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PubMed2005

Tracheal intubation in routine practice with and without muscular relaxation: an observational study.

BACKGROUND AND OBJECTIVE: The ease of endotracheal intubation has been recently shown to affect the incidence of laryngeal injury. There remains controversy as to whether or not a muscle relaxant is routinely required for tracheal intubation. This study examined conditions of intubation in our routine practice, which employs a relaxant-sparing approach. METHODS: All adult patients scheduled for surgery with general anaesthesia were prospectively included. A muscle relaxant was used to facilitate intubation when it was required for the surgical procedure and/or otherwise regarded as necessary by the anaesthesiologist. In the remaining patients, a relaxant-free intubation was performed. Intubating conditions were evaluated in all the patients as well as the post-intubation laryngeal symptoms. RESULTS: Between March and July 2003, 612 patients were consecutively included. A muscle relaxant was used in 32% of patients and no relaxant in the remaining patients (68%). Clinically acceptable intubating scores were observed in 98.4% overall with no significant difference between the two groups. Excellent conditions occurred more frequently in the relaxant group as compared to the relaxant-free group, 87% vs. 72%, P = 0.005. Laryngeal symptoms occurred in 184 (33%) patients with no difference between the two groups. CONCLUSIONS: Our relaxant-sparing approach did not increase the incidence of poor conditions of intubation nor laryngeal symptoms. However, excellent conditions occurred more frequently in the relaxant group. A more flexible approach to the issue of the need for neuromuscular blockade prior to intubation is proposed.

Adult↗
PubMed2006

Comparison of haemodynamic responses to orotracheal intubation with GlideScope videolaryngoscope and fibreoptic bronchoscope.

BACKGROUND AND OBJECTIVE: The GlideScope videolaryngoscope is a newly developed laryngoscope for tracheal intubation recently introduced into clinical anaesthesia. In this randomised clinical study, we compared the haemodynamic responses to orotracheal intubation using a GlideScope videolaryngoscope and a fibreoptic bronchoscope. METHODS: Fifty-six adult patients, ASA I-II scheduled for elective plastic surgery under general anaesthesia requiring orotracheal intubation were randomly allocated to either the GlideScope videolaryngoscope group or the fibreoptic bronchoscope group. After a standard intravenous anaesthetic induction, orotracheal intubation was performed. Noninvasive blood pressure and heart rate were recorded before and after induction, at intubation and for 5 min after intubation at 1 min intervals. RESULTS: As compared with the post-induction values the orotracheal intubations using a fibreoptic bronchoscope and a GlideScope videolaryngoscope resulted in the significant increases in blood pressures which did not exceed their baseline values. In the two groups, heart rates at intubation and within 2 min after intubation were significantly higher than their baseline values. However, there were no significant differences in blood pressures and heart rates at all time points, their maximal values and maximal percent changes during the observation and the times required to reach their maximal values between the two groups. CONCLUSIONS: The orotracheal intubations using a fibreoptic bronchoscope and a GlideScope videolaryngoscope produce similar haemodynamic responses.

Adolescent↗
PubMed1998

Performance of a plastic optical fiber stylet for tracheal intubation of a dog.

OBJECTIVE: We set out to establish whether a novel plastic optical fiber incorporated into an endotracheal tube (ETT) stylet could be used for intubation of a dog. A secondary objective examined the need for a direct illumination source from a laryngoscope. Lastly, the fragility of the system was tested. METHODS: An anesthetized dog was repeatedly intubated using a laryngoscope to elevate the tongue and the view of the larynx conducted through the plastic optical fiber stylet (placed within an endotracheal tube) and displayed on a television monitor. Four prototype identical stylets were tested. Repeated intubations were attempted with each stylet and graded as either successful or failed. All four stylets were tested 10 times each using a Miller 4 blade and direct illumination from the laryngoscope. Two of the four stylets were reused during an additional 10 intubation attempts using a Miller 4 blade and laryngoscope (without batteries) with only ambient light. Finally, one stylet was used for intubation after 10, 20, 30, 40 and 50 sharp 90 degree bend-and-straighten cycles using a Miller 4 blade and laryngoscope for direct illumination. RESULTS: All attempted intubations were successful. However, the image quality was dramatically better when direct illumination from a laryngoscope was used than when ambient light was used. One plastic optical fiber stylet was successfully used to intubate after having been used for 20 intubations and 50 sharp 90 degree bend-and-straighten cycles. A partial lens separation occurred between the 41st and 50th bend cycle but the image remained adequate enough to successfully intubate again. CONCLUSIONS: A novel plastic optical fiber incorporated into an ETT stylet can be used with a laryngoscope for intubation of a dog. Direct illumination from a laryngoscope provides a better television monitor image than when only ambient light is used. The system was durable, withstanding over 20 uses and 40 sharp bend-and-straighten cycles before a lens separation failure occurred.

