Sensitivity of a preanaesthesia screening and triage tool in identifying high-risk patients attending the preanaesthesia assessment clinic in a tertiary referral hospital in Sub-Saharan Africa: a diagnostic accuracy study.

OBJECTIVES: The use of preoperative triage questionnaires is an innovative way to mitigate the shortage of anaesthesiologists and to identify and refer high-risk patients early for evaluation. This study evaluates the diagnostic accuracy of one such questionnaire in identifying high-risk patients in a Sub-Saharan population. DESIGN: Diagnostic accuracy study SETTING: The study was conducted in a preanaesthesia assessment clinic in a tertiary referral hospital in Sub-Saharan Africa. PARTICIPANTS: The study had a sample size of 128, including all patients above the age of 18 scheduled for elective surgery under any modality of anaesthesia other than local anaesthesia presenting to the preanaesthesia clinic. Patients scheduled for cardiac and major non-cardiac surgery and those non-literate in English were excluded. OUTCOME MEASURES: The sensitivity of the preanaesthesia risk assessment tool (PRAT) was the primary outcome measure. Other outcome measures were specificity, positive predictive value and negative predictive value. RESULTS: Majority of patients were young and women with a mean age of 36 referred for obstetric and gynaecological procedures. The sensitivity of the PRAT in identifying high-risk patients was at 90.6% with 95% CI (76.9 to 98.2) in this current study while the specificity, negative predictive value (NPV) and positive predictive value (PPV) were 37.5% with 95% CI (24.0 to 43.7), 92.3% with 95% CI (77.7 to 97.0) and 32.6% with 95% CI (29.6 to 37.3) respectively. CONCLUSION: The PRAT has a high sensitivity and may be used as a screening tool in identifying high risk patients to refer to the anaesthesiologist early before surgery. Adjusting the high risk criteria to fit the anaesthesiologists' assessments may improve the specificity of the tool.

Effect of video-based information on preoperative State trait anxiety inventory scores in adult patients presenting for elective caesarean section: a randomized controlled trial.

Background: Preoperative anxiety is a common occurrence in patients presenting for surgery with a reported incidence of up to 80%. Increased preoperative anxiety has been associated with increased morbidity. Provision of information relating to surgery and anaesthesia to patients has been proven to have benefit in allaying anxiety. However, the best format of information dissemination remains unknown. Objective: To determine the effect of video information in addition to the pre-anaesthetic review on the mean preoperative State anxiety inventory (STAI-S) score in adult patients presenting for elective caesarean section under spinal anaesthesia at Aga Khan University Hospital, Nairobi (AKUHN), and to determine the prevalence of preoperative anxiety in the obstetric population presenting for elective caesarean section at AKUHN. Methods: Thirty-seven adult patients booked for elective caesarean section under spinal anesthesia were randomly assigned to one of two groups. In the study arm; a video was shown to the participants in addition to the standard pre-anaesthetic review. In the control arm the participants only had a standard pre-anaesthetic review. Results: The mean STAI-T score in the sampled population was 45.64 (SD 5.625). The mean baseline STAI-S score was 46.32 (SD 4.911). There was no statistically significant difference in change in STAI score between the video and control arms (p>0.05). Conclusion: On the basis of this study among this population, there was no benefit demonstrated from the use of an information video about spinal anaesthesia on anxiety levels in obstetric patients presenting for a first time spinal.

Effect of video-based information on preoperative State trait anxiety inventory scores in adult patients presenting for elective caesarean section: a randomized controlled trial

Background: Preoperative anxiety is a common occurrence in patients presenting for surgery with a reported incidence of up to 80%. Increased preoperative anxiety has been associated with increased morbidity. Provision of information relating to surgery and anesthesia to patients has been proven to have benefit in allaying anxiety. However, the best format of information dissemination remains unknown. Objective: To determine the effect of video information in addition to the pre-anesthetic review on the mean preoperative State anxiety inventory (STAI-S) score in adult patients presenting for elective caesarean section under spinal anesthesia at Aga Khan University Hospital, Nairobi (AKUHN), and to determine the prevalence of preoperative anxiety in the obstetric population presenting for elective caesarean section at AKUHN. Methods: Thirty-seven adult patients booked for elective caesarean section under spinal anesthesia were randomly assigned to one of two groups. In the study arm, a video was shown to the participants in addition to the standard pre-anesthetic review. In the control arm the participants only had a standard pre-anesthetic review. Results: The mean STAI-T score in the sampled population was 45.64 (SD 5.625). The mean baseline STAI-S score was 46.32 (SD 4.911). There was no statistically significant difference in change in STAI score between the video and control arms (p>0.05). Conclusion: On the basis of this study among this population, there was no benefit demonstrated from the use of an information video about spinal anesthesia on anxiety levels in obstetric patients presenting for a first time spinal

The history of critical care in Kenya.

