Collapsibility of the Upper Airway at Different Concentrations of Propofol Anesthesia.
Eastwood, Peter R. Ph.D.; Platt, Peter R. M.D.; Shepherd, Kelly B.Sc.; Maddison, Kathy B.Sc.; Hillman, David R. M.D. 
Anesthesiology. 103(3):470-477, September 2005

Background: This study investigated the effect of varying concentrations of propofol on upper airway collapsibility and the mechanisms responsible for it.
Methods: Upper airway collapsibility was determined from pressure-flow relations at three concentrations of propofol anesthesia (effect site concentration = 2.5, 4.0, and 6.0 [mu]g/ml) in 12 subjects spontaneously breathing on continuous positive airway pressure. At each level of anesthesia, mask pressure was transiently reduced from a pressure sufficient to abolish inspiratory flow limitation (maintenance pressure = 12 +/- 1 cm H2O) to pressures resulting in variable degrees of flow limitation. The relation between mask pressure and maximal inspiratory flow was determined, and the critical pressure at which the airway occluded was recorded. Electromyographic activity of the genioglossus muscle (EMGgg) was obtained via intramuscular electrodes in 8 subjects.
Results: With increasing depth of anesthesia, (1) critical closing pressure progressively increased (-0.3 +/- 3.5, 0.5 +/- 3.7, and 1.4 +/- 3.5 cm H2O at propofol concentrations of 2.5, 4.0, and 6.0 [mu]g/ml respectively; P < 0.05 between each level), indicating a more collapsible upper airway; (2) inspiratory flow at the maintenance pressure significantly decreased; and (3) respiration-related phasic changes in EMGgg at the maintenance pressure decreased from 7.3 +/- 9.9% of maximum at 2.5 [mu]g/ml to 0.8 +/- 0.5% of maximum at 6.0 [mu]g/ml, whereas tonic EMGgg was unchanged. Relative to the levels of phasic and tonic EMGgg at the maintenance pressure immediately before a decrease in mask pressure, tonic activity tended to increase over the course of five flow-limited breaths at a propofol concentration of 2.5 [mu]g/ml but not at propofol concentrations of 4.0 and 6.0 [mu]g/ml, whereas phasic EMGgg was unchanged.
Conclusions: Increasing depth of propofol anesthesia is associated with increased collapsibility of the upper airway. This was associated with profound inhibition of genioglossus muscle activity. This dose-related inhibition seems to be the combined result of depression of central respiratory output to upper airway dilator muscles and of upper airway reflexes.

Motivation and Maternal Presence during Induction of Anesthesia.
Caldwell-Andrews, Alison A. Ph.D.; Kain, Zeev N. M.D., M.B.A.; Mayes, Linda C. M.D.  Kerns, Robert D. Ph.D.; Ng, Derek B.S. 
Anesthesiology. 103(3):478-483, September 2005

Background: The authors developed a measure to determine whether maternal motivation to be present during induction (Motivation for Parental Presence during Induction of Anesthesia [MPPIA]) is related to children's anxiety during the induction process.
Methods: Mothers and children (aged 2-12 yr) undergoing outpatient, elective surgery and general anesthesia were enrolled in this study (n = 289 dyads). Items to assess motivation for parental presence during induction were selected by experts in anesthesiology, psychology, and child development; mothers completed the resulting 14-item measure as well as assessments of anxiety and coping style. Children's anxiety and compliance was assessed during induction of anesthesia. Factor analysis was performed, and maternal motivation was then examined against children's anxiety during induction of anesthesia.
Results: Factor analysis resulted in four scales with a total variance of 72.3%: MPPIA-Desire, MPPIA-Hesitancy, MPPIA-Anxiety, and MPPIA-Preparation. Analysis supported the reliability (0.89-0.94) and validity of the MPPIA. The authors found that mothers with high MPPIA-Desire and low MPPIA-Hesitancy had children with significantly higher anxiety (P < 0.0001) during induction of anesthesia, as compared with mothers with low MPPIA-Desire and MPPIA-Hesitancy. The authors also found that highly motivated mothers reported significantly higher levels of anxiety (P = 0.007).
Conclusion: Clinicians should be aware that many mothers who have a high desire to be present in the operating room are very anxious and that their children are likely to exhibit high anxiety levels during induction of anesthesia.

