A randomized comparison of hemodynamic changes in response to a heart rate-dependent phenylephrine/ephedrine protocol versus ephedrine-only for spinal hypotension during elective cesarean section.

AIM: To compare incidences of abnormal heart rate (HR) between the phenylephrine/ephedrine protocol (P/E protocol) against the ephedrine-only (C) protocol, conventionally used for treating predelivery hypotension following spinal anesthesia for cesarean section. METHODS: Two hundred and sixty-eight parturients with pre-delivery hypotension after spinal anesthesia were equally randomized to (1) Group P/E (n = 134), phenylephrine 100 mcg in 10 mL intravenously if HR ≥ 60 beats/min (bpm), or ephedrine 6 mg intravenously if HR < 60 bpm, and 2) Group C (n = 134). The primary outcome was the incidence of the parturients with abnormal HR after vasopressor administration. The secondary outcome was the mean differences of HR and hypotensive periods during the pre-delivery period. RESULTS: There was no significant difference of between-group incidences of bradycardia (12.0% in Group P/E vs 6.7% in Group C, p = 0.136) and tachycardia (26.9% vs 35.8%, p = 0.114). Mean HR was 81.9 bpm (95% confidence interval [CI] 79.9, 84.3) in Group P/E, and 88.8 bpm (86.8, 90.6) in Group C (p < 0.001). The duration of hypotension in relation to the time interval from spinal anesthesia to delivery was 20.9% (95% CI 18.4-23.2) in Group P/E, and 26.5% (23.9-29.3) in Group C (p < 0.01). The calculated area under the curve (AUC) of abnormal HR in relation to time was significantly reduced only in Group P/E (p < 0.010). CONCLUSIONS: The incidences of out-of-range HR were comparable, but the P/E protocol resulted in a lower mean HR and better control of systolic blood pressure than the ephedrine-only protocol.

Safety of Phenylephrine in Antihypotensive Treatment during Spinal Anesthesia for Cesarean Section.

OBJECTIVE: In Thailand, hypotension after spinal anesthesia for cesarean section is routinely treated by ephedrine. As incidence of fetal acidosis reportedly increases resulting from placental transfer of ephedrine, phenylephrine, an alpha-1 agonist with less lipid solubility, becomes an alternative. However, the potential development of serious bradycardia after phenylephrine is a concern. The objectives of this study were to investigate the incidence of serious bradycardia and identify risk factors associated with phenylephrine-induced serious bradycardia and other side effects of phenylephrine. MATERIAL AND METHOD: This descriptive cross-sectional study was conducted between July 1, 2014 and March 15, 2015 on 509 parturients undergoing cesarean section under spinal anesthesia. Predelivery hypotension was treated by intravenous phenylephrine 100 mcg and pretherapeutic heart rate (pHR) was recorded. If serious bradycardia (HR < 60 bpm and hypotension or HR <45 bpm) developed, atropine 0.6 mg was administered intravenously. Data were analyzed using multivariable logistic regression and AuROC. RESULTS: Incidence of serious bradycardia was 11% (95% CI: 8.0-14.0). A one bpm increment increase in pHR reduced this incidence by 4% (adjusted OR: 0.96; 95% CI: 0.94-0.98, p < 0.001; AuROC: 0.76). As compared to apHR greater than 80 bpm, apHR of 61 to 80 bpm and a pHR of 60 bpm or lower increased the risk of serious bradycardia by 3.55 times and 12.81 times, respectively. Other risk factors were height (adjusted OR: 0.94; 95% CI: 0.89-0.98, p = 0.015), baseline DBP (adjusted OR: 0.97; 95% CI: 0.94-0.99,p = 0.03), and anesthetic level at first minute (adjusted OR: 1.13; 95% CI: 1.02-1.23, p = 0.02). Benign and temporary abnormal ECG readings were noted. CONCLUSION: Phenylephrine for antihypotensive treatment in spinal anesthesia induces bradycardia. Findings indicate an association between slower HR at time phenylephrine is administered and serious bradycardia. Close ECG monitoring and prompt treatment are required.

Prognostic factors for death and survival with or without complications in cardiac arrest patients receiving CPR within 24 hours of anesthesia for emergency surgery.