Critical care is a young specialty in Kenya. From its humble beginnings in the 1960s to present day Kenya, the bulk of this service has largely been provided by anaesthetists. We provide a detailed account of the growth and development of this specialty in our country, the attempts made by our people to grow this service within our borders and the vital role our international partners have played throughout this process. We also share a selection of our successes over the years, the challenges we have faced and our aspirations as we look to the future.

A randomised controlled trial of the effect of laryngeal mask airway manometry on postoperative sore throat in spontaneously breathing adult patients presenting for surgery at a university teaching hospital.

BACKGROUND: Laryngeal mask airways (LMAs) are widely used in anaesthesia and are considered to be generally safe. Postoperative sore throat (POST) is a frequent complication following LMA use and can be very distressing to patients. The use of an LMA cuff pressure of between 30 and 32cm of H2O in alleviating post-operative sore throat has not been investigated. OBJECTIVE: To compare the occurrence of POST between the intervention group in which LMA cuff pressures were adjusted to 30-32cm of H2O and the control group in which only monitoring of LMA cuff pressures was done, to compare the severity of POST between the two study groups and to compare the LMA cuff pressures between the two study groups. METHODS: Eighty consenting adult patients scheduled to receive general anaesthesia with use of an LMA were randomized into two groups of 40 patients each. Intervention group: LMA airway cuff pressures were adjusted to 30 to 32cm of H2O. Control group: Only had LMA cuff pressures monitored throughout the surgery. All patients were interviewed postoperatively at two, six and twelve hours. Data of their baseline characteristics, occurrence and severity of POST was collected. If POST was present; a Numerical Rating Scale (NRS) was used to assess the severity. Cuff pressures between the two study groups were also determined. RESULTS: The baseline demographic characteristics of the participants were similar. The use of manometry to limit LMA AMBU® AuraOnce™ intracuff pressure to 30-32cm H2O reduced POST in surgical patient's by 62% at 2 hours and 6 hours (Risk Ratio 0.38 95%CI 0.21-0.69)in the intervention group. The median POST pain score in the intervention group was significantly lower than the control group with scores of 0 at 2, 6 and 12 hours post operatively. Routine practice of LMA cuff inflation by anesthesiologists is variable, and the intracuff pressures in the control group were higher than in the intervention group. (P<0.001). CONCLUSION: Among this population, reduction of LMA AMBU® AuraOnce™ intracuff pressure to 30-32cm H2O reduces the occurrence and severity of POST. The LMA cuff pressures should be measured routinely using manometry and reducing the intracuff pressures to 30-32 cm of H2O recommended as best practice.

Comparison of weight-adjusted dose versus fixed dose ondansetron in preventing shivering following spinal anaesthesia for caesarean deliveries.

