Evaluation of the hematological and immunological markers after the first and second doses of BNT162b2 mRNA vaccine.

OBJECTIVE: Both humoral and cellular immunity can be significantly influenced by the immunological responses to vaccination, and both responses are essential. Vaccination is the most consistent, safe, and cost-efficient practice for controlling the COVID-19 pandemic. PATIENTS AND METHODS: Blood samples were collected from participants who received two vaccine doses of COVID-19 Pfizer/BioNTech (BNT162b2) before and on days 7 and 10 after the first and second immunization. We evaluated some hematological and immunological markers responses to the 1st and 2nd doses of the BNT162b2 mRNA (Pfizer/BioNtech) vaccine. RESULTS: In healthy subjects' neutrophil and WBC counts significantly increased compared to those after the first dose. The results of all first-group participant categories demonstrated no discernible variations in lymphocyte counts. There was no change in IgM or IgG in all second-group cohorts, except for a considerable rise in IgG levels in people with a history of coronavirus infection following the second dosage compared to baseline. After the second dose, CD4+ T-cell and CD8+ T-cell levels rose in all groups compared to before the immunization and after the first dosage. Data demonstrated a substantial rise in neutrophil-lymphocyte ratio (NLR) after the second dose of the vaccine. Individuals who had previously had COVID-19 disease experienced a considerable increase in C3 and C4 levels after the first and second dosages compared to baseline. Additionally, compared to their levels after the first dosage, C4 levels increased significantly following the second dosage. Interleukin (IL)-6, IL-15, macrophage colony-stimulating factor (M-CSF), granulocyte colony stimulating factor (G-CSF), interferon gamma-induced protein 10 (IP-10/CXCL10), and macrophage inflammatory protein-1 alpha (MIP-1α/CCL3) levels were increased after boost correlated with Spike antibody levels, supporting their utility as indicators of successful humoral immunity development in response to vaccination. CONCLUSIONS: We can conclude that the Pfizer/BioNTech vaccine produced a more potent T-cell response than humoral ones.

The Effect of Thermocycling on Interfacial Bonding Stability of Self-Etch Adhesives: OCT Study.

OBJECTIVE: The aim of this study was to monitor the behavior of interfacial gaps formed under different bonded polymeric restorations before and after thermocycling (TC), using swept-source optical coherence tomography (SS-OCT) and confirming the obtained findings with confocal laser scanning microscopy (CLSM). MATERIALS AND METHODS: Cylindrical class I cavities were prepared in twenty noncarious human premolar teeth (1.5 mm depth × 3.5 mm diameter) and divided randomly into two groups: TS and SN, according to the adhesive system (n = 10). In the TS group, one-step self-etch adhesive Clearfil Tri-S Bond Plus (Kuraray Noritake Dental, Japan) was used, followed by composite restoration using Estelite Sigma Quick (Tokuyama Dental, Japan). In the SN group, the cavities were restored with the two-step self-etch/composite silorane-based resin restoration system (3M ESPE, USA). All specimens were restored in bulk filling technique and cured in accordance with the manufacturers' instructions. Both groups were imaged under SS-OCT after 24 h and recorded as controls. Then, each group was subjected to thermal challenge using the TC machine (5-55°C) and B-scans were recorded at different TC intervals (2600, 5200, and 10000). In order to confirm the SS-OCT findings, additional specimens were prepared, scanned, and sectioned for CLSM observation. RESULTS: B-scans demonstrated white clusters at the tooth-resin interface that corresponded to the gap location on CLSM images. The TS group showed significantly less gap formation than the SN group before and after TC (p < 0.001). CONCLUSIONS: An optimal composite adaptation can be achieved when the bonded restoration comprises a combination of an adhesive containing 10-MDP monomer and a considerable highly filled composite.

Nondestructive evaluation of microleakage in restored primary teeth using CP-OCT.

