Laparoscopic Adrenal Gland Surgery in Times of COVID - Is a Safety-Interval Before Surgery After COVID-Infection Still Mandatory?

BACKGROUND

Due to a multicenter study early in the coronavirus disease (COVID)-pandemic that revealed an increased risk for postoperative mortality, thromboembolic and pulmonary complications in case of surgery shortly after a COVID infection, current recommendations for planning elective surgeries suggest postponing surgery for at least 7 weeks after COVID infection. However, virus variants have evolved throughout the pandemic, leading to less severe symptoms. Besides, laparoscopic adrenal gland surgery itself is a safe procedure with low morbidity rates. Therefore, this study aimed to compare the perioperative course of patients undergoing laparoscopic adrenalectomy shortly after a COVID-19 infection with those who had not had a recent SARS-CoV-2 infection in 2022.

PATIENTS, MATERIAL, AND METHODS

All patients who underwent laparoscopic adrenalectomy at the Department for General, Visceral and Transplantation Surgery at Ludwig-Maximilian University between January and December 2022 were included.

RESULTS

There was no event of thromboembolic or pulmonary complications in the study population. Duration of surgery did not differ between the two groups; neither did the need for postoperative ICU-admittance nor the duration of ICU-stay. Intraoperative FiO2 did not differ, nor did the SpO2 or the number of different catecholamines. There was a slight trend towards higher noradrenaline dosage among patients after COVID-19 infection. Previous COVID infection did not lead to prolonged hospital stays.

CONCLUSION

The results demonstrate that in case of well-standardized surgical procedures, with a limited surgical trauma and the possibility for patients to be mobilized early, surgery shortly after a mild COVID infection seems safe and reasonable.

Postoperative cognitive dysfunction after beach chair positioning compared to supine position in orthopaedic surgery in the elderly

INTRODUCTION

Postoperative cognitive dysfunction (POCD) occurs in up to 26% of patients older than 60 years 1 week after non-cardiac surgery. Intraoperative beach chair positioning (BCP) is advantageous for some types of shoulder surgery. However, this kind of positioning leads to a downward bound redistribution of blood volume, with possible hypoperfusion of the brain. We hypothesized that patients > 60 years undergoing orthopaedic shoulder surgery in a BCP might experience more POCD than patients operated in the supine position (SP).

MATERIAL AND METHODS

A single-centre, prospective observational trial of 114 orthopaedic patients was performed. Study groups were established according to the type of intraoperative positioning. Anaesthesiological management was carried out similarly in both groups, including types of anaesthetics and blood pressure levels. POCD was evaluated using the Trail Making Test, the Letter-Number Span and the Regensburger Word Fluency Test. The frequency of POCD 1 week after surgery was considered primary outcome.

RESULTS

Baseline characteristics, including duration of surgery, were comparable in both groups. POCD after 1 week occurred in 10.5% of SP patients and in 21.1% of BCP patients (p = 0.123; hazard ratio 2.0 (CI 95% 0.794-5.038)). After 4 weeks, the incidence of POCD decreased (SP: 8.8% vs. BCP: 5.3%; p = 0.463). 12/18 patients with POCD showed changes in their Word Fluency Tests. Near-infrared spectroscopy (NIRS) values were not lower in patients with POCD compared to those without POCD (54% (50/61) vs. 57% (51/61); p = 0.671).

CONCLUSION

POCD at 1 week after surgery tended to occur more often in patients operated in beach chair position compared to patients in supine position without being statistically significant.

[Drug interaction between ceftriaxone and theodrenaline/cafedrine : A case example]

Adverse interactions between intravenous medications which are given simultaneously are a common problem in intensive care medicine. They are usually caused by administering a high number of medications over a limited number of intravenous lines or central venous catheters; however, this issue also arises in routine anesthetic procedures during surgery. The following case report highlights a so far undocumented interaction between the combination of theodrenaline/cafedrine and various antibiotics.Laparoscopic cholecystectomy was performed in a female patient, classified as ASA 1. After induction of general anesthesia 2 g ceftriaxone were administered as a perioperative antibiotic prophylaxis. Simultaneously, i.e. prior to the beginning of surgery, a mild decrease in blood pressure was observed and 2 ml diluted Akrinor® (2 ml theodrenaline/cafedrine + 8 ml NaCl 0.9%) was administered. Directly following this administration a chemical precipitation reaction occurred, and large white pasty flakes were noticed in the intravenous line. The infusion was stopped immediately and all lines were replaced.In order to confirm a causal relationship between the observed precipitation and the simultaneous administration of the two drugs, an in vitro test was performed by mixing Akrinor® with other preparations of cephalosporin antibiotics. The effect observed with ceftriaxone was reproducible and cefazoline also caused a precipitation reaction.

