Performance assessment of a refrigeration system with an integrated condenser under different environmental conditions.

This paper presents a workable vapour compression system (VCS) for evaluating the performance of a refrigeration system with an integrated condenser that uses a long-term alternative refrigerant to halocarbon as a heat transfer medium (R600a). India's refrigeration system uses halocarbon refrigerants due to their excellent thermophysical and thermodynamic properties. Greenhouse gas emissions from halocarbon refrigerants and fossil fuel combustion contribute to global warming that engenders climate change and the deterioration of the ecosystem. The halocarbon refrigerant was discontinued based on high global warming potential. The system was investigated under various ambient temperatures of 16, 20, 24, and 28 °C (oC). The performance of the VCS was analyzed using the parameters of coefficient performance, compressor work, and pull-down time (PDT). The experimental result shows that the vapour compression system obtained its best PDT, enhanced coefficient of performance, and energy reduction when the ambient temperature was 20 °C.

Post-operative Analgesic and Opioid-sparing Effect of a Single-dose Pre-operative Oral Pregabalin in Gynaecological Surgeries.

Background: Post-operative pain treatment is a major challenge in our environment. Opioids may cause respiratory depression post-operatively. Therefore, any combination of opioid and non-opioid analgesics that provides quality post-operative pain control and reduces opioid consumption with its attendant side effects will be highly desirable. Objectives: The aim of this article is to evaluate analgesic benefits and opioid-sparing effects of pre-operative oral pregabalin in patients who undergo abdominal gynaecological surgeries. Materials and Methods: A prospective randomized double-blind placebo-controlled study is carried out at University of Ilorin Teaching Hospital, Kwara State, Nigeria. Eighty-two patients scheduled for gynaecological surgeries were randomized into two equal groups. The patients in the control and study groups received a placebo drug and oral pregabalin 150 mg, respectively, 1 h before induction of general anaesthesia. Post-operative pain intensity using a five-point Verbal Rating Scale, time to first request for analgesia, and 24 h post-operative pethidine consumptions were assessed. Mean values were compared using Student's t-test. Categorical data were compared with the χ 2 test. Level of significance was set at 5% (0.05) and power of the study was 80%. Results: Demographic characteristics were comparable between the two groups. The median pain score was 0-2 (no pain-moderate pain) throughout the study. Post-operative static and dynamic pain scores at 1, 4, and 12 h were significantly higher in the placebo group (<0.001). Twenty-four hours post-operatively, there were no significant differences in static and dynamic pain scores between the two groups (P=0.131 and P=0.384, respectively). Time to first analgesic requirement and total pethidine consumed within 24 h post-operative were 47 ± 19 vs. 258 ± 137 min (P=0.001) and 326.19 ± 62.70 vs. 192.86 ± 55.84 mg (P=0.001) in the control and study groups, respectively. The pre-operative use of pregabalin reduced post-operative opioid requirement by 40.9% in the study group. Nausea and vomiting were more common in the placebo group, whereas dizziness, blurring of vision, and sedation were more common in the pregabalin group. Conclusion: A single pre-operative dose of 150 mg oral pregabalin had significantly greater analgesic effects compared with placebo and reduced post-operative opioid requirements in patients undergoing myomectomy or total abdominal hysterectomy. It should be considered an adjuvant in multimodal pain management regimens following gynaecological surgeries.

Effect of spinal anesthesia on QT interval: Comparative study of severe pre-eclamptic and normotensive parturients undergoing cesarean section.

Aim: This study aimed to compare the effect of spinal anesthesia on QT interval in severe pre-eclamptic and normotensive parturients who underwent cesarean section in a Nigerian tertiary hospital. Patients and Methods: Twelve-lead electrocardiogram (ECG) was obtained before, and at intervals after spinal anaesthesia on fifty severe pre-eclamptic (Group A) and fifty normotensive parturients (Group B) who underwent caesarean section. The effect of spinal anaesthesia on QT interval was compared. Results: The preoperative (baseline) mean QT interval was longer in group A than in group B; 453.10 ± 34.11 ms versus 399 ± 18.79 ms, P < 0.001. The prevalence of prolonged QT interval in the severe pre-eclamptic group before spinal anesthesia was 80% while in the normotensive group it was 0%, P < 0.001. At 5, 30, 60, and 120 min after the establishment of spinal anesthesia, the mean QT interval in the severe pre-eclamptic group was shortened and maintained within normal limits; 414.74 ± 28.05, 418.28 ± 30.95, 411.18 ± 19.21 and 401.36 ± 17.52 ms with P < 0.001 throughout. In the normotensive group, there was no significant change in the mean QT interval. Conclusions: This study demonstrated that the QT interval was more prolonged among the severe pre-eclamptic parturients. Spinal anesthesia using 0.5% hyperbaric bupivacaine normalized the QT interval and maintained it within normal limits during the study period.

