The effect of postoperative fasting on vomiting in children and their assessment of pain

Background:  Mandatory postoperative food intake has been shown to increase nausea and vomiting, and so postoperative fasting has become common practice even if patients request food or drink.
Objective:  We sought to investigate whether postoperative fasting reduces the incidence of postoperative vomiting in children when compared with a liberal regimen in which they are allowed to eat and drink upon request.
Methods:  One hundred forty-seven children scheduled for outpatient surgery were randomized to one of two groups. After anesthesia, patients in the 'fasting' group were expected to fast for 6 h. The children in the 'liberal' group were allowed to eat and drink according to their own needs. The incidence of vomiting and the children's well-being were recorded at several time points over a 24-hour period. Parents were also asked to rate, on a scale of 0–6, how much their children were bothered by fasting, pain, and nausea/vomiting.
Results:  Age (4.8 ± 2.6 years), weight (20 ± 9 kg) and gender (73% boys) were comparable between the groups. The incidence of vomiting was 15% in the liberal and 22% in the fasting group ( P  = 0.39) and, between 1 and 12 h after extubation, children in the liberal group were significantly happier ( P  < 0.001). Children in the liberal group were significantly less bothered by their pain than those in the fasting group ( P  < 0.001).
Conclusion:  Postoperative fasting did not reduce the incidence of vomiting after general anesthesia in children when compared with a liberal regimen. Furthermore, the ability to eat and drink at will decrease the bothersome aspects of pain and lead to happier patients.     

Laryngeal mask airways – to inflate or to deflate after insertion?

Background: Hyperinflation of the laryngeal mask airway (LMA) cuff is known to be a risk factor for airway morbidity and increased leakage around the LMA. While the manufacturers’ recommendation is to inflate the cuff with the maximum recommended volumes and/or to adjust the cuff pressure to <60 cmH₂O, cuff pressures below 40 cmH₂O have been shown to be associated with a minimal rate of sore throat and minimal leakage. However, it remains to be determined whether inflation or deflation is needed to achieve favorable pressures. Therefore, we assessed the need for cuff‐volume adjustment following insertion of the LMA unchanged straight from the sterile packaging in a prospective audit. Methods: One thousand children (0–16 years) undergoing elective surgery were consecutively included in this quality of care audit. After taking the LMA from its sterile packaging, the LMA cuff was emptied and the amount of air recorded. Then, the same amount of air was returned into the LMA, the LMA was inserted into the patient, and the cuff pressure was measured using a calibrated cuff manometer. Results: Following insertion of the LMA (without further inflation or deflation of the cuff), 20.5% of children had cuff pressures ≥60 cmH₂, while 55.7% had LMA cuff pressures <40 cmH₂O. Cuff pressures were also significantly higher in size 1 LMAs (66.6% had cuff pressures ≥60 cmH₂O and 2% <40 cmH₂O) compared with all other sizes (P < 0.05). Furthermore, cuff pressures in LMAs with a poly vinyl chloride (PVC) surface were higher compared to LMAs with a silicone surface (65.2%≥60 cmH₂O and 9.3% <40 cmH₂O vs 9%≥60 cmH₂O and 67.6% <40 cmH₂O, respectively). Conclusions: This study demonstrates that LMAs, particularly when using small‐sized LMAs or LMAs with a more rigid PVC surface, need to be deflated following insertion of the device rather than inflated to avoid cuff hyperinflation. Hence, cuff pressures should be measured routinely using a manometer to minimize potential pressure‐related airway complications.     

Iloprost

Zusammenfassung Iloprost ist ein länger wirkendes Prostazyklinanalogon mit starken vasodilatierenden Eigenschaften. Wird Iloprost per inhalationem angewandt, kommt es bereits kurze Zeit später zu einem deutlichen Abfall des pulmonalvaskulären Widerstands und damit zu einer Senkung des pulmonalarteriellen Drucks; die Wirkdauer wird dabei mit 60–120 min angegeben. Durch die selektiv pulmonale Anwendung können systemische Nebenwirkungen, wie ein systemischer Blutdruckabfall, weitestgehend vermieden werden. Die Verneblung von Iloprost kann entweder mit einem Ultraschallvernebler oder mit einem O₂-Fluss-betriebenen Vernebler durchgeführt werden. Beide Verneblertypen können problemlos in die üblichen Intensivrespiratoren integriert werden. Das Problem der Inhalation von Iloprost im Kreisteil eines Anästhesierespirators wurde durch eine spezielle Konstruktion gelöst.     

Acute thoracic aortic dissection: The basics

With an increasing incidence, aortic dissection is the most common acute illness of the aorta. In the setting of chronic hypertension, with or without other risk factors for aortic dissection, this diagnosis should be considered a diagnostic possibility in patients presenting to the emergency department with acute chest or back pain. Left untreated, about 75% of patients with dissections involving the ascending aorta die within 2 weeks of an acute episode. But with successful initial therapy, the 5-year survival rate increases to 75%. Hence, timely recognition of this disease entity coupled with urgent and appropriate management is the key to a successful outcome in a majority of the patients. This article reviews acute thoracic aortic dissection, including ED diagnosis and management.     