Sniffing Position Improves Pharyngeal Airway Patency in Anesthetized Patients with Obstructive Sleep Apnea.
Isono, Shiroh M.D.; Tanaka, Atsuko M.D.; Ishikawa, Teruhiko M.D.; Tagaito, Yugo M.D.  Nishino, Takashi M.D. 
Anesthesiology. 103(3):489-494, September 2005

Background: Appropriate bag-and-mask ventilation with patent airway is mandatory during induction of general anesthesia. Although the sniffing neck position is a traditionally recommended head and neck position during this critical period, knowledge of the influences of this position on the pharyngeal airway patency is still inadequate.
Methods: Total muscle paralysis was induced with general anesthesia in 12 patients with obstructive sleep apnea, eliminating neuromuscular factors contributing to pharyngeal patency. The cross-sectional area of the pharynx was measured endoscopically at different static airway pressures. Comparison of static pressure-area plot between the neutral and sniffing neck positions allowed assessment of the influence of the neck position change on the mechanical properties of the pharynx.
Results: The static pressure-area curves of the sniffing position were above those of neutral neck position, with increasing maximum cross-sectional area and decreasing the closing pressure at both retropalatal and retroglossal airways. The beneficial effects of the sniffing position were greater in obstructive sleep apnea patients with higher closing pressure and smaller body mass index.
Conclusions: Sniffing position structurally improves maintenance of the passive pharyngeal airway in patients with obstructive sleep apnea and may be beneficial for both mask ventilation and tracheal intubation during anesthesia induction.

Desflurane Enhances Reactivity during the Use of the Laryngeal Mask Airway.
Arain, Shahbaz R. M.D.; Shankar, Hariharan M.D.; Ebert, Thomas J. M.D., Ph.D.
Anesthesiology. 103(3):495-499, September 2005

Background: Desflurane and sevoflurane have markedly different pungencies. The tested hypothesis was that patients breathing equivalent concentrations of desflurane or sevoflurane through a laryngeal mask airway (LMA) would have similar responses.
Methods: After institutional review board approval and informed consent were obtained, 60 patients were enrolled and given intravenous midazolam (14 [mu]g/kg) and fentanyl (1 [mu]g/kg) 5 min before induction of anesthesia. The LMA was inserted at loss of consciousness after 2 mg/kg propofol. When spontaneous breathing returned, a randomly assigned volatile anesthetic was started at an inspired concentration of either 1.8% sevoflurane or 6% desflurane at a fresh gas flow of 6 l/min in air:oxygen (50:50). After 5 min, a controlled movement of the LMA took place. Three minutes later, the inspiratory anesthetic concentration was changed to either 3.6% sevoflurane or 12% desflurane for 3 min. A blinded observer recorded movements and airway events during the start of anesthetic, LMA movement, deepening of the anesthetic, and emergence before LMA removal.
Results: There were no differences at anesthetic start and LMA movement. Desflurane titration to 12% increased heart rate, increased mean arterial blood pressure, and initiated frequent coughing (53% vs. 0% sevoflurane) and body movements (47% vs. 0% sevoflurane). During emergence, there was a twofold greater incidence of coughing and a fivefold increase in breath holding in the desflurane group.
Conclusions: When airway responses to sevoflurane and desflurane were compared in elective surgical patients breathing through an LMA, there were significantly more adverse responses with desflurane at 12% concentrations and during emergence.