Dose related effects of oral clonidine pre-medication on bupivacaine spinal anaesthesia.

INTRODUCTION: The duration of action of sub-arachnoid block is short, and one of the ways to overcome this is the use of oral clonidine. METHODS: 108 patients of ASA I and II, aged 18 to 65 years undergoing lower abdominal surgeries under spinal anaesthesia were randomized into three groups.. Control group A (n=36) no oral clonidine pre-medication, Group B (n=36) and group C (n=36) received 100 µg and 200 µg of oral clonidine pre-medication respectively, 1hr before spinal anaesthesia. Haemodynamic parameters were recorded. Sensory block, degree of motor blockage, and sedation were assessed. RESULTS: Clonidine prolonged the mean duration of motor block by 189.98±26.93 min (100µg) and 191.89±28.13 min (200µg) compared to 117.92±25.13 min in the control group p<0.05. The mean duration of analgesia was 188.19±35 min (100µg) and194±24.58 min (200µg) in the clonidine groups compared to 115.89±26.66 min in control group p<0.05. All the patients were awake in the control group while 71.43% and 100% were drowsy in groups B and C respectively. CONCLUSION: Oral clonidine produces better clinical effects on the onset and duration of Bupivacaine spinal anaesthesia.

The Correlation Between Body Mass Index On The Length From Skin To Lumbar Epidural Space In Nigerian Adults.

BACKGROUND: One of the factors that determine success of an epidural anaesthetic is correctly locating the epidural space. Being able to predict the skin to lumbar epidural space distance can serve as a guide to performing epidural anaesthesia and in turn increase the success rate. AIM: To determine the correlation between the BMI, gender and age on SLESD of adults scheduled for elective surgical procedure under lumbar epidural anaesthesia. DESIGN OF STUDY: It was across sectional descriptive study carried out on consenting patients scheduled for elective surgery under lumbar epidural anaesthesia. SETTING: The study was carried out in the main theatre complex and the obstetric theatre of the University of Ilorin Teaching Hospital, Ilorin, Nigeria. METHODOLOGY: One hundred and twenty patients of ASAI and II physical status between the ages of18-65years scheduled for elective surgical procedures under epidural anaesthesia were enrolled into the study. This was a cross sectional descriptive study involving both sexes. Using a septic technique epidural anaesthesia was established in the sitting position using the midline approach at L3/L4orL4/L5 interspace. The epidural space was identified by loss of resistance to air. TheSLESD in centimetres (cm) was rounded up to the nearest 0.25cm. Data were collected and analyzed using Spearman´s correlation to evaluate the relationship between BMI, weight, sex, age, height and the SLESD. RESULTS: The mean SLESD was 4.60±0.83 cm with a range of 3cm-8cm. The SLESD was significantly influenced by BMI and weight with both having positive correlation and P value of 0.001 and 0.004 respectively. We formulated a relationship between skin to lumbar epidural space and body mass index based on linear regression analysis: Depth cm= a + b × (BMI)Where a =3.33 and b =0.05.There was no correlation between SLESD and height, age or sex of the patients. CONCLUSION: There was positive linear correlation between the body mass index, body weight and the skin to lumbar epidural space distance. Whereas, the age, sex and height had no correlation with the skin to lumbar epidural space distance.

EFFICACY AND SAFETY OF ORAL KETAMINE PREMEDICATION IN CHILDREN UNDERGOING DAY CASE SURGERY.

