Oxygen Desaturation (oxygen + desaturation)

Distribution by Scientific Domains
Distribution within Medical Sciences

Selected Abstracts

Stent Dilatation of a Right Ventricle to Pulmonary Artery Conduit in a Postoperative Patient with Hypoplastic Left Heart Syndrome

Rowan Walsh MD
ABSTRACT A 10-day-old child with hypoplastic left heart syndrome (HLHS) underwent first-stage palliation for HLHS, Norwood procedure with a Sano modification, i.e., placement of a right ventricular to pulmonary artery (RV-PA) conduit. The patient developed progressively worsening systemic oxygen desaturation in the immediate postoperative period. Stenosis of the proximal RV-PA conduit was diagnosed by echocardiography. In the catheterization laboratory stent placement in the conduit was performed. This resulted in increased systemic oxygen saturation. The patient was eventually discharged from the hospital with adequate oxygen saturations. [source]

Dialyzer reactions in a patient switching from peritoneal dialysis to hemodialysis

Robert C. Yang
Many terms have been used to describe the collection of signs and symptoms triggered by the initial use of dialyzers. These reactions can be divided into Type A (hypersensitivity reactions, with the incidence of 4/100,000) and Type B (nonspecific reactions, incidence 3,5/100). Many different mechanisms have been postulated, including complement activation, pulmonary leukostasis, hypersensitivity to ethylene oxide, interaction between the AN69 membrane and angiotensin-converting enzyme inhibitors, and dialysate contamination. An unusual case of dialyzer reactions is presented here, involving a patient who had to discontinue peritoneal dialysis when she was admitted with fungal peritonitis. Upon initiation of hemodialysis, she experienced dyspnea and burning sensation and demonstrated significant leukopenia, thrombocytopenia, and oxygen desaturation. These reactions persisted despite double-rinsing of the dialyzers and the use of several different dialyzers with synthetic membranes (polysulfone and AN69), and a variety of sterilization methods (electron beam and gamma radiation). In the end, a simple measure was found to be effective in preventing further dialyzer reactions in this fascinating case. [source]

Closed suctioning system: Critical analysis for its use

Abstract Aim:, To determine the efficacy and effectiveness of the closed suctioning system. Method:, Literature review articles were accessed from the following databases: PubMed, EMBASE, CINAHL, and Cochrane Library. The literature review criteria included: all publication styles except meta-analysis, participants that were ,18 years, written in English, and published between 1973 and 2008. Results:, This literature review revealed that the efficacy and effectiveness of the closed suctioning system remains to be demonstrated. The device manufacturers' studies focused on cost reduction, cross-contamination, and preservation of the oxygen saturation of patients during endotracheal suctioning; however, the clinical studies focused on the use of closed suctioning systems to prevent ventilator-associated pneumonia. The reviewed studies had small sample sizes with heterogeneous demographics and non-randomized controls. Recent studies suggest that closed suctioning systems are no better than open suctioning systems in terms of mortality, morbidity, or the cost-benefit ratio. A few studies did indicate that the closed suctioning system might reduce the loss of lung volume and oxygen desaturation. Conclusion:, The studies reviewed in this article suggest that the evidence on the efficacy and effectiveness of closed suctioning systems is inconclusive. Only limited populations will benefit clinically from the use of this device. There is a need for further studies with randomized controlled trials to explore the use of closed suction systems and to update current clinical practise guidelines. [source]

Comparison of desaturation and resaturation response times between transmission and reflectance pulse oximeters

Background: In general, there is a response time between actual arterial hypoxemia and its detection by pulse oximeters. We compared the desaturation and resaturation response times between two types of pulse oximeters, transmission and reflectance pulse oximeters, to find out which oximeter has a more rapid response time. Methods: Thirty-three ASA 1 or 2 patients were enrolled in this study. A transmission pulse oximeter was placed on the index finger and a reflectance pulse oximeter was placed on the forehead and monitored simultaneously. After the induction of general anesthesia without pre-oxygenation, we waited until the oxygen saturation value of any of two pulse oximeters declined to 90%, and then mask ventilation was started with 100% oxygen. Oxygen saturation was recorded at an interval of 2 s during this time. Results: The desaturation response time of SpO2 to 95% after apnea was 82.0 s (interquartile range: 67.0,98.5 s) vs. 94.0 s (interquartile range: 84.0,106.5 s) (P<0.001) and SpO2 to 90% was 94.0 s (interquartile range: 75.5,109.5 s) vs. 100.0 s (interquartile range: 84.5,114.5 s) (P<0.001) in the reflectance and transmission oximeters, respectively. The resaturation response time from mask ventilation to 100% SpO2 was 23.25.6 vs. 28.97.6 s (P<0.001) in the reflectance and transmission oximeters, respectively. Conclusion: In clinical situations in which rapid changes in oxygen saturation are expected, we recommend the forehead reflectance pulse oximeter because it responds more quickly in detecting oxygen desaturation and resaturation compared with the transmission pulse oximeter. [source]

