Airways and respiratory function in obese patients. Anaesthetic and intensive care aspects and recommendations

In obese patients, perioperative pulmonary complications have an increased frequency and are associated with higher morbidity and mortality compared with non-obese patients. The management of surgical procedures in these patients is a challenge for the anaesthetist. Knowledge of pathophysiological and pharmacological aspects of the obese patients' condition is essential for their care during preoperative assessment, intra-operative management and, if necessary, postoperative intensive care. Special information on airway and lung protection as well as cases involving laparoscopic surgery, obstetric and paediatric anaesthesia in obese patients are also discussed.     

Priming effects in the fusiform gyrus: changes in neural activity beyond the second presentation

Repetition priming typically leads to a decrease in the activation of sensory cortical areas upon a second exposure to the same visual stimulus. This effect is thought to reflect more efficient or fluent re-processing of previously seen stimuli so that less neural activity is required. Fluent re-processing has been hypothesized to be a potential link from repetition priming to neural changes associated with visual expertise. To examine this potential connection, the neural correlates of priming were examined across eight stimulus repetitions using functional magnetic resonance imaging. Sizeable regions of bilateral ventral occipito-temporal cortex (including the fusiform gyrus) exhibited reduced responses to the second presentation of a stimulus. Most of these areas displayed no further reduction in response to subsequent repetitions of the same stimuli. Because expertise accrues over many exposures, these areas, while clearly involved in priming, do not exhibit an activity pattern consistent with the development of expertise. In contrast, an area in the right posterior fusiform gyrus exhibited reductions in evoked response that grew in magnitude for stimulus repetitions from the second to the eighth presentations. This region exhibits a pattern of activity consistent with a gradual and cumulative enhancement of the fluency effect across trials, suggesting that it may mediate the link between priming and the development of visual expertise.     

Eosinophilic differentiation of the human promyelocytic leukemia cell line, HL-60

HL-60 promyelocytic leukemia cells differentiated to eosinophils and eosinophilic precursors when cultured under mildly alkaline conditions (pH 7.6-7.8) for 7 d without refeeding. New cytoplasmic granules appeared blue in the least mature cells and red in the most mature cells when stained with Wright-Giemsa. The granules also stained with Luxol-fast-blue, a characteristic of eosinophil granules. Furthermore, most cells contained the eosinophil major basic protein (MBP); the Charcot-Leyden Crystal (CLC) protein (lysophospholipase), eosinophil peroxidase, acid phosphatase, and arylsulfatase were also detected in a portion of these cells. The eosinophil major basic protein was found in a high proportion of undifferentiated cells, and thus may be constituitively produced. By examining finely banded chromosomes, translocation break points were demonstrated at q22 on one chromosome 16 and at q23 on the other homologue; abnormalities in this region of the long arm of 16 are a characteristic finding in the recently described syndrome of acute myelomonocytic leukemia (AMMoL) with abnormal bone marrow eosinophils. In common with the bone marrow eosinophils in these patients, the HL-60 eosinophil granules contained chloroacetate esterase and periodic-acid Schiff (PAS) reactive material; crystalloid inclusions were rare. Therefore, the HL-60 cell line appears to be an in vitro model for eosinophilopoiesis and may be specially suited for the study of the abnormal eosinophils seen in certain malignant conditions.     

Agreement of a new whole-blood PT/INR test using capillary samples with plasma INR determinations

PURPOSE: The objective of the study was to compare in anticoagulated patients the international normalized ratio (INR) measured with a new capillary whole-blood device, the i-STAT Portable Clinical Analyser, with conventional plasma INR obtained from the central laboratory. PATIENTS AND METHODS: Between-cartridge variability was first determined with two lyophilized controls with INR levels of 1.60 and 2.75 (n=10). Next, in 35 patients under different intensities of oral anticoagulation, capillary blood INR was measured with two i-STAT devices and was compared to central laboratory plasma INR (Innovin reagent and BCS analyser). RESULTS: Between-cartridge coefficients of variation were 5% (95%, CI 3.4-9.1) and 3% (95%, CI 2.1-5.5) at INR levels of 1.60 and 2.75. Mean INR difference between the two i-STAT devices was 0.1, and the correlation coefficient was 0.98. Between i-STAT and central laboratory INR, the correlation coefficient was 0.95. Bias values were 0.04, 0.2, and -0.04 at INR levels of 2.0, 2.5, and 3.5, respectively. CONCLUSION: The INR measured with the i-STAT Portable Clinical Analyser is precise and compares well with plasma INR performed in a central laboratory.     

The effect of epidural analgesia in labour on maternal respiratory function

Lumbar epidural analgesia during labour has gained widespread acceptance. The impact of epidural analgesia based on mixtures of low-dose local anaesthetic solutions and lipophilic opioids on most clinically relevant obstetric outcomes is minimal. Since the pregnant state per se is associated with important alterations in respiration, we assessed whether a subtle degree of motor blockade brought about by epidural analgesia might compromise respiratory function as assessed by spirometry. Sixty consenting parturients receiving epidural analgesia were consecutively included in this prospective study. We performed spirometry during the antepartum visit and in labour after effective epidural analgesia was established; at both assessments the women were pain-free. Values were within normal ranges but increased significantly after effective epidural analgesia; median (IQR [range]) increase for vital capacity 7.4 (3.0-13 [-12-27])% (p < 0.001); forced vital capacity 4.4 (1.7-9.8 [-13-26])% (p < 0.001); forced expiratory volume in 1 s 5.5 (1.7-8.6 [-14-28])% (p < 0.001); and peak expiratory flow rate 2.3 (-1.6-5.8 [-18-16])% (p = 0.01)). We conclude that epidural analgesia for labour significantly improved respiratory function.     

