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M J Paech

Publications and source records attributed to M J Paech.

At least 19 recordsLinked to original sources
PubMed2006

Skin conductance monitoring compared with Bispectral Index to assess emergence from total i.v. anaesthesia using propofol and remifentanil.

BACKGROUND: Arousal after sevoflurane anaesthesia has been detectable by monitoring changes in skin conductance (SC) with similar accuracy as monitoring Bispectral Index (BIS). As SC monitoring detects changes in sympathetic tone, the measurements might be confounded by the sympatholytic properties of propofol, a component of total i.v. anaesthesia (TIVA). Therefore in this study, monitoring of SC during emergence from TIVA was compared with the monitoring of BIS. METHODS: Twenty-five patients undergoing plastic surgery were investigated. The number of fluctuations of SC per second (NFSC), BIS and haemodynamic variables [systolic blood pressure (SBP) and heart rate (HR)] were recorded simultaneously. The performance of the monitoring devices in distinguishing between the clinical states 'steady-state anaesthesia', 'first clinical reaction' and 'extubation' were compared using the method of prediction probability (Pk) calculation. RESULTS: BIS((R)) showed the best performance in distinguishing between 'steady-state anaesthesia' and 'first reaction' (Pk BIS 0.99 vs NFSC 0.80; P<0.01), and 'steady-state anaesthesia' and 'extubation' (Pk BIS) 1.00 vs NFSC 0.91; P<0.05); the time from first change of BIS or NFSC to a first clinical reaction was significantly longer for NFSC (median BIS 135 s vs NFSC 191 s; P<0.05). BIS and NFSC performed better in distinguishing between the investigated clinical states than SBP and HR. CONCLUSIONS: In this study, BIS was found to predict arousal with a higher probability but slower response times than NFSC in patients waking after TIVA.

Adult↗
PubMed2006

Monitoring of skin conductance to assess postoperative pain intensity.

BACKGROUND: Pain is known to alter the electrogalvanic properties of the skin. The aim of this pilot study was to investigate the influence of postoperative pain on skin conductance (SC) readings. METHODS: After obtaining ethical approval and written informed consent, 25 postoperative patients were asked to quantify their level of pain on a numeric rating scale (NRS, 0-10) at different time points in the recovery room. As a parameter of SC, the number of fluctuations within the mean SC per second (NFSC) was recorded. Simultaneously, the NRS was obtained from patients by a different observer who was blinded to the NFSC values. RESULTS: Data from 110 readings of 25 patients (14 female, 11 male; 21-67 yr) were included. NFSC showed a significant correlation with the NRS (r=0.625; P<0.01), whereas heart rate and blood pressure showed no or very weak correlation with the NRS. NFSC was significantly different between patients with no (NRS=0), mild (NRS=1-3), moderate (NRS=4-5) and severe (NRS=6-10) pain (no: 0.047, mild: 0.089, moderate: 0.242, severe: 0.263; P<0.0001). Post hoc, a cut-off value for NFSC (0.1) was calculated above which a pain score >3 on the NRS was predicted with sensitivity of 89% and specificity of 74%. CONCLUSIONS: The severity of postoperative pain significantly influences SC. Using cut-off values, NFSC may prove a useful tool for pain assessment in the postoperative period.

Adult↗
PubMed2006

Skin conductance monitoring compared with bispectral index monitoring to assess emergence from general anaesthesia using sevoflurane and remifentanil.

BACKGROUND: Changes in skin conductance have previously been reported to correlate well with plasma levels of stress hormones and awakening stimuli. In this study, monitoring of skin conductance during emergence from general anaesthesia was compared with the monitoring of bispectral index (BIS). METHODS: Twenty-five patients undergoing minor elective surgery were investigated. The number of fluctuations in mean skin conductance (NFSC), BIS and haemodynamic parameters were recorded simultaneously. The performance of the monitoring devices to predict and distinguish between the clinical states 'steady-state anaesthesia', 'first reaction' and 'extubation' were compared using the method of prediction probability (P(K)) calculation. RESULTS: Both monitors showed similar performance in distinguishing between 'steady-state anaesthesia' vs 'first reaction' (P(K) NFSC 0.89; BIS 0.94) and 'steady-state anaesthesia' vs 'extubation' (P(K) NFSC 0.96; BIS 0.96). The response times of the monitors, to indicate the likelihood of 'first reaction', were not significantly different. CONCLUSIONS: NFSC, as a parameter of skin conductance, performed similarly to BIS in patients waking after a general anaesthetic.

