Pre-operative fluid bolus for improved haemodynamic stability during minor surgery: A prospectively randomized clinical trial

BACKGROUND

Haemodynamic instability during the induction of anaesthesia and surgery is common and may be related to hypovolaemia caused by pre-operative fasting or chronic diuretic therapy. The aim of our prospective, controlled, randomized study was to test the hypothesis that a predefined fluid bolus given prior to general anaesthesia for minor surgery would increase haemodynamic stability during anaesthetic induction.

METHODS

Two hundred and nineteen fairly healthy adult patients requiring minor surgery were enrolled. All received standard treatment, including a pulse contour analysing device for non-invasive measurement of cardiac index. Infusion therapy was started in all patients at induction. The intervention group (106 patients) was randomized to receive an additional fluid bolus of 8 mL/kg Ringer's acetate solution before the induction of anaesthesia. The primary endpoint was the incidence of haemodynamic instability, defined as a significant reduction of blood pressure or cardiac index during induction of anaesthesia.

RESULTS

The interventional group had a lesser incidence of haemodynamic instability during induction (41.5% vs 56.6%, P = .025). This group also had higher cardiac index, stroke volume index, systolic and mean blood pressure and a greater left ventricular end-diastolic area.

CONCLUSIONS

A fluid bolus prior to anaesthesia reduced the incidence of haemodynamic instability during induction of general anaesthesia. The total fluid volume was slightly greater in the intervention group compared to the control group (1370 ± 439 mL vs 1219 ± 483 mL, P = .007). We conclude that a defined fluid bolus can help stabilizing haemodynamics in patients undergoing general anaesthesia.

A cross-sectional study on preoperative anxiety in adults

OBJECTIVE

The main objective of this study was a detailed comparison of the level of anxiety about surgery and anesthesia. Other objectives included the assessment of the prevalence and intensity of preoperative anxiety.

METHODS

This cross-sectional single-center survey used the validated Amsterdam anxiety and information scale (APAIS) and a modified numeric rating scale (mNRS) to assess preoperative anxiety, anxiety about surgery and anxiety about anesthesia. Prevalences and intensities of anxieties were predominantly analyzed descriptively.

RESULTS

3200 patients were enrolled and 3087 (57% females) were analyzed. 92.6% reported preoperative anxiety according to APAIS scores. The average total APAIS anxiety score (APAIS-A-T) was 9.9 (SD 3.6). 40.5% reported high anxiety (defined as APAIS-A-T > 10). Mean anxiety about surgery (APAIS-A-Su) was higher than mean anxiety about anesthesia (APAIS-A-An): 5.5 (SD 2.1) vs. 4.3 (SD 1.9), p < 0.0001. Accordingly, more patients were substantially more afraid (score difference > 2) of surgery (642, 20.8%, 95% CI 19.4-22.3) than of anesthesia (48, 1.6%, 95% CI 1.2-2.1).

CONCLUSION

Preoperative anxiety is still very common among adult patients scheduled to undergo an elective procedure. Therefore, it should be evaluated routinely. Anxiety about surgery and anxiety about anesthesia differ in many patients. For this reason, anxiety about surgery and anxiety about anesthesia should be assessed separately. This would allow providing a more individualized support of patients to cope with their anxiety and could require particular attention by the surgeon or the anesthetist.

[Premedication visits in departments of anesthesiology in Hessen. Compilation of organizational and performance portfolios]

BACKGROUND

Many anesthesia departments operate a pre-anesthesia assessment clinic (PAAC). Data regarding organization, equipment and structure of such clinics are not yet available. Information about modern anesthesiology techniques and procedures contributes to a reduction in emotional stress of the patients but such modern techniques often require additional technical hardware and costs and are not equally available.

AIM

This survey examined the current structures of PAAC in the state of Hessen, demonstrated current concepts and associated these with the performance and the portfolio of procedures in these departments.

MATERIAL AND METHODS

An online survey was carried out. Data on structure, equipment, organization and available methods were compiled. In addition, anesthesia department personnel were asked to give individual subjective attitudes toward the premedication work.