Animals↗
PubMed1999

A comparison of two silicone-reinforced tracheal tubes with different bevels for use with the intubating laryngeal mask.

Seventy consecutive patients were randomly allocated for intubation through the intubating laryngeal mask airway using a straight reinforced silicone tracheal tube with either a conventional or a modified bevel. The conventional bevel was firm, wedge-shaped and with a leading edge at the side. The modified bevel was soft, hemispherical and with a leading edge in the midline. The intubating laryngeal mask position was adjusted until optimal ventilation was obtained and intubation was attempted using the randomised device. If tactile resistance was felt, a predetermined sequence of adjusting manoeuvres were utilised before a subsequent attempt. The first-attempt successful intubation rate with the conventional bevel was 23/37 (62%) and with the modified bevel was 28/33 (85%). The second-attempt successful intubation rate for the conventional bevel was 12/37 (32%) and for the modified bevel was 4/33 (12%). Intubation failed after three attempts for one patient in each group. Fewer overall intubation attempts were required with the modified bevel (p = 0.033). We conclude that intubation success rates through the intubating laryngeal mask with a straight silicone-reinforced tube are higher with a soft, hemispherical bevel with a leading edge in the midline compared with the firm, wedge-shaped bevel with a leading edge at the side.

Adult↗
PubMed2002

The cardiovascular response to insertion of the intubating laryngeal mask airway.

Sixty-one patients received a standardised anaesthetic and were randomly assigned to three groups: tracheal intubation via direct laryngoscopy, tracheal intubation via an intubating laryngeal mask airway with immediate removal of the device, and tracheal intubation via an intubating laryngeal mask airway with delayed removal. The cardiovascular response to intubation was of a similar magnitude in all groups, although delayed removal of the intubating laryngeal mask airway was associated with a second pressor response. Norepinephrine changed significantly over time following direct laryngoscopy and following immediate removal of the intubating laryngeal mask airway, but not after delayed removal. The findings of this study do not support using the intubating laryngeal mask instead of direct laryngoscopy purely to decrease the response to intubation.

Adult↗
PubMed2003

A clinical evaluation of the Bonfils Intubation Fibrescope.

The Bonfils Intubation Fibrescope is a rigid optical instrument for performing orotracheal intubation. We describe its introduction into our clinical practice in 60 patients with normal airways who required orotracheal intubation for elective surgery. Two anaesthetists each performed 30 attempts to intubate, in turn, in patients who received a standard general anaesthetic with neuromuscular blockade. Intubation was successful in 59 out of 60 cases. The median (IQR [range]) time to intubation was 33 s (24-50 [13-180] s). Median (IQR [range]) verbal rating score for difficulty was 2 (1-3 [0-10]). There was a significant correlation between the intubation times and the verbal rating score (p < 0.01). There was evidence of airway trauma in the single patient in whom intubation failed. The Bonfils Intubation Fibrescope is an effective instrument for orotracheal intubation in normal subjects.

Adult↗
PubMed2000

Role of infection in the development of acquired subglottic stenosis in neonates with prolonged intubation.

OBJECTIVE: To examine whether clinically diagnosed infection correlates with subsequent development of subglottic stenosis in intubated neonates. METHODS: Sixty-two neonatal infants intubated for more than 14 days were examined. Several risk factors for subglottic stenosis, including infection, duration of intubation, frequency of intubation, the size of the endotracheal tube etc., were evaluated by multiple logistic regression analysis. RESULTS: Infection that occurred within 14 days of intubation showed a positive correlation with subsequent subglottic stenosis. The duration of intubation, frequency of intubation and the size of the endotracheal tube did not affect the development of subglottic stenosis. The majority of infections were considered to be respiratory tract infections, including pneumonia. CONCLUSIONS: Infection occurring within 14 days of intubation is considered to be a risk factor for acquired subglottic stenosis in neonates intubated for more than 14 days. Prevention of infection within 14 days of intubation may reduce the incidence of subglottic stenosis in neonates.