Influence of insufflated carbon dioxide on abdominal temperature compared to oesophageal temperature during laparoscopic surgery

BACKGROUND

Body core temperature is an important vital parameter during surgery and anaesthesia. It is influenced by several patient-related and surgery-related factors. Laparoscopy is considered beneficial in terms of a variety of parameters, for example, postoperative pain and length of hospital stay. Non-humidified, non-warmed insufflated CO₂ applied during laparoscopy is standard of care. This prospective observational trial therefore evaluates the impact of non-humidified CO₂ at room temperature on abdominal temperature and its correlation to body core temperature.

METHODS

Seventy patients undergoing laparoscopic surgery were included in this prospective observational study. Temperature was measured oesophageal and abdominal before induction of anaesthesia (T1), right before skin incision (T2), 15 min, 30 min and 60 min after skin incision. All patients were treated according to actual guidelines for perioperative temperature measurement.

RESULTS

Body core temperature and abdominal temperature correlated moderately (r = 0.6123; p < 0.0001). Bland-Altman plot for comparison of methods showed an average difference of 0.4 °C (bias - 0.3955; 95% agreement of bias from - 2.365 to 1.574). Abdominal temperature further decreased after establishing pneumoperitoneum (T2: 36.2 °C (35.9/36.4) to T5: 36.1 °C (35.6/36.4); p < 0.0001), whereas oesophageal temperature increased (T2: 36.2 °C (35.9/36.4) to 36.4 °C (36.0/36.7); p = 0.0296). Values of oesophageal and abdominal measurement points differed at T4 (36.3 °C (36.0/36.6) vs. 36.1 °C (35.4/36.6); p < 0.0001) and T5 (36.4 °C (36.0/36.7) vs. 36.1 °C (35.6/36.4) p = 0.0003).

CONCLUSION

This prospective observational trial shows the influence of insufflated, non-humidified carbon dioxide at room temperature on abdominal temperature during laparoscopic surgery. We show that carbon dioxide applied at these conditions decreases abdominal temperature and therefore might be a risk factor for perioperative hypothermia.

Natriuretic Peptides as a Prognostic Marker for Delirium in Cardiac Surgery-A Pilot Study

Background and Objectives: Delirium is a common and major complication subsequent to cardiac surgery. Despite scientific efforts, there are no parameters which reliably predict postoperative delirium. In delirium pathology, natriuretic peptides (NPs) interfere with the blood–brain barrier and thus promote delirium. Therefore, we aimed to assess whether NPs may predict postoperative delirium and long-term outcomes. Materials and Methods: To evaluate the predictive value of NPs for delirium we retrospectively analyzed data from a prospective, randomized study for serum levels of atrial natriuretic peptide (ANP) and the precursor of C-type natriuretic peptide (NT-proCNP) in patients undergoing coronary artery bypass grafting (CABG) with or without cardiopulmonary bypass (off-pump coronary bypass grafting; OPCAB). Delirium was assessed by a validated chart-based method. Long-term outcomes were assessed 10 years after surgery by a telephone interview. Results: The overall incidence of delirium in the total cohort was 48% regardless of the surgical approach (CABG vs. OPCAB). Serum ANP levels > 64.6 pg/mL predicted delirium with a sensitivity (95% confidence interval) of 100% (75.3–100) and specificity of 42.9% (17.7–71.1). Serum NT-proCNP levels >1.7 pg/mL predicted delirium with a sensitivity (95% confidence interval) of 92.3% (64.0–99.8) and specificity of 42.9% (17.7–71.1). Both NPs could not predict postoperative survival or long-term cognitive decline. Conclusions: We found a positive correlation between delirium and preoperative plasma levels of ANP and NT-proCNP. A well-powered and prospective study might identify NPs as biomarkers indicating the risk of delirium and postoperative cognitive decline in patients at risk for postoperative delirium.