BACKGROUND: Although the demand for esthetic filling of primary teeth with resin composite is increasing, there is no enough data on the adhesive performance of composite restorations in primary teeth. Despite the improvements in resin composites, interfacial gap is still a disadvantage as it may cause marginal staining, secondary caries, and restoration failure. Previous studies have validated the efficiency of optical coherence tomography (OCT) in the evaluation of adhesive interface in permanent teeth, but not in primary teeth. AIMS: The aim of this study was to assess microleakage upon composite restorations in primary teeth using cross-polarization OCT (CP-OCT). METHODOLOGY: Cylindrical class-V cavities were prepared in extracted human primary second molars and divided into four groups randomly. In groups 1 and 2, cavities were restored using Tetric N-Universal adhesive in the self-etch mode followed by IPS Impress Direct Composite and Ceram.x One Universal composite, respectively. In groups 3 and 4, one-step self-etch Prime and Bond Elect adhesive was used followed by ID composite and CX composite in groups 3 and 4, respectively. The specimens were then immersed in a contrasting solution followed by interfacial microleakage examination under CP-OCT. The recorded images were analyzed to quantify the mean gap percentages. RESULTS: All tested groups showed variable degree of interfacial microleakage under composite restorations. Two-way ANOVA showed the composite factor was significantly influencing the results, unlike the adhesive. Group 1 and 2 had the lowest and highest mean gap percentage, respectively, which were significantly different from the other groups. Groups 3 and 4 were not significantly different. CONCLUSION: Based on the current finding, a polymeric restorative system from the same manufacturer reduces the risk of interfacial microleakage in primary teeth.

Microgaps and Demineralization Progress around Composite Restorations.

This study investigated the influence of adhesives and marginal sealing on demineralization progress using optical coherence tomography (OCT). Cavities (4 × 2 mm) were prepared in bovine incisors and restored using Clearfil SE Protect (SP), Bond Force (BF), Scotchbond Universal (SB), or G-Bond Plus (GB), followed by Estelite Flow Quick flowable composite. The control group received no adhesive (n = 10). After 3-d incubation in artificial saliva and 10,000 thermal cycles, gaps at enamel and dentin margins were measured at 8 locations on cross-sectional images obtained from each restoration using swept-source OCT at 1310-nm wavelength. Specimens were demineralized using acidified gel (pH = 4.5) for 5 wk and scanned every week to monitor the lesion progress at the same marginal locations. Repeated-measures analysis of variance showed that demineralization period and adhesive type and their interaction had a significant effect on the lesion size in both substrates (P < 0.001). SP, BF, and SB had significantly lower enamel and dentin initial gaps than the control and GB (P < 0.05). Enamel lesion progress was slower in the fluoride-releasing adhesives SP and BF and significantly different from SB, GB, and the control (P < 0.001). SP and BF dentin lesions were significantly different from GB and the control (P < 0.001), but not from SB (P > 0.05). A significant positive correlation (P < 0.05) was found between initial gap length and formed lesion size in both substrates, which was stronger in enamel (r = 0.63) than dentin (r = 0.35). Microgaps forming at the margins of restorations depend on adhesives and significantly contribute to the progress of demineralization around the margins, while fluoride release may decrease the rate of progression.

Pyrimidine-5-carbonitriles II: synthesis and antimicrobial activity of novel 6-alkyl-2,4-disubstituted pyrimidine-5-carbonitriles.

New series of 6-alkyl-2,4-disubstituted pyrimidine-5-carbonitriles namely, 6-alkyl-2-thiouracil-5-carbonitriles 4c,d, 6-alkyl-2-arylmethylsulfanyl-3,4-dihydro-4-oxopyrimidine-5-carbonitriles 5a-p, 6-alkyl-2-(2-methoxyethylsulfanyl)-3,4-dihydro-4-oxopyrimidine-5-carbonitriles 6a-d, 6-alkyl-2-benzyloxymethylsulfanyl-3,4-dihydro-4-oxopyrimidine-5-carbonitriles 7a-c, 6-alkyl-2-(5-nitrofuran-2-ylmethylsulfanyl)-3,4-dihydro-4-oxopyrimidine-5-carbonitriles 8a-d, 6-alkyl-4-arylthio-2-(benzylsulfanyl)pyrimidine-5-carbonitriles 10a, b and 2-benzylsulfanyl-4-[4-(2-methoxyphenyl)-1-piperazinyl]-6-pentylpyrimidine-5-carbonitrile 11, were synthesized and tested for in vitro activities against a panel of Gram-positive and Gram-negative bacteria and the yeast-like pathogenic fungus Candida albicans. Compounds 4d, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i, 5j, 5k, 5 l, 5p, 7a, 7b, 7c, 8a, 8b, 8c, 8d and 11 -displayed marked antibacterial activity particularly against the tested Gram-positive bacteria. Meanwhile, none of these compounds were proved to be active against Candida albicans.

The 'best fit' endotracheal tube in children --comparison of four formulae.

