Nathan Pace - Profile on Academia.edu (original) (raw)

Papers by Nathan Pace

Survey of Anesthesiology, Oct 1, 1985

The Cochrane library, May 15, 2018

The unanticipated di icult airway is a potentially life-threatening event during anaesthesia or a... more The unanticipated di icult airway is a potentially life-threatening event during anaesthesia or acute conditions. An unsuccessfully managed upper airway is associated with serious morbidity and mortality. Several bedside screening tests are used in clinical practice to identify those at high risk of di icult airway. Their accuracy and benefit however, remains unclear.

Anaesthesia, Mar 6, 2019

Although bedside screening tests are routinely used to identify people at high risk of having a d... more Although bedside screening tests are routinely used to identify people at high risk of having a difficult airway, their clinical utility is unclear. We estimated the diagnostic accuracy of commonly used bedside examination tests for assessing the airway in adult patients without apparent anatomical abnormalities scheduled to undergo general anaesthesia. We searched for studies that reported our pre-specified bedside index screening tests against a reference standard, published in any language, from date of inception to 16 December 2016, in seven bibliographic databases. We included 133 studies (127 cohort type and 6 case-control) involving 844,206 participants. Overall, their methodological quality (according to QUADAS-2, a standard tool for assessing quality of diagnostic accuracy studies) was moderate to high. Our pre-specified tests were: the Mallampati test (6 studies); modified Mallampati test (105 studies); Wilson risk score (6 studies); thyromental distance (52 studies); sternomental distance (18 studies); mouth opening test (34 studies); and the upper lip bite test (30 studies). Difficult facemask ventilation, difficult laryngoscopy, difficult intubation and failed intubation were the reference standards in seven, 92, 50 and two studies, respectively. Across all reference standards, we found all index tests had relatively low sensitivities, with high variability, but specificities were consistently and markedly higher than sensitivities. For difficult laryngoscopy, the sensitivity and specificity (95%CI) of the upper lip bite test were 0.67 (0.45-0.83) and 0.92 (0.86-0.95), respectively; upper lip bite test sensitivity (95%CI) was significantly higher than that for the mouth opening test (0.22, 0.13-0.33; p < 0.001). For difficult tracheal intubation, the modified Mallampati test had a significantly higher sensitivity (95%CI) at 0.51 (0.40-0.61) compared with mouth opening (0.27, 0.16-0.41; p < 0.001) and thyromental distance (0.24, 0.12-0.43; p < 0.001). Although the upper lip bite test showed the most favourable diagnostic test accuracy properties, none of the common bedside screening tests is well suited for detecting unanticipated difficult airways, as many of them are missed.

Purpose Neuraxial hydromorphone has been reported to provide rapid onset of labour analgesia, eff... more Purpose Neuraxial hydromorphone has been reported to provide rapid onset of labour analgesia, effective segmental pain relief, and a longer duration of action than commonly used lipophilic opioids. This study was conducted to test the hypothesis that intrathecal Author contributions Jill M. Mhyre, the principal investigator, was responsible for the concept, design, and analysis of the study, and wrote the final manuscript. She had access to all of the data and takes full responsibility for the integrity of the data and the accuracy of the data analysis.

The Cochrane library, Oct 18, 2016

Anaesthetic interventions for prevention of awareness during surgery.

Canadian Journal Of Anesthesia/journal Canadien D'anesthésie, Nov 1, 1990

Anesthesiology

Background There is insufficient prospective evidence regarding the relationship between surgical... more Background There is insufficient prospective evidence regarding the relationship between surgical experience and prolonged opioid use and pain. The authors investigated the association of patient characteristics, surgical procedure, and perioperative anesthetic course with postoperative opioid consumption and pain 3 months postsurgery. The authors hypothesized that patient characteristics and intraoperative factors predict opioid consumption and pain 3 months postsurgery. Methods Eleven U.S. and one European institution enrolled patients scheduled for spine, open thoracic, knee, hip, or abdominal surgery, or mastectomy, in this multicenter, prospective observational study. Preoperative and postoperative data were collected using patient surveys and electronic medical records. Intraoperative data were collected from the Multicenter Perioperative Outcomes Group database. The association between postoperative opioid consumption and surgical site pain at 3 months, elicited from a teleph...

Cochrane Database of Systematic Reviews, 2019

Transient neurological symptoms (TNS) following spinal anaesthesia with lidocaine versus other lo... more Transient neurological symptoms (TNS) following spinal anaesthesia with lidocaine versus other local anaesthetics in adult surgical patients: a network meta-analysis.

