Perioperative Pulmonary Atelectasis: Part II. Clinical Implications.

The development of pulmonary atelectasis is common in the surgical patient. Pulmonary atelectasis can cause various degrees of gas exchange and respiratory mechanics impairment during and after surgery. In its most serious presentations, lung collapse could contribute to postoperative respiratory insufficiency, pneumonia, and worse overall clinical outcomes. A specific risk assessment is critical to allow clinicians to optimally choose the anesthetic technique, prepare appropriate monitoring, adapt the perioperative plan, and ensure the patient's safety. Bedside diagnosis and management have benefited from recent imaging advancements such as lung ultrasound and electrical impedance tomography, and monitoring such as esophageal manometry. Therapeutic management includes a broad range of interventions aimed at promoting lung recruitment. During general anesthesia, these strategies have consistently demonstrated their effectiveness in improving intraoperative oxygenation and respiratory compliance. Yet these same intraoperative strategies may fail to affect additional postoperative pulmonary outcomes. Specific attention to the postoperative period may be key for such outcome impact of lung expansion. Interventions such as noninvasive positive pressure ventilatory support may be beneficial in specific patients at high risk for pulmonary atelectasis (e.g., obese) or those with clinical presentations consistent with lung collapse (e.g., postoperative hypoxemia after abdominal and cardiothoracic surgeries). Preoperative interventions may open new opportunities to minimize perioperative lung collapse and prevent pulmonary complications. Knowledge of pathophysiologic mechanisms of atelectasis and their consequences in the healthy and diseased lung should provide the basis for current practice and help to stratify and match the intensity of selected interventions to clinical conditions.

Predicting the need for retreatment in venous sinus stenting for idiopathic intracranial hypertension.

BACKGROUND: Idiopathic intracranial hypertension is a disease of raised intra-cranial pressure of unknown etiology. Lateral cerebral venous sinus stenosis (VSS) has been increasingly reported in these patients, and stenting has emerged as an alternative treatment for medically refractory symptoms. Treatment efficacy on meta-analysis appears promising, but identifying which patients are likely to benefit most, and which are likely to require repeat procedures, is currently unclear. METHODS: We retrospectively reviewed a prospectively collected database of 79 patients treated with venous sinus stenting at a single academic center with minimum follow-up of 18 months. We extracted baseline clinical data, as well as manometry at lumbar puncture and during angiography, and used logistic regression to identify parameters that could predict stent failure. RESULTS: Retreatment rate after successful VSS was 13.9%. Lumbar puncture opening pressure (OP) was shown to significantly predict treatment failure (ß=0.06; OR=1.064 (1.003-1.135); P=0.039). This effect remained significant when age, sex and body mass index were added to the model (ß=0.06; OR=1.066 (1.002-1.140); P=0.043). OP was correlated with venous sinus manometry readings in the superior sagittal and transverse sinus pre-stent placement, as well trans-stenotic gradient (P<0.001). CONCLUSIONS: Higher lumbar puncture OP was associated with an increased risk of stent failure in transverse sinus stenting for idiopathic intracranial hypertension, although the performance of this model as a linear discriminator was poor. Further studies are required to better assess which patients are at greatest risk of treatment failure.

Advances in Management of Esophageal Motility Disorders.

The widespread adoption of high-resolution manometry (HRM) has led to a restructuring in the classification of esophageal motility disorder classification summarized in the Chicago Classification, currently in version 3.0. It has become apparent that the cardinal feature of achalasia, impaired lower esophageal sphincter relaxation, can occur in several disease phenotypes: without peristalsis, with premature (spastic) distal esophageal contractions, with panesophageal pressurization, or even with preserved peristalsis. Furthermore, despite these advances in diagnostics, no single manometric pattern is perfectly sensitive or specific for idiopathic achalasia and complimentary assessments with provocative maneuvers during HRM or interrogating the esophagogastric junction with the functional luminal imaging probe during endoscopy can be useful in clarifying equivocal or inexplicable HRM findings. Using these tools, we have come to conceptualize esophageal motility disorders as characterized by obstructive physiology at the esophagogastric junction, smooth muscle esophagus, or both. Recognizing obstructive physiology as a primary target of therapy has become particularly relevant with the development of a minimally invasive technique for performing a calibrated myotomy of the esophageal circular muscle, the POEM procedure. Now and going forward, optimal management is to render treatment in a phenotype-specific manner: e.g. POEM calibrated to patient-specific physiology for spastic achalasia and spastic disorders of the smooth muscle esophagus, more conservative strategies (pneumatic dilation) for the disorders limited to the sphincter.