Patient-related and anesthesia-dependent determinants for postoperative delirium after oral and maxillofacial surgery. Results from a register-based case-control study

OBJECTIVE

To identify risk factors for postoperative delirium (POD) after general oral and maxillofacial surgery.

MATERIAL AND METHODS

2420 patients were screened postoperatively for POD using the Nursing Delirium Screening Scale (NuDESC) before discharge from the post anesthesia caring unit (PACU). Basic health data and risk factors were collected. For analysis the study group (n=41) was compared to a control group of 164 randomly selected patients (case-control-ratio=1:4). To identify risk factors for POD multivariable logistic regression models were used. To see whether estimations remain stable, regression analysis was repeated for the subgroup of patients not undergoing dentoalveolar surgery (n=105). To estimate the risk for dentoalveolar surgery a logistic regression model was performed.

RESULTS

Dementia was the only significant risk factor for POD (Odds ratio 41.5; 95% CI 5.48-314), also for patients undergoing other than dentoalveolar surgery (58.1; 1.70-1983). Patients undergoing dentoalveolar surgery were more often suffering from dementia (35.5; 2.85-441), other psychiatric and neurological disorders (3.15; 1.05-9.43), were of younger age (0.97; 0.94-1.00) and had higher anesthesiological risk (3.95; 1.04-14.9).

CONCLUSION

Patients with dementia are at higher risk to develop POD after oral and maxillofacial surgery. We found a strong interdependence between age, dementia, ASA-Score and dentoalveolar surgery.

[Cardiorespiratory effects of perioperative positioning techniques]

The supine position is still the most frequently used type of positioning during surgical procedures. Positions other than the supine position lead to physiological alterations that have a relevant influence on the course of anesthesia and surgery. As a matter of principle, hemodynamic stability is at risk because venous blood is pooled in the lower positioned body parts. In addition, head down positions (Trendelenburg position) may lead to an impairment of respiratory function by reducing lung volumes as well as lung compliance. Upright positions (beach chair position) are characterized by a relative hypovolemia accompanied by a reduction of mean arterial pressure, cardiac output and stroke volume, whereas pulmonary functions remain unchanged. Some severe adverse events have been described in the literature (e.g. intraoperative apoplexy, postoperative blindness). The pathophysiological principles and effects of hemodynamic alterations as well as potential strategies to avoid complications are presented and discussed in this lead article. Head down positions, especially the Trendelenburg position, cause a relative (intrathoracic) hypervolemia and an increase in cardiac preload that is usually well-tolerated in patients without heart problems; however, the Trendelenburg position, especially if combined with a capnoperitoneum, significantly impairs pulmonary function, can have a negative effect on intracerebral pressure and may reduce blood flow of intra-abdominal organs. The pathophysiological intraoperative changes caused by Trendelenburg positioning are described and approaches suitable for risk reduction are discussed. The prone position and lateral decubitus position have little influence on the intraoperative homeostasis. Nevertheless, there is an ongoing discussion concerning the efficacy of a 15° left lateral position during caesarean section, which is also discussed in a separate section of this review.

The influence of body mass index on temperature management during general anaesthesia-A prospective observational study

RATIONALE, AIMS, AND OBJECTIVES

During general anaesthesia, body core temperature is influenced by several factors that are either anaesthesia-related (type and duration of anaesthesia and fluid management), surgery-related (type of surgery and extent of the surgical procedure), or patient-related (age, gender, body weight, and preoperative body core temperature). Interestingly, data concerning body mass index (BMI) and its influence on patients' temperature are sparse. The aim of this study was to evaluate the impact of BMI on body core temperature under general anaesthesia.

METHODS

A single centre, prospective, observational study was conducted at a university hospital. Two cohorts (lower limb surgery and abdominal surgery) were evaluated. Patients were treated according to actual German guidelines for the prevention of hypothermia. Temperature was measured sublingually prior to anaesthesia and during the first 60 minutes of anaesthesia. Each cohort was divided in three subgroups (BMI < 24 kg m^-2 , BMI 25-34.9 kg m^-2 , and BMI > 35 kg m^-2 ) according to body weight.