The effect of common origin of the carotid arteries in neurologic outcome after neonatal ECMO

Background

Common origin of the carotid arteries (COCA) is a normal anatomic variant reported to occur in approximately 11% of the general population. The objective of this study was to determine whether this variant places venoarterial extracorporeal membrane oxygenation (ECMO) patients at a higher risk for adverse neurologic sequelae owing to potential occlusion of both carotid arteries by the arterial cannula.

Methods

The authors reviewed clinical records and echocardiograms of the initial 220 ECMO patients at their institution. Aortic arch morphology was determined by a pediatric cardiologist blinded to all other data. After exclusion of predetermined patients, 131 patients were divided into 2 groups: those with separate origin of the carotid arteries (n = 111) and those with COCA (n = 20). The neurologic outcome variables studied included the results of magnetic resonance imaging (MRI); computed tomography (CT); electroencephalogram (EEG); brainstem auditory-evoked response (BAER), head ultrasound scan, and Bayley Scales of Infant Development reported as Psychomotor Developmental Index (PDI) and Mental Developmental Index (MDI).

Results

COCA had no predictive value in determining PDI and MDI outcomes and no significance in predicting an increased risk of adverse neurologic sequelae based on MRI, CT, EEG, BAER, or head ultrasound scan.

Conclusions

This study confirms that COCA is a common aortic arch variant (15%, n = 20 of 131) and that this variant does not appear to increase the risk of neurologic injury in infants undergoing venoarterial ECMO.     

Kataraktoperation bei einem Patienten mit schwerem obstruktivem Schlafapnoesyndrom

Der vorliegende Bericht beschreibt das Atemwegsmanagement in Allgemeinanästhesie während einer Kataraktoperation (ophthalmologische Operation mit vergleichsweise niedrigen chirurgischen Stimuli) bei einem Patienten mit bekanntem schwerem obstruktiven Schlafapnoesyndrom. Aufgrund der psychischen Vorbelastung des Patienten konnte der Eingriff nicht in reiner Lokalanästhesie durchgeführt werden. In Anbetracht des Schweregrades des Schlafapnoesyndroms wollte man in der Anästhesieführung die Funktion der oberen Atemwege möglichst wenig einschränken. Man entschloss sich, das nasale CPAP- ("Continuous Positive Airway Pressure"-)Gerät, das dem Patienten für die nächtliche CPAP-Therapie bestens bekannt war, während der Anästhesieführung einzusetzen. Der Patient wurde mit kontinuierlichen Gaben von Propofol und Remifentanil unter Erhaltung der Spontanatmung anästhesiert. Am Ende der Operation wurde der Patient unter weiterführender nasaler CPAP-Applikation im Aufwachraum überwacht und anschließend problemlos auf die Abteilung verlegt. Die Bedeutung des perioperativen Fortführens der kontinuierlichen Überdruckbeatmung bei Patienten mit obstruktivem Schlafapnoesyndrom wird diskutiert.     

Improved survival for adenocarcinoma of the ampulla of Vater: fifty-five consecutive resections

HYPOTHESIS: After resection of an adenocarcinoma of the ampulla of Vater, certain clinical and pathologic characteristics influence long-term survival. DESIGN: Retrospective case series. SETTING: Major academic medical and pancreatic surgical center. PATIENTS: Fifty-five consecutive patients who underwent Whipple resection for ampullary adenocarcinoma from 1988 through 2001. INTERVENTIONS: Pylorus-preserving Whipple resection in 32 patients and standard Whipple resection in 23 patients. MAIN OUTCOME MEASURES: Postoperative survival. A multivariate Cox proportional hazards model was used to determine the effects of various factors on long-term survival after resection. RESULTS: There were no operative deaths, and all patients left the hospital. After a mean follow-up of 46.9 months, the overall 5-year Kaplan-Meier survival estimate was 67.7%. The median survival of the entire group has not yet been reached. Five-year postoperative survival estimates for node-negative (n = 32) and node-positive patients (n = 23) were 76.5% and 53.4%, respectively (P =.26). Patients whose tumors demonstrated perineural invasion (n = 12) had a 5-year survival estimate of 29.2% vs 78.8% for those whose did not (P<.001). On multivariate analysis, the absence of perineural invasion (P<.001) was an independent predictor of significantly improved postoperative survival. CONCLUSIONS: Compared with previous reports from our own and other centers, this series demonstrates improved postoperative survival by 10% to 20% in patients undergoing Whipple resection for adenocarcinoma of the ampulla of Vater. The reasons for this improved outcome are unclear, and the effect of adjuvant treatment cannot be determined from this analysis. The major factor associated with prolonged survival was the absence of perineural invasion in the resected tumor specimen.