首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 343 毫秒
1.
BACKGROUND AND STUDY AIMS: The usefulness of topical pharyngeal anesthesia is not well established. The aim of the present study was to determine its benefits in relation to patient tolerance and facilitation of the procedure in unsedated patients undergoing upper gastrointestinal endoscopy. PATIENTS AND METHODS: A randomized double-blind study comparing Topicaina spray - a mixture of benzocaine butyl aminobenzoate (butoforme), amethocaine, and butacaine - and a placebo was carried out on 256 outpatients referred for diagnostic endoscopy. No additional premedication was used. After the examination, both the tolerance to and difficulty of the intubation and examination were evaluated by patients and endoscopists respectively, using visual analogue scales and a questionnaire. RESULTS: Three patients (1.2%) did not tolerate the endoscopy. One patient was excluded for unexpected therapeutic endoscopy. One hundred twenty-five patients received the active spray and 127 received the placebo. The two groups were similar with respect to patient characteristics. Both intubation and examination, assessed with visual analogue scales, were better tolerated (both p = 0.0001) and more easily performed (p = 0.02 and p = 0.0001 respectively) in the active treatment group. Patients receiving the active spray had a better tolerance for the procedure, according to questionnaire replies. CONCLUSIONS: Topical pharyngeal anesthesia in unsedated patients undergoing diagnostic upper gastrointestinal endoscopy improves tolerance and makes examination easier.  相似文献   

2.
BACKGROUND: Although nocturnal pulseoximetry is routinely performed in obstructive sleep apnea syndrome (OSAS), pulseoximetry over a 24-h period has not been studied. HYPOTHESIS: The purpose of the study was to determine whether simultaneous 24-h oxygen desaturation and electrocardiographic (ECG) recording might be used to screen for daytime sleep sequelae in patients with OSAS. METHODS: Simultaneous recording of arterial oxygen saturation (SpO2) and ECG was conducted over a 24-h period in 18 male patients with OSAS (mean age 51.3 years) who were diagnosed by standard polysomnography (PSG), and in 15 age-matched healthy subjects (mean age 52.7 years) as controls to evaluate circadian variation of these parameters. The measures of heart rate variability (HRV) were calculated from 24-h ambulatory ECGs. Seventeen patients with OSAS showed excessive daytime sleepiness (EDS). We calculated the duration in which SpO2 decreased to < 90% (duration of SpO2 < 90%). The number of apnea/hypopneas per hour (AHI) during sleep was investigated with Apnomonitors (Chest MI, Co., Tokyo) on the same day as the SpO2 recordings. RESULTS: Controls showed no episodes of oxygen desaturation. In patients with OSAS, driving (33.3% of patients with OSAS) was the most common activity in which SpO2 decreased to < 90%, followed by daytime napping (27.8%) and resting after meals (22.2%). The duration of SpO2 < 90% over a 24-h period correlated significantly with the duration levels recorded during sleep (r = 0.99, p < 0.05) and in the afternoon (r = 0.62, p < 0.05), and with the AHI (r = 0.55, p < 0.05), but not with the duration of SpO2 < 90% in the morning. The number of ventricular premature beats correlated significantly with the duration of SpO2 < 90% for a 24-h period, but not with measures of HRV. Ventricular tachycardia was found in two (11.1%) and ST-T depression in three patients (16.6%) with underlying cardiac diseases. CONCLUSION: Our results suggest that daytime sleep attacks accompanied by oxygen desaturation in patients with moderate to severe OSAS may contribute to the occurrence of traffic or cardiovascular accidents. We conclude that 24-h ambulatory recordings of SpO2 and ECG are useful for screening for daytime sleep sequelae associated with the potential risk of this pathology in OSAS during social activities.  相似文献   