PURPOSE: To determine prognostic factors for death and survival with or without complications in cardiac arrest patients who received cardiopulmonary resuscitation (CPR) within 24 hours of receiving anesthesia for emergency surgery. PATIENTS AND METHODS: A retrospective cohort study approved by the Maharaj Nakorn Chiang Mai University Hospital Ethical Committee. Data used were taken from records of 751 cardiac arrest patients who received their first CPR within 24 hours of anesthesia for emergency surgery between January 1, 2003 and October 31, 2011. The reviewed data included patient characteristics, surgical procedures, American Society of Anesthesiologist (ASA) physical status classification, anesthesia information, the timing of cardiac arrest, CPR details, and outcomes at 24 hours after CPR. Univariate and polytomous logistic regression analyses were used to determine prognostic factors associated with the outcome variable. P-values of less than 0.05 were considered statistically significant. RESULTS: The outcomes at 24 hours were death (638/751, 85.0%), survival with complications (73/751, 9.7%), and survival without complications (40/751, 5.3%). The prognostic factors associated with death were: age between 13-34 years (OR =3.08, 95% CI =1.03-9.19); ASA physical status three and higher (OR =6.60, 95% CI =2.17-20.13); precardiopulmonary comorbidity (OR =3.28, 95% CI =1.09-9.90); the condition of patients who were on mechanical ventilation prior to receiving anesthesia (OR =4.11, 95% CI =1.17-14.38); surgery in the upper abdominal site (OR =14.64, 95% CI =2.83-75.82); shock prior to cardiac arrest (OR =6.24, 95% CI =2.53-15.36); nonshockable electrocardiography (EKG) rhythm (OR =5.67, 95% CI =1.93-16.62); cardiac arrest occurring in postoperative period (OR =7.35, 95% CI =2.89-18.74); and duration of CPR more than 30 minutes (OR =4.32, 95% CI =1.39-13.45). The prognostic factors associated with survival with complications were being greater than or equal to 65 years of age (OR =4.30, 95% CI =1.13-16.42), upper abdominal site of surgery (OR =10.86, 95% CI =1.99-59.13), shock prior to cardiac arrest (OR =3.62, 95% CI =1.30-10.12), arrhythmia prior to cardiac arrest (OR =4.61, 95% CI =1.01-21.13), and cardiac arrest occurring in the postoperative period (OR =3.63, 95% CI =1.31-10.02). CONCLUSION: The mortality and morbidity in patients who received anesthesia for emergency surgery within 24 hours of their first CPR were high, and were associated with identifiable patient comorbidity, age, shock, anatomic site of operation, the timing of cardiac arrest, EKG rhythm, and the duration of CPR. EKG monitoring helps to identify cardiac arrest quickly and diagnose the EKG rhythm as a shockable or nonshockable rhythm, with CPR being performed as per the American Heart Association (AHA) CPR Guidelines 2010. The use of the fast track system in combination with an interdisciplinary team for surgery, CPR, and postoperative care helps to rescue patients in a short time.

Incidence of and factors associated with perioperative cardiac arrest within 24 hours of anesthesia for emergency surgery.