BACKGROUND: Spinal anaesthesia is an effective regional anaesthesia technique, which is preferred in almost 86% of caesarean sections in the United States and United Kingdom. Eighty percent of caesarean sections done at the Aga Khan University hospital are under spinal anaesthesia. Shivering is a common complication of spinal anaesthesia, it occurs in 40%-64% of patients after neuraxial anaesthesia. Shivering may cause maternal and fetal hypoxemia, maternal discomfort and a problem to the anaesthesiologists when it comes to monitoring the patient during caesarean sections. Ondansetron a 5-HT3 receptor antagonist is effective in treatment and prevention of post-spinal anesthesia shivering. In published studies, use of a fixed dose in patients with different weights, masked the dose effect ondansetron in preventing shivering, such that not adjusting the dose according to the weight of patients' resulted in a higher occurrence of shivering. No study has compared different doses of ondansetron in preventing shivering in parturient women who have had spinal anaesthesia for caesarean section. OBJECTIVES: To determine if a weight-adjusted dose is better than a fixed dose of ondansetron in preventing shivering following spinal anesthesia for caesarean delivery. METHOD: This was a randomized, double-blinded controlled trial of 124 women scheduled for elective caesarean surgery. The women were randomized into two equal groups. The intervention group received intravenous ondansetron weight adjusted dosing at 0.1mg/kg and the control group received a fixed dose of 4mg before spinal anesthesia. The occurrence and severity of shivering and other outcomes, such as headache, pruritus were assessed and recorded during the surgery and post-operative period. RESULTS: A total of 124 patients were included in the study. Social demographic data and baseline vital signs did not differ significantly between the groups. Shivering was observed in 14 patients (22.6%) in the control group that received 4mg ondansetron and 7 patients (11.3%) in the intervention group that had 0.1mg/kg of ondansetron, but there was no statistical difference between the groups (p- value 0.090). The severity of shivering was greater in the control group compared to intervention group where patients who developed grade two shivering were 8.1% to 0% respectively. (P value 0.047). There was no difference in the occurrence of pruritus between the two groups. No patient required treatment for very severe shivering. CONCLUSION: This study, found that ondansetron weight adjusted dose at 0.1mg/kg, reduced the severity of shivering when compared to a fixed dose ondansetron at 4mg.

Effect of low-dose ketamine versus fentanyl on attenuating the haemodynamic response to laryngoscopy and endotracheal intubation in patients undergoing general anaesthesia: a prospective, double-blinded, randomised controlled trial.

BACKGROUND: The use of drugs to attenuate the haemodynamic response to laryngoscopy and endotracheal intubation is the standard of care during elective surgery. Current evidence is conflicting concerning the best agent and optimal dose for this purpose. In the majority of cases, fentanyl is widely utilized to attenuate haemodynamic responses. Ketamine, an established available drug, has been scarcely studied in this regard at low doses and against varying doses of other common agents. OBJECTIVE: To compare the overall occurrence of hypertension and tachycardia immediately pre-intubation (post-induction) until 10 minutes post intubation between the study group receiving fentanyl at 1.0 µg/kg and the other receiving ketamine at 0.5 mg/kg, to compare the occurrence of post-induction hypotension and the occurrence of neuropsychiatric phenomena during emergence between the two groups. METHODS: One hundred and eight ASA I and II patients aged 18-65 years scheduled for elective surgery under general anaesthesia were randomized into two groups: Control group: received fentanyl 1.0 µg/kg intravenously. Intervention group: received ketamine 0.5 mg/kg intravenously. General anaesthesia was standardized in both groups. The patients and physicians administering anaesthesia were blinded to the study. Haemodynamic responses were evaluated by determining heart rate and blood pressure immediately before laryngoscopy and at 2.5, 5, 7.5 and 10 minutes. Neuropsychiatric phenomena were assessed upon recovery from anaesthesia. RESULTS: One hundred and eight ASA I and II patients scheduled to undergo elective surgery were included in this study, 54 participants (50%) in the fentanyl arm and 54 (50%) in the ketamine arm. Baseline demographic characteristics were similar between the groups. There were more hypertensive episodes in the ketamine arm (11%) compared to the fentanyl arm (1.85%), but not achieving statistical significance: Fisher's exact test, p=0.06. There was no significant difference in the number of episodes of tachycardia between the Ketamine group 7/54 (13%) and the fentanyl group, 6/54 (11%); x2=0.05, p=0.82. Hypotensive episodes were more common in those who received Fentanyl, 41/54 (76%), compared to ketamine recipients, 21/54 (39%), X2=16.9, p<0.001. The use of Ketamine was associated with less episodes of hypotension, adjusted odds ratio = 0.18 (95% confidence interval 0.07, 0.45). CONCLUSION: We conclude, based upon findings in this study group, that there is no difference in the occurrence of hypertension with the use ketamine at 0.5 mg/kg in combination with Propofol at 2.0 mg/kg. In this regard, ketamine provides a viable alternative to fentanyl at 1.0 µg/kg for attenuating the pressor response to laryngoscopy and endotracheal intubation. Additionally, our results suggest that ketamine may protect against post-induction (pre-laryngoscopy) hypotension.