RESULTS

A total of 206 patients were evaluated. One hundred four underwent lower limb surgery; 102 underwent abdominal surgery. After induction of anaesthesia, temperature dropped in all subgroups, but this decline was more pronounced in patients with lower BMI. Significant differences concerning temperature changes were observed in abdominal surgery between low and high BMI groups. After 60 minutes of anaesthesia, group-dependent temperature differences had levelled out, and relevant differences compared with preoperative temperatures could no longer be observed in any of the groups.

CONCLUSION

Current guidelines provide effective protection against perioperative hypothermia. In the current study, this was true for obese as well as normal weight patients.

The impact of phosphate-balanced crystalloid infusion on acid-base homeostasis (PALANCE study): study protocol for a randomized controlled trial

Background

This study aims to investigate the effects of a modified, balanced crystalloid including phosphate in a perioperative setting in order to maintain a stable electrolyte and acid-base homeostasis in the patient.

Methods/design

This is a single-centre, open-label, randomized controlled trial involving two parallel groups of female patients comparing a perioperative infusion regime with sodium glycerophosphate and Jonosteril® (treatment group) or Jonosteril® (comparator) alone. The primary endpoint is to maintain a stable concentration of weak acids [A^-] according to the Stewart approach of acid-base balance. Secondary endpoints are measurement of serum phosphate levels, other acid-base parameters such as the strong ion difference (SID), the onset and severity of postoperative nausea and vomiting (PONV), electrolyte levels and their excretion in the urine, monitoring of renal function and glycocalyx components, haemodynamics, amounts of catecholamines and other vasopressors used and the safety of the infusion regime.

Discussion

Perioperative fluid replacement with the use of currently available crystalloid preparations still fail to maintain a stable acid-base balance and experts agree that common balanced solutions are still not ideal. This study aims to investigate the effectivity and safety of a new crystalloid solution by adding sodium glycerophosphate to a standardized crystalloid preparation in order to maintain a balanced perioperative acid-base homeostasis.

Trial registration

EudraCT number 201002422520. Registered on 30 November 2010.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2051-z) contains supplementary material, which is available to authorized users.

[State of the art in fluid and volume therapy : A user-friendly staged concept]

Adequate fluid therapy is highly important for the perioperative outcome of our patients. Both, hypovolemia and hypervolemia can lead to an increase in perioperative complications and can impair the outcome. Therefore, perioperative infusion therapy should be target-oriented. The main target is to maintain the patient's preoperative normovolemia by using a sophisticated, rational infusion strategy.Perioperative fluid losses should be discriminated from volume losses (surgical blood loss or interstitial volume losses containing protein). Fluid losses as urine or perspiratio insensibilis (0.5-1.0 ml/kg/h) should be replaced by balanced crystalloids in a ratio of 1:1. Volume therapy step 1: Blood loss up to a maximum value of 20% of the patient's blood volume should be replaced by balanced crystalloids in a ratio of 4(-5):1. Volume therapy step 2: Higher blood losses should be treated by using iso-oncotic, preferential balanced colloids in a ratio of 1:1. For this purpose hydroxyethyl starch can also be used perioperatively if there is no respective contraindication, such as sepsis, burn injuries, critically ill patients, renal impairment or renal replacement therapy, and severe coagulopathy. Volume therapy step 3: If there is an indication for red cell concentrates or coagulation factors, a differentiated application of blood and blood products should be performed.

[Knowledge and implementation of the S3 guideline on delirium management in Germany]

BACKGROUND

Delirium is a common complication in critical care. The syndrome is often underestimated due to its potentially no less dangerous course as a hypoactive delirium. Therefore, current guidelines ask for a structured, regular and routine screening in all intensive care units. If delirium is diagnosed, symptomatic therapy should be initiated promptly.

OBJECTIVES

The aim of the current study was to evaluate recent German anesthetists' strategies regarding delirium care compared to the German guidelines for sedation and delirium in intensive care.

METHODS

In an online survey German hospitals' senior anesthetists (n = 922) were interviewed anonymously between May and June 2015 regarding guideline use in delirium management in German intensive care units. In 33 direct questions the anesthetists were invited to answer items regarding the structure of their hospitals, intensive care and delirium therapy in order to review their knowledge of the German delirium guidelines that expired in 2014.