British Journal of Anaesthesia, 2016

Background: Improvement of postoperative pain and other perioperative outcomes remain a significa... more Background: Improvement of postoperative pain and other perioperative outcomes remain a significant challenge and a matter of debate among perioperative clinicians. This systematic review aims to evaluate the effects of perioperative i.v. lidocaine infusion on postoperative pain and recovery in patients undergoing various surgical procedures. Methods: CENTRAL, MEDLINE, EMBASE, and CINAHL databases and ClinicalTrials.gov, and congress proceedings were searched for randomized controlled trials until May 2014, that compared patients who did or did not receive continuous perioperative i.v. lidocaine infusion. Results: Forty-five trials (2802 participants) were included. Meta-analysis suggested that lidocaine reduced postoperative pain (visual analogue scale, 0 to 10 cm) at 1-4 h (MD -0.84, 95% CI -1.10 to -0.59) and at 24 h (MD -0.34, 95% CI -0.57 to -0.11) after surgery, but not at 48 h (MD -0.22, 95% CI -0.47 to 0.03). Subgroup analysis and trial sequential analysis suggested pain reduction for patients undergoing laparoscopic abdominal surgery or open abdominal surgery, but not for patients undergoing other surgeries. There was limited evidence of positive effects of lidocaine on postoperative gastrointestinal recovery, opioid requirements, postoperative nausea and vomiting, and length of hospital stay. There were limited data available on the effect of systemic lidocaine on adverse effects or surgical complications. Quality of evidence was limited as a result of inconsistency (heterogeneity) and indirectness (small studies). Conclusions: There is limited evidence suggesting that i.v. lidocaine may be a useful adjuvant during general anaesthesia because of its beneficial impact on several outcomes after surgery.

Cochrane Database of Systematic Reviews, 2014

Editorial group: Cochrane Anaesthesia Group. Publication status and date: Edited (no change to co... more Editorial group: Cochrane Anaesthesia Group. Publication status and date: Edited (no change to conclusions), published in Issue 5, 2016.

Drugs for preventing postoperative nausea and vomiting

Reviews, 2002

Journal of Clinical Monitoring, 1988

We hypothesized that functional residual capacity (FRC) could be used as a noninvasive indicator ... more We hypothesized that functional residual capacity (FRC) could be used as a noninvasive indicator of "optimal" positive end-expiratory pressure (PEEP), the level of PEEP that results in venous admixture below 15% with an inspired oxygen fraction less than 0.5. We compared several variables for PEEP optimization--oxygen transport, total respiratory system compliance, FRC-based compliance, mixed venous oxygen saturation, end-tidal to arterial carbon dioxide tension difference, and arterial oxygen saturation--by producing four different PEEP levels, 0, 5, 10, and 15 cm H20, in 24 mongrel dogs in which pulmonary injury was produced. The data were regressed versus PEEP by using analysis of variance for regression. Venous admixture (F1,23 = 149.3; P < 0.0001), endtidal to arterial carbon dioxide tension difference (F1,23 = 64.9; P < 0.0001), and oxygen transport (F1,23 = 95.1; P < 0.0001) decreased linearly with PEEP. FRC (F1,23 = 248.1; P < 0.0001) and arterial oxygen saturation (F1.23 = 66.9; P < 0.0001) increased linearly with PEEP. Total respiratory system compliance (FL23 = 66.6; P < 0.0001) and mixed venous oxygen saturation (F1,23 = 12.2; P < 0.002) had a quadratic relationship with respect to PEEP with a peak at 5 cm H20. FRC-based compliance did not have a significant relationship to PEEP. The maximum values of total respiratory system compliance, FRC-based compliance, mixed venous oxygen saturation, and oxygen transport did not occur at PEEP levels that corresponded to a venous admixture below 15% ("optimal" PEEP). In this canine oleic acid lung injury model, maximizing these variables would be a poor technique for PEEP titration. FRC and arterial oxygen saturation had a strong relationship to PEEP and venous admixture, and these two would be good noninvasive variables for use in PEEP titration.