PURPOSE: To determine the incidence of and factors associated with perioperative cardiac arrest within 24 hours of receiving anesthesia for emergency surgery. PATIENTS AND METHODS: This retrospective cohort study was approved by the ethical committee of Maharaj Nakorn Chiang Mai Hospital, Thailand. We reviewed the data of 44,339 patients receiving anesthesia for emergency surgery during the period from January 1, 2003 to March 31, 2011. The data included patient characteristics, surgical procedures, American Society of Anesthesiologists (ASA) physical status classification, anesthesia information, location of anesthesia performed, and outcomes. Data of patients who had received topical anesthesia or monitoring anesthesia care were excluded. Factors associated with cardiac arrest were identified by univariate analyses. Multiple regressions for the risk ratio (RR) and 95% confidence intervals (CI) were used to determine the strength of factors associated with cardiac arrest. A forward stepwise algorithm was chosen at a P-value <0.05. RESULTS: The incidence (within 24 hours) of perioperative cardiac arrest in patients receiving anesthesia for emergency surgery was 163 per 10,000. Factors associated with 24-hour perioperative cardiac arrest in emergency surgery were age of 2 years or younger (RR =1.46, CI =1.03-2.08, P=0.036), ASA physical status classification of 3-4 (RR =5.84, CI =4.20-8.12, P<0.001) and 5-6 (RR =33.98, CI =23.09-49.98, P<0.001), the anatomic site of surgery (upper intra-abdominal, RR =2.67, CI =2.14-3.33, P<0.001; intracranial, RR =1.74, CI =1.35-2.25, P<0.001; intrathoracic, RR =2.35, CI =1.70-3.24, P<0.001; cardiac, RR =3.61, CI =2.60-4.99, P<0.001; and major vascular; RR =3.05, CI =2.22-4.18, P<0.001), respiratory or cardiovascular comorbidities (RR =1.95, CI =1.60-2.38, P<0.001 and RR =1.38, CI =1.11-1.72, P=0.004, respectively), and patients in shock prior to receiving anesthesia (RR =2.62, CI =2.07-3.33, P<0.001). CONCLUSION: The perioperative incidence of cardiac arrest within 24 hours of anesthesia for emergency surgery was high and associated with multiple factors such as young age (≤2 years old), cardiovascular and respiratory comorbidities, increasing ASA physical status classification, preoperative shock, and surgery site. Perioperative care providers, including surgeons, anesthesiologists, and nurses, should be prepared to manage promptly this high risk group of surgical patients.

The initial success rate of cardiopulmonary resuscitation and its associated factors in patients with cardiac arrest within 24 hours after anesthesia for an emergency surgery.

PURPOSE: To determine the initial success rate and its associated factors on cardiopulmonary resuscitation (CPR) in patients with cardiac arrest within 24 hours after receiving anesthesia for an emergency surgery. PATIENTS AND METHODS: After the hospital ethical committee gave approval for this study, the anesthesia providers recorded all relevant data regarding CPR in patients with cardiac arrest within 24 hours after anesthesia for emergency surgery at Maharaj Nakorn Chiang Mai Hospital, a university hospital in Northern Thailand. Only data from the cardiac arrest patients who received the first CPR attempt were included in the analysis. The end point of the initial success of CPR was return of spontaneous circulation (ROSC). Factors related to ROSC were determined by univariate analyses and multiple logistic regression analysis. The odds ratios (OR) and 95% confidence intervals (CI) were used to calculate the strength of the factors associated with the ROSC. RESULTS: Of the 96 cardiac arrest patients, 44 patients (45.8%) achieved ROSC. Factors associated with ROSC were electrocardiogram monitoring for detected cardiac arrest (OR =4.03; 95% CI =1.16-14.01; P=0.029), non-shock patients before arrest (OR =8.54; 95% CI =2.13-34.32; P=0.003), timing to response of activated CPR team within 1 minute (OR =9.37; 95% CI =2.55-34.39; P<0.001), having trained CPR teams (OR =8.76; 95% CI =2.50-30.72; P<0.001), and administration of more than one dose of epinephrine (OR =5.62; 95% CI =1.32-23.88; P<0.019). CONCLUSION: Patients undergoing anesthesia for an emergency surgery are at risk for perioperative cardiac arrest with high mortality which requires immediate CPR. Our results have confirmed that early detection of cardiac arrest by vigilant electrocardiogram monitoring and prompt management with a qualified team are important factors in improving the success of CPR. Emergency surgical patients at risk for cardiac arrest should be promptly managed, with facilities available not only during the operation but also during the pre- to postoperative period.

Effect of noise block using earplugs on propofol sedation requirement during extracorporeal shock wave lithotripsy.