BACKGROUND: Uncuffed endotracheal tubes are still being recommended by most pediatric of anesthetists at our Institutes. Different algorithms and formulae have been proposed to choose the best-fitting size of the tracheal tube. The most widely accepted is related to the age of the child [inner diameter [ID] in mm = (age in yr/4) + 4; the second is a body, length-related formula (ID in mm = 2 + height in cm/30); the third, a multivariate formula (ID in mm = 2.44 + age in yr x 0.1 + height in cm x 0.02 + weight in kg x 0.016]5; the fourth, the width of the 5th fingernail is used for ID prediction of the ETT (ID in mm = maximum width of the 5th fingernail). The primary endpoint of this prospective study was to compare the size of the 'best fit' tracheal tube with the size predicted using each of the above mentioned formulae. PATIENTS AND METHODS: With Institutional Ethics Committee approval and parental consent, 27 boys, 23 girls, ASA I-III, 2-10 years, scheduled for different surgical procedures requiring general anesthesia and endotracheal intubation, were enrolled in the study. The size of 'best fit' endotracheal tubes in those children were compared. The internal diameter considered the 'best fit' by the attending pediatric anesthesiologist was compared to age-based, length-based, multivariate-based and 5th fingernail width-based formulae. For all tests, P < 0.05 was considered to be statistically significant. RESULTS: The mean (SD) IDs for the 'best fit', age-based, length-based, multivariate and 5th fingernail techniques were 5.31 (0.691), 5.54 (0.622), 5.82 (0.572), 5.71 (0.67) and 5.43 (0.821) mm, respectively. CONCLUSIONS: The age-based and 5th fingernail width-based predictions of ETT size are more accurate than length-based and multivariate-based formulae in terms of mean value and case matching.

Ultrasound-guided transversus abdominis plane block: description of a new technique and comparison with conventional systemic analgesia during laparoscopic cholecystectomy.

BACKGROUND: The transversus abdominis plane (TAP) block is usually performed by landmark-based methods. This prospective, randomized, and double-blinded study was designed to describe a method of ultrasound-guided TAP block and to evaluate the intra- and postoperative analgesic efficacy in patients undergoing laparoscopic cholecystectomy under general anaesthesia with or without TAP block. METHODS: Forty-two patients undergoing laparoscopic cholecystectomy were randomized to receive standard general anaesthetic either with (Group A, n=21) or without TAP block (Group B, n=21). Ultrasound-guided bilateral TAP block was performed with a high frequent linear ultrasound probe and an in-plane needle guidance technique with 15 ml bupivacaine 5 mg ml(-1) on each side. Intraoperative use of sufentanil and postoperative demand of morphine using a patient-controlled analgesia device were recorded. RESULTS: Ultrasonographic visualization of the relevant anatomy, detection of the shaft and tip of the needle, and the spread of local anaesthetic were possible in all cases where a TAP block was performed. Patients in Group A received significantly less [corrected] intraoperative sufentanil and postoperative morphine compared with those in Group B [mean (SD) 8.6 (3.5) vs 23.0 (4.8) microg, P<0.01, and 10.5 (7.7) vs 22.8 (4.3) mg, P<0.05]. CONCLUSIONS: Ultrasonographic guidance enables exact placement of the local anaesthetic for TAP blocks. In patients undergoing laparoscopic cholecystectomy under standard general anaesthetic, ultrasound-guided TAP block substantially reduced the perioperative opioid consumption.

Venous air embolism during the use of a Nd YAG laser.

We report a case of a 47-year-old female who suffered a cardiac arrest during sub-mucosal diathermy of the inferior turbinate using a Nd YAG laser. The possible causes of the cardiac arrest are discussed. Venous air embolism due to Nd YAG laser was thought to be the most likely cause in this case. Although venous air embolism has previously been reported during nasal sinus surgery and choanal atresia when using a Nd YAG laser, the occurrence of this complication during a relatively minor surgical procedure has not previously been reported. It is important, therefore, to raise the awareness of this life threatening complication during use of a Nd YAG laser regardless of the duration of surgery. We recommend the use of appropriate methods and techniques to avoid this life threatening complication during the use of Nd YAG laser even for relatively short procedures.

Pain relief following thoracoscopic sympathectomy for palmar hyperhidrosis: a prospective randomised double-blind study.