3.
BACKGROUND AND STUDY AIMS: Recently, attention has been drawn to the significant occurrence of respiratory and other complications during upper intestinal endoscopy. This prospective study was designed to compare the incidence and severity of oxygen desaturation when two different methods of oxygen delivery were used during elective oesophagogastroduodenoscopy. PATIENTS AND METHODS: After local medical ethics committee approval and written informed consent, one hundred patients undergoing elective oesophagogastroduodenoscopy were randomly allocated to receive supplemental oxygen at either four litres per minute via nasal specular or ten litres per minute through a specially modified non-rebreathing mask. Oxygen saturations during endoscopy facilitated by midazolam sedation were recorded, and non-parametric tests were used to compare the oxygen saturations in the two groups. RESULTS: The mean oxygen saturations were significantly better during the procedure for American Society of Anesthesiology (ASA) grade 2 and 3 patients who received oxygen with the modified mask than for those who received oxygen via nasal specular (98.6% vs. 97.0%, P = 0.004 for ASA grade 2 and 98.4% vs. 95.5, P = 0.006 for ASA grade 3). CONCLUSIONS: For ASA grade 2 and 3 patients, the modified non-rebreathing mask significantly improves oxygen saturations during upper intestinal endoscopy. This technique should be more widely used for patients at moderate and high risk.  相似文献   

4.
We evaluated the diagnostic accuracy and reproducibility of results obtained by home oximetry for the screening of sleep apnea/hypopnea syndrome. Our subjects were 40 patients who underwent home oximetry (12 patients for 1 night, 28 patients for 2 nights) followed by all-night polysomnography. Their mean age was 50.7 +/- 11.2 years; mean body mass index (BMI), 27.6 +/- 4.4 kg/m2; and mean apnea/hypopnea index (AHI), 36.0 +/- 26.0 hr-1. The data obtained by home pulse oximetry were fed into a personal computer, and utilized to calculate the desaturation cycles per hour (oxygen desaturation index (ODI) of 2-4%) and the percentage of time that SpO2 measured less than 90% (T 90). Polysomnography was used to monitor the number of apnea and hypopnea episodes per hour of sleep (AHI). With sleep apnea/hypopnea syndrome defined as AHI > or = 15, the diagnostic sensitivity and specificity of home pulse oximetry were 73.5% and 83.3%, respectively, when ODI-3 > or = 15 was used as the diagnostic standard. Patients who showed false negative results had a lower mean BMI (25.5 +/- 3.0) than those who showed true positive results (28.8 +/- 4.6). The reproducibility of ODI-3 data obtained at home was very high (r = 0.964, n = 28). In conclusion, home pulse oximetry seems to be a very useful tool for the detection of apnea/hypopnea syndrome, but false negative results should be considered a possibility, especially in patients who are not obese.  相似文献   

5.
In order to determine the level of hypoxemia which is sufficient to impair maximal performance, seven well-trained male cyclists [maximum oxygen consumption (VO2max) > or = 5 l.min-1 or 60 ml.kg-1.min-1] performed a 5-min performance cycle test to exhaustion at maximal intensity as controlled by the subject, under three experimental conditions: normoxemia [percentage of arterial oxyhemoglobin saturation (%SaO2) > 94%], and artificially induced mild (%SaO2 = 90 +/- 1%) and moderate (% SaO2 = 87 +/- 1%) hypoxemia. Performance, evaluated as the total work output (Worktot) performed in the 5-min cycle test, progressively decreased with decreasing % SaO2 [mean (SE) Worktot = 107.40 (4.5) kJ, 104.07 (5.6) kJ, and 102.52 (4.7) kJ, under normoxemia, mild, and moderate hypoxemia, respectively]. However, only performance in the moderate hypoxemia condition was significantly different than in normoxemia (P = 0.02). Mean oxygen consumption and heart rate were similar in the three conditions (P = 0.18 and P = 0.95, respectively). End-tidal partial pressure of CO2 was significantly lower (P = 0.005) during moderate hypoxemia compared with normoxemia, and ventilatory equivalent of CO2 was significantly higher (P = 0.005) in both hypoxemic conditions when compared with normoxemia. It is concluded that maximal performance capacity is significantly impaired in highly trained cyclists working under an % SaO2 level of 87% but not under a milder desaturation level of 90%.  相似文献   