OBJECTIVE: To determine effect of noise block using earplugs on reducing propofol infusion needed to maintain a constant bispectral index (BIS) values in patients undergoing extracorporeal shock wave lithotripsy (ESWL). MATERIAL AND METHOD: Fifty-eight patients (18-65 years) with nephrolithiasis undergoing ESWL, having ASA physical status I or II and have normal hearing function tested by audiometry were enrolled in this randomized, double-blind, controlled trial. Patients were randomized and allocated into two groups: noise blocked group (earplugs inserted into both ears) and control group (earplugs not inserted). Sedation by target-controlled infusion was started with 1.2 mcg/mL of propofol and propofol target concentration was adjusted gradually by 0.2 mcg/ml every 5 minutes intraoperatively to achieve and maintain bispectral index (BIS) values within 75-80% until the procedure finished. Total amount of propofol (mg), BIS values (%), ambient noise level (dB) and patient satisfaction (1-5) were measured. RESULTS: The amount of propofol infusion needed to maintain a constant BIS index value in patients undergoing ESWL in the noise blocked group was significantly lower than that in the control group (6.91 +/- 2.05 vs. 8.23 +/- 2.16 mg/kg/m2/hr, p = 0.021). Patient satisfaction was similar in both groups (4 [1] vs. 4 [1], p = 0.929). CONCLUSION: Noise diminution in ambient operating room can reduce the amount of propofol needed to maintain light sedation during ESWL.

Difficult intubation in the adult patients undergoing oropharygolaryngeal, neck, and maxillofacial procedures: Thai Anesthesia Incident Monitoring Study (Thai AIMS).

BACKGROUND: Difficult intubation is one of the common anesthetic related complications during the perioperative period. In the patients with pathology or disease involving the oropharyngolarynx, neck, or maxillo-facial region, they might have a potentially higher risk than the general population. OBJECTIVE: To determine the characteristics and the contributing factors of difficult intubation in the adult patients undergoing oropharyngolaryngeal, neck, and maxillofacial procedures, and the factors minimizing this incidence and the suggested corrective strategies. MATERIAL AND METHOD: All incident reports of difficult intubation in the adult patients who received general anesthesia for the procedure involving the oropharyngolarynx, neck, and maxillofacial region from the Thai Anesthesia Incident Monitoring Study (Thai AIMS) database were identified. The details of the reports, the contributing factors, the factors those minimizing the incident, and the suggestive corrective strategies were studied. RESULTS: There were 26 (1.3%) incident reports of difficult intubation from the database. This occurred in 35%, 58%, and 15% of the patients with Mallampati class 1-2, thyromental distance equal or more than 5 cm or 3 fingerbreadths, and combined both parameters, respectively. Forty two percent of cases were judged as an unplanned difficult intubation. Twenty-seven, 23, and 19 percent of the patients had tumor or carcinoma at the oropharyngolarynx, deep neck infection, and maxillofacial fracture, respectively. Nearly half of the adverse events accompanied with difficult intubation were desaturation. No immediate fatally and late outcome was reported. Patients' disease/anatomy was the major contributing factor that might relate to the incidence. Previous experience, experienced assistance, and high vigilance were the factors minimizing incidence. Suggestive corrective strategies were guideline practices, additional training, and improved supervision. CONCLUSION: Carefully preoperative airway assessment and additional attention focused on the pathology or disease were the principle tasks. Algorithms for both anticipated and unanticipated difficult airway as well as alternative airway equipments should be implemented.

Profile Soft-Seal Cuff for general anesthesia under ambulatory gynecologic laparoscopy.

OBJECTIVE: To compare the severity of throat discomfort in terms of sore throat, dysphagia, and dysphonia caused by LMA-ProSeal (PLMA) and Profile Soft-Seal Cuff (PSSC) in early (2 hour) and late (24 hour) postoperative period after ambulatory gynecologic laparoscopy. DESIGN: Randomized double-blind controlled trial. MATERIAL AND METHOD: One hundred and thirty eight patients undergoing ambulatory gynecologic laparoscopy in Chulalongkorn Memorial Hospital were randomly allocated into two groups. One group was intubated with Profile-Soft-Seal Cuff (PSSC), while the other with ProSeal LMA (PLMA). Four-leveled score of sore throat, dysphagia, dysphonia, nausea, or vomiting symptoms at 2 and 24 hours and 5-leveled satisfaction score to both techniques at 24 hours postoperatively were evaluated. RESULTS: The patients in the PLMA group had less severe symptoms of sore throat (p = 0.016) and dysphonia (p = 0.003) than those in the PSSC group at 2 hour. No difference was detected for dysphagia, nausea, vomiting, and satisfaction scores at 24 hour postoperatively. CONCLUSION: PLMA caused less sore throat and dysphonia in the early postoperative period than PSSC did PLMA can be used as an alternative airway device for anesthesia in ambulatory gynecologic laparoscopy.