BACKGROUND: Acute pain management following thoracoscopic sympathectomy (TS) has been described in the literature. The combination of interpleural (IP) injection of bupivacaine and intramuscular injection. (I.M) NSAIDs has not been reported. Therefore we conducted this randomized controlled trial to compare this technique to other reported techniques described for postoperative analgesia following TS. METHODS: 40 patients scheduled to have TS under general anesthesia for the treatment of hyperhidrosis were randomly allocated into 4 groups. Group 1 received 1.5 mg/kg b.w I.M pethidine at end of surgery. Group 2 received ketoprofen 100 mg I.M at end of surgery. Group 3 received 0.4 ml/kg b.w interpleural bupivacaine 0.5%. Group 4 received a combination of I.M ketoprofen (100 mg) in addition to interpleural bupivacaine (0.4 ml/kg). Postoperative pain was assessed using the 11- point numeric rating score (NRS) at 7 different intervals. First, immediately on admission to PACU, every 2 hours for the next 8 hours then at 12 and at 24 hours. Pain was assessed at rest, during deep inspiration and while coughing. ANOVA was used for statistical analysis and Chi-square test for comparing of the data where P values <0.05 were considered significant. RESULTS: The NRS at rest was 3.2 (1.9), 2.4 (1.6), 3 (1.9) and 0.7 (0.9) at Groups 1, 2, 3 and 4 respectively with significant difference in Group 4 versus other Group (P < 0.05) at 2 hours postoperatively and up to 24 hours postoperatively. The same trend was also found during maximal inspiration and while coughing. Opioid consumption in 24 hours was significantly reduced in Group 4 compared to other Groups. CONCLUSIONS: Combination of IP bupivacaine and I.M ketoprofen provided superior analgesia when compared to each modality alone and was better than intramuscular pethidine injection in terms of NRS and the consumption of rescue morphine postoperatively. Further studies are needed on large sample size to confirm our results.

Melatonin premedication and the induction dose of propofol.

BACKGROUND AND OBJECTIVES: Melatonin (N-acetyl-5-methoxytryptamine) is the main indolamine secreted by the pineal gland. Many studies showed that premedication with melatonin is associated with preoperative anxiolysis and sedation without impairment of cognitive and psychomotor skills and without prolonging recovery. We hypothesized that melatonin decreases the amount of propofol required to produce an adequate depth of hypnosis at induction time. METHODS: After approval from the research committee of the anaesthesia department, informed written consent was taken from 45 adult patients undergoing different surgical procedures. They were allocated randomly into three groups according to the premedication. At 100 min preoperatively, premedication was given in the form of oral melatonin 3 mg (M3 group), oral melatonin 5 mg (M5 group) or no premedication (P group). After preoxygenation an anaesthesiologist who was blinded to the premedication injected propofol 10 mg over 5 s every 15 s until the bispectral index (BIS) score fell to 45. The total dose of propofol required to achieve a BIS score of 45 was recorded. Response to verbal commands and eyelash reflex was evaluated and correlated to the BIS score and propofol dosage. When a BIS score of 45 was reached, tracheal intubation was accomplished after administration of a narcotic and muscle relaxant. RESULTS: The mean (standard devitation (SD)) induction dose of propofol producing a BIS score of 45 was 134 (25) mg in the placebo group vs. 115 (19.5) and 114 (20.9) mg in the M3 and M5 groups, respectively (P < 0.05). The propofol dose required to achieve loss of eyelash reflex and loss of response to verbal commands was more in the placebo group. Anxiety score as assessed by visual analogue scale (VAS) scored more in the placebo group than both melatonin groups. Time spent in the recovery room did not differ between the three groups. CONCLUSION: Melatonin premedication, in an oral dose of either 3 or 5 mg, reduced the required dose of propofol to achieve a BIS score of 45, reflecting a sufficient level of hypnosis for tracheal intubation without prolongation of postoperative recovery room stay.

Hajj-associated acute respiratory infection among hajjis from Riyadh.

A prospective cohort study was conducted to estimate the incidence of acute respiratory infections (ARI) among hajjis registered at primary health care centres of Riyadh. Out of 1027 hajjis, 39.8% developed symptoms of ARI. The incidence of ARI was not statistically significantly associated with age, sex, educational status or smoking. The risk of illness was significantly higher among diabetics, hajjis who stayed longer in the hajj area and who prayed at Namera mosque. Use of a facemask by men, but not use of a facecover by women, was a significant protective factor against ARI.