[Trends in computed tomography characteristics, intracranial pressure monitoring and surgical management in severe traumatic brain injury: Analysis of a data base of the past 25 years in a neurosurgery department]. / Evolución temporal en las características de la tomografía computarizada, presión intracraneal y tratamiento quirúrgico en el traumatismo craneal grave: análisis de la base de datos de los últimos 25 años en un servicio de neurocirugía.

OBJECTIVE: To describe the radiological characteristics, surgical indications, procedures, and intracranial pressure monitoring of a representative cohort of severe traumatic brain injury (sTBI) cases collected over the past 25years, and to analyse the changes that have occurred by dividing the period into 3 equal time periods. METHODS: An observational cohort study was conducted on consecutive adult patients (>14years of age) with severe closed TBI (Glasgow Coma Scale score [GCS]≤8) who were admitted during the first 48hours after injury to the Hospital 12 de Octubre from 1987 to 2012. The most relevant radiological findings, surgical procedures, and intracranial monitoring indications reported in the literature were defined and compared in 3 equal time periods (1987-1995, 1996-2004, and 2005-2014). RESULTS: A significant increase was observed in subdural haematomas with lesions over 25cc, and midline shift in the last period of time. The incidence of subarachnoid haemorrhage increased significantly with time. There was a progression to a worse computed tomography (CT) classification from the initial CT scan in 33% of cases. Surgery was performed on 721 (39.4%) patients. Early surgery (<12hours) was performed on 585 (81.1%) patients, with the most frequent being for extra-cerebral mass lesions (subdural and epidural haematomas), whereas delayed surgery (>12hours) was most frequently performed due to an intracerebral haematoma. Surgical treatment, both early and late was significantly lower with respect to the first time period. Decompressive craniectomy with evacuation of the mass lesion was the preferred procedure in the last time period. Intracranial pressure monitoring (ICP) was carried out on 1049 (57.3%) patients, with a significantly higher frequency in the second period of time. There was adherence to Guidelines in 64.4% of cases. Elevated/uncontrolled ICP was more significant in the first time period. CONCLUSIONS: As a result of the epidemiological changes seen in traumatic brain injury, a different pattern of morphological injury is described, as depicted in the CT, leading to a difference in practice during this period of observation.

Comparison of venous sinus manometry gradients obtained while awake and under general anesthesia before venous sinus stenting.

INTRODUCTION: Venous sinus stenting is a popular treatment strategy for patients with high venous sinus pressure gradients across a site of outflow obstruction. Little is known about the effect of anesthesia on venous sinus pressure measurements. OBJECTIVE: To compare venous manometry performed in patients under general anesthesia and while awake. METHODS: A prospective database was accessed to retrospectively identify patients who had undergone venous sinus stenting. Pressure gradients were compared between those patients who underwent manometry while awake and before stenting under general anesthesia. RESULTS: Thirty patients with both general anesthesia and awake pressure recordings were identified. Pressure measurements were highly variable but overall were higher under general anesthesia by an average of 5.8 mm Hg (1.7; p=0.002). A significant difference between awake and general anesthesia pressure measurements was detected in the sigmoid sinus (5.8 mm Hg (2.0); p=0.005) and the jugular vein (8.1 mm Hg (3.9); p=0.040). Only 11/30 (36.7%) pressure gradients remained within 5 mm Hg of the original awake gradient when repeated under general anesthesia; 9/30 (30%) patients had gradients that were at least 10 mm Hg different across procedures. CONCLUSIONS: Calculated pressure gradients were markedly affected by anesthesia. These findings suggest that candidacy for stenting should be determined with venous manometry while patients are awake owing to the unpredictable and highly variable effect of general anesthesia on pressure measurements and an apparent tendency to underestimate the degree of venous outflow obstruction.

Esophageal dysfunction in different stages of Parkinson's disease.

BACKGROUND: Dysphagia is a clinically relevant symptom in patients with Parkinson's disease (PD) leading to pronounced reduction in quality of life and other severe complications. Parkinson's disease-related dysphagia may affect the oral and pharyngeal, as well as the esophageal phase of swallowing. METHODS: To examine the nature and extend of esophageal dysphagia in different stages of PD and their relation to oropharyngeal dysfunction, we examined 65 PD patients (mean age 66.3±9.7 years, mean disease duration 7.9±5.8 years, mean Hoehn & Yahr [H&Y] stage 2.89±0.91) and divided into three groups (early [H&Y I+II; n=21], intermediate [H&Y III; n=25], and advanced stadium [H&Y IV+V; n=19]), using esophageal high-resolution manometry (HRM) to detect esophageal motor disorders. Oropharyngeal impairment was assessed using fiberoptic endoscopic evaluation of swallowing. KEY RESULTS: Major esophageal motor disorders were detected in nearly one third of the PD patients. Minor impairment of the esophageal body was present in 95% of participants and throughout all disease stages with pathological findings especially in peristalsis and intrabolus pressure (IBP). The IBP was found to significantly increase in the advanced stadium. Although dysfunction of the upper and lower esophageal sphincters was observed in individual patients, alterations in these esophageal segments revealed no statistical significance compared with normative data. No clear association was found between the occurrence of oropharyngeal dysphagia and esophageal impairment. CONCLUSIONS & INFERENCES: Esophageal body impairment in PD is a frequent phenomenon during all disease stages, which possibly reflects α-synucleinopathy in the enteric nervous system.