Nerve Stimulator-guided Paravertebral Blockade Combined with Sevoflurane Sedation versus General Anesthesia with Systemic Analgesia for Postherniorrhaphy Pain Relief in Children: A Prospective Randomized Trial.
Naja, Zouheir M. M.D.; Raf, Martin M.D.; El Rajab, Mariam M.D.; Ziade, Fouad M. Ph.D.; Al Tannir, Mohamad A. M.P.H.; Lonnqvist, Per Arne Ph.D.
Anesthesiology. 103(3):600-605, September 2005

Background: Improvement of the duration of postoperative analgesia is desirable in children undergoing inguinal hernia repair.
Methods: Fifty children aged 5-12 yr were prospectively randomized to receive either paravertebral nerve blockade or general anesthesia (sevoflurane-fentanyl-nitrous oxide-oxygen) combined with standardized postoperative systemic analgesia, both combined with light sevoflurane anesthesia, for inguinal hernia repair.
Results: Mean pain scores were significantly lower in paravertebral nerve blockade patients compared with patients treated with systemic analgesia during the entire 48-h observational period (P < 0.05). Analgesic consumption was significantly higher in the systemic analgesia group (88%) compared with the paravertebral nerve blockade group (32%) (P < 0.001). Parental satisfaction was significantly higher (80 vs. 48%; P < 0.05) and same-day discharge was possible in a higher proportion of patients in the paravertebral blockade group (80% vs. 52%; P < 0.05).
Conclusions: Paravertebral nerve blockade was associated with improved postoperative pain relief; reduced analgesic consumption, and faster hospital discharge compared with a systemic analgesia protocol in children undergoing herniorrhaphy.

Predicting Postoperative Pain by Preoperative Pressure Pain Assessment.
Hsu, Yung-Wei M.D.; Somma, Jacques M.D.; Hung, Yu-Chun M.D.; Tsai, Pei-Shan Ph.D. ; Yang, Chen-Hsien M.D. ; Chen, Chien-Chuan M.D.
Anesthesiology. 103(3):613-618, September 2005

Background: The goal of this study was to evaluate whether preoperative pressure pain sensitivity testing is predictive of postoperative surgical pain.
Methods: Female subjects undergoing lower abdominal gynecologic surgery were studied. A pressure algometer was used preoperatively to determine the pressure pain threshold and tolerance. A visual analog scale (VAS) was used to assess postoperative pain. A State-Trait Anxiety Inventory was used to assess patients' anxiety. Subjects received intravenous patient-controlled analgesia for postoperative pain control. The preoperative pain threshold and tolerance were compared with the postoperative VAS pain score and morphine consumption.
Results: Forty women were enrolled. Their preoperative pressure pain threshold and tolerance were 141 +/- 65 kPa and 223 +/- 62 kPa, respectively. The VAS pain score in the postanesthesia care unit and at 24 h postoperatively were 81 +/- 24 and 31 +/- 10, respectively. Highly anxious patients had higher VAS pain scores in the postanesthesia care unit (P < 0.05). Pressure pain tolerance was significantly correlated with the VAS at 24 h postoperatively (P < 0.001, r = -0.52). Pressure pain tolerance after fentanyl administration (mean, 272 +/- 68 kPa) correlated significantly with morphine consumption in the first 24 h postoperatively (P < 0.002, r = -0.48).
Conclusions: Assessment of preoperative pressure pain tolerance is significantly correlated with the level of postoperative pain. Pain tolerance assessment after fentanyl was administered and fentanyl sensitivity predicted the dose of analgesics used in the first 24 h after surgery. The algometer is thus a simple, useful tool for predicting postoperative pain and analgesic consumption.

ACTA ANAESTHESIOLOGICA SCANDINAVICA - TOP

Changes in the auditory evoked potentials index by induction doses of four different intravenous anesthetics
T. Nishiyama
Volume 49 Issue 9 Page 1326  - October 2005