Exploratory Analysis of Cerebral Oxygen Reserves During Sleep Onset in Older and Younger Adults

Barbara W. Carlson RN
OBJECTIVES: To explore differences in cerebral oxygen reserves during sleep in old and young adults. DESIGN: Descriptive cross-sectional study. SETTING: General clinical research center. PARTICIPANTS: Nine old (aged 65,84) and 10 young (aged 21,39) adults. MEASUREMENTS: Subjects were monitored during the first nightly sleep cycle using standard polysomnography, including measures of arterial oxyhemoglobin saturation (SaO2). Changes in regional cerebral oxyhemoglobin saturation (rcSO2) were used to estimate cerebral oxygen reserves. General linear models were used to test group differences in the change in SaO2 and rcSO2 during sleep. RESULTS: Older subjects had lower SaO2 than young subjects before sleep (baseline) (F(1,18)=5.1, P=.04) and during sleep (F(1,18)=10.7, P=.01). During sleep, half of the older subjects and none of the younger ones had SaO2 values below 95%. In addition, the older subjects had more periods of oxygen desaturation (drops in SaO2,4%) (chi-square=24.3, P=.01) and lower SaO2 levels during desaturation (F(1,18)=11.1, P<.01). Although baseline values were similar, rcSO2 decreased during sleep 2.1% in older subjects (F(1,8)=3.8, P=.05) but increased 2.1% during sleep in younger subjects (F(1,9)=4.6, P=.04). When the older subjects awakened from sleep, rcSO2, but not SaO2, returned to baseline; both returned to baseline in younger subjects. CONCLUSION: This exploratory analysis generated the hypothesis that lower SaO2, combined with declines in regional blood flow, contributes to decline in cerebral oxygen reserves during sleep in older subjects. Further study will assess the effects of factors (e.g., medical conditions, subclinical disorders, and sleep architecture) that might account for these differences. [source]

Pre-hospital use of ketamine in paediatric trauma

Objectives: To describe the use of ketamine in children by a pre-hospital physician-based service. Methods: A five and a half year retrospective database review of all patients aged <16 years who were attended by London's Helicopter Emergency Medical Service and given ketamine. Results: One hundred and sixty-four children met the inclusion criteria. The median age was 10 years (range 0,15 years). One hundred and four (63%) had a Glasgow Coma Scale (GCS) of 15 and 153 (93%) had a GCS>8 before administration of ketamine. Patients received from 2 to 150 mg ketamine IV (mean=1.0 mg/kg) and 112 (68%) received concomitant midazolam (0.5,18 mg, mean=0.1 mg/kg). One hundred and forty-one (86%) received ketamine intravenously and 23 (14%) intramuscularly. Only 12 patients (7%) were trapped. The most common mechanisms of injury in those who received ketamine were road traffic collisions, burns and falls. Conclusion: The safe delivery of adequate analgesia and appropriate sedation is a priority in paediatric pre-hospital care. Ketamine was predominantly used in awake non-trapped patients with blunt trauma for procedural sedation and analgesia. Detailed database searches did not demonstrate loss of airway, oxygen desaturation or clinically significant emergence reactions after ketamine administration. This study failed to demonstrate any major side effects of the drug and reassured us that the safety profile of the drug in this environment is likely to be satisfactory. The use of ketamine in trapped children was rare. [source]

Mixed venous oxygen desaturation during early mobilization after coronary artery bypass surgery

