Anesthesia and analgesia
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Anesthesia and analgesia · May 1998
Comparative StudyA comparison of awake versus paralyzed tracheal intubation for infants with pyloric stenosis.
This prospective, nonrandomized, observational study of 76 infants with pyloric stenosis was conducted at an academic children's hospital and compared awake versus paralyzed tracheal intubation in terms of successful first attempt rate, intubation time, heart rate (HR) and arterial hemoglobin oxygen saturation (SpO2) changes, and complications. Three groups were determined by intubation method: awake (A) with an oxygen-insufflating laryngoscope, after rapid-sequence induction (R), or after modified rapid-sequence induction (M) including ventilation through cricoid pressure. Successful first attempt intubation rate was 64% for Group A versus 87% for paralyzed Groups R and M (P = 0.028). Median intubation time was 63 s in Group A versus 34 s in Groups R and M (P = 0.004). Transient, mild decreases in mean HR and SpO2 and incidences of significant bradycardia and decreased SpO2 did not vary by group. Complications, including bronchial or esophageal intubation, emesis, and oropharyngeal trauma, were few. Senior anesthesiologists intervened in four tracheal intubations. We advocate anesthetized, paralyzed tracheal intubation because struggling with conscious infants takes longer, often requires multiple attempts, and prevents neither bradycardia nor decreased SpO2. After induction, additional mask ventilation with O2 confers no advantage over immediate tracheal intubation in preserving SpO2. ⋯ In our children's hospital, awake tracheal intubation was not superior to anesthetized, paralyzed intubation in maintaining adequate oxygenation and heart rate or in reducing complications, and should be abandoned in favor of the latter technique for routine anesthetic management of otherwise healthy infants with pyloric stenosis.
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Uptake of inhaled anesthetics may be measured as the amount of anesthetic infused to maintain a constant alveolar concentration of anesthetic. This method assumes that the patient absorbs all of the infused anesthetic, and that none is lost to circuit components. Using a standard anesthetic circuit with a 3-L rebreathing bag simulating the lungs, and simulating metabolism by input of carbon dioxide, we tested this assumption for halothane, isoflurane, and sevoflurane. Our results suggest that after washin of anesthetic sufficient to eliminate a material difference between inspired and end-tidal anesthetic, washin to other parts of the circuit (probably the ventilator) and absorbent (soda lime) continued to remove anesthetic for up to 15 min. From 30 min to 180 min of anesthetic administration, circuit components absorbed trivial amounts of isoflurane (12 +/- 13 mL vapor at 1.5 minimum alveolar anesthetic concentration, slightly more sevoflurane (39 +/- 15 mL), and still more halothane (64 +/- 9 mL). During this time, absorbent degraded sevoflurane (321 +/- 31 mL absorbed by circuit components and degraded by soda lime). The amount degraded increased with increasing input of carbon dioxide (e.g., the 321 +/- 31 mL increased to 508 +/- 48 mL when carbon dioxide input increased from 250 mL/min to 500 mL/min). Measurement of anesthetic uptake as a function of the amount of anesthetic infused must account for these findings. ⋯ Systems that deliver inhaled anesthetics may also remove the anesthetic. Initially, anesthetics may diffuse into delivery components and the interstices of material used to absorb carbon dioxide. Later, absorbents may degrade some anesthetics (e.g., sevoflurane). Such losses may compromise measurements of anesthetic uptake.
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Anesthesia and analgesia · May 1998
Sterility of anesthetic and resuscitative drug syringes used in the obstetric operating room.
Because of the constant threat of emergent cesarean delivery, anesthetic induction and resuscitation drugs are often drawn into syringes and stored in the obstetric operating room (OR). This study investigated the potential for bacterial and fungal contamination of six drugs (thiopental, succinylcholine, ephedrine, atropine, lidocaine, and oxytocin) often prepared in the obstetric OR. A total of 756 drug syringes were prepared and stored in the obstetric OR for 8 days using normal clinical practices. Starting on Day 0, and subsequently on Days 4 and 8 of the experiment, 42 syringes of each drug were randomly selected from the pool, filtered through a 0.45-microm porosity sterile cellulose filter, and cultured on 5% sheep blood agar. Of the 756 syringes tested, none grew organisms of any type, which indicates a probability of drug sterility of > or = 0.9961 (95% confidence interval [CI]). The data from the cultures performed on syringes on Day 0 indicate a probability of initial contamination of < or = 0.018 (95% CI). This study demonstrates a high probability of sterility in drugs drawn into sterile syringes and stored at room temperature in an OR environment for up to 8 days. ⋯ Drug syringes stored in emergency operating rooms are discarded after 24 h because of possible contamination. We searched for microorganisms in drug syringes stored in the operating room for up to 8 days. No microbes were detected using standard sterility testing techniques. Adopting longer storage periods could result in significant cost savings.