6.
The purpose of this investigation was to examine if exercise-induced arterial oxyhemoglobin desaturation selectively observed in highly trained endurance athletes could be related to differences in the pulmonary diffusing capacity (DL) measured during exercise. The DL of 24 male endurance athletes was measured using a 3-s breath-hold carbon monoxide procedure (to give DLCO) at rest as well as during cycling at 60% and 90% of these previously determined VO2max. Oxyhemoglobin saturation (SaO2%) was monitored throughout both exercise protocols using an Ohmeda Biox II oximeter. Exercise-induced oxyhemoglobin desaturation (DS) (SaO2% < 91% at VO2max) was observed in 13 subjects [88.2 (0.6)%] but not in the other 11 nondesaturation subjects [NDS: 92.9 (0.4)%] (P < or = 0.05), although VO2max was not significantly different between the groups [DS: 4.34 (0.65) l/min vs NDS: 4.1 (0.49) l/min]. At rest, no differences in either DLCO [ml CO.mmHg-1.min-1: 41.7 (1.7) (DS) vs 41.1 (1.8) (NDS)], DLCO/VA [8.2 (0.4) (DS) vs 7.3 (0.9) (NDS)], MVV [l/min: 196.0 (10.4) (DS) vs 182.0 (9.9) (NDS)] or FEV1/FVC [86.3 (2.2) (DS) vs 82.9 (4.7) (NDS)] were found between groups (P > or = 0.05). However, VE/VO2 at VO2max was lower in the DS group [33.0 (1.1)] compared to the NDS group [36.8 (1.5)] (P < or = 0.05). Exercise DLCO (ml CO.mmHg-1.min-1) was not different between groups at either 60% VO2max [DS: 55.1 (1.4) vs NDS: 57.2 (2.1)] or at 90% VO2max [DS: 61.0 (1.8) vs NDS: 61.4 (2.9)]. A significant relationship (r = 0.698) was calculated to occur between SaO2% and VE/VO2 during maximal exercise. The present findings indicate that the exercise-induced oxyhemoglobin desaturation seen during submaximal and near-maximal exercise is not related to differences in DL, although during maximal exercise SaO2 may be limited by a relatively lower exercise ventilation.  相似文献   

7.
OBJECTIVE: The purpose of this study was to determine the prevalence of upper gastrointestinal tract lesions in children with human immunodeficiency virus (HIV) infection who undergo endoscopy of the upper gastrointestinal tract and to identify important clinical predictors of abnormal endoscopic results. METHODS: All HIV-infected children who underwent endoscopy and were followed at Children's Hospital, Boston, from January 1985 to August 1994 were studied. The main outcome measure was endoscopic results, which were categorized into observational, histologic, and microbiologic findings. Potential predictors included height, weight, nutritional interventions, HIV disease stage, CD4 T-lymphocyte count, medications, active infections, and indications for endoscopy. RESULTS: Forty-three endoscopies in unique patients are reported. Most children had advanced HIV infection (67% acquired immunodeficiency syndrome, mean CD4 T-lymphocyte count z score = -2.71, weight z score = -2.04). An abnormal endoscopic finding was discovered in 93% of children and confirmed by histologic, microbiologic, or a combination of these studies in 72% of children. Thirty-five percent of children had an opportunistic pathogen identified endoscopically; 65% of these pathogens were previously undiagnosed. Observational findings often were poor indicators of histologic and microbiologic abnormalities. Independent predictors of abnormal histologic findings include younger age at endoscopy (odds ratio (OR) = 1.16 per year, 95% confidence interval (CI) (1.02, 1.33)) and guaiac-negative stools (OR = 16.7, 95% CI (1.92, 142.9)). Independent predictors of finding a pathogen at the time of endoscopy include a greater number of indications for endoscopy (OR = 2.6 per indication, 95% CI (1.3, 5.3)) and diagnosis of acquired immunodeficiency syndrome (OR = 16.4, 95% CI (1.3, 213)). No other gastrointestinal, nutritional, or immunologic parameters were significantly predictive of endoscopic outcomes. Medical management was changed in 70% of children because of the endoscopic findings. CONCLUSIONS: Endoscopy is a useful tool to direct therapy against peptic and infectious disorders of the upper gastrointestinal tract in children with HIV infection. Specific gastrointestinal symptoms are not useful predictors of abnormal results.  相似文献   