Adolescent↗
PubMed2006

Hypertrophic cardiomyopathy and caesarean section: intraoperative use of transthoracic echocardiography.

A pregnant woman with severe hypertrophic cardiomyopathy was monitored with transthoracic echocardiography to guide management of fluids and vasopressors during elective caesarean section. After insertion of intravenous, arterial and central venous cannulae, a transthoracic echocardiogram was performed noting left ventricular cavity size and contractility, systolic anterior motion of the mitral valve and left ventricular outflow tract obstruction. Following combined spinal-epidural anaesthesia, serial examinations were made intraoperatively. Short-lived haemodynamic instability ensued just before the incision and with administration of oxytocin. Her postoperative course was complicated by post-partum haemorrhage requiring radiological intervention but she ultimately recovered fully. Maintaining preload to avoid worsening of left ventricular outflow tract obstruction is essential in these patients. A transthoracic echocardiogram is easily performed, of low risk and provides more useful information than a pulmonary artery catheter.

Adult↗
PubMed2006

Bronchial mucus transport velocity in patients receiving anaesthesia with propofol and morphine or propofol and remifentanil.

In vitro morphine does not reduce cilia beat frequency, a key factor determining bronchial mucus transport velocity. There are no reports about the effect of remifentanil on bronchial mucus transport. We compared the bronchial mucus transport velocity in patients having total intravenous anaesthesia with either propofol and morphine, or propofol and remifentanil. Twenty patients scheduled for elective surgery were randomly allocated to the two groups. Fifteen minutes after insertion of the laryngeal mask airway, bronchial mucus transport velocity was assessed by fibreoptic observation of the movement of methylene blue dye applied to the right main bronchus. Compared with morphine, bronchial mucus transport velocity was significantly reduced in patients receiving remifentanil (morphine mean (SD) 9.2 (5.8) vs remifentanil 4.2 (3.0) mm.min(-1), p = 0.028). Anaesthesia with remifentanil may lead to significantly impaired bronchociliary clearance in comparison to morphine. This could have clinical implications, in particular in patients at risk.

Adult↗
PubMed2006

An unusual presentation of a pituitary tumour in the early postpartum period.

The case of a parturient, who first presented with a partial oculomotor nerve palsy shortly after caesarean delivery while participating in a clinical trial, is presented. The anaesthesia for the caesarean delivery involved a combined spinal-epidural with intrathecal bupivacaine and postoperative epidural pethidine patient-controlled analgesia. The trial was examining the possible effects of magnesium infusions on acute and chronic pain. The partial oculomotor nerve palsy was an unusual presentation and the signs and symptoms were transient. Magnetic resonance imaging confirmed the presence of a presumed pituitary macroadenoma. Possible reasons for the timing of onset and the rapid resolution of symptoms, and the implications and management of pituitary pathology in the peripartum period, are considered. The uncomplicated course of a later caesarean delivery in the same patient, using the same anaesthesia technique, is also noted.

Adenoma↗
PubMed2005

Cerebrospinal fluid and serum concentrations of beta-trace protein during pregnancy.

We conducted a prospective observational study among a cohort of 40 term parturients undergoing spinal anaesthesia for elective Caesarean section, to determine the concentration of beta-trace protein in cerebrospinal fluid (CSF) and serum. Serum and CSF samples, taken at the time of dural puncture, were assayed by nephelometry. The mean serum beta-trace protein concentration was 0.39 mg.l(-1) and the mean CSF concentration was 27.9 mg.l(-1), giving a mean ratio of CSF to serum concentration of 76. This ratio is higher than that published for non-pregnant females and for males because of both a higher mean CSF and a lower mean serum beta-trace protein concentration. The concentration correlated positively with both serum creatinine and gestational age. If these concentrations are used to estimate the normal range, we propose that the nephelometric measurement of beta-trace protein might prove a useful diagnostic test for cerebrospinal fluid-cutaneous fistula in parturients.

Adult↗
PubMed2005

Randomised, crossover comparison of the single-use SoftSeal and the LMA Unique laryngeal mask airways.