Effect of removal of AuraOnce™ laryngeal mask in awake or deep anaesthesia: a randomized controlled trial.

BACKGROUND: The manufacturer Ambu® recommends that the AuraOnce™ laryngeal mask be removed once the patient is fully awake. Studies have shown benefit in removal of the laryngeal mask airway while a patient is deeply anaesthetized. Current evidence is inconclusive, as to which approach is preferable and safer in adults. METHODS: one hundred and sixteen adult patients were randomly assigned to two groups of 58. For the deep arm; The AuraOnce™ laryngeal mask was removed after attaining an end tidal minimum alveolar concentration of Isoflurane of 1.15%. Occurrence of airway complication(s) (One or more of the following; Airway obstruction requiring airway manipulation; Laryngospasm; Desaturation to 90% or less on pulse oximetry) was noted until the subject was fully awake (appropriate response to command) in the post-anaesthesia care unit. For the awake arm; The AuraOnce™ laryngeal mask was removed on attaining an end tidal minimum alveolar concentration of Isoflurane of <0.5% and an appropriate response to command or obtaining appropriate response to command irrespective of end tidal concentration. Occurrence of airway complication(s) in theatre and post anaesthesia care unit was recorded. Time to theatre exit was recorded for both groups. RESULTS: Baseline demographic characteristics were similar between the groups. More airway complications were encountered in the Deep arm - 13 (22.4%) relative to the Awake arm -5 (8.6%), this was found to be statistically and clinically significant, P value P=0.040, odds ratio 3.0622; 95% CI, 1.0139 to 9.2483. CONCLUSION: The removal of the AuraOnce™ laryngeal mask while the patient is still deeply anaesthetised is not as safe as or safer than awake removal.

Effect of target controlled propofol infusion versus intermittent boluses during oesophagogastroduodenoscopy: a randomized controlled trial.

BACKGROUND: Propofol is administered as intermittent boluses to achieve deep sedation to facilitate oesophagogastroduodenoscopy. Target controlled infusion (TCI) can be employed for this purpose. METHODS: 176 adults were randomly allocated into two groups of 88 patients. Control group: Received an initial bolus of propofol 1mg/kg, with repeat boluses of 0.25mg/kg. Intervention group: Received an initial target effect-site concentration of 4mcg/ml, followed by maintenance target effect-site concentration of 2.5mcg/ml, titrated by 0.5mcg/ml from baseline infusion rate as needed. Oxygen saturation, blood pressure and heart rate were evaluated immediately before administering the sedative and at 2.50, 5.00, 7.50 and 10.00 minutes. Oxygen desaturation below 90% in both study groups was recorded. Sedation starting time, stopping time, waking up time and overall duration of time to recovery of participants in each study arm was recorded. RESULTS: More hypoxic episodes were observed in the intermittent bolus group with statistically significant association between control and the incidence of hypoxia: Chi square test, p=0.037. There were more hypotensive episodes in the TCI group but not achieving statistical significance: Chi square test for association X2(1) = 0.962, p=0.327.The time to recovery between the two groups was comparable, with 18.84 ± 10.76 minutes in the bolus group and 19.72 ± 9.27 minutes in the TCI group; no statistically significant difference was shown: Student's t-test, p=0.0564. CONCLUSION: TCI of propofol was associated with fewer episodes of hypoxia compared to intermittent bolus administration. Similar hemodynamic profiles and comparable time to recovery were demonstrated by these two sedation techniques.

A randomized control trial comparing train of four ratio > 0.9 to clinical assessment of return of neuromuscular function before endotracheal extubation on critical respiratory events in adult patients undergoing elective surgery at a tertiary hospital in Nairobi.

