment approach. Clinical experience and some studies suggest administration of sustained release opioids because of better comfort for the patient and less risks for addiction. The opioids should be selected due to the specific side effects of the different drugs. For patients with pre-existing constipation transdermal fentanyl should be preferred. Antidepressant medications have been used for the treatment of chronic back pain, though there is only little scientific evidence for their effectiveness. There is no evidence for the use of antidepressants in acute low back pain. Trials of muscle relaxants for patients with acute back pain have used a wide range of agents, e. g. benzodiazepines. They mostly reduce acute back pain, but they have significant adverse effects including drowsiness and psychological and physical dependence even after relatively short treatment. Benzodiazepines are not indicated in the treatment of chronic back pain. Drugs are sometimes necessary for the patients to begin and persevere a multimodal treatment program. Drug therapy should be terminated as soon as other treatment strategies succeed. Unfortunately, no studies exist evaluating the place of analgesics within a multimodal treatment program.

[Posttraumatic pain. Causes and therapeutic possibilities]. / Posttraumatische Schmerzen. Ursachen und Therapiemöglichkeiten.

Each patient has the right of a dedicated pain therapy according to the state of the art. However an efficient pain therapy is not possible without knowing the cause of pain. In most posttraumatic pain situations peripheral nociceptors are activated and normal afferences are conducted via an intact nociceptive system. In contrast, neuropathic pain pain is caused by lesions of the nervous system itself. Mechanisms of central sensibilization and involvement of the sympathetic nervous system may lead to chronification of such pain conditions. The therapeutic regime of nociceptive and neuropathic pain is demonstrated by algorithms of treatment modalities. Apart from classic non-opioid analgesics, co-analgesics and opioids have an important status in chronic pain management as well. Prescription of these substances has to follow strictly defined standards of pain therapy. Blockades with local anaesthetics as mono-therapy of chronic pain are obsolete. In posttraumatic pain, however, a certain number of adjuvant blockades or infiltrations of triggerpoints may be helpful. The exceptional place of sympathetic blockades are in diagnosis and therapy of sympathetic maintained pain (SMP).

Combination of extracorporeal membrane oxygenation (ECMO) and pulmonary lavage in a patient with pulmonary alveolar proteinosis.

We describe a rare case of pulmonary alveolar proteinosis in a young woman with dyspnea and progressive hypoxaemia due to the alveolar deposition of insoluble, surfactant-like material. Routine treatment includes whole-lung-lavage (WLL) using double-lumen-tubes for selective lavaging of each lung. We performed three whole-lung-lavages and used veno-venous extracorporeal membrane oxygenation (v-vECMO) to support oxygenation during these procedures.

[Inadvertent potassium chloride infusion in an epidural catheter]. / Versehentliche Infusion von Kaliumchlorid in einen Epiduralkatheter.

In a 65 years old male patient 38 cc of a 7.45% potassium chloride-solution was inadvertently infused within 3 hours into an epidural catheter on the first postoperative day. The epidural potassium chloride administration resulted in a paresis and painful paraesthesia of the patient's legs and a level of sensory blockade to TH 11. Furthermore vegetative symptoms like hypertension and tachycardia were observed. For therapy a single bolus of 40 mg dexamethasone was administered intravenously followed by an epidural infusion of sodium chloride 0.9% 99 cc/h for several hours. About 6 hours after the start of infusion all symptoms had disappeared. It is proposed that the use of colour-coded epidural catheter devices and coloured electrolyte solutions as well as infusion-pumps with a larger reservoir that reduce the frequency of syringe changes would be helpful in avoiding such complications.

Post-traumatic pain. Causes and therapeutic concepts.

Each patient has the right of a dedicated pain therapy according to the state of the art. However an efficient pain therapy is not possible without knowing the cause of pain. In most posttraumatic pain situations peripheral nociceptors are activated and normal afferences are conducted via an intact nociceptive system. In contrast, neuropathic pain pain is caused by lesions of the nervous system itself. Mechanisms of central sensibilization and involvement of the sympathetic nervous system may lead to chronification of such pain conditions. The therapeutic regime of nociceptive and neuropathic pain is demonstrated by algorithms of treatment modalities. Apart from classic non-opioid analgesics, co-analgesics and opioids have an important status in chronic pain management as well. Prescription of these substances has to follow strictly defined standards of pain therapy. Blockades with local anaesthetics as mono-therapy of chronic pain are obsolete. In posttraumatic pain, however, a certain number of adjuvant blockades or infiltrations of triggerpoints may be helpful. The exeptional place of sympathetic blockades are in diagnosis and therapy of sympathetic maintained pain (SMP).

[Are tramadol enantiomers for postoperative pain therapy better suited than the racemate? A randomized, placebo- and morphine-controlled double blind study]. / Sind Tramadol-Enantiomere für die postoperative Schmerztherapie besser geeignet als das Racemat? Eine randomisierte, Plazebo- und Morphin-kontrollierte Doppelblindstudie.