Novel insights into esophageal diagnostic procedures.

The 21st century offers new advances in diagnostic procedures and protocols in the management of esophageal diseases. This review highlights the most recent advances in esophageal diagnostic technologies, including clinical applications of novel endoscopic devices, such as ultrathin endoscopy and confocal laser endomicroscopy for diagnosis and management of Barrett's esophagus; novel parameters and protocols in high-resolution esophageal manometry for the identification and better classification of motility abnormalities; innovative connections between esophageal motility disorder diagnosis and detection of gastroesophageal reflux disease (GERD); impedance-pH testing for detecting the various GERD phenotypes; performance of distensibility testing for better pathophysiological knowledge of the esophagus and other gastrointestinal abnormalities; and a modern view of positron emission tomography scanning in metastatic disease detection in the era of accountability as a model for examining other new technologies. We now have better tools than ever for the detection of esophageal diseases and disorders, and emerging data are helping to define how well these tools change management and provide value to clinicians. This review features novel insights from multidisciplinary perspectives, including both surgical and medical perspectives, into these new tools, and it offers guidance on the use of novel technologies in clinical practice and future directions for research.

High-resolution colonic motility recordings in vivo compared with ex vivo recordings after colectomy, in patients with slow transit constipation.

BACKGROUND: The pathogenesis of slow transit constipation (STC) remains poorly understood, with intrinsic and extrinsic abnormalities implicated. Here, we present high-resolution colonic manometry recordings from four STC patients recorded before total colectomy, and subsequently, ex vivo, after excision. METHODS: In four female, treatment-resistant STC patients (median age 35.5 years), a fiber-optic manometry catheter (72 sensors spaced at 1 cm intervals) was placed with the aid of a colonoscope, to the mid-transverse colon. Colonic manometry was recorded 2 h before and after a meal. After the colectomy, ex vivo colonic manometry was recorded in an organ bath. Ex vivo recordings were also made from colons from 4 patients (2 male; median age 67.5 years) undergoing anterior resection for nonobstructive carcinoma ('control' tissue). KEY RESULTS: A large increase in 'short single propagating contractions' was recorded in STC colon ex vivo compared to in vivo (ex vivo 61.3 ± 32.7 vs in vivo 2.5 ± 5/h). In STC patients, in vivo, the dominant frequency of contractile activity was 2-3 cycle per minute (cpm), whereas 1-cpm short-single propagating contractions dominated ex vivo. This same 1-cpm frequency was also dominant in control colons ex vivo. CONCLUSIONS & INFERENCES: In comparison to control adults, the colon of STC patients demonstrates significantly less propagating motor activity. However, once the STC colon is excised from the body it demonstrates a regular and similar frequency of propagating activity to control tissue. This paper provides interesting insights into the control of colonic motor patterns.

Esophagogastric junction contractile integral (EGJ-CI) quantifies changes in EGJ barrier function with surgical intervention.

BACKGROUND: Esophagogastric junction contractile integral (EGJ-CI) assesses EGJ barrier function on esophageal high resolution manometry (HRM). We assessed EGJ-CI values in achalasia and gastroesophageal reflux disease (GERD) to determine if postoperative EGJ-CI changes reflected surgical intervention. METHODS: Twenty-one achalasia patients (42.8 ± 3.2 years, 62% F) with HRM before and after Heller myotomy (HM) and 68 GERD patients (53.9 ± 1.8 years, 66% F) undergoing antireflux surgery (ARS) were compared to 21 healthy controls (27.6 ± 0.6 years, 52% F). Esophagogastric junction contractile integral (mmHg.cm) was calculated using the distal contractile integral measurement across the EGJ, measured above the gastric baseline and corrected for respiration. Pre and postsurgical EGJ-CI and conventional lower esophageal sphincter pressure (LESP) metrics were compared within and between these groups using non-parametric tests. Correlation between EGJ-CI and conventional LESP metrics was assessed. KEY RESULTS: Baseline EGJ-CI was higher in achalasia compared to GERD (p < 0.001) or controls (p = 0.03). Esophagogastric junction contractile integral declined by 59.2% after HM in achalasia (p = 0.001), and increased by 26.3% after ARS in GERD (p = 0.005). End-expiratory and basal LESP decreased by 74.5% and 64.5% with HM, but increased by only 17.8% and 4.3% with ARS. Differences were noted between Dor vs Toupet fundoplication in achalasia (p = 0.007), and partial vs complete ARS in GERD (p = 0.03). Esophagogastric junction contractile integral correlated modestly with both end-expiratory and basal LESP (Pearson's r of 0.8 for all), but was less robust in GERD (0.7). CONCLUSIONS & INFERENCES: Esophagogastric junction contractile integral has clinical utility in assessing EGJ barrier function at baseline and after surgical intervention to the EGJ, and could complement conventional EGJ metrics.