Hajj-associated acute respiratory infection among hajjis from Riyadh

A prospective cohort study was conducted to estimate the incidence of acute respiratory infections [ARI] among hajjis registered at primary health care centres of Riyadh. Out of 1027 hajjis, 39.8% developed symptoms of ARI. The incidence of ARI was not statistically significantly associated with age, sex, educational status or smoking. The risk of illness was significantly higher among diabetics, hajjis who stayed longer in the hajj area and who prayed at Namera mosque. Use of a facemask by men, but not use of a facecover by women, was a significant protective factor against ARI

Metabolic, hormonal and gastric fluid and pH changes after different preoperative feeding regimens.

PURPOSE: To evaluate the metabolic, hormonal and gastric fluid and pH changes after administration of a small volume of different preoperative feeding regimens. METHODS: In a prospective, randomized, double-blind study 375 adult patients were allocated to one of five groups. Patients ingested 60 ml honey, glucose-fructose-sucrose-maltose mixture (GFSM), apple juice or water two hours before surgery or continued their overnight fast (controls). Blood samples were obtained from an indwelling venous catheter before the administration of feeding regimens and before induction of anesthesia for determination of glucose, triglycerides, insulin, epinephrine and norepinephrine concentrations. Before anesthesia induction, patients were asked to grade the degree of thirst and hunger. After tracheal intubation residual gastric volume (RGV) was suctioned through an orogastric tube. RESULTS: Administration of honey, GFSM, apple juice or water resulted in increases in RGV without changes in the gastric pH. The median RGV values were 15 ml in controls and 20-25 ml in other groups. Thirst was noted after administration of fluids containing sugars. Hunger was noted in the apple juice group. Plasma concentrations of glucose increased and triglycerides decreased after ingestion of fluids containing sugars. Plasma insulin concentrations decreased in GFSM and apple juice groups. Norepinephrine concentrations increased in the control, apple juice and water groups. CONCLUSIONS: Small volumes of fluid increased RGV (P < 0.05). Apple juice resulted in increased incidence of thirst and hunger and plasma glucose and norepinephrine concentrations. Compared with GFSM or apple juice, honey had a gentler effect on plasma glucose and insulin concentrations.

Determinants of case fatality rates of meningococcal disease during outbreaks in Makkah, Saudi Arabia, 1987-97.

We studied case-fatality rates (CFRs) among cases of meningococcal disease (MCD) admitted to Makkah (Saudi Arabia) hospitals during the period 1988-97. Of 483 cases, 431 (89.2%) were due to strains of serogroup A, 31 (6.4%) to serogroup W135, 16 (3.3%) to serogroup C, and 5 (10%) to serogroup B. Eighty-one patients died (case fatality rate (CFR)) 16.8%, 95% CI 13.5%, 20.4%). The CFR in infections due to serogroup A strains was 14.8%, and for other serogroups it was 32.7% (95% CI 20.3%, 47.1%). The CFR of MCD due to N. meningitidis serogroup A increased steadily with age (P<0.05). Seeking first medical help at a foreign Hajj medical mission and being treated in a non-specialized hospital were associated with a higher case fatality rate.

Comparative clinical pharmacology of rocuronium, cisatracurium, and their combination.

BACKGROUND: The comparative clinical pharmacology of cisatracurium and rocuronium and their combinations has not been reported. In this study, the authors compared the relative potency and the clinical profile and characterized the interaction of both drugs. METHODS: Two hundred twenty adults classified as American Society of Anesthesiologists physical status I and anesthetized with propofol-fentanyl-nitrous oxide were studied. In part 1, the neuromuscular-blocking effects of cisatracurium and rocuronium were assessed after administration of bolus doses of 20-50 microg/kg and 100-300 microg/kg, respectively. In part 2, we compared the time course of 1xED50, 1, 1.5, and 2xED95 doses of both drugs (where ED50 and ED95 are, respectively, the doses producing 50% and 95% depression of the first twitch height [T1]). In part 3, equieffective combinations of both drugs were studied to characterize their interaction. RESULTS: The calculated ED50 values and their 95% confidence intervals were 111 (107-115) and 26.2 (25.8-26.5) microg/kg [corrected] for rocuronium and cisatracurium, respectively. Compared with equipotent doses of cisatracurium, rocuronium had a faster onset, and a faster spontaneous T1 and train-of-four recovery times that were significant except at maximum recovery with the 2xED95 dose. The interaction between rocuronium and cisatracurium was synergistic, and the time profile of the combination group was different from that of the single-dose groups. CONCLUSIONS: Cisatracurium is four to five times more potent than rocuronium. Rocuronium had a faster onset of action, a shorter clinical duration, and a faster spontaneous recovery rate compared with equipotent doses of cisatracurium.