BACKGROUND: Oral premedication for paediatric age group is an uncommon practice amongst anaesthetists in Nigeria. Both parents and the child suffer some form of emotional or psychological distress. AIM: To determine the efficacy and safety of oral formulated ketamine for premedication in children scheduled for ambulatory surgeries. METHODS: Seventy three children aged 1 - 6 years with American Society of Anesthesiologists (ASA) physical status I-II were prospectively studied. They were assigned randomly to receive either 5 mg/kg (Group A), 10 mg/kg (Group B), or no ketamine (Group C).The children were observed for acceptance of premedication, sedation and anxiolysis at 10, 20 and 30 minutes after drug administration. Behavior/response of each child at the time of separation from parents, intravenous access, and acceptance of facemask for induction, postanaesthetic arousal state and complications were also recorded. RESULTS: There were 73 children in this study with a mean age of 37.4±18.0 months. The groups were comparable in age. The studied agent was tolerated by both groups that received premedication with no significant difference (P 0.73). Adequate sedation and anxiolysis were observed in groups A and B, (52%, 84%) and (68%, 88%) respectively. However, more children in group B (82.6%) had satisfactory behaviour at separation from parents and a better acceptance of anaesthetic face mask (64%) at induction than those in groups A and C (33.3%, 21.7%, respectively). No side effect was recorded in either of the premedication groups or the control group. CONCLUSION: Oral ketamine is acceptable and safe premedication for children. It provided good sedation, relieved anxiety and had no side effect in the children at the studied doses.

Predictors of maternal mortality among critically ill obstetric patients.

AIM: Evaluation of the predictors of maternal mortality among critically ill obstetric patients managed at the intensive care unit (ICU). METHODS: A case control study to evaluate the predictors of maternal mortality among critically ill obstetric patients managed at the intensive care unit (ICU) of the University of Ilorin Teaching Hospital, Ilorin, Nigeria from 1st January 2010 to 30th June 2013. Participants were critically ill obstetric patients who were admitted and managed at the ICU during the study period. Subjects were those who died while controls were age and parity matched survivors. Statistical analysis was with SPSS-20 to determine chi square, Cox-regression and odds ratio; p value < 0.05 was significant. RESULTS: The mean age of subjects and controls were 28.92 ± 5.09 versus 29.44 ± 5.74 (p = 0.736), the level of education was higher among controls (p = 0.048) while more subjects were of low social class (p = 0.321), did not have antenatal care (p = 0.131) and had partners with lower level of education (p = 0.156) compared to controls. The two leading indications for admission among subjects and controls were massive postpartum haemorrhage and severe preeclampsia or eclampsia. The mean duration of admission was higher among controls (3.32 ± 2.46 versus 3.00 ± 2.58; p = 0.656) while the mean cost of ICU care was higher among the subjects (p = 0.472). The statistical significant predictors of maternal deaths were the patient's level of education, Glasgow Coma Scale (GCS) score, oxygen saturation, multiple organ failure at ICU admission and the need for mechanical ventilation or inotrophic drugs after admission. CONCLUSION: The clinical state at ICU admission of the critically ill obstetric patients is the major outcome determinant. Therefore, early recognition of the need for ICU care, adequate pre-ICU admission supportive care and prompt transfer will improve the outcome.

Coagulation profile in severe pre-eclampsia and eclampsia in Ilorin, Nigeria: implications for anaesthetic management in operative obstetrics.

BACKGROUND: Severe preeclampsia and eclampsia are associated with coagulopathy which may be a contraindication to central neural axial blockade for caesarean section. Many investigations of bleeding tendencies are not done in our environment because of logistic reasons and emergency presentations of these patients.The study was designed to determine the coagulation profile of severe preeclamptic and eclamptic women in labour and possibly arrive at affordable and readily available investigation(s) that can be used in excluding bleeding tendencies in these patients. STUDY DESIGN: In a prospective study, 50 severely preeclamptic/eclamptic patients in labour and, 50 parturients with normal pregnancies, and, in labour were recruited. Full blood count including platelet count, prothrombin time (PT) using the International Normalized Ratio (INR) and partial thromboplastin time with kaolin (PTTK) were done in all the patients. RESULTS: Mean platelet count was significantly lower in study patients than in controls, 158.1 × 10(9)/l versus 216.9 × 10(9)/l, p = 0.0001. Mean INR and PTTK were within the reference values for the reagents used but mean INR was significantly greater in cases than in controls, 1.06 ± 0.01 versus 0.92 ± 0.01 (p = 0.001) while PTTK was also significantly longer in cases than in controls, 38.4 ± 0.21 versus 34.3 ± 0.44 seconds (p = 0.002). CONCLUSION: As platelet count can be readily obtained and it is affordable in our environment, it can be used in assessing bleeding tendencies in these patients for their effective management.