British Journal of Anaesthesia, 2013

This year has marked the 20th anniversary of the Cochrane Collaboration. During its lifetime, the... more This year has marked the 20th anniversary of the Cochrane Collaboration. During its lifetime, the Collaboration has become recognized around the world as the largest organization worldwide concerned with the production, dissemination, and maintenance of highest quality systematic reviews for healthcare. The Cochrane Anaesthesia Review Group (CARG) within the Collaboration is a little younger, having been founded in 2000. This editorial will attempt to focus on how this global effort started, on progress to date, and on future challenges. The Collaboration is named after Archie Cochrane (1909 -1988), a Scottish epidemiologist whose varied career included fighting in the International Brigade during the Spanish Civil War, acting as medical officer in a prisoner of war camp during World War II, and serving as Professor of Chest Diseases at the Welsh National School of Medicine. In 1969, he became fulltime director of the Medical Research Council's epidemiology unit, focusing particularly on randomized controlled trials (RCTs) of new therapeutic interventions. This approach was coloured by his wartime experiences; having observed the natural resilience (even without effective medical treatment) of the human body against disease, he was naturally sceptical of claims of effectiveness of new treatments. His book Effectiveness and Efficiency: Random Reflections on Health Services (1972) 1 is often acknowledged to be the start of the whole 'evidence-based medicine' movement. In it, he challenged the medical profession to locate and bring together all the randomized trials in each specialty. Epidemiologists and obstetricians were the first to respond to the challenge, the book Effective Care in Pregnancy

Frequent Hypoxemia and Apnea after Sedation with Midazolam and Fentanyl

Anesthesiology, 1990

More than 80 deaths have occurred after the use of midazolam (Versed), often in combination with ... more More than 80 deaths have occurred after the use of midazolam (Versed), often in combination with opioids, to sedate patients undergoing various medical and surgical procedures. We investigated the respiratory effects of midazolam (0.05 mg.kg-1) and fentanyl (2.0 micrograms.kg-1) in volunteers. The incidence of hypoxemia (oxyhemoglobin saturation less than 90%) and apnea (no spontaneous respiratory effort for 15 s) and the ventilatory response to carbon dioxide were evaluated. Midazolam alone produced no significant respiratory effects. Fentanyl alone produced hypoxemia in half of the subjects and significant depression of the ventilatory response to CO2, but did not produce apnea. Midazolam and fentanyl in combination significantly increased the incidence of hypoxemia (11 of 12 subjects) and apnea (6 of 12 subjects), but did not depress the ventilatory response to CO2 more than did fentanyl alone. Adverse reactions linked to midazolam and reported to the Department of Health and Human Services highlight apnea- and hypoxia-related problems as among the most frequent adverse reactions. Seventy-eight per cent of the deaths associated with midazolam were respiratory in nature, and in 57% an opioid had also been administered. All but three of the deaths associated with the use of midazolam occurred in patients unattended by anesthesia personnel. We conclude that combining midazolam with fentanyl or other opioids produces a potent drug interaction that places patients at a high risk for hypoxemia and apnea. Adequate precautions, including monitoring of patient oxygenation with pulse oximetry, the administration of supplemental oxygen, and the availability of persons skilled in airway management are recommended when benzodiazepines are administered in combination with opioids.

Oral Transmucosal Fentanyl Citrate for Premedication in Adults

Anesthesia & Analgesia, 1996

This study was designed to assess the efficacy of oral transmucosal fentanyl citrate (OTFC) for p... more This study was designed to assess the efficacy of oral transmucosal fentanyl citrate (OTFC) for premedication in an adult population and to determine its effects on anxiety, sedation, gastric volume, and gastric fluid acidity. The fentanyl citrate is incorporated in a lozenge mounted on a handle (oralet). The effects of OTFC, placebo oralet, and no premedication were compared in a prospective, double-blind study on 90 adult ASA physical status I and II patients undergoing same-day admission surgery. Patients were randomly assigned to one of three groups: OTFC group (n = 30), placebo group (n = 30), and control group (n = 30). Arterial blood pressure, heart rate, respiratory frequency, and oxygen saturation determined by pulse oximetry were recorded before any premedication was given, and then every 10 min until the patient was taken to the operating room. Baseline anxiety and sedation levels were assessed to ensure group similarity immediately before premedication was given and at the more anxiety-provoking phase upon entering the operating room. Anxiety levels were rated using the Spielberger State-Trait Anxiety Inventory short form and sedation levels were assessed with the Ramsay scale. Side effects, as reported by the patients, were also recorded. Gastric contents were aspirated via an orogastric tube after induction of anesthesia and were measured for volume and pH. No significant differences were found among the three groups in mean arterial pressure, heart rate, or respiratory frequency. Initial oxygen saturation levels in all groups decreased after 30 min but not less than 96% except for one patient in the OTFC group, who decreased to 88%. On entering the operating room, the OTFC group demonstrated significantly higher levels of anxiolysis than the control group, but no significant differences were seen between the OTFC and the placebo groups or the placebo and control groups. Mean gastric volumes (OTFC, 29 mL; placebo, 26 mL; control, 24 mL) and pH (OTFC, 2.0; placebo, 1.8; control, 2.1) were similar in all groups. There were no significant differences among the groups in levels of sedation achieved. Mild dizziness or light-headedness was the most commonly reported side effect in 23% of the OTFC group. In the OTFC group, 71.4% like the premedicant effect as compared to 46.4% of the placebo group. Most of the groups found the oralet method of premedicant delivery very acceptable. This study demonstrates that the OTFC oralet is an effective anxiolytic in adults. It has minimal side effects and is prepared in an acceptable format. There was no measurable increase in gastric contents or acidity in the oralet groups, compared to those patients who were given nothing by mouth.