Comparison of suxamethonium and different combinations of rocuronium and mivacurium for rapid tracheal intubation in children.

The use of suxamethonium in children is associated with undesirable side effects. The synergistic effect of a rocuronium-mivacurium combination can be considered as an acceptable alternative to suxamethonium in clinical practice. The calculated ED50 of the rocuronium-mivacurium mixture was only 62% of the predicted value assuming a purely additive interaction. The use of this combination has not been evaluated in children. In this two-part study, we assessed the intubating conditions and pharmacodynamics of suxamethonium, rocuronium, mivacurium or a rocuronium-mivacurium combinations in children. We studied 120 ASA I children of both sexes, aged 3-10 yr. Children were premedicated with trimeprazine 2 mg kg-1 orally, and received fentanyl 2 micrograms kg-1 and propofol 2 mg kg-1 for induction of anaesthesia. They were allocated randomly to receive one of the following drugs or drug combinations: suxamethonium 1.0 mg kg-1, mivacurium 0.2 mg kg-1, rocuronium 0.6 or 0.9 mg kg-1, mivacurium 0.1 mg kg-1 with rocuronium 0.3 mg kg-1 or mivacurium 0.15 mg kg-1 with rocuronium 0.45 mg kg-1. In part 1, 60 s after administration of the neuromuscular blocking drug or drug combination, tracheal intubation was performed in 60 children by mimicking rapid sequence induction, and intubating conditions were evaluated by a blinded investigator according to a standard score. In part 2, neuromuscular monitoring was established before administration of neuromuscular blocking agent(s) and the time from injection of drug or drug combination until complete ablation of T1 (onset) and recovery of T1 to 25% (duration) were recorded in another 60 children. The frequency of distribution of excellent or good intubating conditions in the higher dose of rocuronium and the combination groups were similar to those in the suxamethonium group, but significantly different (P < 0.05) from those in the mivacurium group. Mean onset time was faster in the suxamethonium (55.1 (SD 11.4) s), rocuronium 0.9 mg kg-1 (70.5 (37.7) s), mivacurium 0.1 mg kg-1 with rocuronium 0.3 mg kg-1 (67 (35.9) s) and mivacurium 0.15 mg kg-1 with rocuronium 0.45 mg kg-1 (55 (26.7) s) groups compared with the mivacurium 0.2 mg kg-1 (116 (26.8) s) and rocuronium 0.6 mg kg-1 (97.9 (29) s) groups. This study demonstrated that the combination of rocuronium 0.45 mg kg-1 and mivacurium 0.15 mg kg-1 could possibly be considered as an acceptable alternative to suxamethonium when rapid sequence induction of anaesthesia is indicated in children because it provides uniform excellent intubating conditions and complete neuromuscular block in < 60 s.

Edrophonium and human plasma cholinesterase combination for antagonism of mivacurium-induced neuromuscular block.

We have compared the reversal characteristics of mivacurium after administration of an edrophonium-plasma cholinesterase (PCHE) combination with that produced by each antagonist alone. Forty ASA I adults were given mivacurium 0.15 mg kg-1 during fentanyl-thiopentone-nitrous oxide-isoflurane anaesthesia. TOF stimulation was applied to the ulnar nerve every 12 s, and the force of contraction of the adductor pollicis muscle was recorded. When spontaneous recovery of first twitch height (T1) reached 10% of its initial control value, patients were allocated randomly to one of four groups (n = 10 in each). Neuromuscular function in patients in group 1 (control group) was allowed to recover spontaneously. Patients in groups 2-4, respectively, received edrophonium 1 mg kg-1 (group ED), exogenous PCHE equivalent to activity present in 25 ml kg-1 of human plasma (group PCHE) or edrophonium 1 mg kg-1 with exogenous human PCHE equivalent to the activity present in 25 ml kg-1 of human plasma (combination group). The time to attain a TOF ratio of 0.75 in the combination group was 4.6 (SD 0.9) min. This was shorter (P < 0.01) than that observed in patients in the control (16.8 (3.3) min), ED (8.9 (3.6) min) and PCHE (9.3 (1.6) min) groups. There was no difference in recovery indices between groups ED and PCHE. We have demonstrated that the edrophonium-PCHE combination significantly accelerated recovery of mivacurium-induced block compared with that observed with the use of individual antagonists.