Background: Many studies have investigated the electroencephalographic changes during the induction and maintenance of anesthesia. However, no comparative studies have been performed on the effects of intravenous anesthetics on the auditory evoked potentials index (AAI). The present study was performed to compare the changes in AAI caused by induction doses of thiopental, propofol, midazolam and ketamine.
Methods: Eighty females, aged 30-70 years, referred for mastectomy, had anesthesia induced with thiopental 4 mg/kg, propofol 2 mg/kg, midazolam 0.1 mg/kg or ketamine 1 mg/kg (each 20 patients). The response to verbal command and the AAI were measured every minute for 5 min.
Results: The AAI decreased to less than 40 within 1 min with thiopental and propofol. The AAI increased after 3 min with thiopental, but remained low with propofol. The AAI gradually decreased to less than 40 within 4 min with midazolam, but was higher than the AAI with propofol or thiopental. The AAI increased significantly with ketamine. The AAIs at the loss of verbal command were 19 ± 7 with thiopental, 21 ± 8 with propofol, 31 ± 10 with midazolam and 92 ± 2 with ketamine.
Conclusion: The AAI correlated with changes in hypnotic level, as measured by the response to verbal command, with induction doses of thiopental, propofol and midazolam, but not with ketamine. The AAI decreased to lower levels with propofol and thiopental than with midazolam at the induction of anesthesia.

Comparison of alfetanil and ketamine in combination with propofol for patient-controlled sedation during fiberoptic bronchoscopy
J. Hwang, Y. Jeon, H.-P. Park, Y.-J. Lim and Y.-S. O
Volume 49 Issue 9 Page 1334 - October 2005

Background: During fiberoptic bronchoscopy, propofol, ketamine, benzodiazepines, and opiates are most commonly used, alone or in combination for sedation. The aim of this study was to compare the clinical efficacy of propofol/ketamine with propofol/alfentanil for patient-controlled sedation (PCS) during fiberoptic bronchoscopy.
Method: Patients undergoing fiberoptic bronchoscopy were randomly assigned to receive either propofol/alfentanil (PA group; n = 138) or propofol/ketamine (PK group; n = 138) via a patient-controlled analgesia (PCA) device for sedation and analgesia. Changes in blood pressure, heart rate (HR), and oxygen saturation were monitored. Degree of patient and bronchoscopist satisfaction was evaluated using a 10-cm visual analog scale (VAS) (0 = extremely uncomfortable to 10 = extremely comfortable).
Results: After sedation, systolic arterial pressure (SAP) decreased in the PA group, but SAP was stable in the PK group. Compared with values immediately before starting bronchoscopy, SAP and HR increased during the procedure in both groups (P < 0.05). Patients in the PK group showed more satisfaction [(9.5 (6 alt=- align=bottom>10) vs. 9.0 (610)), P < 0.05] and amnesia (82% vs. 61%, P < 0.01). Despite these differences, the majority (greater than 90%) of the patients in both groups stated that they were comfortable during the procedure.
Conclusion: Our results show that although both techniques proved effective for sedation in patients undergoing fiberoptic bronchoscopy, ketamine is superior to alfentanil when used in combination with propofol because of the high patient satisfaction and amnesia.

Blood-borne factors possibly associated with post-operative nausea and vomiting: an explorative study in women after breast cancer surgery
E. Oddby-Muhrbeck, S. Eksborg, A. Helander, P. Bjellerup, S. Lindahl and P. Lönnqvist
Volume 49 Issue 9 Page 1346 - October 2005

Background: The pathophysiology behind post-operative nausea and vomiting (PONV) is still not fully understood, especially with respect to gender. According to PONV risk scores, female gender is the strongest predictor for PONV. The risk for PONV after general anaesthesia for breast cancer surgery is 50-80%. The aim of the present explorative study was to identify blood-borne factors that might be associated with the development of PONV in women undergoing breast cancer surgery as a basis for further studies.
Methods: Fifty patients were enrolled prospectively in the study. A standardized sevoflurane-based anaesthetic was used. Blood samples for the analysis of vasopressin, gastrin, cholecystokinin, epinephrine, norepinephrine, dopamine, serotonin, platelet count and blood glucose were taken at six pre-determined time points peri-operatively, and PONV was assessed during 24 h.
Results: PONV was found in 27 of 47 patients completing the study. Patients with PONV had a larger variability of the platelet count (P = 0.001), a reduced platelet count on the first post-operative day (P = 0.02) and a less pronounced relationship between the platelet count and whole blood serotonin (P = 0.004) compared with non-PONV patients. A lack of a decrease in epinephrine levels in response to the induction of anaesthesia (P = 0.03) and increased levels of vasopressin (P < 0.001), epinephrine (P = 0.005) and blood glucose (P = 0.004) were observed in the early post-operative period in PONV patients.
Conclusion: Three different platelet-associated factors and an altered epinephrine pattern were found to be associated with the occurrence of PONV after breast cancer surgery.