I. Kirkeby-Garstad
Background:, Early postoperative mobilization induces a marked reduction in mixed venous oxygen saturation (SvO2) after aortic valve replacement. We investigated whether a similar desaturation occurs among coronary artery bypass grafting (CABG) patients, and if the desaturation was related to the preoperative ejection fraction (EF). Methods:, Thirty-one CABG patients with a wide range in EF were included in an open observational study. We recorded hemodynamic and oxygenation variables during mobilization on postoperative day 1 and day 2 using a pulmonary artery catheter. Results:, Patients with an EF ranging from 24 to 87% were mobilized without clinical problems. SvO2 at rest was 65.4 4.9% (mean SD) on day 1 and 64.3 5.8% on day 2 (NS). During mobilization, cardiac index and oxygen delivery were reduced while oxygen consumption was increased (P -values: 0.000, 0.007 and 0.000, respectively). Consequently, oxygen extraction increased, resulting in a marked reduction in SvO2,42.9 8.3% on day 1 and 47.4 8.5% on day 2 (P = 0.025 between days). Several pre-, intra- and postoperative factors were tested as possible predictors for SvO2 during mobilization. No factor contributed substantially. Conclusion:, Patients with CABG exhibit a marked desaturation during early postoperative mobilization. Preoperative ejection fraction did not affect SvO2 during exercise. The clinical consequences and underlying mechanism require further investigation. [source]

Alleviation of Pulmonary Hypertension by Cardiac Resynchronization Therapy is Associated with Improvement in Central Sleep Apnea

Background: Recent studies have demonstrated that cardiac resynchronization therapy (CRT) reduces sleep apnea in heart failure (HF); however, the mechanism of benefit remains unclear. Methods: Overnight polysomnography (PSG) was performed in consecutive HF patients who were scheduled for CRT implant. Patients with sleep apnea defined by an apnea-hypopnea index (AHI) of >10/hour were recruited and underwent echocardiogram examination at baseline and 3 months after CRT. Results: Among 37 HF patients screened, 20 patients (54%) had sleep apnea and 15 of them consented for the study. After 3 months of CRT, there was a significant improvement in New York Heart Association functional class (3.1 0.1 vs 2.1 0.1, P < 0.01), quality-of-life (QoL) score (62.9 3.3 vs 56.1 4.5, P = 0.02), left ventricular ejection fraction (LVEF, 28.8 2.5% vs 38.1 2.3%, P < 0.01), and reduction in pulmonary artery systolic pressure (PASP, 41.0 2.7 vs 28.6 2.2 mmHg; P < 0.01) compared with baseline. Repeated PSG after CRT demonstrated a reduction in the duration of arterial oxygen desaturation ,95% (251.2 36.7 vs 141.0 37.1 minutes), AHI (27.5 4.7 vs 18.1 3.0, P = 0.05), and number of central sleep apnea (CSA) (7.8 2.6 vs 3.0 1.3/hour, P = 0.03), but not number of obstructive sleep apnea (OSA, 8.6 3.3 vs 7.2 2.3/hour, P = 0.65) compared to baseline. Percentage change in PASP was significantly correlated with percentage changes in LVEF (r=,0.57, P = 0.04), AHI (r = 0.5, P = 0.05), and number of CSA episodes (r = 0.55, P = 0.02). Conclusions: The results demonstrated that CRT significantly reduces CSA in patients with HF. Importantly, we have noted a decrement of PASP correlated to drop in CSA which maybe one of the mechanisms explaining this observation. Future studies are required to confirm our finding and elucidate other possible mechanisms in this regard. [source]

An acute pain service improves postoperative pain management for children undergoing selective dorsal rhizotomy

Summary Background:, A continuous epidural infusion of morphine is the pain treatment modality for children undergoing selective dorsal rhizotomy (SDR) in our institution. The aim of the study was to evaluate the impact of having an organized acute pain service (APS) on postoperative pain management of these children. Methods:, We conducted a retrospective cohort study using anesthetic records and the APS database to compare the postoperative pain management of children undergoing SDR before and after the introduction of the APS at the Montreal Children's Hospital in April 2001. Ninety-two consecutive children who had their surgery between January 1997 and July 2006 were included. We collected data regarding postoperative pain, opioid-induced side effects, complications (sedation, desaturations < 92%), and hospital length of stay. Results:, Pain scores were documented more frequently after the implementation of the APS (61% vs 48.5%). Sedation scores were documented only after the implementation of the APS. Postoperative desaturation was significantly more frequent in the pre-APS group compared to the APS group (45.5% vs 6.8%, P < 0.001). Despite the fact that the epidural catheter was in place for the same duration for both groups [median of 3 days (3,3 25,75%ile)], the duration of hospitalization was 1 day shorter in the APS group compared to the pre-APS group [median of 5 (5,5 25,75%ile) vs 6 (5,6 25,75%ile) days, P < 0.001]. Conclusions:, Although we recognize that it is possible that there were changes in care not related specifically to the introduction of a dedicated APS that occurred in our institution that resulted in improvements in general postoperative care and in length of stay, our study did show that having an organized APS allowed to significantly decrease the incidence of postoperative oxygen desaturation and to decrease the hospital length of stay by 1 day. [source]