Anesthesia & Analgesia, Jun 1, 2005

We recently reported several cases consistent with transient radicular irritation after spinal an... more We recently reported several cases consistent with transient radicular irritation after spinal anesthesia with hyperbaric 5% lidocaine. The present prospective, blind, nonrandomized study was performed to determine the incidence of these transient neurologic symptoms and to identify factors that might be associated with their occurrence. We studied 270 patients scheduled for gynecologic or obstetric procedures under spinal anesthesia. For spinal anesthesia, either 5% lidocaine in 7.5% glucose or 0.5% bupivacaine in 8.5% glucose was used. Patients were evaluated on postoperative day 3 by a quality assurance nurse who was unaware of the drug given or details of the anesthetic technique. Transient neurologic symptoms were observed in 37% of patients receiving 5% lidocaine, whereas only one patient receiving 0.5% bupivacaine had transient hypesthesia of the lateral aspect of the right foot. These results suggest that symptoms were the result of a specific drug effect. However, because of the limitations of the study one cannot conclude that lidocaine per se was the cause.

BMJ, 2011

Objective To systematically determine the most efficacious approach for preventing pain on inject... more Objective To systematically determine the most efficacious approach for preventing pain on injection of propofol. Design Systematic review and meta-analysis. Data sources PubMed, Embase, Cochrane Library, www.clinicaltrials.gov, and hand searching from the reference lists of identified papers. Study selection Randomised controlled trials comparing drug and non-drug interventions with placebo or another intervention to alleviate pain on injection of propofol in adults. Results Data were analysed from 177 randomised controlled trials totalling 25 260 adults. The overall risk of pain from propofol injection alone was about 60%. Using an antecubital vein instead of a hand vein was the most effective single intervention (relative risk 0.14, 95% confidence interval 0.07 to 0.30). Pretreatment using lidocaine (lignocaine) in conjunction with venous occlusion was similarly effective (0.29, 0.22 to 0.38). Other effective interventions were a lidocaine-propofol admixture (0.40, 0.33 to 0.48); pretreatment with lidocaine (0.47, 0.40 to 0.56), opioids (0.49, 0.41 to 0.59), ketamine (0.52, 0.46 to 0.57), or non-steroidal anti-inflammatory drugs (0.67, 0.49 to 0.91); and propofol emulsions containing medium and long chain triglycerides (0.75, 0.67 to 0.84). Statistical testing of indirect comparisons showed that use of the antecubital vein and pretreatment using lidocaine along with venous occlusion to be more efficacious than the other interventions. Conclusions The two most efficacious interventions to reduce pain on injection of propofol were use of the antecubital vein, or pretreatment using lidocaine in conjunction with venous occlusion when the hand vein was chosen. Under the assumption of independent efficacy a third practical alternative could be pretreatment of the hand vein with lidocaine or ketamine and use of a propofol emulsion containing medium and long chain triglycerides. Although not the most effective intervention on its own, a small dose of opioids before induction halved the risk of pain from the injection and thus can generally be recommended unless contraindicated.

Classification.Wang.Messina.Ward.grade

The classification system that tracks patients level of consciousness during anesthesia and surge... more The classification system that tracks patients level of consciousness during anesthesia and surgery. Grades 0 to 5 were assigned to each of the 160 included RCTs

Anesthesia Techniques.xlsx

Different IV techniques were compared to IV techniques and volatile techniques and other techniqu... more Different IV techniques were compared to IV techniques and volatile techniques and other techniques. Inadequate anesthesia protocol are summarized from some of the RCTs

ACE 130 reviewer #2.MWa response.classification table.docx

An analysis by the expert peer reviewer #2 and expert coauthor, MaW, of our classification system