Gestational Age↗
PubMedDate not supplied

Prehospital rapid-sequence intubation: a pilot training program.

OBJECTIVE: To develop a training program enabling paramedics to use sedation and paralytic medications to facilitate endotracheal intubation in patients who otherwise could not be successfully intubated. METHODS: Paramedics underwent a training program consisting of six hours of didactic education, two four-hour mannequin labs, one four-hour animal intubation lab, and operating room experience. Rapid-sequence intubation (RSI) runs were reviewed for appropriateness in patient selection and medication use. Non-RSI runs were reviewed to determine whether appropriate patients were being missed. Intubation success rates continue to be followed. Long-term quality assurance includes monthly run reviews, periodic quizzes, and unannounced on-site practical tests. RESULTS: 101 patients have been intubated using RSI, including medical, trauma, pediatric, and adult cases. Of all patients receiving RSI drugs, 100 of 101 were successfully intubated. There were no undetected esophageal intubations. Paramedics were able to demonstrate proper patient selection and appropriately administer RSI medications. The use of sheep labs was a critical component of this training because it permitted multiple intubations in a live model possessing an airway quite similar to that of the human. The gum elastic bougie was felt to be critical in the intubation of three patients. CONCLUSION: This RSI training model can serve as a template for other agencies seeking to implement RSI. Limitations of this model include the availability of live animal labs and the expense of conducting the training. Intense medical director involvement has been key to the success of this prehospital RSI program.

Airway Obstruction↗
PubMed1998

Relationship between difficult tracheal intubation and obstructive sleep apnoea.

The upper airway abnormalities predisposing to difficult tracheal intubation may also predispose to obstructive sleep apnoea (OSA). The potential association is important as both conditions increase perioperative risk and patients with a trachea that is difficult to intubate may need assessment for OSA. We determined if patients with difficult intubation are at greater risk of OSA and, if so, whether or not they have characteristic clinical or radiographic upper airway changes. We studied 15 patients in whom the trachea was difficult to intubate and 15 control patients. Each was evaluated clinically (Mallampati score, thyromental distance, neck circumference, head extension), polysomnographically (apnoea-hypoponea index (AHI)) and radiographically (lateral cephalometry). AHI was greater in the difficult intubation group (mean 28.4 (SD 31.7)) compared with controls (5.9 (8.9)) (P < 0.02); eight of 15 patients in the difficult intubation group and two of 15 in the control group had an AHI > 10 (P < 0.03). Difficult intubation, but not OSA, was associated (P < 0.05) with a smaller thyromental distance and mandibular length, and greater soft palate length. Both difficult intubation and OSA were associated (P < 0.05) with a greater Mallampati score, anterior mandibular depth, and smaller mandibular and cervical angles. OSA, but not difficult intubation, was associated (P < 0.05) with increased neck circumference, tongue area and craniocervical angle, and decreased head extension, mandibular ramus length and atlantooccipital distance. We conclude that difficult intubation and OSA are related significantly. They share anatomical features which act to reduce the skeletal confines of the tongue. Patients with OSA may compensate, when awake, by increasing craniocervical angulation, which increases the space between the mandible and cervical spine and elongates the tongue and soft tissues of the neck.

Adult↗
PubMed1997

A comparison of light wand and suspension laryngoscopic intubation techniques in outpatients.

UNLABELLED: Endotracheal intubation can produce postoperative sore throat and hoarseness, as well as changes in cardiovascular variables. A major goal of ambulatory surgery is the prompt return of patients to their daily activities. Postoperative sore throat may impede this and may decrease patient satisfaction with their anesthetic and surgical experience. We conducted a prospective, randomized study in 40 outpatients having lower extremity arthroscopies to compare the effects of direct laryngoscopy and light wand intubation on cardiovascular changes, sore throat, hoarseness, and dysphagia. Subjects were randomly assigned to either Group A (endotracheal intubation by rigid laryngoscopy) or Group B (endotracheal intubation with a light wand). A standardized anesthetic technique was used. Heart rate and blood pressure were recorded before induction, after induction but before endotracheal intubation, and at 1-min intervals for the first 5 min after intubation. Sixteen to twenty-four hours postoperatively, the incidence and severity of sore throat, hoarseness, and dysphagia was assessed by a follow-up phone call. This study demonstrated no clinically significant difference in cardiovascular variables between the two techniques. Patients had a significantly lower incidence and severity of sore throat, hoarseness, and dysphagia when a light wand was used for intubation. In conclusion, this study suggests that light wand intubation may decrease the incidence and severity of postoperative sore throat, hoarseness, and dysphagia, thereby potentially increasing satisfaction in ambulatory surgical patients. IMPLICATIONS: This prospective, randomized study found that the incidence and severity of postoperative sore throat, hoarseness, and difficulty in swallowing among ambulatory surgical patients is more frequent when they are endotracheally intubated with a rigid laryngoscope than with a light wand. The authors, therefore, recommend more frequent use of the light wand for endotracheal intubation.