Relationship between Health-Related Quality of Life, Pain, and Functional Disability in Neuropathic Pain Patients with Failed Back Surgery Syndrome

Objectives:  Patients with failed back surgery syndrome (FBSS) and chronic neuropathic pain experience levels of health-related quality of life (HRQoL) that are considerably lower than those reported in other areas of chronic pain. The aim of this article was to quantify the extent to which reductions in (leg and back) pain and disability over time translate into improvements in generic HRQoL as measured by the EuroQoL-5D and SF-36 instruments.
Methods:  Using data from the multinational Prospective, Randomized, Controlled, Multicenter Study of Patients with Failed Back Surgery Syndrome trial, we explore the relationship between generic HRQoL—assessed using two instruments often used in clinical trials (i.e., the SF-36 and EuroQol-5D)—and disease-specific outcome measures (i.e., Oswestry disability index [ODI], leg and back pain visual analog scale [VAS]) in neuropathic patients with FBSS.
Results:  In our sample of 100 FBSS patients, generic HRQoL was moderately associated with ODI (correlation coefficient: −0.462 to −0.638) and mildly associated with leg pain VAS (correlation coefficient: −0.165 to −0.436). The multilevel regression analysis results indicate that functional ability (as measured by the ODI) is significantly associated with HRQoL, regardless of the generic HRQoL instrument used. On the other hand, changes over time in leg pain were significantly associated with changes in the EuroQoL-5D and physical component summary scores, but not with the mental component summary score.
Conclusions:  Reduction in leg pain and functional disability is statistically significantly associated with improvements in generic HRQoL. This is the first study to investigate the longitudinal relationship between generic and disease-specific HRQoL of neuropathic pain patients with FBSS, using multinational data.     

Hämodynamisches Monitoring in der perioperativen Phase

A regular hydration status and compensated vascular filling are targets of perioperative fluid and volume management and, in parallel, represent precautions for sufficient stroke volume and cardiac output to maintain tissue oxygenation. The physiological and pathophysiological effects of fluid and volume replacement mainly depend on the pharmacological properties of the solutions used, the magnitude of the applied volume as well as the timing of volume replacement during surgery. In the perioperative setting surgical stress induces physiological and hormonal adaptations of the body, which in conjunction with an increased permeability of the vascular endothelial layer influence fluid and volume management. The target of haemodynamic monitoring in the operation room is to collect data on haemodynamics and global oxygen transport, which enable the anaesthetist to estimate the volume status of the vascular system. Particularly in high risk patients this may improve fluid and volume therapy with respect to maintaining cardiac output. A goal-directed volume management aiming at preventing hypovolaemia may improve the outcome after surgery. The objective of this article is to review the monitoring devices that are currently used to assess haemodynamics and filling status in the perioperative setting. Methods and principles for measuring haemodynamic variables, the measured and calculated parameters as well as clinical benefits and shortcomings of each device are described. Furthermore, the results for monitoring devices from clinical studies of goal-directed fluid and volume therapy which have been published will be discussed.     

The influence of catecholamines on pseudocholinesterase enzymatic activity. Results of a laboratory investigation

Objective Acceleratory and inhibitory receptors have been described on the pseudocholinesterase (PCHE) molecule. An increased PCHE activity has been reported in patients with chronic pain and anxiety, conditions known to be correlated with increased plasma catecholamine levels. Aim of this laboratory investigation was to determine whether catecholamines have an effect on PCHE activity, as this knowledge could help to define the role of PCHE in the assessment of stress.Methods After Ethics committee approval and written informed consent, 3 ml of blood was collected from five healthy volunteers. Fourteen samples of 50 μl each were prepared from each of the volunteer’s plasma. Epinephrine (25, 50, 100, 200, 400 and 1000 pg) and norepinephrine (50, 100, 200, 400, 800 and 2000 pg) were added to samples of each subject. Sodium-chloride solution was added to control samples. PCHE activity was photometrically assessed.Results PCHE activity was significantly higher after the addition of epinephrine (median 8304 versus 7386 U/l). This effect was not dose-dependent. PCHE activity did not change after addition of norepinephine.Conclusions This mechanism might explain previous findings that showed higher levels of PCHE activity in the presence of chronic pain and anxiety. In the absence of a dose–response curve in the concentration range studied, PCHE activity does not appear to be suitable for the assessment of levels of stress.Ledowski T, Paech MJ, Clarke M, Schug SA, The influence of catecholamines on pseudocholinesterase enzymatic activity. Results of a laboratory investigation.