8.
BACKGROUND: Between September 1985 and July 1990, the first 100 consecutive patients (50 female and 50 male) undergoing primary uncut Collis-Nissen fundoplication performed by one surgeon were reviewed. METHODS: Median age was 62 years and ranged from 19 to 89 years. Indications for repair included gastroesophageal reflux in 56 patients, obstructive symptoms in 34, and a combination of both in 10. An upper gastrointestinal endoscopy was performed in 99 patients; all were abnormal. Esophagitis was documented in 53 patients, large diaphragmatic hernia in 36, stenosis in 18, "Cameron's erosions" in 17, Barrett's disease in 13, and other findings in 9 patients. An abnormal upper gastrointestinal series was demonstrated in 96 of 97 patients evaluated. Motility studies were performed in 95 patients, and 11 had abnormal peristalsis. All procedures were performed through a left thoracotomy. RESULTS: Complications occurred in 23 patients and included respiratory failure in 6, atrial fibrillation in 3, atelectasis in 3, pneumonia in 2, myocardial infarction in 2, and chylothorax, severe dysphagia, early breakdown of repair, cardiac tamponade, hematuria, spinal headache, and intraoperative perforation by dilator in 1 each. There were 2 postoperative deaths, both cardiac in origin. Median hospitalization was 8 days (range, 6 to 76 days). The first 25 patients had 10 complications (40%) and 2 deaths (8%). The remaining 75 patients had 13 complications (17%) and no deaths (mortality, p = 0.06; morbidity, p = 0.03). Follow-up was complete in all patients for a median of 100 months (range, 3 to 138 months). Eighty-six of the 98 operative survivors are currently alive. At last follow-up, excellent functional results were observed in 58 patients (59%), good in 24 (25%), fair in 8 (8%), poor in 7 (7%), and unknown in 1 (1%). CONCLUSION: We conclude that the uncut Collis-Nissen fundoplication provides good to excellent long-term results in 84% of patients. Operative mortality and morbidity is acceptable but is associated with a learning curve.  相似文献   

9.
We investigated factors of daytime sleepiness in 22 middle-aged male patients with sleep apnea syndrome (SAS) using the Epworth sleepiness scale (ESS) and polysomnography. The subjects were classified into two groups according to ESS score as follows; low ESS group: ESS score < 10, and high ESS group; ESS score > or = 10. ESS score was significantly correlated with duration in which nocturnal oxygen saturation decreased below 90% (Time of SpO2 < 90%) (r = 0.54, p < 0.05). Time of SpO2 < 90% and percent of movement arousals at the termination of apnea/hypopnea (number of movement arousal/total number of apnea/hypopneas x 100) were significantly higher in high ESS group than in low ESS group. Our findings suggest that the severity of oxygen desaturation and sleep fragmentation caused by arousal response at the termination of apnea/hypopnea may be important factors of daytime sleepiness in patients with SAS.  相似文献   

10.
BACKGROUND AND STUDY AIMS: The presumptive diagnosis of Candida esophagitis has been included in the Centers for Disease Control (CDC) case definition for full-blown AIDS since 1987. Endoscopic examination should be reserved for patients showing symptoms despite treatment. The purpose of this study was to assess the degree of diagnostic accuracy of the CDC presumptive clinical criteria and to determine the usefulness of upper digestive endoscopy in the diagnosis of Candida esophagitis in patients infected with HIV-1, with and without a previous AIDS-defining event. PATIENTS AND METHODS: A total of 144 HIV-1 infected patients who had undergone an upper digestive endoscopy were studied retrospectively. To determine the risk and the predictive value of the clinical markers, only the 84 patients without prior antimycotic therapy were included. RESULTS: Of the 84 patients without previous treatment, 34 (41%) had a history of an AIDS-defining illness. Candida esophagitis was found on endoscopy in 11 of the AIDS and 28 of the non-AIDS cases. Oral thrush, either alone (relative risk [R.R.] 9.4; 95% C.I. 2.4-36.4; p < 0.01; positive predictive value [PPV] 82%) or in combination with esophageal symptoms (R.R. 7.4; 95% C.I. 2.5-21.9; p < 0.01; PPV 89%), was a reliable marker of Candida esophagitis only in patients with a previous AIDS-defining event. The diagnostic value of the CDC presumptive pattern was confirmed by a multivariate analysis after controlling for the CD4 cell count (R.R. 9.3; 95% C.I. 2.3-25.3; p < 0.01). On the other hand, in HIV-1 positive patients without a previous AIDS-defining event, the diagnostic accuracy of oral candidiasis, either alone (R.R. 1.4; 95% C.I. 0.8-2.4; p n.s.; PPV 64%) or in combination with esophageal symptoms (R.R. 1.1; 95% C.I. 0.7-1.8; p n.s.; PPV 60%), was too low to allow a reliable diagnosis of Candida esophagitis. CONCLUSIONS: A presumptive diagnosis of Candida esophagitis on the basis of the CDC clinical criteria is a valid diagnostic method only in HIV-1 infected patients with a previous diagnosis of full-blown AIDS. Upper digestive endoscopy should be performed in symptomatic patients with no history of an AIDS-defining illness, especially if the diagnosis of esophageal candidiasis is important for surveillance purposes.  相似文献   