High success rate and low incidence of headache and neurological symptoms with two spinal needle designs in children
H. Kokki, M. Turunen, M. Heikkinen, M. Reinikainen and M. Laisalmi
Volume 49 Issue 9 Page 1367 - October 2005

Background: In children, only a few trials have evaluated the use of spinal needles with special tip designs. In this study, we compared the success rate and incidence of post-dural puncture complaints of two small-gauge spinal needle designs used in children undergoing spinal anaesthesia (SA).
Methods: Three hundred and three children aged 9 months to 17 years presenting for subumbilical surgery were randomly assigned to have a 26G Atraucan (n = 156) or 27G Whitacre (n = 147) spinal needle for SA. The number of attempts to obtain successful cerebrospinal fluid (CSF) return and the success rate of SA were recorded. The first week of recovery was recorded by a diary.
Results: Both groups had a similar one-attempt success rate: 80% in the Atraucan group and 81% in the Whitacre group. Failure to obtain CSF occurred in one patient in the Atraucan group and in two patients in the Whitacre group. Paraesthesia was observed more commonly in the Whitacre group (10%) than in the Atraucan group (2%) (P = 0.004). The success rate of SA was 96%, with no differences between the two needles; one child was given general anaesthesia and 11 children (3%) a single dose of supplemental analgesia for the skin incision. Forty-one children (15%) developed a headache, 13 of which were classified as post-dural puncture headache (PDPH), seven cases (5%) in the Atraucan group and six (4%) in the Whitacre group; none of the children required a blood patch. Fifteen children (10%) in the Atraucan group and nine (7%) in the Whitacre group developed low back pain. Two children (1%) in the Atraucan group and four (3%) in the Whitacre group developed transient neurological symptoms (TNSs).
Conclusion: Both needles were associated with a high success rate and a low incidence of complaints.

The pre-emptive analgesic effect of intra-articular bupivacaine in arthroscopic knee surgery
B. Tuncer, C. A. Babacan and M. Arslan
Volume 49 Issue 9 Page 1373  - October 2005

Background: The purpose of this study was to determine whether intra-articular injection of bupivacaine prior to surgery provided better pain control after arthroscopic meniscectomy as compared with post-operative administration of bupivacaine.
Methods: Forty patients of American Society of Anesthesiologists (ASA) class I or II undergoing arthroscopic meniscectomy were assigned in a randomized, double-blinded manner into two groups: Group I received 20 ml of 2.5 mg/ml bupivacaine without epinephrine 30 min before skin incision and 20 ml of saline immediately after skin closure. Group II received identical injections in reverse order. All patients received total intravenous anesthesia. Post-operative pain scores were evaluated at 1, 2, 4, 6, 8, 12 and 24 h at rest and movement of the knee, using a 10-cm visual analog scale (VAS). The time to first analgesic use and 24-h analgesic consumption were recorded.
Results: Pain scores were lower in Group I compared with Group II at 1, 2, 4 and 6 h at rest and on movement (P < 0.05). The time to first analgesic use was longer in Group I, but there was no statistically significant difference in 24-h analgesic consumption.
Conclusion: Intra-articular bupivacaine administered before surgery provided a statistically significant reduction in post-operative pain scores compared with post-operative bupivacaine administration.

