Arterial oxygen desaturation during emergent nonsedated upper gastrointestinal endoscopy in the emergency department

A prospective study was conducted to see whether emergent esophagogastroduodenoscopy (EGD) in patients with active upper gastrointestinal (GI) bleeding is associated with more oxygen desaturation than nonemergent EGD. Emergent EGD was performed in the study patients with active upper GI bleeding. Nonemergent EGD was performed in the control patients. Determination of oxygen saturation (Sao₂) was measured by pulse oximeter. A decrease in Sao₂ of>4% was more frequent in the study patients (26%, 13 of 50) than in controls (6%, 3 of 50) (P < .01). During EGD, mean oxygen saturation decreased significantly in both groups of patients. After EGD, mean oxygen saturation did not recover toward the pre-endoscopy insertion level in the study group (P < .01). A linear association was found that oxygen DESATURATION = 5.46 + 0.15 (status) − 0.06 (baseline oxygen saturation). Emergent EGD for active upper GI bleeding in the emergency department tends to be associated with more frequent significant oxygen desaturation than nonemergent EGD. Continuous oxygen supplementation and oxygen saturation monitoring may be used during emergent nonsedated EGO in the emergency department.     

Arterial oxygen desaturation during treadmill and bicycle exercise in patients with chronic obstructive airways disease

Nine men with severe chronic obstructive airways disease (COAD), known to desaturate on exercise, performed a 6 min self-paced walk on a treadmill, followed by a bicycle exercise with workloads adjusted to mimic the oxygen consumption achieved on the treadmill. During both exercises, ventilation, oxygen consumption, carbon dioxide production, PaO2, PaCO2, pH and arterial lactate were measured and subjective breathlessness recorded. A reasonable match of oxygen consumption between the two exercises was achieved. In all subjects PaO2 fell to a lower level during treadmill compared with bicycle exercise. Ventilation, carbon dioxide production and arterial lactate were higher during bicycle exercise. Subjective breathlessness was greater during bicycle exercise, in proportion to the higher ventilation on the bicycle. The greater anaerobiosis occurring on the bicycle led to acidosis and an increased ventilation, minimizing the exercise fall in PaO2. Bicycle testing may seriously underestimate exercise desaturation occurring during level walking in patients with severe COAD.     

Non-cardiac pulmonary edema following intravenous contrast injection

Acute non-cardiogenic pulmonary edema (NCPE) following intravenous administration of contrast media is a rare but life-threatening complication of radiologic contrast material. We recently observed this complication as an idiosyncratic reaction following a coelio-mesenteric arteriography.     

Arterial oxygen desaturation during endoscopic ultrasonography combined with gastroscopy: a safety evaluation in out-patients.

BACKGROUND AND STUDY AIMS: Data concerning potential clinically relevant arterial oxygen desaturation (SaO2 <90.0 %) during endoscopic ultrasonography (EUS) combined with a prior conventional gastroscopy are not available, but are nevertheless important in view of the increasing numbers of examinations and relevant safety standards. We therefore continuously measured SaO2 before and during the periods of gastroscopy and subsequent EUS in order to answer the question of whether EUS has additional effects on arterial oxygen desaturation. A secondary aim of the study was to define patients with particular risks for decreased SaO2. PATIENTS AND METHODS: SaO2 was continuously monitored in 96 outpatients before and during the endoscopic procedures. After sedation with midazolam, an exploratory gastroscopy was performed, followed by endoscopic ultrasonography. RESULTS: In all patients undergoing gastroscopy followed by EUS (n = 96), SaO2 values significantly decreased from 96.5 +/- 2.6 % to 92.4 +/- 4.7 % (P < 0.0001). Analysis of the time-related SaO2 courses showed that the minimal SaO2 was reached after 7.5 minutes. The SaO2 curves in patients with desaturation (n = 29) were similar to those in patients who had no desaturation, except for a significantly lower nadir (88.6 +/- 5.3 %, P< 0.0001). The SaO2 time courses in all patients showed no further decrease or a second minimum during the EUS period, as might have been expected with the insertion of a second instrument. Baseline (pre-procedure) and minimal SaO2 were significantly correlated (T(s): 0.604, P<0.038). Quantitative analysis yielded the lowest significant percentage of desaturation, with baseline SaO2 equal to or above 97.5 % (6.3 %, P< 0.038). CONCLUSIONS: EUS following an exploratory gastroscopy under mild sedation causes no additional reduction in SaO2. Patients with an initial arterial oxygen saturation equal to or above 97.5 % may have a low probability of desaturation during the combined procedure after sedation with one single midazolam dose, and are therefore unlikely to need further monitoring after an initial assessment. Patients below this limit, however, should be continuously monitored, due to the increasing probability of desaturation below this limit.     