[Standards and innovations in the diagnosis of gastroesophageal reflux disease]. / Standards und Innovationen in der Diagnostik der gastroösophagealen Refluxkrankheit.

Gastroesophageal reflux disease (GERD) is one of the most common gastrointestinal diseases in the world. This article gives an overview about diagnostic procedures for GERD. Standard procedures such as pH-metry, Bilitec and manometry and also new diagnostic tools such as combined multichannel intraluminal impedance (MII) and pH-metry and Bravo Capsule are described in detail. Established endoscopy criteria as well as innovative techniques such as magnification, narrow band imaging and computed virtual chromoendoscopy are also presented. Not all of these procedures need to be used in every patient. Therefore, it is important to know the technical aspects, indications, advantages and disadvantages of each method in order to appropriately use any of these tests. The final goal is to characterise GERD and provide the patient with an appropriate therapy.

The changing use of esophageal manometry in clinical practice.

OBJECTIVE: Clinical practice guidelines now advise against the use of esophageal manometry in the early evaluation of unexplained chest pain. We examined data from patients referred for manometric evaluation over a 10-yr period (1987-1996) to see if clinicians were changing practice patterns and whether manometric diagnoses were affected by the changes. METHODS: Principal indications for the procedure and manometric findings were extracted from a review of 1162 subjects referred to a single clinical laboratory. The tracings were analyzed using a standardized classification method and categorized according to a pathophysiology-based scheme. Referral indications and manometric diagnoses were compared for the first and second 5-yr periods of study. RESULTS: Chest pain as a referral indication declined from the first to the second half of the study period (odds ratio, 0.44; p < 0.0001), whereas dysphagia and preoperative evaluations became more common (odds ratio, 1.3; p < 0.05; odds ratio, 13.7; p < 0.0001, respectively). Similarly, hypermotility disorders decreased in frequency (odds ratio, 0.63; p = 0.0001), whereas hypomotility disorders increased (odds ratio, 1.6; p < 0.01). The decrease in hypermotility disorders was solely related to a decrease in nonspecific spastic disorders, including nutcracker esophagus (odds ratio, 0.58; p < 0.0001); the proportion of diagnoses of achalasia and diffuse esophageal spasm remained stable. CONCLUSIONS: These data show that practice patterns are already following current guidelines. They also reflect the disillusionment of clinicians with the poor specificity of manometry in chest pain management, the increasing popularity of antireflux surgery, yet the ongoing observation that nonspecific spastic disorders are closely associated with unexplained chest pain and may have a still-undefined pathogenetic role.

Current advances in rhinomanometry.

Current advances in rhinomanometry were reviewed in this paper. Active posterior rhinomanometry with a "head-out" body plethysmography may be the least invasive method currently available for measuring nasal patency. In general, active anterior rhinomanometry with a face mask or a nasal nozzle has been employed in various studies throughout the world. Nasal resistance as calculated from the equation R = 0.78 (delta P/V)1.33 at any points on a pressure/flow curve, or averaged nasal resistance may be the most suitable expression for nasal patency. Values for nasal resistance at delta P 100 Pa in Japanese patients or delta P 150 Pa in Caucasians have been widely employed as standard objective data for nasal obstruction, although rhinomanometric results sometimes do not agree with subjective evaluation of nasal obstruction. Nasal airflow acceleration or peak flow index during nasal breathing at rest can be applied as warranted to confirm an objective diagnosis of symptomatic nasal obstruction. Further, nationality and anthropological characteristics can be related to the severity and type of stuffiness.

Manometría directa del esfínter de Oddi: un modelo experimental / Direct manometry of the Oddi's sphincter: experimental model

la evaluación intraoperatoria de las vías biliares es uno de los aspectos que más preocupa al cirujano cuando realiza procedimientos sobre esa área. En el presente trabajo se propone y prueba un modelo experimental de medición directa de la presión del esfínter de Oddi utilizando un catéter con balón inflable, conectado a un transductor. Se utilizaron un total de 5 perros, a los cuales se les realizó cilecistectomía y manometría directa con balón inflable, obteniendo resultados similares a los obtenidos por otros autores con métodos más laboriosos