BRITISH JOURNAL OF ANAESTHESIA - TOP

Allergic reactions in anaesthesia: are suspected causes confirmed on subsequent testing?
M. Krøigaard, L. H. Garvey, T. Menné and B. Husum
British Journal of Anaesthesia 2005 95(4):468-471

Background. The aim of this retrospective survey of possible allergic reactions during anaesthesia was to investigate whether the cause suspected by anaesthetists involved corresponded with the cause found on subsequent investigation in the Danish Anaesthesia Allergy Centre (DAAC).
Methods. Case notes and anaesthetic charts from 111 reactions in 107 patients investigated in the DAAC were scrutinized for either suspicions of or warnings against specific substances stated to be the cause of the supposed allergic reaction.
Results. In 67 cases, one or more substances were suspected. In 49 of these (73%) the suspected cause did not match the results of subsequent investigation, either a different substance being the cause or no cause being found. Only five cases (7%) showed a complete match between suspected cause and investigation result. In the remaining 13 cases (19%) there was a partial match, the right substance being suspected, but investigations showed an additional allergen or several substances, including the right substance being suspected.
Conclusions. An informed guess is not a reliable way of determining the cause of a supposed allergic reaction during anaesthesia and may put a significant number of patients at unnecessary risk. Some patients may be labelled with a wrong allergy, leading to unnecessary warnings against harmless substances, and some patients may be put at risk of subsequent re-exposure to the real allergen. Patients with suspected allergic reactions during anaesthesia should be referred for investigation in specialist centres whenever possible.

Combined nebulization and spray-as-you-go topical local anaesthesia of the airway
K. A. Williams, G. L. Barker, R. J. Harwood and N. M. Woodall
British Journal of Anaesthesia 2005 95(4):549-553

Background. Twenty-five anaesthetists underwent awake fibreoptic intubation using a combination of nebulization and topical local anaesthesia. Plasma lidocaine concentrations were measured and the quality of the local anaesthesia was assessed.
Methods. After i.v. glycopyrrolate 3 µg kg^–1 and intranasal xylometolazone 0.1%, lidocaine 4% 200 mg was administered by nebulizer. Supplementary lidocaine to a maximum total of 9 mg kg^–1 was applied directly and via a fibreoptic endoscope. Nasotracheal intubation was performed once the vocal cords became unreactive. Heart rate, non-invasive blood pressure and oxygen saturation were recorded at 5-min intervals. Blood sampling commenced with a baseline sample and continued at 10 min intervals until 60 min after final administration of local anaesthetic. Subjects graded levels of anxiety, pain and coughing using written and visual analogue scales.
Results. Conditions for fibreoptic endoscopy and intubation were good. Seventeen received the maximum lidocaine dose of 9 mg kg^–1. The average dose used was 8.8 mg kg^–1. All plasma lidocaine concentrations assayed were below 5 mg litre^–1. Four volunteers reported feeling lightheaded after the procedure, despite normal blood pressure. Of these, two had the highest plasma lidocaine concentrations recorded: 3.5 and 4.5 mg litre^–1. Twenty-two of the 25 subjects found endoscopy and intubation acceptable, three found it enjoyable and no subject rated it as distressing.
Conclusions. This method of airway anaesthesia was acceptable to this small group of unsedated subjects. It produced good conditions for fibreoptic intubation. A maximum calculated lidocaine dose of 9 mg kg^–1 did not produce toxic plasma concentrations of lidocaine.

CANADIAN JOURNAL OF ANESTHESIA - TOP

The ProSeal^TM laryngeal mask airway: a review of the literature
Tim Cook, Gene Lee,  and Jerry P. Nolan
Canadian Journal of Anesthesia 52:739-760 (2005)

Purpose: To analyze and summarize the published literature relating to the ProSeal LMA (PLMA): a modification of the ‘classic LMA’ (cLMA) with an esophageal drain tube (DT), designed to improve controlled ventilation, airway protection and diagnosis of misplacement.
Source: Articles identified through Medline and EMBASE searches using keywords ‘Proseal’, ‘ProSeal’ and ‘PLMA’. Hand searches of these articles and major anesthetic journals from January 1998 to March 2005.
Principal findings: Searches identified 59 randomized controlled trials or clinical studies and 79 other publications. Compared to the cLMA, PLMA insertion takes a few seconds longer. First attempt insertion success for the PLMA is lower, but overall success is equivalent. Airway seal is improved by 50%. The DT enables early diagnosis of mask misplacement, allows gastric drainage, reduces gastric inflation and may vent regurgitated stomach contents. Evidence suggests, but does not prove, that the correctly placed PLMA reduces aspiration risk compared with the cLMA. PLMA use is associated with less coughing and less hemodynamic disturbance than use of a tracheal tube (TT). Comparative trials of the PLMA with other supraglottic airways favour the PLMA. Clinicians have extended the use of the PLMA inside and outside the operating theatre including use for difficult airway management and airway rescue.
Conclusions: The PLMA has similar insertion characteristics and complications to other laryngeal masks. The DT enables rapid diagnosis of misplacement. The PLMA offers significant benefits over both the cLMA and TT in some clinical circumstances. These and clinical experience with the PLMA are discussed. 