RESULTS

The 249 senior anesthetists who responded to the survey, can be associated with (or represent) a quarter of German intensive care beds and cases, respectively. In every tenth clinic that runs an intensive care unit the guideline was unknown. In three of four intensive care units physicians specified a preferred delirium score, the CAM-ICU (49.4 %) is used most frequently. With knowledge of the guidelines more often a recommended delirium score is used (p = 0.017). However, only 53.6 % of the respondents ascertain a score every eight hours and 36 % have no facility for standardized documentation in the records. At intensive care rounds, a possible diagnosis of delirium is an inherent part in only 34.9 % of the responders even with guideline knowledge. The particular gold standard for the therapy of delirium (alphaagonists for vegetative symptoms; 89.6 %, benzodiazepines for anxiety, 77.5 %; antipsychotics in 86.7 % for psychotic symptoms) is implemented more often with growing knowledge of the guidelines. The latter applies to the implementation of structured programs for delirium prophylaxis, cognition and therapy.

CONCLUSION

For the first time, this study documents knowledge and implementation of the German S3 guidelines for delirium in intensive care. Overall, the guidelines for delirium care are less well executed than those for sedation. With growing knowledge of the guidelines, diagnosis and treatment of delirium fits the guidelines more frequently. The facility to document a delirium score in intensive records is insufficient. Especially a nursing-based delirium strategy could possibly improve implementation of the guidelines, claiming an eight-hour screening and documentation. However, the small number of hospitals that have integrated the guidelines into in-house standard operating procedures (40 %) shows urgent need for optimization. A re-evaluation involving all relevant caretakers could probably improve the implementation of guidelines in intensive care and perioperative medicine.

The intravascular volume effect of Ringer's lactate is below 20%: a prospective study in humans

Introduction

Isotonic crystalloids play a central role in perioperative fluid management. Isooncotic preparations of colloids (for example, human albumin or hydroxyethyl starch) remain nearly completely intravascular when infused to compensate for acute blood losses. Recent data were interpreted to indicate a comparable intravascular volume effect for crystalloids, challenging the occasionally suggested advantage of using colloids to treat hypovolemia. General physiological knowledge and clinical experience, however, suggest otherwise.

Methods

In a prospective study, double-tracer blood volume measurements were performed before and after intended normovolemic hemodilution in ten female adults, simultaneously substituting the three-fold amount of withdrawn blood with Ringer's lactate. Any originated deficits were substituted with half the volume of 20% human albumin, followed by a further assessment of blood volume. To assess significance between the measurements, repeated measures analysis of variance (ANOVA) according to Fisher were performed. If significant results were shown, paired t tests (according to Student) for the singular measurements were taken. P < 0.05 was considered to be significant.

Results

A total of 1,097 ± 285 ml of whole blood were withdrawn (641 ± 155 ml/m² body surface area) and simultaneously replaced by 3,430 ± 806 ml of Ringer's lactate. All patients showed a significant decrease in blood volume after hemodilution (-459 ± 185 ml; P < 0.05) that did not involve relevant hemodynamical changes, and a significant increase in interstitial water content (+2,157 ± 606 ml; P < 0.05). The volume effect of Ringer's lactate was 17 ± 10%. The infusion of 245 ± 64 ml of 20% human albumin in this situation restored blood volume back to baseline values, the volume effect being 184 ± 63%.

Conclusions

Substitution of isolated intravascular deficits in cardiopulmonary healthy adults with the three-fold amount of Ringer's lactate impedes maintenance of intravascular normovolemia. The main side effect was an impressive interstitial fluid accumulation, which was partly restored by the intravenous infusion of 20% human albumin. We recommend to substitute the five-fold amount of crystalloids or to use an isooncotic preparation in the face of acute bleeding in patients where edema prevention might be advantageous.

[Options and limits of interscalene nerve blocks]

Regional anaesthesia has gained increasing importance during the last decades. Successful regional anaesthesia for shoulder surgery requires a detailed knowledge of the relevant anatomy. Interscalene nerve blocks are most frequently used to anaesthetize the shoulder and among them the techniques according to Winnie, Meier, Pippa and Borgeat are the most popular. The techniques described by Meier and Borgeat are characterized by low complication rates. They are efficient for the majority of surgical procedures and therefore offer an interesting supplementation or an alternative to general anaesthesia. When carried out as a catheter-technique they provide a high quality postoperative pain therapy.