Raynaud's phenomenon in a child presenting as oxygen desaturation during transfusion with cold blood

Summary We report a case of Raynaud's phenomenon (RP) triggered by transfusion of cold blood to a pediatric burn patient under general anesthesia. The child was febrile so a decision was made to not use a blood warmer. When the blood was rapidly administered the child suddenly developed ,desaturation'. The child was placed on 100% oxygen, adequate ventilation assured, and the color of his oral mucosa assessed as ,pink'. Placement of the oximeter on the opposite hand revealed 100% saturation. To our knowledge, this is the first case of apparent RP reported in a pediatric patient triggered by transfusion of cold blood. [source]

Sedation with ketamine and low-dose midazolam for short-term procedures requiring pharyngeal manipulation in young children

Summary Background:, Pediatric intestinal biopsy procedures including considerable transpharyngeal manipulation of a wire-guided metal capsule require adequate sedation or anesthesia. This retrospective cohort study was designed to evaluate intravenous sedation with ketamine and low-dose midazolam in young children undergoing these procedures before and also after discharge from the hospital. Methods:, A total of 244 biopsy procedures in 217 children under the age of 16 years were evaluated. All anesthesia records were reviewed according to a defined study protocol and in 145 cases the parents were also interviewed by telephone to obtain further information on possible adverse effects before and after discharge. Results:, Ketamine and low-dose midazolam were carefully titrated by an experienced anesthesia team at an approximate dose ratio of 40 : 1 (total doses 2.3 and 0.05 mgkg,1) in continuously monitored spontaneously breathing children. Possibly associated problems before discharge were salivation (5.7%), vomiting (4.9%), oxygen desaturation (3.3%), laryngospasm (2.5%) and rash (1.2%) according to the patient records and blurred vision (27%), nausea and vomiting (19%), vertigo (13%) and hallucinations or nightmares (3.5%) according to telephone interviews. Few, mild and transient problems remained after discharge from the hospital. Conclusions:, Careful titration of ketamine and low-dose midazolam provides adequate sedation for nonsurgical pediatric short-term procedures also requiring considerable pharyngeal manipulation, particularly considering the low number of serious airway problems such as laryngospasm. The high incidence of late postoperative problems suggests that prospective studies should be designed for long-term follow-up of young children subjected to sedation or anesthesia. [source]

Episodes of hypoxemia during synchronized intermittent mandatory ventilation in ventilator-dependent very low birth weight infants

Steve R.E. Firme MD
Abstract Distinct patterns of asynchrony, and episodes of hypoxemia, may occur in a spontaneously breathing preterm infant during conventional intermittent mandatory ventilation (IMV) on traditional time-cycled, pressure-limited ventilators. Synchronized IMV (SIMV) and assist/control ventilation are frequent modes of patient-triggered ventilation used with infant ventilators. The objective of this study was to use computerized pulse oximetry to quantify the occurrence of episodes of hypoxemia (oxygen desaturation) during SIMV vs. IMV, in preterm infants ,1,250 g who required mechanical ventilation at ,14 days of age. We performed a randomized, crossover study with each infant being randomized to IMV or SIMV (Infant Star ventilator) for initial testing for a 1-hr period. Patients were subsequently tested on the alternate modality after a stabilization period of 10 min at the same ventilator and fractional inspired oxygen concentration (FiO2) settings. Pulse oximetry data were obtained with a Nellcor N-200 monitor, a microcomputer, and a software program (SatMaster). An investigator blinded to the randomized assignment evaluated all measurements. Eighteen very low birth weight (VLBW) infants with a birth weight of 777,,39 g (mean,,SEM) and gestational age 25.1,,0.3 weeks were studied. The average pulse oximeter oxygen saturation (SaO2) was higher on SIMV than IMV (P,<,0.01). During SIMV, these infants had significantly fewer episodes of hypoxemia (duration of episodes of oxygen desaturation as a percentage of scorable recording time) to 86,90% SaO2 (P,<,0.01), 81,85% SaO2 (P,<,0.01), and 76,80% SaO2 (P,<,0.05) when compared to IMV. There was also a significant decrease in percentage of time of desaturation to SaO2,<,90% (P,=,0.002),,<,85% SaO2 (P,=,0.003), and <80% SaO2 (P,=,0.02) during SIMV vs. IMV. Our preliminary findings indicate that the use of SIMV in a population of VLBW ventilator-dependent infants (,14 days of age) results in better oxygenation and decreased episodes of hypoxemia as compared to IMV. 2005 Wiley-Liss, Inc. [source]