Near fatal respiratory distress following massive ether intravenous injection

To the best of our knowledge, no case of ether-induced acute respiratory distress syndrome (ARDS) has been published as yet. A 36-year-old female developed pneumonitis which showed all the characteristics of a chemical-associated ARDS due to intravenous self-administration of ether: the hemodynamic investigation demonstrated a normal blood flow pattern with low left-heart filling pressure while the anteroposterior roentgenogram evidenced disseminated bilateral lung edema. Advanced symptomatic respiratory support including inhaled nitric oxide and steroidal anti-inflammatory use was the treatment of choice. Received: 29 December 1997 Accepted: 11 March 1998     

Anaphylactoid reaction and non-cardiac pulmonary edema following intravenous contrast injection

A case of severe anaphylactoid reaction following injection of intravenous contrast is described, and a discussion of the treatment of severe allergic reactions follows. The patient's presentation was unusual in that she rapidly developed massive non-cardiac pulmonary edema as the primary symptom, along with hypotension and hypokalemia, a syndrome similar to adult respiratory distress syndrome. The development of the reaction along with the unusual presentation is discussed and a detailed discussion of the generalized treatment of anaphylactoid and anaphylactic reactions is presented. Additionally, several errors in management that may have delayed resolution of the symptoms and prolonged the period of instability in the patient's condition are discussed and critiqued.     

A comparison of midazolam with remifentanil for the prevention of myoclonic movements following etomidate injection

Etomidate is a popular anaesthetic induction agent, but it frequently causes myoclonic movements. Although both benzodiazepines and opioids reduce myoclonus, there has been no comparative study between these agents. Thus, we conducted a prospective, randomized study to compare midazolam and remifentanil as pre-treatment agents for reducing etomidate-induced myoclonus in 90 adults undergoing surgery. Patients were pre-treated before the etomidate injection, either with saline (Group C), midazolam 0.5 mg/kg (Group M) or remifentanil 1 microg/kg (Group R). Both Groups M and R showed a significantly lower incidence of myoclonus compared with Group C (17%, 17% and 77%, respectively). The incidence of myoclonus was not significantly different between Groups M and R, but 10% (n = 10) of the patients in Group R experienced remifentanil-related side-effects. We conclude that midazolam is probably a better choice than remifentanil for reducing etomidate-induced myoclonus during anaesthesia induction.     

针对性护理干预联合咪达唑仑静推对纤支镜治疗患者的疗效观察

目的观察针对性护理干预联合咪达唑仑静推对纤支镜治疗患者的疗效。方法选择肺结核、支气管结核患者160例,按照随机数表法分为研究组和对照组,各80例,对照组术前采用常规护理和常规麻醉,研究组患者给予针对性护理联合咪达唑仑静脉推注,麻醉后记录患者的血压(BP)、风险比(HR)、相对危险度(RR)、Sp O2波动情况;采用抑郁自评量表(SDS)和焦虑自评量表(SAS)对患者的抑郁和焦虑情绪进行评价,记录2组患者不良反应。结果麻醉后,研究组患者的BP、HR、RR、Sp O2波动值均较对照组小(P0.05);护理干预后,研究组患者焦虑评分显著低于对照组(P0.05);研究组患者总有效率为93.75%,对照组为70.00%,研究组有效率高于对照组(P0.05);研究组出现2例呛咳,1例中止检查,2例躁动;对照组出现10例呛咳,9例躁动,4例中止检查,研究组不良反应发生率较对照组小(P0.05)。结论针对性护理联合咪达唑仑静推能够显著提高纤支镜治疗的疗效,且安全有效,值得临床应用。     

Protection against oxygen toxicity by intravenous injection of liposome-entrapped catalase and superoxide dismutase

Survival of rats exposed to 100% oxygen was increased from 69.5 +/- 1.5 to 118.1 +/- 9.9 h (mean +/- SEM, P less than 0.05) when liposomes containing catalase and superoxide dismutase were injected intravenously before and during exposure. The increased survival time in 100% oxygen was also associated with significantly less fluid in the pleural cavity. Rats injected with catalase- and superoxide dismutase-containing liposomes, which had increased survival in 100% oxygen, had increased lung wet weight upon autopsy compared with saline-injected controls (2.9 +/- 0.2 g/lung vs. 4.8 +/- 0.4 g/lung, mean +/- SE, P less than 0.05). Intravenous injection of control liposomes along with catalase and superoxide dismutase in the suspending buffer decreased the mean pleural effusion volume 89% and had no significant effect on survival time. Lung catalase and superoxide dismutase activities were increased 3.1- and 1.7-fold, respectively, 2 h after a single intravenous injection of liposomes containing catalase or superoxide dismutase. Superoxide dismutase activity was also significantly greater than controls in both air- and 100% oxygen-exposed rat lungs, when enzyme activity was assayed 24 h after cessation of injection of control and oxygen-exposed rats with enzyme-containing liposomes every 12 h for 36 h. Free superoxide dismutase and catalase injected intravenously in the absence of liposomes did not increase corresponding lung enzyme activities, affect pleural effusion volume, lung wet weight, or extend the mean survival time of rats exposed to 100% oxygen. The clearance of liposome-augmented 125I-labeled catalase from lung and plasma obeyed first order kinetics according to a one-compartment model. When clearance of liposome-augmented catalase activity or radioactivity were the parameters used for pharmacokinetic studies, the half-life of augmented lung catalase was 1.9 and 2.6 h, respectively. The half-life of liposome-entrapped catalase and superoxide dismutase activity in the circulation was 2.5 and 4 h, respectively, while intravenously injected catalase and superoxide dismutase had a circulation half-life of 23 and 6 min, respectively.     