The goal of this prospective, randomised and double-blind pilot-study was to investigate the analgesic potency and the side-effects of tramadol enantiomers in clinical practice. One hundred patients recovering from orthopaedic surgery with a postoperative pain intensity of more than 50 on a visual analogue scale 0-100 mm (Table 1) were recruited for the study. They were treated in a randomised, double-blind way with a maximal dose of 150 mg i.v.(+)-,(-)-tramadol, racemate, or 15 mg i.v. morphine or saline in the placebo group (5 groups, 20 patients each). The primary criterium of efficacy was the number of responders defined as patients with a pain reduction of at least 20 on VAS after 40 min. In case of pain, responders were allowed to continue with the double-blind drug up to six hours. The non-responders were treated with morphine as the rescue analgesic. The secondary criterium was the incidence and severity of side-effects. Six patients terminated the study prematurely. One patient was excluded because of an allergic reaction to morphine, one patient could not be treated sufficiently with morphine, four were excluded because of protocol violations. There were 8 responders in the (+)-tramadol-,6 in the (-)-tramadol- and 6 in the racemate group, 16* (P < 0.05) in the morphine group, and 5 in the placebo group. Pain intensity after 40 min was reduced by 20 (p < 0.05), 17 (p < 0.05), 17 (p < 0.05), 36 (p < 0.01 vs placebo, p < 0.05 vs (+)-,(-)-tramadol, and racemate group) and 5 mm on the VAS in the (+)-, (-)-, (+/-)-tramadol-, morphine- and placebo-group, respectively. Thirty eight adverse events like nausea, vomiting, PCO2-increase, and urinary retention occurred in 20 patients, most frequently in the (+)-tramadol- and morphine group. Sedation was significantly less profound in the (-)-tramadol group 1-4 h postoperatively. There were no side-effect in the tramadol racemate group. The enantiomers were equal to the racemate in analgesic potency, but inferior by far to morphine. They showed more adverse events and, hence, can not be preferred to the racemate in postoperative pain therapy.

[Neurophysiological aspects of pain and its consequences for the anesthetist]. / Neurophysiologische Aspekte von Schmerz und ihre Konsequenzen für den Anästhesisten.

Nociception is a protective system of the body which prevents it from injury and tissue damage. Human beings respond to noxious stimuli by moving away. They learn by pain to avoid these situations in future. Shortly after major injury, there is a limited analgesic period allowing the body to flee the area of danger, later on, emerging pain compels the body to rest and supports recuperation. While acute pain has a certain meaning, chronic pain does not. It induces a comprehensive suffering including loss of initiative, appetite and vigilance. It reduces life-quality, often accompanied by depressive moods. Acute pain causes changes in the central nervous system leading to an increased sensitivity of nociception (hyperalgesia). During healing, the central processing of noxious stimuli is normalised taking minutes to weeks. Sometimes, unknown factors initiate chronification of pain. Changes on a molecular level in peripheral tissue as well as in the central nervous system induce "cellular early genes", a synthesis of c-fos, c-jun and other proteins favouring the chronification of pain. All efforts have to be made to depress or interrupt such a development. One of the first steps to pain prophylaxis in a hospital is an optimal surgical technique: incision, extension, limited tissue damage and minimal invasive surgery should guarantee the smallest impairment of the nociceptive system possible. However, nociceptive input is intense and of long duration and leads to central sensibilisation. Postoperative pain has lost its function as surgery anticipates healing. Pain induces a reduction of ventilation, circulation, digestion and increases the risk of other disorders. There is need of aggressive pain treatment for humanitarian reasons and for reasons of late sequelae like permanent pain and increased reduction of function. This is of pivotal importance in patients with amputations or sympathetic reflex dystrophy (SRD). Antinociception is best provided by regional anaesthesia technique with a combination of local anaesthetics and opioids which results in better outcome. Hence, regional anaesthesia techniques are strongly indicated in those patients. Good antinociception may be even more important than it is assumed today. Anand demonstrated a lower morbidity and mortality in 45 newborns undergoing cardiothoracic surgery, when general anaesthesia was performed with high-dose sufentanil versus halothane supplementary doses of morphine. Anaesthesiologists have to reconsider the quality of general anaesthesia: the antinociception of their regimen.

A new pneumatic pump for extracorporeal circulation: TPP (true pulsatile pump). Experimental and first clinical results.

A pulsatile, membrane type pump, TPP, was developed for use in routine cardiac surgery. The artificial ventricle consists of a polycarbonate housing with an inlet and outlet polyurethane tricuspid valve. The membrane is actuated hydraulically. For pre-clinical studies, we designed a study in sheep. After a pump run of 6 hours the animals were allowed to recover and sacrificed after 72 hours. All clinical parameters returned to normal values (p > 0.05 vs. control values). During pump run we found elevated free plasma hemoglobine. However, these values returned to normal until the end of the observation period. Thereafter, the device was used in ten routine cardiac surgery procedures. All patients survived the procedure and were discharged from hospital. The postoperative course of lab parameters (kidney, liver and blood count) was no different to routine cardiac surgical procedures. This pulsatile pump system can thus be safely employed in cardiac surgery.