Three components of obstructive sleep apnea/hypopnea syndrome

Takayuki Kumano-Go
Abstract The aims of this study were to calculate the apnea,hypopnea index (AHI), which represented as the number of apnea,hypopnea occurrences per hour, the 4% oxygen desaturation index (ODI4) and the breathing-related arousal index (B-ArI) in polysomnographic studies of obstructive sleep apnea/hypopnea syndrome (OSAHS) patients and to investigate whether there was any relationship between each pair of scoring schemes. Thirty-four cases of OSAHS were studied. Total OSAHS patients were subdivided into those with a high AHI (> 25), and those with a low AHI (< 25). The correlation between each pair of scoring schemes for OSAHS with a high AHI showed high value. The correlation between AHI and ODI4 for OSAHS with a low AHI was 0.18 and that between AHI and B-ArI showed a weak correlation of 0.59, while that between ODI4 and B-ArI was only ,0.078. Our results mean that oxygen desaturation and arousal occur separately in mild or moderate OSAHS patients, even though they are diagnosed with the same level of OSAHS by means of AHI. Breathing-related arousal without oxygen desaturation often occurs in mild or moderate OSAHS patients. We previously reported that AHI does not accurately reflect the severity of the increase in negativity of esophageal pressure manifested as respiratory efforts. We consider that the comprehension and assessment of OSAHS can be improved by the systematic differentiations among the three components: oxygen desaturation, arousals and respiratory efforts. [source]

Effects of hypoxia on diaphragmatic fatigue in highly trained athletes

Ioannis Vogiatzis
Previous work suggests that exercise-induced arterial hypoxaemia (EIAH), causing only moderate arterial oxygen desaturation (: 92 1%), does not exaggerate diaphragmatic fatigue exhibited by highly trained endurance athletes. Since changes in arterial O2 tension have a significant effect on the rate of development of locomotor muscle fatigue during strenuous exercise, the present study investigated whether hypoxia superimposed on EIAH exacerbates the exercise-induced diaphragmatic fatigue in these athletes. Eight trained cyclists (: 67.0 2.6 ml kg,1 min,1; mean s.e.m.) completed in balanced order four 5 min exercise tests leading to different levels of end-exercise (64 2, 83 1, 91 1 and 96 1%) via variations in inspired O2 fraction (: 0.13, 0.17, 0.21 and 0.26, respectively). Measurements were made at corresponding intensities (65 3, 80 3, 85 3 and 90 3% of normoxic maximal work rate, respectively) in order to produce the same tidal volume, breathing frequency and respiratory muscle load at each . The mean pressure time product of the diaphragm did not differ across the four exercise tests and ranged between 312 28 and 382 22 cmH2O s min,1. Ten minutes into recovery, twitch transdiaphragmatic pressure (Pdi,tw) determined by bilateral phrenic nerve stimulation, was significantly (P= 0.0001) reduced after all tests. After both hypoxic tests (: 0.13, 0.17) the degree of fall in Pdi,tw (by 26.9 2.7 and 27.4 2.6%, respectively) was significantly greater (P < 0.05) than after the normoxic test (by 20.1 3.4%). The greater amount of diaphragmatic fatigue in hypoxia at lower leg work rates (presumably requiring smaller leg blood flow compared with normoxia at higher leg work rates), suggests that when ventilatory muscle load is similar between normoxia and hypoxia, hypoxia exaggerates diaphragmatic fatigue in spite of potentially greater respiratory muscle blood flow availability. [source]