Oxygen desaturation in adults following inhaled metaproterenol therapy

Following bronchodilator therapy in asthmatic patients, a fall in arterial oxygen tension (PaO2) has been attributed to increased perfusion of persistently underventilated alveoli. We used continuous noninvasive pulse oximetry to evaluate the extent and timing of oxygen saturation (SaO2) decrease in adults following metaproterenol inhalation for acute bronchospasm. We also examined the effect of supplemental oxygen upon these factors. Baseline and peak drop in SaO2 after completion of the first bronchodilator therapy were measured and the percent change in SaO2 was calculated. A total of 47 patient visits were studied; 10 patients received supplemental oxygen. Mean age was 38 +/- 17.9 years. Baseline was SaO2 = 94.6 +/- 2.9%, peak drop SaO2 = 91.4 +/- 3.4%, and percent change in SaO2 = -3.4 +/- 2.5%. The mean time to peak drop was 24.4 +/- 15.4 minutes in the 40 patients, with an observed drop after initial treatment. The absolute change in SaO2 from baseline was significant both with and without oxygen (P less than .05 and less than .01, respectively). The group receiving oxygen had a significantly smaller percent drop and a larger proportion of patients showing no drop in SaO2 (P less than 0.01 and less than 0.03, respectively). Clinically significant oxygen desaturation can occur within 30 minutes of inhaled bronchodilator therapy. Supplemental oxygen (2-3 L/min) helps blunt the metaproterenol-induced drop in SaO2.     

Pharmacokinetics and metabolism of intravenous midazolam in preterm infants.

BACKGROUND: Midazolam, a benzodiazepine, is finding expanded use in neonatal intensive care units. We studied the pharmacokinetics and metabolism of midazolam after a single intravenous dose in preterm infants. METHODS: The pharmacokinetics of midazolam and its hydroxylated metabolite (1-OH-midazolam) after a single 0.1 mg/kg intravenous dose of midazolam were determined in 24 preterm infants (gestational age, 26 to 34 weeks; postnatal age, 3 to 11 days). Blood samples were obtained before drug administration and at 0.5, 1, 2, 4, 6, 12, and 24 hours after the start of the infusion. Midazolam and 1-OH-midazolam concentrations were determined by use of gas chromatography-mass spectrometry. RESULTS: Total body clearance, apparent volume of distribution, and plasma half-life of midazolam were (median [range]): 1.8 (0.7-6.7) ml/kg per min, 1.1 (0.4-4.2) L/kg, and 6.3 (2.6-17.7) h, respectively. In 19 of 24 preterm infants, 1-OH-midazolam concentrations could be detected: 1-OH-midazolam (1-OH-M) maximal concentration of drug in plasma (C(max)), time to reach C(max) (T(max)), and 1-OH-M/M area under the concentration-time curve from time zero to the last sampling time point (AUC(0-t)) ratio were [median (range)]: 8.2 (<0.5-68.2) ng/ml, 6 (1-12) h, and 0.09 (<0.001-1), respectively. Midazolam plasma clearance was increased in those infants who had indomethacin (INN, indometacin) exposure. DISCUSSION: Consequent to immature hepatic cytochrome P450 3A4 (CYP3A4) activity, midazolam clearance and 1-OH-midazolam concentrations are reduced markedly in preterm infants as compared to concentrations in previous reports from studies in older children and adults. Indomethacin exposure and its apparent impact on midazolam clearance support alteration of drug disposition produced by a patent ductus arteriosus or by the direct effects of indomethacin on hemodynamic or renal function.     

静脉输液拔针后按压方法的研究

目的 探讨静脉输液拔针后局部按压的最佳方法,最大限度地保护患者的血管.方法 将620例患者随机分成2组,设为对照组和观察组各310例,分别采用交换式按压(传统按压法)和非交换式按压(小鱼际肌直接按压法)进行对比研究.结果 观察组在静脉输液拔针后疼痛、针眼出血、皮下淤血等次数均明显低于对照组,2组比较差异有统计学意义(P<0.01).结论 静脉输液拔针后采用小鱼际肌直接按压优于传统的按压法,值得临床推广.