11.
BACKGROUND: Routine diagnostic endoscopy is commonly obtained for low-risk patients with acute upper gastrointestinal bleeding despite evidence from controlled trials that it does not improve patient outcome. OBJECTIVE: To determine whether endoscopy is being overutilized for these patients or whether considerations not addressed in the trials could justify its widespread use. METHODS: Twenty-five patients recovering from a recent hemorrhage and 22 primary care physicians used the analytic hierarchy process to perform an individualized analysis regarding the diagnostic management of acute upper gastrointestinal bleeding. The results were used to determine whether routine endoscopy was consistent with each subject's interpretation of relevant data and judgments regarding the relative importance of five management goals. The authors then compared the proportion of subjects in each group who preferred endoscopy over two non-endoscopy strategies (upper gastrointestinal series and no routine diagnostic test) with 85%, the current rate of endoscopy at the authors' hospital. RESULTS: Endoscopy was preferred by 92% (97.5% CI: 70%-98%) of the patients and 55% (97.5% CI: 31%-77%) of the physicians. The patients ranked identifying the cause of bleeding the second most important management goal after avoiding a poor outcome from the acute bleeding episode. CONCLUSIONS: The current rate of diagnostic endoscopy is higher than would be expected based on physicians' preferences but quite consistent with patients' preferences. Patients regard knowledge of the bleeding site as important, even if this information will not affect management or prognosis. Attempts to assess the use of diagnostic endoscopy and other diagnostic tests should take both patient preferences and the pure value of diagnostic information into account.  相似文献   

12.
OBJECTIVE: To review the paediatric upper gastrointestinal endoscopy service in a paediatric department in Hong Kong. METHODS: Records of all endoscopies undertaken in this department from May 1995 to January 1996 were retrieved and analysed. RESULTS: The commonest indication for upper endoscopy was dyspepsia with 88% positive histological findings. Helicobacter pylori (H. pylori) was found in 25% of this group of children. CONCLUSION: Paediatric upper gastrointestinal endoscopy service is invaluable in a paediatric department by providing useful diagnostic information which would otherwise be missed.  相似文献   

13.
The effects of epidural fentanyl on the incidence of maternal hypoxaemia during labour and on neonatal welfare were examined. Women were randomly allocated to receive one of two epidural infusions, bupivacaine 0.125% alone or bupivacaine 0.0625% with 2.5 micrograms.ml-1 fentanyl, and maternal arterial oxygen saturation was monitored continuously until delivery. The median incidence of desaturation (SpO2 < 95%) during the active phase of the second stage of labour was significantly greater in the fentanyl group than in controls (2.9 versus 0.6 min.h-1, p = 0.02). Similarly, the incidence of desaturation to SpO2 < or = 90% was greater in the fentanyl group than in controls (p = 0.02). There was no correlation between maternal oxygenation or plasma fentanyl concentration and neonatal welfare as measured by umbilical arterial and venous blood gas and acid base status, Apgar score and Neurologic and Adaptive Capacity Score.  相似文献   