EMLA Cream coated on the rigid bronchoscope for tracheobronchial foreign body removal in children

Hai Yu MD
Abstract Objectives: Removal of a tracheal or bronchial foreign body is a common emergent surgical procedure in children. The anesthetic management can be challenging. EMLA Cream (EC) has been widely used to provide topical anesthesia. In the present study, we evaluate the efficacy and safety of EC coated on the rigid bronchoscope for tracheobronchial foreign body removal in children undergoing intravenous anesthesia with spontaneous ventilation. Study Design: The authors conducted a randomized, double-blind, placebo-controlled clinical trial. Methods: Thirty patients were randomized to receive either EC or placebo (lubricant ointment) coated on the rigid bronchoscope. Intravenous anesthesia and spontaneous ventilation were performed in all patients. Heart rate, blood pressure, pulse oxygen saturation (SpO2) and frequency and degree of breath holding were recorded. After surgery, the bronchoscopist rated overall surgical manipulation as excellent, fair, and poor. The durations of postoperative care were also recorded. Results: Episodes of oxygen desaturation (SpO2 < 90%) occurred in 3/15 (20%) patients in the EC group and in 9/15 (60%) patients in the control group (P < .05). Occurrences and degrees of breath holding were less in the EC group than that in the control group (P < .05). Ranks of surgical manipulation were excellent in 80% of patients in the EC group versus 13% of patients in the control group (P < .05). The durations of postoperative care were shorter in the EC group than that in the control group (P < .05). Conclusions: EC coated on the rigid bronchoscope combined with intravenous anesthesia could provide more efficacious and safer anesthesia for tracheobronchial foreign body removal in children under spontaneous ventilation. Laryngoscope, 119:158,161, 2009 [source]

Overnight Hospital Stay Is Not Always Necessary after Uvulopalatopharyngoplasty,

FACS, Jeffrey H. Spiegel MD
Abstract Objectives: To determine whether patients with obstructive sleep apnea who undergo uvulopalatopharyngoplasty (UPPP) have a significant incidence of postoperative complications that would justify overnight postoperative observation in the hospital. Study Design: Part 1: review of published medical literature to determine incidence of postoperative complications. Part 2: retrospective review of 117 patients undergoing UPPP with or without additional procedures. Methods: A literature search for existing studies describing the postoperative complications after UPPP for obstructive sleep apnea was conducted. After this, the records of 117 patients who had undergone UPPP at a university-based medical center during a 5-year span were reviewed. Results: Respiratory events occur in 2% to 11% of cases. These include airway obstruction (e.g., laryngospasm), postobstructive pulmonary edema (POPE), and desaturation. Airway obstruction occurred in the immediate postoperative setting. POPE was rare and usually occurred within minutes after the conclusion of the surgical procedure. Desaturation could occur at any time, but the severity was usually equivalent to that found on preoperative sleep study. Hemorrhage occurred in 2% to 14% of cases and had a biphasic incidence, occurring either immediately postoperatively or several days after surgery. Depending on definition, hypertension was observed in between 2% and 70% of patients postoperatively. This was most commonly diagnosed and treated in the immediate postoperative setting. In most reports, arrhythmia and angina occurred in less than 1% of cases. Conclusions: The majority of complications after UPPP with or without additional procedures occur within 1 to 2 hours after surgery. Postoperative oxygen desaturation is usually no worse than that that was observed on preoperative polysomnography findings. A 2 to 3 hour observation period may be suitable for patients after UPPP; if a patient experiences no complications and is maintaining adequate oxygenation and analgesia, same-day discharge from recovery room may be considered. [source]

Effect of suxamethonium vs rocuronium on onset of oxygen desaturation during apnoea following rapid sequence induction