Multicentered study of model of difficult endotracheal intubation by incident reports from university and non-university hospitals.

OBJECTIVE: To compare the characteristics, causative factors, outcomes, prevention, and suggested preventive strategies of difficult intubation between university (U) and general community (non-U) hospitals. MATERIAL AND METHOD: One thousand nine hundred and ninety-six reports were reviewed from Thai anesthesia incident monitoring study (Thai AIMS) conducted in 51 hospitals nationwide between January and June 2007. Thirty-four cases ofDI were reported from U hospitals and 69 cases from non-U hospitals. The described details on each report on dfficult intubation (DI) in adults undergoing general anesthesia were thoroughly reviewed by three reviewers to give their consensus opinions on causative factors, outcomes, contributing preventive factors, and strategies for corrections. Descriptive statistics were used for data analysis. RESULTS: Patient factors were the most common cause of DI (88% in U and 87% in non-U hospitals). Fifty percent of U and 51% of non-U DI cases were consequences of human errors, which were preventable and mostly based on knowledge (88% vs. 71%) and rules of practice (23% vs. 51%). Substitution of an intubating anesthesiologist, reducing the size of endotracheal tubes, and stylet guided technique were the three commonly used methods after DI. MacCoy laryngoscope, fiber optic-aided intubation, laryngeal mask airway and Frova introducer were commonly used as substitutes for the standard laryngoscope. Inadequate experience was the major problem of U hospitals, which required additional training to gain more skill. The most common problem ofDI in non-U hospitals was inadequate preanesthetic evaluation. Therefore, they required practice guidelines and experienced assistants in difFicult situations. CONCLUSION: Half of DI cases were preventable. DI cases in Non-U hospitals were mostly caused by inadequate preanesthetic evaluation. This indicates the necessities of providing practice guidelines and experienced assistants. In U hospitals, in-training practice of intubation should be performed under supervision. More advanced substitution techniques were applicable in U hospitals.

A survey of awareness, opinion and reported use of clinical practice guidelines (CPG) of the Royal College of Anesthesiologists of Thailand.

BACKGROUND: Up to the present (2006), The Royal College of Anesthesiologists of Thailand (RCAT) has proposed and revised six practice guidelines. For guidelines to achieve their objectives, anyone who gets involved needs to be aware of the guidelines, be able to accept, and adhere to them. Although the authors did introduce their guidelines by several passive means, the authors have not yet ascertained what the result were. OBJECTIVE: The primary objective of the present study was to assess awareness, opinion, limitation, and reported use of guidelines. The secondary objective was to identify factors associated with variation, agreement, and reported use of guidelines. MATERIAL AND METHOD: A cross sectional, self-report survey study was conducted. An anonymous questionnaire including prepaid-addressed reply envelopes was mailed to 600 anesthesiologists and 1,300 nurse anesthetists, nationwide, based on the college's list. The questions covered respondents' general characteristics: awareness, agreement, and reported use of the existing guidelines; opinion on implementation media, which guidelines the members need, their local guidelines, and the impact of guidelines on their practice. All data were extracted and reported using descriptive statistics. Multiple logistic regression was done to identify factors associated with an agreement with and a reported use of the guidelines. RESULTS: The overall response rate was 33.4% and nurse anesthetists had a higher response than anesthesiologists. Forty-six percent of the respondents were aware of the existing guidelines. This result corresponded to percentage of those who had read the guidelines (41%). Among the six existing guidelines, the least two guidelines reported use of and agreement with, were those for labor analgesia and conscious sedation (23-28%, 24-28%). The guidelines for spinal anesthesia received the most response (46%). For respondents who had read the guidelines, most of them (80% to 94%) rated the level of agreement and reported use as good to excellent. The respondents also rated the announcement of the guidelines during the annual meeting of the Royal College of Anesthesiologists of Thailand as the best implementation strategy. Impracticability, inadequate dissemination, and un-cooperation among colleagues were the three most important obstacles of using the guidelines. In addition, the present study demonstrated three significant factors, anesthesiologists, regional hospitals, and general hospitals, as associated with reporting frequent use of and high agreement with the guidelines. CONCLUSION: The low level of awareness and reported use of the present guidelines among the members reflects poor implementation and dissemination. However the present study reveals some information that will guide the authors to introduce intensive and targeted interventions to encourage the members to comply and adhere to the guidelines designed to improve the quality of patients' care.