We performed a randomised, crossover, single-blind trial among 168 patients, to compare the single-use SoftSeal and LMA Unique laryngeal mask airways in spontaneously breathing adults. Size-3 and -4 laryngeal mask airways, inserted by experienced anaesthetists, performed equivalently for successful first-time placement (148 (91%) vs 155 (96%) for the SoftSeal and LMA Unique, respectively). The SoftSeal was more often rated as difficult to insert (27 (17%) vs 4 (3%); p < 0.001) and was more likely to show evidence of mucosal trauma after the first insertion (14 (10%) vs 5 (4%); OR 1.3 (95% CI 1.3-11.3); p < 0.05). The fibreoptic view of the larynx was better through the SoftSeal (vocal cords not visible in 27 (17%) vs 44 (27%); p < 0.05) and it more frequently provided a ventilation seal at 20 cmH(2)O (93 (59%) vs 62 (39%); OR 2.15 (CI 1.44-3.21); p < 0.001). In contrast to the LMA Unique(trade mark), its cuff pressure did not increase during nitrous oxide anaesthesia (median (IQR [range]) decrease 3 (- 20-23 [-40-94]) cmH(2)O vs increase of 16 (-2-39 [-54-112]) cmH(2)O; p < 0.01). Both devices were equivalent for the success of first-time insertion and performed satisfactorily clinically. There were some performance differences, but either appears suitable for airway management in spontaneously breathing patients.

Adult↗
PubMed2005

A comparison of the lateral, Oxford and sitting positions for performing combined spinal-epidural anaesthesia for elective Caesarean section.

One hundred women were randomly allocated to the left lateral, Oxford or sitting position for induction of combined spinal-epidural anaesthesia for Caesarean section using 2.5 ml hyperbaric bupivacaine 0.5% and 10 mug fentanyl. Women in the left lateral were then turned to the right lateral position; women in the Oxford position were turned to the same position on their opposite side; and women in the sitting group were turned to the supine left tilt position. Women remained in these positions until ready for surgery, which was conducted in the supine position with a wedge placed under the right hip. Ephedrine requirements before re-positioning for surgery were less in the sitting position than in the other two positions: median (IQR [range]) doses for the lateral, Oxford and sitting groups were 21 (12-30 [6-48]), 18 (7.5-24 [6-48]) and 12 (6-21 [6-42]) mg, respectively; p = 0.04. Sensory block to touch sensation at the T5 dermatomal level was most quickly achieved in the lateral position with median (IQR [range]) block onset times for the lateral, Oxford and sitting groups of 9 (6-13 [4-30]), 15.5 (9-22 [4-34]) and 14 (9-18[6-36]) min, respectively; p = 0.004. In the Oxford position, more epidural catheters required dosing to achieve a sensory block of T5 before surgery: the number of patients (proportion) bolused in the lateral, Oxford and sitting groups was 1 (3%), 7 (22%) and 1 (3%), respectively; p = 0.01. We did not demonstrate any advantage in using the Oxford position for combined spinal-epidural anaesthesia for elective Caesarean section.

Adult↗
PubMed2004

Intrathecal fentanyl-induced pruritus during labour: the effect of prophylactic ondansetron.

Fentanyl is commonly used for spinal analgesia during labour but it is associated with a high incidence of pruritus. This randomised, double-blind, placebo-controlled study was performed to evaluate the effect of prophylactic ondansetron on the incidence and severity of pruritus among parturients receiving intrathecal fentanyl as part of combined spinal-epidural analgesia. Seventy-three women were randomised to receive either saline placebo (group P, n = 25), ondansetron 4 mg (group O4, n = 23) or ondansetron 8 mg (group O8, n = 25) intravenously before intrathecal fentanyl 25 micrograms and bupivacaine 2 mg. The incidence and severity of pruritus were measured using a verbal rating and a visual analogue scale, and by the requirement for rescue anti-pruritic medication (naloxone). The overall incidence of pruritus was 95% (group P 100%, group O4 95%, group O8 90%). There were no significant differences between groups for severity of pruritus or requirement for treatment (naloxone given to 45%, 28% and 35% of groups P, O4 and O8 respectively). Secondary outcomes such as the incidence of headache, pain and nausea were not significantly different between groups. We conclude that prophylactic ondansetron 4 or 8 mg intravenously was ineffective in reducing the incidence or severity of intrathecal fentanyl-induced pruritus during labour.