14.
Early experience with continuous monitoring of jugular venous oxygen saturation (SjvO2) suggested that this technology might allow early identification of global cerebral ischaemia in patients with severe head injury. The purpose of the present study was to examine the relationship between episodes of jugular venous desaturation and neurological outcome. One hundred and sixteen severely head-injured patients had continuous monitoring of SjvO2 during days 1-5 after injury. Episodes of jugular venous desaturation (SjvO2 < 50% for more than 10 minutes) were prospectively identified, and the incidence of desaturation was correlated with neurological outcome: 77 episodes of desaturation occurred in 46 of the 116 patients; 27 had one episode and 19 had multiple episodes of desaturation. The causes of these episodes were systemic (n = 36), cerebral (n = 35), or both (n = 6). Most of the episodes were less than 1 hour in duration, and it is probable that many of them would not have been detected without continuous measurement of SjvO2. Episodes of desaturation were most common on day 1 after injury, and were twice as common in patients with a reduced cerebral blood flow as in patients with a normal or elevated cerebral blood flow. The occurrence of jugular venous desaturation was strongly associated with a poor neurological outcome. The percentage of patients with a poor neurological outcome was 90% with multiple episodes of desaturation and 74% in patients with one desaturation, compared to 55% in patients with no episodes of desaturation. When adjusted for all co-variates that were found to be significant, including age, Glasgow coma score, papillary reactivity, type of injury, lowest recorded cerebral perfusion pressure, and highest recorded temperature, the incidence of desaturation remained significantly associated with a poor outcome. Although a cause and effect relationship with outcome cannot be established in this study, the data suggest that monitoring SvO2 might allow early identification and therefore treatment of many types of secondary injury to the brain.  相似文献   

15.
BACKGROUND: Cost-effectiveness analysis, Helicobacter pylori research and the development of proton pump inhibitors are having an increasing impact on the management of dyspepsia. However, clinical trials have not always included both H. pylori diagnosis and proton pump inhibitors in their protocols. METHODS: Patients who were referred for upper gastrointestinal endoscopy by their general practitioner were randomized to either prompt endoscopy followed by directed medical treatment (conventional group, n=38), or to empirical treatment with omeprazole and, in the case of symptom relapse, serological screening for H. pylori infection followed by eradication therapy in seropositive patients (empirical group, n=42). The study lasted for up to 1 year. RESULTS: In the empirical group, only 13 patients (31%) underwent endoscopy. The average number of days for which the patients kept records of their dyspeptic symptoms was 266 (95% CI: 226-307) in the empirical group, of which 166 (95% CI: 128-204) were symptom-free. In the conventional group, 159 (95% CI: 119-198) out of 255 days (95% CI: 209-302) were recorded as symptom-free. The average medical cost in the empirical group was $284 (95% CI: 218-350) and in the conventional group $491 (95% CI: 383-600). In the empirical group, two malignancies were found, whereas in the conventional group one malignancy was found. CONCLUSIONS: The empirical drug treatment strategy in patients with persistent dyspeptic symptoms resulted in 69% fewer diagnostic endoscopies with lower medical costs and equal effectiveness in the first year, compared to prompt endoscopy followed by directed medical treatment.  相似文献   

16.
BACKGROUND: The impact of upper endoscopy in patients with upper gastrointestinal hemorrhage treated in community practice is unknown. Thus we examined the effectiveness of endoscopy performed within 24 hours of admission (early endoscopy). METHODS: Medical records of 909 consecutive hospitalized patients with upper gastrointestinal hemorrhage who underwent endoscopy at 13 hospitals in a large metropolitan area were reviewed. We evaluated unadjusted and severity-adjusted associations of early endoscopy with recurrent bleeding or surgery to control hemorrhage, length of hospital stay, and associations of endoscopic therapy in patients with bleeding ulcers or varices. RESULTS: Early endoscopy was performed in 64% of patients and compared with delayed endoscopy and was associated with clinically significant reductions in adjusted risk of recurrent bleeding or surgery (odds ratio [OR] 0.70: 95% CI [0.44, 1.13]) and a 31% decrease in adjusted length of stay (95% CI: [24%, 37%]). In patients at high risk for recurrent bleeding, the use of early endoscopic therapy to control hemorrhage was associated with reductions in recurrent bleeding or surgery (OR 0.21: 95% CI [0.10, 0.47]) and length of stay (-31%: 95% CI [-44%, -14%). CONCLUSION: In this study of community-based practice, the routine use of endoscopy, and in selected cases endoscopic therapy, performed early in the clinical course of patients with upper gastrointestinal hemorrhage was associated with reductions in length of stay and, possibly, the risk of recurrent bleeding and surgery.  相似文献   