BACKGROUND: There is increasing evidence that the incidence of postoperative residual paresis after using neuromuscular blockers ranges from 24 to 50% in post anaesthesia care unit (PACU) and is associated with postoperative complications such as critical respiratory events as evidenced by hypoxia, hypoventilation and upper airway obstruction. Quantitative neuromuscular monitoring (such as the assessment of Train of four (TOF) ratio) and reversal of neuromuscular blockers has been shown to reduce postoperative residual paresis. There are very few outcome studies on effect of residual paresis in PACU. There is a paucity of published randomized controlled trials investigating whether using a TOF ratio ≥0.9 before endotracheal extubation compared to clinical assessment of return of neuromuscular function reduces the incidence of critical respiratory events in PACU. OBJECTIVE: To determine whether using TOF ratio ≥ 0.9 compared to clinical assessment of return of neuromuscular function before endotracheal extubation reduces the incidence of critical respiratory events in PACU. METHODS: Onehundred sixty eight adult patients in ASA physical status I and II requiring general anaesthesia for elective surgery with cisatracurium as the muscle relaxant were randomized into 2 groups of 84 each. Group 1 were patients who required a TOF ratio of ≥0.9 before extubation. Group 2 patients were extubated based on clinical assessment of return of adequate neuromuscular function by the anaesthetist as is the standard of practice at the Aga Khan University hospital Nairobi. General anaesthesia was standardized in both groups. Both the investigators and patients were blinded during the study.Once the patient was transferred to PACU, oxygen saturation (SP02), respiratory rate and any signs of upper airway obstruction as demonstrated by stridor, laryngospasms or requirement of any airway manipulation was recorded for the first 30 minutes. Duration of anaesthesia and surgery was also recorded. Patient demographics were recorded and analyzed. RESULTS: There was no statistical difference between the 2 groups in terms of patient demographics, duration of surgery and anaesthesia and duration since last muscle relaxant was given. In terms of hypoxia on arrival in PACU, the incidence of mild hypoxia (SPO2 90-93%) was 11% in clinical assessment groupversus 5% in TOF group P-value 0.149 while severe hypoxia (SPO2 <90%) was 19% versus 10% P-value 0.078. During the first 30 minutes in PACU, the incidence of mild hypoxia (SPO2 90-93%) was statistically significant between the 2 groups (12% in clinical assessment group versus 1% in TOF group, P-value 0.005) while severe hypoxia (SPO2 <90%) was 7% versus 5%, P-value 0.373. The incidence of upper airway obstruction was statistically significant between the two groups (45% in clinical assessment group versus 14% in TOF group P-value<0.0001 for patients requiring airway maneuver, 21% versus 2% P-value <0.0001 for those who required tactile stimulation and 31% versus 12% were snoring, P-value 0.003. Logistic regression analysis revealed TOF group was less likely associated with mild hypoxia (OR 0.09 95% CI 0.01-0.71 P-value 0.023), tactile stimulation (OR 0.09 95% CI 0.02-0.40 P-value 0.002), airway maneuver (OR 0.20 95% CI 0.10-0.43 P-value <0.001) and snoring (OR 0.30 95% CI 0.13-0.68 P-value 0.04). CONCLUSION: Among this population, there is a lower incidence of critical respiratory events in PACU with the use of neuromuscular monitoring using TOF ratio ≥0.9 to assess neuromuscular function before endotracheal extubation compared with the use of clinical assessment methods.

A comparison of risk of hypotension using standard doses of remifentanil versus dexmedetomidine infusions in adult patients undergoing surgery under general anaesthesia at the Aga Khan University Hospital, Nairobi.

