The correlation between esophageal and abdominal pressures in mechanically ventilated patients undergoing laparoscopic surgery.

BACKGROUND: Intrathoracic pressure in patients undergoing laparoscopic surgery may be affected by intra-abdominal pressure during surgery. We investigated the relationship between intra-abdominal pressure (Pabd) and esophageal pressure (Pes) in mechanically ventilated patients undergoing laparoscopic surgery. METHODS: We prospectively studied 43 consenting patients over 18 y of age who were scheduled for elective laparoscopic surgery with plans for intra-operative intubation and paralysis. After establishing a good level of inter-observer agreement on Pes measurements, Pes was measured by one observer for each patient using an esophageal catheter. Pabd and Pes were recorded before and after abdominal insufflation. We used regression analysis to model the relationship between Pabd and Pes. RESULTS: Patients' ages varied from 22 to 78 y, with a mean of 53.2 ± 14.6 y. Body mass index (BMI) varied from 13.7 to 60.5 kg/m2, with a mean of 33.7 ± 10.5. PEEP was 5-7 cm H2O for 19 patients and 0 cm H2O for the remainder. Most patients underwent gastric bypass surgery (n = 11); others underwent hernia repair (n = 9), colon resection (n = 7), cholecystectomy (n = 6), and various other surgeries (n = 10). Using univariate analyses, baseline Pabd was significantly correlated with baseline Pes (estimate of model coefficient [95% CI]: 0.79 [0.36-1.21], R2 = 0.24, P = .001), as was BMI (0.29 [0.19-0.40], R(2) = 0.41, P < .001). However, a multivariable analysis showed no significant correlation with baseline Pabd (0.10 [-0.46 to 0.65], P = .73), whereas BMI remained highly significant (0.27 [0.11-00.43], P = .001) with R2 = 0.40. Due to unexpected uniformity of abdominal inflation pressures (generally 20.4 cm H2O) during surgery, data were not amenable to assessment of correlation between changes in abdominal and esophageal pressures after inflation. CONCLUSION: There was a limited correlation between baseline Pes and Pabd in patients undergoing elective laparoscopic surgery, suggesting a limited value of Pabd measurements in the management of mechanically ventilated patients.

Copd.

INTRODUCTION: Chronic obstructive pulmonary disease (COPD) is a disease state characterised by airflow limitation that is not fully reversible. The airflow limitation is usually progressive and associated with an abnormal inflammatory response of the lungs to noxious particles or gases. Classically, it is thought to be a combination of emphysema and chronic bronchitis, although only one of these may be present in some people with COPD. The main risk factor for the development and deterioration of COPD is smoking. METHODS AND OUTCOMES: We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of maintenance drug treatment in stable COPD? What are the effects of smoking cessation interventions in people with stable COPD? What are the effects of non-drug interventions in people with stable COPD? We searched: Medline, Embase, The Cochrane Library, and other important databases up to April 2010 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA). RESULTS: We found 119 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions. CONCLUSIONS: In this systematic review, we present information relating to the effectiveness and safety of the following interventions: alpha(1) antitrypsin, antibiotics (prophylactic), anticholinergics (inhaled), beta(2) agonists (inhaled), corticosteroids (oral and inhaled), general physical activity enhancement, inspiratory muscle training, nutritional supplementation, mucolytics, oxygen treatment (long-term domiciliary treatment), peripheral muscle strength training, psychosocial and pharmacological interventions for smoking cessation, pulmonary rehabilitation, and theophylline.

Does early intervention with inhaled corticosteroids alter the natural history of mild persistent asthma?

In most patients, both adults and children, who have a new diagnosis of asthma and whose symptoms are mild but persistent, treatment with inhaled corticosteroids (ICS) should be recommended as soon as the diagnosis is made. This is a cost-effective and safe treatment. Patients should be cautioned that their asthma will not be cured with short-term treatment and that their symptoms may recur and their lung function may decline again if treatment is discontinued. If patients are reluctant to use ICS daily for long periods of time, it would be reasonable to delay the onset of treatment with ICS. They could subsequently be managed with intermittent therapy with either ICS or in combination with other medications, such as long-acting beta-agonists. Initial therapy with leukotriene receptor antagonist is not likely to be as effective as initial therapy with ICS. Since treatment adjustments based on eosinophil counts in sputum can reliably predict short-term responses to corticosteroids and help identify the appropriate add-on therapy, it may be useful to use this measurement, when available, to guide intermittent therapy.