Clinical experiences of one--lung ventilation in adults using the Univent.

OBJECTIVE: To assess the clinical use and intraoperative problems of the Univent tube for one-lung ventilation (OLV). STUDY DESIGN: A cross-sectional descriptive study. MATERIAL AND METHOD: The records of 44 patients undergoing OLV with the Univent tube (Fuji System Corporation, Tokyo) at Chulalongkorn Memorial Hospital, Bangkok, Thailand from 1997 to 2003 were reviewed. The present study data included the techniques of the Univent blocker placement, frequencies of successful OLV being used as an alternative device after failed left-sided double lumen tube (LDLT), and related intraoperative problems during OLV. RESULTS: The blinded rotation method was used for 32 out of 44 cases of the Univent blocker placement, and the success rate of the correct sided placement on the needed bronchus was higher on the right (91.3%) than on the left (66.7%). Therefore, fiberoptic aided technique should be more appropriate for the left-sided blockade. Three successful intubations by the Univent after failed LDLT were found. Two of these had narrow glottic apertures, whereas the other had a stiff neck. Two successful patients after failed bronchial blockades by LDLT according to the anatomical deviation of the carina were demonstrated. However, clinical problems during OLV with the Univent tube were:--air trapping, inadequate OLV, herniated bronchial cuff and crossed contamination. CONCLUSION: The Univent tube can be an alternative to LDLT for OLV under the presence of available fiberoptic bronchoscopes, close monitoring and special precautions.

A randomized controlled study of three targets of propofol plasma concentration in patients undergoing uterine dilation and curettage.

AIM: To compare the efficacy and the complications of three target levels of propofol plasma concentration in patients undergoing uterine dilation and curettage. METHODS: Sixty-nine patients were randomly allocated to receive propofol target controlled infusion at different target concentrations of 4 (group I), 5 (group II) and 6 (group III) mcg/mL combined with 1 microg/kg of fentanyl and 66% of nitrous oxide. Patients' movement during the procedure, hemodynamic variables, oxygen saturation, end tidal carbon dioxide, time to sleep and awake, and bispectral index score were recorded. RESULTS: Seven patients in group I, one in group II, and none in group III (P < 0.05) moved grossly during the procedure. More patients in group III developed hypotension (5 vs 0 and 2 in group I and II, P < 0.05), but no difference was found regarding respiratory complication. No difference was found in time to sleep, but time to wake was longer in group III. CONCLUSION: Propofol infusion at the target concentration of 5 microg/mL was recommended for uterine dilation and curettage when it was administered with fentanyl 1 microg/kg and nitrous oxide 66% under close monitoring and appropriate respiratory management.

A placebo-controlled, randomized trial of droperidol versus metoclopramide for outpatients undergoing gynecological laparoscopy under conscious sedation.

This study compared the prophylactic antiemetic efficacy and the adverse effects of 0.5 mg droperidol, 5.0 mg metoclopramide, and placebo for outpatients undergoing gynecological laparoscopy under conscious sedation. One hundred and fifty outpatients were randomly allocated, in a randomized double-blind manner, into three groups to receive intravenous normal saline, 0.5 mg droperidol, and 5.0 mg metoclopramide before operation. Conscious sedation using intravenous pethidine, midazolam and local infiltration were given to each patient during the operation. Emetic symptoms were graded twice by the patients, at discharge time and the 24th post-operative hour. The difference of antiemetic effect of both study drugs failed to reach statistical significance. There was also no statistical difference of intra-operative hypoxemia, sedation score, and discharge time among the groups. Therefore, using 0.5 mg droperidol or 5.0 mg metoclopramide is not effective in providing antiemetic prophylaxis for outpatients undergoing gynecological laparoscopy under conscious sedation.