BACKGROUND: Remifentanil and dexmedetomidine are common agents used in general anaesthesia, monitored anaesthesia care and critical care. When combined with inhaled or intravenous anaesthetic agents intra-operatively, they provide analgesia, lower general anaesthetic requirements and provide sedation and analgesia in the peri-operative period if indicated. Pharmacodynamically, they cause hypotension and bradycardia which are reversible if well managed. Past studies of these drugs have shown a significant proportion of patients with hypotension when compared with similar agents or in isolation. This study compares these two drugs on the effect of hypotension when used as adjuncts to general anaesthesia at low dose standard rate of infusions. OBJECTIVE: To compare the proportion of hypotension episodes in a group of adult patients receiving dexmedetomidine infusion at 0.4mcg/kg/hr versus a group receiving remifentanil infusion at 0.2mcg/kg/min, severity of hypotension and physician interventions in each group. METHODS: One hundred and four patients scheduled for elective surgery under general anaesthesia were randomized into two groups: Control group; received remifentanil infusion at 0.2mcg/kg/minIntervention group; received dexmedetomidine at 0.4mcg/kg/hr.General anaesthesia was standardized in both groups. The patients were blinded to the study. Baseline blood pressures of all patients were determined prior to induction. The patient's demographic characteristics were recorded. The number of patients who developed hypotension, the frequency of hypotension and the physician interventions were recorded and analysed. RESULTS: The age and gender characteristics were different between the two groups (p values <0.023 and 0.05 respectively) however they did not affect the proportion of patients with hypotension. The weight, baseline pressures and ASA status of the patients within the groups were similar. The operative procedures varied within the groups. General surgery did not influence the outcome of hypotension in both arms. The duration of surgery in remifentanil group exceeded that of Dexmedetomidine p value<0.0005 however the time to the first episode of hypotension was similar between the groups. The episodes of hypotension were fewer in the dexmedetomidine arm and the proportion of patients with hypotension were higher in the remifentanil arm, p value<0.001, R.R 0. = 0.5938, 95% C.I= 0.329-0.819 The physician interventions administered were similar between the two groups except the use of ephedrine between the groups. CONCLUSION: Among this population, at standard infusion rates, the proportion of patients that risk hypotension was greater in those undergoing elective surgery receiving remifentanil at 0.2mcg/kg/min than in dexmedetomidine at 0.4mcg/kg/hr under isoflurane based anaesthesia.

A randomized controlled trial to assess the effect of a ketamine infusion on tourniquet hypertension during general anaesthesia in patients undergoing upper and lower limb surgery.

BACKGROUND: Tourniquet hypertension arising from tourniquet inflation remains a primary concern to the anaesthetist. One drug commonly used to manage tourniquet hypertension is ketamine. No studies have examined the effect of ketamine on tourniquet hypertension for a period of more than one hour or an infusion of the same. OBJECTIVE: To compare the effect of an intravenous infusion of ketamine versus placebo on tourniquet induced hypertension in patients undergoing upper and lower limb surgery under general anaesthesia. METHODS: Forty six adult patients scheduled for upper and lower limb surgery under general anaesthesia were randomized into two equal groups. The ketamine group received an intravenous bolus of 0.1mg/kg of ketamine followed by an infusion of 2ug/kg/min. The saline group received an intravenous bolus of physiological saline followed by an infusion of saline. All the patients were reviewed post-operatively. Data of the baseline characteristics, haemodynamic changes, post-tourniquet pain and side effects were collected. If post-tourniquet pain was present post-operatively, a visual analogue scale (VAS) was used to assess its severity. RESULTS: 46 patients successfully completed the trial. There were no significant differences between the groups for baseline patient demographics. The incidence of tourniquet hypertension was higher in the saline group (26.1%) compared with ketamine group (4.6%) with a 95% confidence interval. The difference was shown to be statistically significant ('P'<0.05). There was an increase in systolic blood pressure after 60 minutes of tourniquet inflation in the saline group but the difference was not statistically significant('P'>0.866). There were no significant differences between the groups as regards diastolic blood pressure and heart rate. VAS scores did not differ between the two groups. Statistically, there was no difference found between the two groups. Side effects were minimal in the ketamine group whilst in the saline group, nausea and vomiting were predominant but were also not statistically significant. CONCLUSION: Based on the results of this study, there was a difference in the proportion of tourniquet hypertension between the ketamine and saline groups for patients undergoing upper and lower limb orthopaedic surgery under general anaesthesia.

The effect of a preanaesthesia clinic consultation on adult patient anxiety at a tertiary hospital in Kenya: a cohort study.