Adult↗
PubMed1999

The intubating laryngeal mask airway with and without fiberoptic guidance.

UNLABELLED: We conducted this feasibility study using the intubating laryngeal mask airway (ILMA) and a polyvinyl chloride tracheal tube to compare success rates, hemodynamic effects, and postoperative morbidity with two methods of tracheal intubation. After ethics approval and informed consent, 90 healthy ASA physical status I or II women with normal airways were enrolled in the randomized, controlled study. After a standardized inhaled anesthesia induction protocol, tracheal intubations using ILMA with fiberoptic guidance (ILMA-FOB) and ILMA inserted blindly without fiberoptic guidance (ILMA-Blind) were compared with the control group of direct laryngoscopy (laryngoscopy group). All 90 patients were successfully ventilated. For tracheal intubation, success rates were equal in all three groups (97%). Total intubation times were longer for the ILMA-FOB group (77 s versus 48.5 s for laryngoscopy and 53.5 s for ILMA-Blind). The laryngoscopy group had a larger increase in mean arterial blood pressure to tracheal intubation. There were no differences in postoperative sore throat or hoarseness among the groups. In conclusion, success rates are equally high for tracheal intubation using ILMA-Blind and ILMA-FOB techniques in women with normal airways. IMPLICATIONS: The intubating laryngeal mask airway (ILMA) can be used as a primary airway for oxygenation and ventilation. Both methods of tracheal intubation using the ILMA were equally successful. Postoperative morbidity in the ILMA groups was similar to that in the laryngoscopy group. For women with normal airways, both the ILMA inserted blindly and the ILMA with fiberoptic guidance are suitable alternatives to laryngoscopy for tracheal intubation.

Adult↗
PubMed1992

Complications of endotracheal intubation and mechanical ventilation in infants and children.

OBJECTIVE: To assess the frequency of complications of endotracheal intubation and mechanical ventilation. DESIGN: Prospective cohort study. SETTING: Pediatric tertiary multidisciplinary ICU. PATIENTS: Eight hundred sixty-nine serial patients, of whom 500 were endotracheally intubated and 431 were mechanically ventilated. INTERVENTIONS: Daily clinical observation. MAIN OUTCOME MEASURES: Age, diagnosis, endotracheal tube size, type of ventilator and humidification, duration of intubation and mechanical ventilation, ventilatory settings, and complications (accidental extubation, tissue damage, endobronchial intubation, postintubation stridor, endotracheal tube blockage, pulmonary airleak, bronchopulmonary dysplasia, pulmonary atelectasis) were recorded. RESULTS: The median patient age was 10 months (25th and 75th quartiles: 1 month and 15 yrs). The median duration of endotracheal intubation and mechanical ventilation was 4 days and 2 days, respectively. A total of 186 complications were recorded in 119 (24%) patients. No deaths were due to intubation or ventilation. The overall frequency of accidental extubation was 3.2% of patients at a rate of 1.26 extubations/100 intubation days. In nonventilated, unsedated patients with croup or epiglottitis, the frequency of accidental extubation was 23% at a rate of 11.83 extubations/100 intubation days. Lung atelectasis occurred in 7.8%, airleak in 6.8%, and infection in 2.3% of patients. Other complications included tissue damage (3.4%), endobronchial intubation (2.4%), postintubation stridor (2.4%), bronchopulmonary dysplasia (2.3%), and endobronchial tube blockage (0.8%). CONCLUSIONS: Complications were related to the duration of intubation and mechanical ventilation.

Adolescent↗
PubMed2000

Accounting for intubation status in predicting mortality for victims of motor vehicle crashes.