[Metabolic alkalosis despite hyperlactatemia and hypercapnia. Interpretation and therapy with help of the Stewart concept]

Acid-base disturbances are commonly found in critically ill patients and are often associated with fatal complications. The basis of a successful treatment is a thorough understanding of the causes of these disorders. The "classical methods" to explain acid-base disorders--pH, base excess and bicarbonate concentration--mostly do not provide a causal correlation to the underlying pathology. An unusual case of a combined respiratory-metabolic disorder with hyperlactatemia and hypercapnia is presented. An acidosis masked by hypochloremic and hypoalbuminemic alkalosis was identified with the help of Stewart's concept and finally permitted a successful therapy. The modern Stewart concept provides enhanced information, enabling an exact diagnosis and causal therapy even in complex cases.

Does patient-controlled continuous interscalene block improve early functional rehabilitation after open shoulder surgery?

BACKGROUND

Early mobilization after shoulder surgery plays a vital role in successful functional rehabilitation. However, postoperative pain often reduces, or even prevents, effective physiotherapy. We investigated the effect of analgesia via patient-controlled interscalene technique on early functional rehabilitation after open shoulder surgery.

METHODS

Eighty-seven patients were randomly assigned to one of two groups: patient-controlled continuous interscalene block (PCISB) and patient-controlled i.v. (opioid) analgesia (PCA). Interscalene block was performed preoperatively; otherwise analgesic protocols were started in the postanesthesia care unit and were continued for 72 h. Physiotherapy was performed for 60 min a day on day 2 and 3 after surgery according to a standardized protocol. Maximum mobility was defined as the range of motion that could be achieved with pain as the limiting factor. Efficiency of functional rehabilitation was evaluated 1 day before and 3 days after surgery with the help of a multimodal scoring system (Constant-Score) that evaluates pain, daily life activity, strength and range of motion. Maximum intensity of pain was also monitored via Visual Analog Scales for the first 72 h after surgery and during in-hospital physiotherapy.

RESULTS

Constant-Score rates were significantly improved by the interscalene block. However, no significant differences in mobility and strength sub-scores were observed between the groups. Compared with PCA, PCISB proved to be beneficial concerning pain at rest at 6 h (P < 0.001), 24 h (P = 0.044), and 72 h (P = 0.013) and for pain during physiotherapy at 48 h after surgery (P = 0.016).

CONCLUSION

Compared with opioid-based PCA, PCISB improved analgesia, but not function, during early rehabilitation of the shoulder joint.

Determinanten des insensiblen Flüssigkeitsverlustes

Accurate perioperative fluid balance is the basis of a targeted infusion regimen. However, neither the initial status nor perioperative changes of the fluid compartments can be reliably measured in daily routine. In particular, insensible losses are not consistently assessed, so that substitution therapy is generally empirical. The object of this paper is to communicate the scientific data on this topic. Preoperative fasting (10 h) does not per se cause intravascular hypovolemia. In adults, total basal evaporation by way of the skin and airways and of any wounds during major abdominal interventions is usually less than 1 ml/kg/h. An inconstant fluid and protein shift towards the interstitial space perioperatively seems to be associated with hypervolemia, which suggests it should be preventable. The decisive factor in this context seems to be deterioration of the endothelial glycocalyx, whose further patho-physiological impact is currently only partially known. Clinical studies have revealed a link between fluid restriction and improved outcome after major abdominal surgery.

CSF tau protein phosphorylated at threonine 231 correlates with cognitive decline in MCI subjects

In this longitudinal study of 77 patients with mild cognitive impairment (MCI), the authors analyzed whether levels of tau protein phosphorylated at threonine 231 (p-tau(231)) in CSF correlate with progression of cognitive decline. High CSF p-tau(231) levels at baseline, but not total tau protein levels, correlated with cognitive decline and conversion from MCI to AD. Independently, old age and APOE-epsilon 4 carrier status were predictive as well. Our data indicate that an increased p-tau(231) level is a potential risk factor for cognitive decline in patients with MCI.

Differential diagnosis of Alzheimer disease with cerebrospinal fluid levels of tau protein phosphorylated at threonine 231

BACKGROUND

Phosphorylation of tau protein at threonine 231 (using full-length tau, 441 amino acids, for the numbering scheme) (p-tau(231)) occurs specifically in postmortem brain tissue of patients with Alzheimer disease (AD) and can be sensitively detected in cerebrospinal fluid (CSF).