Adult↗
PubMed2004

Management of a parturient with paroxysmal nocturnal haemoglobinuria.

We present the case of a 30-year-old parturient diagnosed in the first trimester of her first pregnancy as having paroxysmal nocturnal haemoglobinuria. Pancytopenia necessitated regular transfusion of blood products. The risks of infection, haemorrhage and thrombosis, in the presence of severe thrombocytopenia, mild neutropenia and prophylactic anticoagulation, posed management challenges. We discuss the pathophysiology of paroxysmal nocturnal haemoglobinuria and the impact of pregnancy on the disorder, particularly on maternal morbidities such as thrombosis. The issues relevant to antenatal and peripartum obstetric, haematological and anaesthetic care for vaginal delivery are considered. Severe thrombocytopenia proved a contraindication to regional techniques and she required general anaesthesia for evacuation of a retained placenta. The post-partum period was complicated by fever and a requirement for blood products. Management of these problems, of prophylactic anticoagulation and subsequent therapy, are discussed.

Adult↗
PubMed2004

Synacthen Depot for the treatment of postdural puncture headache.

We conducted a prospective, randomised, double-blind trial to study the effect of Synacthen Depot in 18 parturients with postdural puncture headache following deliberate or accidental dural puncture. Women were randomly allocated to receive either Synacthen Depot 1 mg (1 ml) or 0.9% saline 1 ml intramuscularly. Using a 10-cm visual analogue scale, severity of headache was measured before and at intervals until 48 h after injection. There was no difference in the severity of headache or requirement for epidural blood patch. We conclude that there is no advantage to the use of Synacthen Depot 1 mg for the treatment of postdural puncture headache.

Adult↗
PubMed2004

Randomized evaluation of the single-use SoftSeal and the re-useable LMA Classic laryngeal mask.

A number of laryngeal masks are available, including both re-usable and single-use masks. Single-use laryngeal masks may decrease the risk of transmitting prion infections. We performed a single-blind randomized trial in 200 spontaneously breathing female patients under general anaesthesia with nitrous oxide, to compare a new single-use laryngeal mask, the SoftSeal (Portex Ltd, U.K.), with a re-usable laryngeal mask, the LMA Classic (Laryngeal Mask Company Ltd., Cyprus). The primary outcome was successful insertion at the first attempt. Size 4 single-use (n = 99) or re-usable (n = 100) laryngeal masks, inserted by experienced anaesthetists, were equivalent for successful placement at the first attempt (90% versus 91% respectively). The single-use mask was less easy to insert (47% difficult versus 9%, P < 0.001). Clinical and anatomical tests of position and function were similar. The cuff pressure of the re-usable mask increased significantly compared with the single-use mask (median +10 cm versus -2 cm H2O, P < 0.001). Forty per cent of patients allocated the single-use mask and 20% of those allocated the re-usable mask experienced sore throat at 24 hours postoperatively (P < 0.05). An estimation of cost per patient use was greater for the re-usable mask. We conclude that the SoftSeal single-use laryngeal mask and the LMA Classic re-usable laryngeal mask airway are of similar clinical utility in terms of successful insertion and airway maintenance. The re-usable laryngeal mask was easier to insert and associated with less postoperative sore throat, but costs were higher.

Adolescent↗
PubMed2003

A new formulation of nasal fentanyl spray for postoperative analgesia: a pilot study.

Twenty-four gynaecological patients receiving postoperative patient-controlled analgesia were enrolled in an open cross-over pilot study evaluating two new formulations of nasal fentanyl spray. The primary outcome was the bioavailability of nasal fentanyl in comparison with intravenous fentanyl. This manuscript describes the clinical outcomes of quality of postoperative analgesia and patient acceptability. There were 21 complete data sets for both sequences of the cross-over design. In randomised order, patients received approximately 50 microg of fentanyl in a single dose by intranasal and intravenous administration, but separated by at least 2 h. Analgesia was of rapid onset (within 5 min) and similar quality. There was no significant difference in side-effects. Four patients experienced mild nasal stinging and although 10 (42%) preferred intravenous administration, seven (29%) preferred intranasal and six (25%) had no preference. We conclude that these formulations of fentanyl, delivered as nasal spray, have potential clinical utility.