ANAESTHESIA, Issue 4 2010
S. K. Taha
Summary This study investigates the effect of suxamethonium vs rocuronium on the onset of haemoglobin desaturation during apnoea, following rapid sequence induction of anaesthesia. Sixty patients were randomly allocated to one of three groups. Anaesthesia was induced with lidocaine 1.5 mg.kg,1, fentanyl 2 ,g.kg,1 and propofol 2 mg.kg,1, followed by either rocuronium 1 mg.kg,1 (Group R) or suxamethonium 1.5 mg.kg,1 (Group S). The third group received propofol 2 mg.kg,1 and suxamethonium 1.5 mg.kg,1 only (Group SO). The median (IQR [range]) time to reach SpO2 of 95% was significantly shorter in Group S (358 (311,373 [215,430]) s) than in Group R (378 (370,393 [366,420]) s; p = 0.003), and shorter in Group SO (242 (225,258 [189,370]) s) than in both Group R (p < 0.001) and Group S (p < 0.001). When suxamethonium is administered for rapid sequence induction of anaesthesia, a faster onset of oxygen desaturation is observed during the subsequent apnoea compared with rocuronium. However, time to desaturation is prolonged whenever lidocaine and fentanyl precede suxamethonium. [source]

Patient-maintained propofol sedation: a follow-up safety study using a modified system in volunteers

ANAESTHESIA, Issue 4 2002
F. Henderson
Summary Patient-maintained sedation is a mode of patient-controlled sedation during which propofol is administered using a target-controlled infusion, with patient demand increasing the target concentration. A system tested previously for safety in our institution resulted in oversedation. Aiming to improve safety, we modified the system by increasing the lockout period to 4 min, reducing the starting concentration to 0.5 g.ml,1 and the increments on demand to 0.1 g.ml,1. As in the previous study, healthy volunteers attempted to render themselves unconscious by frequently pressing the demand button. To assess effects on memory, volunteers were given keywords to remember every 15 min. The maximum target concentration reached varied between 1.0 and 2.5 g.ml,1. No volunteers lost consciousness, however, one volunteer had a brief period of apnoea and oxygen desaturation. The Cp50 for loss of memory for words was 1.26 g.ml,1. Although this version represents an improvement, we conclude that the system is not yet completely suitable for use without anaesthetic supervision. [source]

Thiopental pharmacokinetics in newborn infants: a case report of overdose

Elisabeth Norman
Abstract Thiopental may be used for sedation before intubation in newborn infants. A boy, born at 33 weeks of gestation (gw); birth weight 2435 g, was prescribed thiopental 3 mg/kg before intubation. He developed temporary hypotension and oxygen desaturation, and remained unconscious for longer than expected with a suppressed electroencephalography for 48 h. Serum thiopental concentration was 82, 59, 42 and 32 ,mol/L after 20 min and 6, 24 and 68 h respectively. Serum concentrations from five newborn infants at the same time points after intubation with the same thiopental dose were used as reference values, and indicated a 10-fold overdose in the index case. The cause of the overdose could not be identified. The infant recovered; cerebral magnetic resonance imaging at the age of 42 gw and psychomotor development at 2 years were normal. These results show that thiopental concentrations are variable in neonates and there is a high risk of dosage error as no specific paediatric formulation is available. Conclusion:, Well-designed procedures and continuous education are required to prevent errors and adverse events during drug delivery to newborn infants. To develop a safe method of administration for thiopental, an extended pharmacokinetic and pharmacodynamic study in neonates is warranted. [source]

Risk factors for adverse events in children with colds emerging from anesthesia: a logistic regression

Summary Background:, Recent upper respiratory infection (URI) in children increases respiratory adverse events following anesthesia for elective surgery. The increased risk continues weeks after resolution of acute URI symptoms. Few systematic analyses have explored specific risk factors. This logistic regression explores the relationship between preoperative URI symptoms and adverse events during emergence from anesthesia. Methods:, Data were combined from control groups of several prospective observational and interventional studies in elective pediatric anesthesia in a tertiary care pediatric hospital. In each study, a blinded observer, distinct from the anesthesia care team, prospectively recorded the presence of stridor, oxygen desaturations (and their duration), coughing and laryngospasm. Parents were subsequently asked about the presence of 10 cold symptoms during the 6 weeks prior to operation. Results:, Our model, based on a dataset of 335 patients, did not demonstrate an association between any particular symptoms and the rate of respiratory adverse events during emergence from anesthesia, with the exception of low-grade fever which appeared to be mildly protective. Respiratory adverse events were affected by the airway management technique (device used and timing of extubation), and adverse events were increased if peak URI symptoms had occurred within the preceding 4 weeks. Conclusions:, Specific preoperative symptoms were not useful in predicting respiratory adverse events during emergence from anesthesia. [source]