BACKGROUND: Preoperative anxiety is a common perioperative complication seen in approximately 11-80% of adults undergoing surgery. One of the goals of the preanaesthesia clinic is to allay anxiety. A preanaesthesia clinic evaluation has been shown to reduce anxiety however current studies on anxiety and the preanaesthesia clinic have not quantified this reduction. OBJECTIVE: To determine the reduction in anxiety in patients evaluated in the clinic versus those evaluated in the ward. METHODS: Fifty one adult patients with 28 patients in anaesthesia clinic (AC) group and 23 in the ward (W) group were sequentially recruited from both the surgical, gynaecology and antenatal outpatient clinics and the wards. The patient's State Trait Anxiety Index (STAI) was taken once the patient was booked for theatre. The patients then had a preanaesthesia evaluation either in the preanaesthesia outpatient clinic (PAC) or in the wards. Another STAI score was taken in the preoperative area in theatre on the day of surgery. The difference in the change of STAI scores in both groups was then analysed. RESULTS: Fifty one adult patients were recruited with 28 in the AC group and 23 in the W group. The majority of patients were female (n=38). Statistically significant difference was seen in the reduction of the anxiety scores between the clinic group 2.143 (C.I=1.384-2.902) and ward group 0.74(C.I=0.17-1.31) with a p value=0.0051.There was also significant difference in reduction in anxiety scores within ward group in the patients with no prior anaesthetic experience having a greater reduction than those with prior anaesthetic experience. There were no other significant differences between the two groups. CONCLUSION: Patients evaluated in the anaesthesia clinic had a greater reduction in their anxiety but it was not as much as hypothesised which may be due to the multi-factorial nature of preoperative anxiety. A larger multicenter study is recommended to increase generalizability to the population.

A randomised controlled trial comparing weight adjusted dose versus fixed dose prophylactic phenylephrine infusion on maintaining systolic blood pressure during caesarean section under spinal anaesthesia.

BACKGROUND: Spinal anaesthesia is the standard of care for elective caesarean delivery. It has advantages over general anaesthesia. However the sympathetic blockade induced by spinal anaesthesia results in an 80 percent incidence of hypotension without prophylactic management. Current evidence supports co-loading with intravenous fluids in conjunction with the use of vasopressors as the most effective way to prevent and treat the hypotension. Phenylephrine is the accepted vasopressor of choice in the parturient. A prophylactic phenylephrine infusion combined with a fluid co-load is proven to be an effective and safe method of maintaining maternal hemodynamic stability. While most published studies have assessed the effectiveness of a prophylactic phenylephrine fixed dose infusion, few studies have assessed the effect of a prophylactic phenylephrine weight adjusted dose infusion on maintaining maternal hemodynamic stability following spinal anesthesia for a cesarean delivery. OBJECTIVE: To compare the incidence of hypotension between women undergoing elective caesarean section under spinal anaesthesia, receiving prophylactic phenylephrine infusion at a fixed dose of 37.5 micrograms per minute versus a weight adjusted dose of 0.5 micrograms per kilogram per minute. METHODS: One hundred and eight patients scheduled for non-urgent caesarean section under spinal anaesthesia were randomized into 2 groups; control group and intervention group using a computer generated table of numbers. Control group; Received prophylactic phenylephrine fixed dose infusion at 37.5 micrograms per minute. Intervention group; Received prophylactic phenylephrine weight adjusted dose infusion at 0.5 micrograms per kilogram per minute. RESULTS: The two groups had similar baseline characteristics in terms of; Age, sex, weight and height. There was a 35.2% incidence of hypotension in the fixed dose group and an 18.6% incidence of hypotension in the weight adjusted dose group. This difference was found to be of borderline statistical significance p-value 0.05, and the difference in the incidence rates between the two groups was found to be statistically significant p= 0.03. The difference in the incidence of reactive hypertension and bradycardia between the two groups was not statistically significant: p-value of 0.19 for reactive hypertension and p-value of 0.42 for the incidence of bradycardia. There was also no statistically significant difference in the use of phenylephrine boluses, use of atropine, intravenous fluid used and the number of times the infusion was stopped. CONCLUSION: Among this population, the incidence of hypotension was significantly less in the weight adjusted dose group than in the fixed dose group. There was no difference in the number of physician interventions required to keep the blood pressure within 20% of baseline, and no difference in the proportion of reactive hypertension or bradycardia between the two groups. Administering prophylactic phenylephrine infusion at a weight adjusted dose of 0.5 micrograms per kilogram per minute results in a lower incidence of hypotension compared to its administration at a fixed dose of 37.5 micrograms per minute.

A randomized controlled trial comparing haemodynamic stability in elderly patients undergoing spinal anaesthesia at L5, S1 versus spinal anaesthesia at L3, 4 at a tertiary African hospital.