Administration, Intranasal↗
PubMed2003

The efficacy and cost-effectiveness of prophylactic 5-hydroxytryptamine3 receptor antagonists: tropisetron, ondansetron and dolasetron.

There are currently three 5-hydroxytryptamine3 (5-HT3) receptor antagonists available in Australia. In this randomized, double-blind, parallel group study the prophylactic antiemetic effect of a single dose of tropisetron 2 mg, ondansetron 4 mg or dolasetron 12.5 mg was compared after major gynaecological surgery. One hundred and eighteen patients (group T n = 42; group O n = 36; group D n = 40) were evaluated for nausea, vomiting, recovery characteristics and satisfaction for 24 hours postoperatively. A cost-effectiveness analysis was performed. Rescue antiemetic, prochlorperazine 12.5 mg i.m., was given if vomiting occurred more than 10 minutes after arrival in the recovery room. If prochlorperazine was ineffective one hour after administration, droperidol 1 mg i.v. was given. There were no significant differences between groups for the incidence of vomiting during consecutive epochs until 24 hours postoperatively or overall (57%, 75% and 72.5% for groups T, O and D respectively, P = 0.18). The incidence and number of rescue antiementic treatments for nausea or vomiting were similar. The incidence of nausea and the overall and interval nausea scores were similar except for lower "worst nausea" score in group T between 12 and 18 hours (P = 0.02). Recovery times, satisfaction and cost per patient did not differ between groups. We conclude that the risk of postoperative nausea and vomiting remained high in this setting despite 5-HT3 receptor antagonist prophylaxis and that the choice between these agents should be based on the lowest available acquisition cost.

Antiemetics↗
PubMed2003

Use of oral and implantable naltrexone in the management of the opioid impaired physician.

Doctors are at an increased risk for prescription drug use, particularly opioids and benzodiazpines. This use can interfere with work function and has major potential negative implications for patient safety. Oral naltrexone, an opioid antagonist, has been used as part of a management strategy for opioid dependent physicians. While some patients stabilize on oral naltrexone, others relapse to opioid use. An alternative method of naltrexone maintenance involves the injection or surgical insertion of a sustained release preparation of naltrexone. This approach dramatically improves compliance, removing the onus from the previously opioid impaired physician to use daily oral naltrexone. This article describes the cases of four opioid-impaired doctors who received naltrexone (either oral or implant) as part of their management. The authors conclude that monitoring daily oral naltrexone use and detecting early opioid relapse is difficult, placing both the opioid impaired physician and their patients at risk. In contrast, by using implantable naltrexone, compliance is assured and opioid abstinence can virtually be guaranteed for five months. It is argued that naltrexone implants offer a level of protection not achieved with any previous treatment. It is recommended that management should involve early and close collaboration between the treating doctor and the Medical Board, with initial treatment, ongoing monitoring and follow-up being a Medical Board requirement for registration.

Administration, Oral↗
PubMed2002

The effect of anaesthetic technique on postoperative nausea and vomiting after day-case gynaecological laparoscopy.

Gynaecological surgery is of high emetogenic potential and both total intravenous anaesthesia (TIVA) and prophylactic antiemetic therapy may reduce the incidence of postoperative nausea and vomiting (PONV). We studied 144 patients scheduled for day-case gynaecological laparoscopy in a randomized trial comparing balanced inhalational anaesthesia and prophylactic dolasetron (group I+D) with propofol TIVA and dolasetron (group T+D) or TIVA alone (group T). The primary outcome of "complete response" (no vomiting, no treatment for PONV) was not significantly different among groups (34%, 51%, 32%; groups I+D vs T+D vs T, P=0.12). During the first hour after surgery, group I+D had nausea of greater severity (P<0.03). During hospital admission, group T had more vomiting (P<0.03). From discharge until 24 hours postoperatively, 55% of group I+D experience nausea and 38% vomited. The incidence and severity of nausea were significantly lower in the TIVA groups (P<0.04 and <0.05 respectively). There were no significant differences between groups T+D and T, although comparing all groups the complete response rate was highest and the post-discharge incidence and severity of nausea lowest in group T+D. In conclusion, propofol TIVA, with or without dolasetron, reduced postoperative nausea, but not perioperative vomiting or antiemetic requirement, when compared with inhalational anaesthesia plus dolasetron.

Adult↗