OBJECTIVES

To determine to what extent CSF levels of p-tau(231) distinguish patients with AD from control subjects and from patients with other dementias, and to investigate whether p-tau(231) levels are a better diagnostic marker than levels of total tau protein (t-tau) in CSF.

DESIGN AND SETTING

Cross-sectional, multicenter, memory clinic-based studies.

PARTICIPANTS

One hundred ninety-two patients with a clinical diagnosis of AD, frontotemporal dementia (FTD), vascular dementia, Lewy body dementia, or other neurological disorder and healthy controls.

MAIN OUTCOME MEASURES

Levels of CSF tau proteins as measured with enzyme-linked immunosorbent assays.

RESULTS

Mean CSF levels of p-tau(231) were significantly elevated in the AD group compared with all other groups. Levels of p-tau(231) did not correlate with dementia severity in AD, and discriminated with a sensitivity of 90.2% and a specificity of 80.0% between AD and all non-AD disorders. Moreover, p-tau(231) levels improved diagnostic accuracy compared with t-tau levels when patients with AD were compared with healthy controls (P =.03) and demented subjects (P<.001), particularly those with FTD (P<.001), but not those with vascular and Lewy body dementias. Sensitivity levels between AD and FTD were raised by p-tau(231) compared with t-tau levels from 57.7% to 90.2% at a specificity level of 92.3% for both markers.

CONCLUSION

Increased levels of CSF p-tau(231) may be a useful, clinically applicable biological marker for the differential diagnosis of AD, particularly for distinguishing AD from FTD.

Ropivacaine 7.5 mg/ml versus bupivacaine 5 mg/ml for interscalene brachial plexus block--a comparative study

We investigated ropivacaine 75 mg/ml in comparison with bupivacaine 5 mg/ml in patients receiving interscalene brachial plexus block (ISB) and general anaesthesia. In this randomized, double-blind, prospective clinical trial, each patient received an ISB block according to the technique originally described by Winnie and a catheter technique as per Meier. The rapidity of onset and the quality of sensory and motor block were determined. After general anaesthesia had been induced further parameters evaluated were consumption of local anaesthetic, opioid and neuromuscular blocking drug. After arrival in the recovery room, the patients were assessed for intensity of pain using a visual analog scale (VAS). One hundred and twenty patients were included in the study. The onset and development of sensory block was similar in both groups. Development and quality of motor block was also nearly identical for both local anaesthetics. Consumption of neuromuscular blocking drug and opioid did not differ between ropivacaine and bupivacaine. In the recovery room the mean pain score was less than 25 in both groups. There were no significant differences in terms of onset and quality of sensory or motor block during the intraoperative and early postoperative period. In addition we did not identify any side-effects related to the administration of the local anaesthetics. Ropivacaine 7.5 mg/ml and bupivacaine 5mg/ml proved to be nearly indistinguishable when administered for interscalene brachial plexus block.

Ropivacaine 2 mg/mL vs. bupivacaine 1.25 mg/mL with sufentanil using patient-controlled epidural analgesia in labour

BACKGROUND

In recent studies, minimum local analgesic concentrations have been defined as 0.93 mg/mL for bupivacaine and 1.56 mg/mL for ropivacaine for epidural analgesia for the first stage of labour, resulting in an analgesic potency ratio of 1 : 0.6. In the current study we compared ropivacaine and bupivacaine in a PCEA system (combined with sufentanil) taking this potency ratio into account but administering drug doses providing sufficient analgesia for all stages of labour.

METHODS

In a prospective, double-blinded study 114 parturients were randomised to receive either ropivacaine 2 mg/mL with sufentanil 0.75 microg/mL or bupivacaine 1.25 mg/with sufentanil 0.75 microg/mL. After epidural catheter placement, PCEA was available with boluses of 4 mL, a lock-out time of 20 min and no basal infusion rate. We evaluated pain intensity during contractions, sensory and motor function, duration of labour, mode of delivery and neonatal outcome. Consumption of local anaesthetic and opioid drugs and PCEA system variables were recorded.