BACKGROUND: Two of the important predictors of mortality for trauma patients are the Glasgow Coma Scale and the respiratory rate. However, for intubated patients, the verbal response component of the Glasgow Coma Scale and the respiratory rate cannot be accurately obtained. This study extends previous work that attempts to predict mortality accurately for intubated patients without using verbal response and respiratory rate. METHODS: The New York State Trauma Registry was used to identify 1994 and 1995 victims of motor vehicle crashes (MVCs). For the subset of patients who were not intubated, we developed two statistical models to predict mortality: one did not contain verbal response or respiratory rate, and the other contained a predicted verbal response. These were compared with a model that did include verbal response and respiratory rate. We also compared the predictive abilities of the first two models for all MVC patients (intubated and nonintubated) and determined the extent to which intubated patients were at increased risk of dying in the hospital after having adjusted for other predictors of mortality. RESULTS: For nonintubated patients, the statistical model without verbal response and the model with predicted verbal response had slightly better discrimination and worse calibration than the model that included verbal response and respiratory rate. Predicted verbal response did not improve the strength of the model without verbal response. For all MVC patients (intubated and nonintubated), predicted verbal response was not a significant predictor of mortality when used in combination with the other predictors. Intubation status was a significant predictor, with intubated patients having a higher probability of dying in the hospital than patients with otherwise identical risk factors. CONCLUSION: Inpatient mortality for intubated MVC patients can be accurately predicted without respiratory rate or verbal response. There appears to be no need for predicted verbal response to be part of the prediction formula, but intubation status is an important independent predictor of mortality and should be used in statistical models that predict mortality for MVC patients.

Accidents, Traffic↗
PubMed1993

Orotracheal intubation in patients with potential cervical spine injuries. An indication for the gum elastic bougie.

The conditions for emergency tracheal intubation of patients with cervical spine injury were simulated in 157 patients during induction of anaesthesia for routine surgery. The view of the larynx obtained during laryngoscopy with the head in the optimum intubating position was compared with that obtained when manual in-line stabilisation of the cervical spine and cricoid pressure were used. During laryngoscopy with cervical stabilisation, the view of the larynx was reduced in 45% of patients, and in 22% of patients nothing was visible beyond the epiglottis. To assess the ease of intubation with the neck stabilised and with cricoid pressure applied, patients were randomised to either direct visual intubation (n = 79), or intubation aided by a gum elastic bougie (n = 78). The median time taken for visual intubation was 20 s, but in six patients intubation took over 45 s. In addition, five patients in this group could not be directly intubated. Using the gum elastic bougie all patients, including the failures from the visual group, were intubated within 45 s (median 25 s). We recommend the gum elastic bougie as an aid to intubating the patient with suspected cervical spine injury, particularly when the glottis is not immediately visible.

Cervical Vertebrae↗
PubMed1995

Double burst stimulation for monitoring neuromuscular blockade for tracheal intubation.

Responses to double burst stimulation were palpated every 15 s after intravenous administration of vecuronium 0.2 mg.kg-1 in 60 adult patients under anaesthesia. Intubating conditions and neuromuscular responses to tracheal intubation were assessed at disappearance of one or both palpable responses to double burst stimulation in groups of 30 patients randomly divided, although in group A patients, tracheal intubation could be performed at disappearance of one palpable response to double burst stimulation; 27 out of 30 patients (90%) had mild to moderate bucking on intubation. In this group, only five patients (16.66%) had good intubating conditions. In group B, where tracheal intubation was attempted at disappearance of both palpable responses, intubating conditions were good in 28 out of 30 patients (93.33%) and there was no response to tracheal intubation in 26 out of 30 patients (86.66%). Palpation of evoked response to double burst stimulation can be used to predict intubating conditions and neuromuscular response to tracheal intubation with nondepolarising muscle relaxants such as vecuronium.

Adult↗
PubMed2006

A comparison of tracheal intubation using the Airtraq or the Macintosh laryngoscope in routine airway management: A randomised, controlled clinical trial.

The Airtraq laryngoscope is a novel single use tracheal intubation device. We compared the Airtraq with the Macintosh laryngoscope in patients deemed at low risk for difficult intubation in a randomised, controlled clinical trial. Sixty consenting patients presenting for surgery requiring tracheal intubation were randomly allocated to undergo intubation using a Macintosh (n = 30) or Airtraq (n = 30) laryngoscope. All patients were intubated by one of four anaesthetists experienced in the use of both laryngoscopes. No significant differences in demographic or airway variables were observed between the groups. All but one patient, in the Macintosh group, was successfully intubated on the first attempt. There was no difference between groups in the duration of intubation attempts. In comparison to the Macintosh laryngoscope, the Airtraq resulted in modest improvements in the intubation difficulty score, and in ease of use. Tracheal intubation with the Airtraq resulted in less alterations in heart rate. These findings demonstrate the utility of the Airtraq laryngoscope for tracheal intubation in low risk patients.