17.
OBJECTIVE: To assess the response of healthy infants to airway hypoxia (15% oxygen in nitrogen). DESIGN: Interventional study. SETTINGS: Infants' homes and paediatric ward. SUBJECTS: 34 healthy infants (20 boys) born at term; mean age at study 3.1 months. 13 of the infants had siblings whose deaths had been ascribed to the sudden infant death syndrome. INTERVENTION: Respiratory variables were measured in room air (pre-challenge), while infants were exposed to 15% oxygen (challenge), and after infants were returned to room air (post-challenge). MAIN OUTCOME MEASURES: Baseline oxygen saturation as measured by pulse oximetry, frequency of isolated and periodic apnoea, and frequency of desaturation (oxygen saturation < or = 80% for > or = 4 s). Exposure to 15% oxygen was terminated if oxygen saturation fell to < or = 80% for > or = 1 min. RESULTS: Mean duration of exposure to 15% oxygen was 6.3 (SD 2.9) hours. Baseline oxygen saturation fell from a median of 97.6% (range 94.0% to 100%) in room air to 92.8% (84.7% to 100%) in 15% oxygen. There was no correlation between baseline oxygen saturation in room air and the extent of the fall in baseline oxygen saturation on exposure to 15% oxygen. During exposure to 15% oxygen there was a reduction in the proportion of time spent in regular breathing pattern and a 3.5-fold increase in the proportion of time spent in periodic apnoea (P < 0.001). There was an increase in the frequency of desaturation from 0 episodes per hour (range 0 to 0.2) to 0.4 episodes per hour (0 to 35) (P < 0.001). In 4 infants exposure to hypoxic conditions was ended early because of prolonged and severe falls in oxygen saturation. CONCLUSIONS: A proportion of infants had episodes of prolonged (< or = 80% for > or = 1 min) or recurrent shorter (< or = 80% for > or = 4 s) desaturation, or both, when exposed to airway hypoxia. The quality and quantity of this response was unpredictable. These findings may explain why some infants with airway hypoxia caused by respiratory infection develop more severe hypoxaemia than others. Exposure to airway hypoxia similar to that experienced during air travel or on holiday at high altitude may be harmful to some infants.  相似文献   

18.
BACKGROUND: Renal functional reserve is the normal increase in renal blood flow after a protein load, and reduced or absent renal functional reserve is an early index of renal impairment. Renal blood flow is frequently reduced during acute oedematous exacerbations of chronic obstructive pulmonary disease (COPD). It is possible that patients with severe COPD in the stable state may have a reduced or absent renal functional reserve which could be a factor in oedema formation. METHODS: Sixteen stable patients with severe COPD and five normal controls were studied. The mean (SD) arterial oxygen and carbon dioxide tensions (PaO2, PaCO2) and forced expiratory volume in one second (FEV1) of patients with COPD were 8.1 (1.04) kPa, 6.3 (0.69) kPa, and 0.74 (0.27) 1, respectively. The pulsatility index (PI), an index of renovascular resistance, was measured non-invasively by Doppler ultrasonography at baseline and at intervals after a protein load of 250 g steak. RESULTS: The PI fell after the protein load in the normal subjects from 1.04 (0.19) to 0.84 (0.17), mean difference 0.20, 95% confidence interval of difference (CI) 0.14 to 0.27, p < 0.001. In the COPD group there was no change; baseline PI = 1.04 (0.16), PI after protein load = 1.08 (0.19), mean difference = -0.04, 95% CI-0.11 to 0.04, p = NS. Six of the patients with COPD were normocapnic and 10 were hypercapnic (PaCO2 > or = 6.0 kPa). The normocapnic patients had no significant change in PI (baseline PI = 1.07 (0.15), PI after protein load = 1.01 (0.16), mean difference = 0.06, 95% CI -0.03 to 0.15) while in the hypercapnic patients the PI tended to rise (baseline PI = 1.03 (0.17), PI after protein load = 1.12 (0.21), mean difference = -0.09, 95% CI 0.18 to 0.007, p = 0.06). CONCLUSIONS: Renal haemodynamics were unchanged after a protein load in patients with severe COPD, suggesting that they had no renal functional reserve. This may be a factor in the development of oedema frequently seen in patients with severe COPD, particularly in hypercapnic patients.  相似文献   