BACKGROUND: Spinal anaesthesia is a routinely used anaesthetic technique in elderly patients (> 60 years) undergoing operations involving the lower limbs, lower abdomen, pelvis and the perineum. Spinal anaesthesia has several advantages over general anaesthesia including stable haemodynamic variables, less blood loss, less post-operative pain, faster recovery time and less post-operative confusion. Despite these advantages, the sympathetic blockade induced by spinal anaesthesia can result in hypotension, bradycardia, dysrhythmias and cardiac arrests. Conventionally, spinal anaesthesia is performed at the level of L3,4 interspace; with a reported incidence of hypotension in the elderly ranging between 65% and 69%. A possible strategy for reducing spinal induced hypotension would be to minimize the peak block height to as low as possible for the planned procedure. OBJECTIVE: To determine the difference in haemodynamic stability between elderly patients undergoing spinal anaesthesia at L5, S1 interspace compared to those at L3, 4. METHODS: Thirty two elderly patients scheduled for lower limb or pelvic surgery under spinal anaesthesia were randomized into 2 groups (control group and intervention group) using a computer generated table of numbers. Control group; received 2.5 mls 0.5% hyperbaric bupivacaine injected intrathecally at the L3, 4 interspace and Intervention group; 2.5mls 0.5% hyperbaric bupivacaine injected intrathecally at the L5, S1 interspace. RESULTS: The two groups had similar baseline characteristics in age, sex, body mass index and use of anti-hypertensive medications. There was 68.8% proportion of hypotension in the control group and 75% in the intervention group. The difference was not found to be statistically significant (p= 0.694). During the study period, there were 106 episodes of hypotension, out of which, 65 were in the control group and 41 in the intervention group (p=0.004).. Linear regression analysis of the decrease in mean arterial pressures (MAP) showed a higher decrease in MAP in the control group (p 0.018). There were more crystalloids used in the control group (1006mls ± 374) than in the intervention group (606mls ±211) with a p< 0.0001. There was no difference in the amounts of vasopressors used between the two groups (p=0.288). There was no difference in the change in heart rates, conversion to general anaesthesia, use of supplementary intravenous fentanyl and the peak maximum block level achieved. The time to peak maximum sensory block level was 9.06min and 13.07min in the control group and intervention groups, respectively (p<0.0001). CONCLUSION: Among this population, there was no difference in the proportion of those with hypotension between the elderly patients who received their spinal anaesthesia at L3,4 and those who received spinal anaesthesia at L5,S1. The intervention group had better outcomes with significantly less episodes of hypotension. It took a longer time to achieve a maximum peak sensory block in the intervention group. Performing spinal anaesthesia at the level of L5,S1 was found to provide an adequate sensory block for a wide range of pelvic, perineal and lower limb surgeries.

Blood transfusion and oxygen extraction ratio in patients admitted to the general intensive care unit: a quasi experimental study

Introduction: Blood transfusion is commonly undertaken in critically ill patients; and studies have suggested the use of oxygen extraction ratio (O2ER) as an additional transfusion trigger in critically ill patients. The aim of this study was to establish the relationship between blood transfusion and oxygen extraction ratio in adult patients admitted to the general intensive care unit, using central venous oxygen saturation instead of mixed venous oxygen saturation.Methods: Arterial and central venous blood samples were drawn and a blood gas analysis immediately before commencement of blood transfusion was undertaken. At least 15 min after completion of the transfusion, similar samples were drawn and the blood gas analysis was repeated. The O2ER before and after transfusion was then calculated. Using paired student's t-test, we checked whether the mean difference between the two O2ERs was statistically significant. Results: We enrolled 58 patients in the study, the mean (±SD) haemoglobin concentration before transfusion was 7.38 g/dl (±1.71). The mean change in haemoglobin concentration following blood transfusion was 2.29 g/dl (±1.18), after transfusing an average of 1.95 (±0.83) units of packed cells. Mean O2ER was 0.27 (±0.11)before, and 0.25 (±0.12) after RBC transfusion. The mean change in O2ER was 0.018 SD ± 0.10 (95% CI, 0.043­0.007; P = 0.15). Linear regression analysis showed no statistically significant relationship between change in haemoglobin concentration and change in O2ER; p-value = 0.12. Discussion: The change in oxygen extraction ratio was not statistically significant following blood transfusion in adult patients admitted to the general ICU at a tertiary teaching hospital. Further studies are required especially in patients with increased pre transfusion O2ER to evaluate the usefulness of this measurement as a possible transfusion trigger