Obstructive sleep apnea uncovered after high spinal anesthesia: a case report
Paul M. Wieczorek, MDCM and Francesco Carli, MD MPHIL FRCA FRCPC
Canadian Journal of Anesthesia 52:761-764 (2005)

Purpose: To illustrate how a patient’s previously undiagnosed obstructive sleep apnea was uncovered after administration of a spinal anesthetic with a high sensory blockade, and to discuss possible explanations for this occurrence and anesthetic implications.

Clinical features: A 55-yr-old male presented for osteotomy and open reduction and internal fixation of his left femur secondary to malunion from a previous fracture. Past medical history consisted of hypertension, hypercholesterolemia, bipolar disorder, gastroesophageal reflux disease, and cluster headaches. A combined spinal-epidural technique was chosen. Isobaric bupivacaine 0.5% (15 mg), was provided for the spinal anesthetic, along with 1 mg iv midazolam for procedural sedation and 0.5 mg iv droperidol for mild nausea. Throughout the operation, many apneic events were noted, often with respiratory efforts. The patient was easily arousable during each event and would breathe normally until the next episode. Vital signs remained stable throughout. Postoperative respirology consultation was requested, and a sleep study revealed severe obstructive sleep apnea. The patient was subsequently started on continuous positive airway pressure with marked improvement in symptoms, including the cluster headaches.

Conclusion: Recent literature suggests that high spinal blockade can result in altered levels of arousal by producing a de-afferentation of peripheral proprioceptive and sensory stimuli necessary for maintaining an awake state. In patients predisposed to upper airway obstruction, decreasing the level of consciousness can result in airway obstruction as occurs during sleep in these patients. This serves to underline the importance of considering capnography for all cases utilizing a neuraxial anesthetic technique.

PUB MED - TOP

Local bupivacaine-epinephrine infiltration combined with general anesthesia for adult tonsillectomy.
Ginstrom R, Silvola J, Saarnivaara L. Department of Otorhinolaryngology--Head & Neck Surgery, Helsinki University Central Hospital, Helsinki, Finland. robert.ginstrom@welho.com
Acta Otolaryngol. 2005 Sep;125(9):972-5

OBJECTIVE: Pain and intra- and postoperative bleeding are problems associated with tonsillectomy/adenotonsillectomy. In order to make tonsillectomy/adenotonsillectomy better suited to outpatient surgery, solutions to these problems should be found. One possibility may be the combination of local and general anesthesia. The aim of this study was to find out if such a combination is beneficial in tonsillectomy/adenotonsillectomy.
MATERIAL AND METHODS: We performed a prospective, randomized, double-blind, controlled study on 64 adult (adeno)tonsillectomy patients to investigate the possible benefits of infiltrating the peritonsillar space with a BE solution.
RESULTS: In the recovery room, the BE group experienced less pain than a control group infiltrated with saline; subsequently there was no significant difference between the groups concerning pain. The average volume of intraoperative bleeding and the operation time were significantly smaller in the BE group. Postoperative bleeding from the tonsillar fossae occurred in 19% (6/31) of the patients in the BE group and in 18% (6/33) in the saline group.
CONCLUSION: Use of a solution of bupivacaine (5 mg/ml)-epinephrine (5 microg/ml) (BE) is beneficial in reducing intraoperative bleeding and decreasing the operation time in adult (adeno)tonsillectomy patients.

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