19.
OBJECTIVES: The effectiveness of upper endoscopy in unselected patients with upper gastrointestinal hemorrhage has not been well studied. This study was undertaken to identify factors associated with the performance of early endoscopy (ie, within 1 day of hospitalization) and, after adjusting for these factors, to determine associations between early endoscopy and in-hospital mortality, length of stay, and performance of surgery. METHODS: Subjects in this observational cohort study were 3,801 consecutive admissions with upper gastrointestinal hemorrhage to 30 hospitals in a large metropolitan region. Demographic and clinical data were abstracted from hospital records. A multivariable model based on factors that potentially could relate to the decision to perform endoscopy was developed to determine the propensity (0 to 100%) for early endoscopy in each patient. RESULTS: Early endoscopy was performed in 2,240 patients (59%), and although it was not associated with mortality after adjusting for severity of illness among all patients, it was associated with a higher risk of death for patients in the lowest propensity group. Early endoscopy was associated with a lower likelihood of upper gastrointestinal surgery in all patients and in the two highest propensity groups and with a shorter length of stay in the entire cohort and in all subgroups. CONCLUSIONS: In the absence of specific contraindications, early endoscopy should be considered because of associated reductions in length of stay and surgical intervention. Further studies are needed to identify subgroups in whom the procedure may be associated with adverse effects on survival.  相似文献   

20.
OBJECTIVES: To evaluate jugular venous oxygen saturation (SjVO2), measured with a fiberoptic oximetry catheter, and brain tissue oxygen saturation, measured by near-infrared spectroscopy (NIRSO2), as monitors of cerebral oxygenation during cardiopulmonary bypass surgery. DESIGN: Prospective, clinical study. SETTING: Operating room of a Veterans Administration Hospital. PATIENTS: Nineteen patients undergoing moderate hypothermic cardiopulmonary bypass surgery. INTERVENTIONS: SjvO2 and NIRSO2 were monitored in the patients during the surgical procedure. MEASUREMENTS AND MAIN RESULTS: Moderate hypothermic cardiopulmonary bypass surgery had two distinct cerebral hemodynamic phases. While the patients were hypothermic, SjvO2 averaged 80 +/- 7% and none of the patients had an increase in cerebral lactate production. During the rewarming period, however, reductions in SjvO2 to < 50% occurred in 16 (84%) patients and increased cerebral anaerobic metabolism developed in 11 (58%) patients. SjvO2 during rewarming was dependent on mean arterial pressure, with 60 mm Hg appearing to be a critical value. Two other factors appeared to also contribute to the jugular desaturation, a low hematocrit and a rapid warming time. The SjvO2 catheter had excellent performance during the surgery. The average difference between paired measurements of SjvO2 by the catheter and in blood samples was -0.4 +/- 4.25%, and the correlation between the two measurements was highly significant (r2 = .93; p < .001). The NIRSO2 trended with the SjvO2 in most patients (r2 = .63; p < .001). CONCLUSIONS: The study confirms other studies showing that jugular venous desaturation can occur during rewarming after cardiopulmonary bypass surgery. Presently, SjvO2 appears to be a better monitor of cerebral oxygenation than NIRSO2. However, NIRSO2 has promise as a noninvasive monitor of cerebral oxygenation if future developments allow more quantitative measurements of oxygen saturation.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号