RESULTS

Of the anesthesia departments in Hessen 84 % participated in the survey of which 91 % operated a PAAC. A preoperative contact with the anesthesiologist who would perform anesthesia existed in only 19 % of the departments. Multimedia processing concepts for informed consent in a PAAC setting were in general rare. Many modern procedures and anesthesia techniques were broadly established independent of the hospital size. Regarding the individual and subjective attitudes of anesthetists towards the work, the psychological and medical importance of the pre-medication visit was considered to be very high.

CONCLUSION

The PAACs are now well established. This may make economic sense but is accompanied by an anonymization of care in anesthesiology. The high quality, safety and availability of modern anesthesiology procedures and monitoring concepts should be communicated to patients all the more as an expression of trust and high patient safety. These factors can be facilitated in particular by multimedia tools which have as yet only been sparsely implemented in PAACs.

[Caesarean sections under regional anesthesia: pros and cons of supplementary oxygen]

The routine administration of supplemental oxygen to women undergoing elective caesarean section under regional anesthesia in order to optimize oxygen supply to the fetus is common anesthetic practice in many German hospitals. However, this practice has been controversially discussed in the non-German literature for many years. This review presents and discusses the pros and cons of routinely providing supplemental oxygen to a parturient during caesarean section on the basis of the literature published over the last 30 years. Proponents of routine oxygen administration point to potential and unforeseeable risks of caesarean sections and consider the prophylactic administration of oxygen based on physiological considerations to be advantageous in terms of patient safety. Interestingly, data regarding the effects of an increased maternal FIO2 on improvement of fetal oxygenation are inconsistent, therefore, no unambiguous recommendation concerning which FIO2 to choose can be given. Opponents of routine oxygen supplementation allude above all to an increase in free radical activity in both mother and fetus; however, data in this respect are not consistent either. As supplemental oxygen to patients undergoing elective caesarean section without any risk factors under regional anesthesia is associated with potential risks while no advantage has so far been demonstrated, routine administration of oxygen has to be challenged and is no longer considered to be indicated by many. On the contrary, in cases of emergency with a concomitant risk of hypoxia for mother and fetus, administration of oxygen is indispensable in the light of present data.

[Anaesthesiological experience and factoid public information - effects, interactions and possible strategies for perioperative stress reduction]

BACKGROUND

Preoperative stress influences perioperative complications. Their severity is influenced by advanced information and previous experience. This study evaluates the emotional effects of these factors.

METHODS

In a prospective observational study we documented existing anaesthesiological pre-information and previous experience of 461 patients (255 w/206 m) individually. In addition, we recorded the affective emotional condition of each patient before and after the premedication visit via a visual analogue scale (VAS) and a test of current stress (KAB).

RESULTS

248 patients had previous anaesthesiological pre-information. Of those 61 were of a negative nature. These patients showed a significantly higher level of stress and anxiety compared to those with positive information. 41 of 388 patients reported bad experiences with increased anxiety and stress. The premedication visits caused a significant attenuation of the overall stress level in patients with negative experience/information.

CONCLUSION

During the individual premedication visit, patients should be asked directly about negative pre-information and perioperative experience. Thus the conversation can be customised to the individual stress factors and show empathy as well. Independent of any medical intervention, this approach can be an effective contribution to stress reduction.

[Epidural anesthesia in obstetrics: an accidentally placed intrathecal catheter--remove it or use it?]

Epidural anesthesia is an established method in obstetrics. Despite constant practical experiences and established techniques, accidental penetrations of the dura and therefore malpositioning of the catheter in the intrathecal space are still present. This can result in post spinal headaches, a higher dispersion of the local anesthetic followed by life-threatening respiratory insufficiency and loss of overall conscious delivery. In consideration of these risks removal of the misplaced catheter and proper reinsertion in a higher position is standard. Thus significant emotional stress and re-exposure to the risks of the procedure for the parturient is accepted. We report of a 30-year-old primipara with secondary realized intrathecal placement. In due consideration of the current state of labor, we decided to leave the catheter in place and initiate a pain therapy applying bupivacain via this catheter immediately after the motor block had ceased. Within the first stage of labor sufficient pain relief was established. There was no change in tonicity. It resulted in a normal unproblematic vaginal birth. After an initial irritation due to the high dispersion the patient described a noticeable alleviation of pain during the adequate controlled labor.