RESULTS

Mean total consumption as well as mean hourly drug consumption was significantly increased in the ropivacaine-sufentanil group. No differences in analgesic quality, sensory or motor blocking potencies or neonatal outcome variables between groups were detected. Frequency of instrumental deliveries was significantly increased in the ropivacaine-sufentanil group.

CONCLUSIONS

The results support the findings of previously published studies postulating ropivacaine to be 40-50% less potent for labour epidural analgesia compared to bupivacaine. However, we observed an increased frequency of instrumental deliveries with ropivacaine. To evaluate the clinical relevance of these findings, further investigations are warranted.

[Induction of anesthesia for a patient with sleep apnea syndrome]

Based on a case report, we offer brief guidelines on the perioperative management of patients with Sleep-Apnea-Syndrome (SAS) who present with a high incidence of a difficult airway and a high risk of respiratory depression during the perioperative period. A 39 year old male patient with a body mass index of 34.22 kg/m2 and receiving continuous-positive-airway-pressure-(CPAP) therapy for known SAS was scheduled for elective plastic surgery. After induction of anaesthesia and direct laryngoscopy no adequate airway could be established and the patient became hypoxic, hypercapnic and developed hypotension and bradycardia. With the use of a laryngeal mask airway the patient was stabilized and did not show neurologic sequale after immediate awakening. The following fiberoptic intubation of the awake patient, still showing tendency of upper airway obstruction, confirmed the difficult anatomical structures. The subsequent general anesthesia was uneventful. The patient received CPAP therapy and was monitored during the first postoperative night in the Intensive Care Unit. He made an uneventful recovery. He was advised to have regional anaesthesia or planned fiberoptic intubation, where possible, in the case of further anesthetic intervention. SAS has major implications for the anaesthesiologist and whenever patients exhibiting the high risk factors (obesity, male sex, history of intense snoring, impaired daytime performance, nonrefreshing daytime naps) are presented for surgery this condition should be considered. Elective surgery should be postponed until after adequate examination and treatment when necessary. Patients with SAS should always be suspected of having cardiopulmonary dysfunctions such as hypertension, cardiac dysrhythmia or cor pulmonale. It is most important to avoid sedative premedication, to initiate CPAP therapy preoperatively, to encourage regional anaesthesia if possible and to ensure close monitoring over the complete perioperative period. Planned fiberoptic intubation, preferably with surgical personnel available for an emergency airway, is a safe method for the induction of anaesthesia. Postoperatively, patients are at high risk from respiratory depression, even in the awake state. Postoperative opioid analgesia, no matter what route, should only be given under close monitoring. Independently of regional or general anaesthesia there is an increased risk of respiratory depression in the middle of the first postoperative week, suspected to be caused by the catching up on lost REM-sleep, due to shifts in the normal sleep pattern during the first postoperative days.

[Quality of pain management in preclinical care of acutely ill patients]

The aim of this study was to evaluate the quality of pain management in prehospital emergency care and to get more information about the administration of analgesics in prehospital patients.

METHODS

Patients with painful diseases or injuries who had been brought to Munich hospital's were included in the study. Immediately after having reached the hospitals' emergency department, they were evaluated using a 101-point visual analogue scale for the severity of pain at four predefined periods. Information about the patient, the diagnosis, and the analgesic treatment used by the emergency teams were drawn from the patient's chart.

RESULTS

A total of 462 patients were included in the study. The mean pain score on arrival of the emergency team was 64 points; 36.5% of the patients were treated with analgesics. In 28.1% the emergency team tried to reduce pain through external measures (i.e., setting of fractures). In 35.3% there was no therapeutic intervention. In cases in which analgesic therapy was initiated, a definite reduction in pain was achieved during emergency care. Visual analogue scores decreased from 70 points at the beginning to 29 points at arrival to the hospital's emergency department. Analgesics were most frequently used for patients with cardiopulmonary diseases (47.2%), followed by patients with traumatic accidents (35.5%) and patients with acute abdominal pain (25.2%). Of the analgesics, opioids were given most frequently (87.0%). Nonopioid analgesic agents were used in 32.1%. The results of our investigation demonstrate that in many cases the administration of analgesics is not individualized to the patients needs.

CONCLUSION

During the prehospital period of emergency care many patients suffer from severe pain. The development of patient-oriented concepts concerning pain management could contribute to improvement of pain therapy in prehospital emergency medicine.