Adult↗
PubMed2004

Assessment of tracheal intubating conditions in children using remifentanil and propofol without muscle relaxant.

BACKGROUND: Tracheal intubation in children can be achieved by deep inhalational anaesthesia or an intravenous anaesthetic and a muscle relaxant, suxamethonium being widely used despite several side-effects. Studies have shown that oral intubation can be facilitated safely and effectively in children after induction of anaesthesia with propofol and alfentanil without a muscle relaxant. Remifentanil is a new, ultra-short acting, selective mu-receptor agonist that is 20-30 times more potent than alfentanil. This clinical study was designed to assess whether combination of propofol and remifentanil could be used without a muscle relaxant to facilitate tracheal intubation in children. METHODS: Forty children (5-10 years) admitted for adenotonsillectomy were randomly allocated to one of two groups to receive remifentanil 2 microg.kg(-1) (Gp I) or remifentanil 3 microg.kg(-1) (Gp II) before the induction of anaesthesia with i.v. propofol 3 mg.kg(-1). No neuromuscular blocking agent was administered. Intubating conditions were assessed using a four-point scoring system based on ease of laryngoscopy, jaw relaxation, position of vocal cords, degree of coughing and limb movement. Mean arterial pressure (MAP) and heart rate (HR) measured noninvasively before induction of anaesthesia to 5 min after intubation (seven time points). RESULTS: Tracheal intubation was successful in all patients without requiring neuromuscular blocking agent. Intubating conditions were clinically acceptable in 10 of 20 patients (50%) in Gp I compared with 18 of 20 patients (90%) in Gp II (P < 0.05). MAP and HR decreased in both groups after induction of anaesthesia (P < 0.01). Both HR and MAP were significantly lower in Gp II compared with Gp I after tracheal intubation (P < 0.01). No patient in the present study developed bradycardia or hypotension. CONCLUSIONS: We conclude that remifentanil (3 microg.kg(-1)), administered before propofol (3 mg.kg(-1)) provides acceptable tracheal intubating conditions in children, and completely inhibited the increase in HR and MAP associated with intubation.

Adenoidectomy↗
PubMed1998

Intragastric intubation: important aspects of the model for administration of ethanol to rat pups during the postnatal period.

One technique for the controlled delivery of ethanol to neonatal rat pups is intragastric intubation. Often, the vehicle used for delivery of ethanol is composed of a nutrient mixture to compensate for decreased suckling or other possible nutritional compromise. This study analyzed the selection of nutrient vehicle, the combination of experimental treatment groups within a litter, and the overall litter size on the growth rate of ethanol-intubated and intubated-control pups, compared with mother-raised control pups. Sprague-Dawley rat pups were raised in litters of 8 or 10, and administered ethanol by intragastric intubation with 20% (v/v) Sustacal or 80% (v/v) Intralipid-II nutrient vehicle. Pups were treated between postnatal days 2 and 10, and body weight was analyzed on day 10. Pups were assigned to a treatment group as either intubated ethanol, intubated control, or nonintubated mother-raised controls. Experimental comparison by statistical analyses was performed to identify the optimal treatment design (mixed treatment groups in a single litter or a single treatment group per litter), the optimal vehicle (Sustacal or Intralipid-II), and the optimal number of pups per litter (8 vs. 10). The analyses demonstrate that the mixing of intubated control, intubated ethanol, and nonintubated mother-raised control treatment groups within a single litter introduced an uncontrolled variable that confounded measurement of ethanol-specific alterations. The sensitivity of treatment groups to inclusion in mixed litters was dependent on the nutrient vehicle and thus nutritional adequacy. Our results suggest that an optimal design was achieved with eight pups per litter. Furthermore, ethanol intubated and intubated control pups grow at a rate identical to parallel litters of eight mother-raised control pups when Intralipid-II is used as nutrient vehicle, and a single treatment group is present in a litter. Optimization of these experimental parameters has provided an excellent neonatal rat model for analysis of specific ethanol effects on brain development during the third trimester.

Animals↗