Comparison between intubation and the laryngeal mask airway in moderately obese adults

BACKGROUND

Obesity is a well-established risk factor for perioperative pulmonary complications. Anaesthetic drugs and the effect of obesity on respiratory mechanics are responsible for these pathophysiological changes, but tracheal intubation with muscle relaxation may also contribute. This study evaluates the influence of airway management, i.e. intubation vs. laryngeal mask airway (LMA), on postoperative lung volumes and arterial oxygen saturation in the early postoperative period.

METHODS

We prospectively studied 134 moderately obese patients (BMI 30) undergoing minor peripheral surgery. They were randomly assigned to orotracheal intubation or LMA during general anaesthesia with mechanical ventilation. Premedication, general anaesthesia and respiratory settings were standardized. While breathing air, we measured arterial oxygen saturation by pulse oximetry. Inspiratory and expiratory lung function was measured preoperatively (baseline) and at 10 min, 0.5, 2 and 24 h after extubation, with the patient supine, in a 30 degrees head-up position. The two groups were compared using repeated-measure analysis of variance (ANOVA) and t-test analysis. Statistical significance was considered to be P<0.05.

RESULTS

Postoperative pulmonary mechanical function was significantly reduced in both groups compared with preoperative values. However, within the first 24 h, lung function tests and oxygen saturation were significantly better in the LMA group (P<0.001; ANOVA).

CONCLUSIONS

In moderately obese patients undergoing minor surgery, use of the LMA may be preferable to orotracheal intubation with respect to postoperative saturation and lung function.

Zygocactus virus X-based expression vectors and formation of rod-shaped virus-like particles in plants by the expressed coat proteins of Beet necrotic yellow vein virus and Soil-borne cereal mosaic virus

Expression vectors were constructed from 35S promoter-containing full-length cDNA clones of Zygocactus virus X (ZVX). The expression of foreign genes was driven by the ZVX coat protein (cp) subgenomic promoter. It was successful only when the variable region downstream of the conserved putative promoter region GSTTAAGTT(X(12-13))GAA was retained. Most of the ZVX cp gene, except for a short 3' part, was replaced by the corresponding sequence of the related Schlumbergera virus X (SVX) and its cp subgenomic promoter to enable encapsidation of the transcribed RNA by an SVX/ZVX hybrid cp. Vector-expressed cp of Beet necrotic yellow vein virus (BNYVV) assembled in Chenopodium quinoa, Tetragonia expansa and Beta vulgaris leaves into particles resembling true BNYVV particles. The virus produced from these constructs retained its ability to express BNYVV cp in local infections during successive passages on C. quinoa. This ability was lost, however, in the rarely occurring systemic infections.

Molecular characterisation of potexviruses isolated from three different genera in the family Cactaceae

The genome properties of three potexviruses which previously had been isolated from different genera in the family Cactaceae and had been found to be only distantly related serologically have been studied. The sequence of the 3040 3' terminal nucleotides of the genomic RNA of isolate K11 from Schlumbergera bridgesii and the complete RNA sequences of isolates B1 and CC10 from Zygocactus sp. and Opuntia sp., respectively, were determined. Starting sequences were obtained by means of immunocapture reverse transcription PCR using primers derived from highly conserved sequences in other potexviral RNAs. The known parts of the sequences were extended by means of random-primed cDNAs and specific primers derived from the known parts of the sequences. The genome structure of the three viruses resembles that of other potexviruses. The conserved motifs typical for replication-associated proteins, triple gene block (TGB) proteins and coat proteins of potexviruses were readily identified in the translation products of the five open reading frames. The 3' untranslated regions of the three RNAs are folded into secondary structures containing three characteristic hairpins. Rather low percentages of amino acid sequence identities ranging from 62% to 76% for the coat proteins and 41% to 49% for TGB proteins 3 suggest that these viruses should be regarded as distinct virus species for which the names Zygocactus virus X, Schlumbergera virus X and Opuntia virus X are proposed. It is also suggested that the name Cactus virus X which originally was coined for all three virus isolates should no longer be used.