Enzymatic versus pharmacologic antagonism of profound mivacurium- induced neuromuscular blockade.

BACKGROUND: Mivacurium, a nondepolarizing muscle relaxant, is hydrolyzed by butyrylcholinesterase. The use of butyrylcholinesterase for antagonism of profound mivacurium-induced blockade has not been studied in humans. In part 1 of this two-part study, the authors examined the relationship between the posttetanic count (PTC) and recovery from profound mivacurium-induced blockade. In part 2, an attempt was made to antagonize a quantified level of profound mivacurium-induced blockade using either butyrylcholinesterase, edrophonium, or neostigmine. METHODS: Eighty-seven ASA physical status 1 or 2 adult patients were given 0.15 mg.kg-1 mivacurium during fentanyl-thiopental-nitrous oxide-isoflurane anesthesia. They were randomly assigned to eight groups. Neuromuscular function was monitored by recording the mechanomyographic response of the adductor pollicis to PTC and train-of-four (TOF) stimulation in all patients except those in group 1 where the TOF was the only pattern used. In part 1, neuromuscular function was allowed to recover spontaneously in ten patients (group 1; control-TOF) until TOF ratio (the amplitude of the fourth evoked response as a fraction of the first evoked response T4/T1) had reached 0.75. The temporal relationship between PTC and the first reaction to TOF stimulation was determined in another 31 patients, and neuromuscular function in 10 of these patients was allowed to recover spontaneously until TOF ratio had reached 0.75. The temporal relationship between PTC and the first reaction to TOF stimulation was determined in another 21 patients, and neuromuscular function in 10 of these patients was allowed to recover spontaneously, until TOF ratio had reached 0.75 (group 2; control-PTC). In part 2, the antagonism of mivacurium-induced profound (PTC > or = 1; groups 3-6) and 90% block (groups 7-8) of twitch height were investigated in another 56 patients. Groups 3 and 7 received neostigmine 0.06 mg.kg-1 whereas groups 4 and 8 received edrophonium 1 mg.kg-1, respectively. Groups 5 and 6 received exogenous human butyrylcholinesterase equivalent to activity present in 25 or 70 ml.kg-1 of human plasma, respectively. RESULTS: Neither butyrylcholinesterase nor edrophonium shortened the times from first PTC response to TOF = 0.75 compared to group 2. Neostigmine resulted in prolongation of recovery time. There was a linear relationship (r = -0.80; P = 0.00001) between PTC and time of onset of TOF response. CONCLUSIONS: There appears to be no clinical advantage in attempting to antagonize profound mivacurium-induced neuromuscular blockade.

Heat exhaustion during mass pilgrimage--is there a diagnostic role for pulse oximetry?

Every year over 2 million pilgrims (Hajjis) gather from different countries to perform the sacred ritual, the fifth pillar of Islam, Hajj. Several nationalities from different climates come to Saudi Arabia which is located in a subtropical area with a hot and humid climate during the long summer season. This undertaking is characterised by several days of continuous physical, spiritual, and emotional exertion following their homeland. Several factors predispose them to heat exhaustion, such as the hot climate, excessive physical exercise, lack of acclimatisation, overcrowding, illiteracy, old age, diseases, and over zealous performance of Hajj during the peak sunshine hours. Several thousands of pilgrims suffer from heat exhaustion which is a minor form of heat illness that can easily be detected and treated. Patients are usually discharged having fully recovered, but if heat exhaustion is not treated immediately, it may result in heat stroke with serious sequelae. Cases that need further observation and management are admitted to hospital, particularly those who have associated medical disorders. This study was designed to investigate the role of pulse oximetry in detecting hypoxaemia in patients suffering from heat exhaustion. One hundred fifty-five patients from 26 different countries were enrolled in this study. Their ages ranged from 18 to 83 years. There were 51 (33%), 48 (31%), and 56 (36%) from Asia, the Middle East and Africa, respectively. One hundred thirty-four patients (86.5%) showed a form of hypoxia which necessitated O2 administration. Mild hypoxia (91-94% O2 saturation) was detected in 81 patients (52.3%) and moderate to severe hypoxia (< 90% O2 saturation) was detected in 53 (34.2%) patients.