Outcomes of intensive care management of traumatic brain injury in a resource-challenged tertiary health centre.

BACKGROUND: Improved surgical care and protocol-driven intensive care interventions for head injured patients have contributed to the overall reduction in mortality in developed countries. The aim of this study is to highlight the clinical outcomes of patients with severe traumatic brain injury managed in the multispecialty ICU of our institution. STUDY DESIGN: The medical records of all patients with severe TBI managed in our 3-bedded non-dedicated ICU over a 24-month period were reviewed. Data on demographic characteristics, mechanism of injury, neuroimaging and interventions were obtained and the primary outcome measure was the mortality. RESULTS: Fifty one patients, age ranged from 2-75 years and median age of 30 years were studied. The male sex was more involved (M;F of 12;1) and motorcycle crashes caused the majority of the injury (19,{37%}). None of the patients received pre-hospital care and about half (25 {49 %}) presented six hours post trauma. Cranial CT scan showed intracranial haemorrhage in 7 of the 21 patients stabled for neuroimaging. Overall mortality was 70%, with highest mortality recorded in those who did not have post injury brain CT scan (58% vs 82%, p = 0.066). CONCLUSION: Mortality from severe TBI is very high in our environment where routine pre-hospital care and prompt transfer to neurosurgical centres are not practiced. Lack of facilities for monitoring intracranial pressure and arterial blood gases in our ICU also contributed to the high mortality.

Effect of wound infiltration with bupivacaine on pulmonary function after elective lower abdominal operations.

BACKGROUND: Subcutaneous or intrafascial wound infiltration of local anaesthetic with systemic opioids has been shown to enhance patient comfort with improved analgesia and reduced opioid requirements. OBJECTIVE: To demonstrate improved pulmonary function when postoperative analgesia was provided by combined bupivacaine wound infiltration and systemic opioid. METHODS: In a prospective, randomized, placebo-controlled study, 46 patients (23 per group) scheduled for elective gynaecological surgery under general anaesthesia had subcutaneous and intrafascial wound infiltration of 40 ml, 0.25% bupivacaine (study patients) or 40 ml 0.9% saline (control) just before the end of surgery. Forced vital capacity (FVC), forced expiratory volume in 1 second (FEV1) and peak expiratory flow rate (PEFR) were done before surgery and at 6, 12 and 24 hours postoperatively. Student's T and chi-square tests were used for tests of significance set at P < 0.05. Postoperative analgesia was provided with intramuscular morphine 0.15 mg/kg 4 hourly and 10mg/kg of intravenous paracetamol as rescue analgesia. RESULTS: PEFR, FVC and FEV1 were reduced in both the control and study groups but the reduction was greater in the control group. CONCLUSION: Bupivacaine wound infiltration produced statistically significant elevations in pulmonary function tests results at all assessment periods.

Comparative study of the haemodynamic effects of propofol and thiopentone in modified electroconvulsive therapy in Nigerians.

BACKGROUND: Electroconvulsive therapy provokes abrupt changes in systemic haemodynamics. We compared the effects of propofol and thiopentone on haemodynamic responses of patients scheduled for ECT between September 2008 and March 2009 in two Nigerian tertiary hospitals. METHODS: In a prospective, randomized study, 40 patients scheduled for ECT were allocated into 2 groups of 20 each. Anaesthesia was induced with either 1mg/kg propofol (PG) or 5 mg/kg thiopentone (TG) and 0.5mg/kg suxamethonium prior to ECT. Heart rate (HR), blood pressure- systolic (SBP), mean arterial (MAP) and diastolic (DBP) were taken before ECT and at 1 and 5 minutes postictal. The means of the increases in haemodynamic parameters were compared. RESULTS: There were significant increases in mean HR in both groups at 1 and 5 min and the increases were comparable between the 2 groups (p = 0.784). The increases in SBP were not significant in both groups and were comparable (p = 0.988). The increases in mean DBP were not significant in both groups but it was significantly greater in TG (p = 0.012). Increase in MAP was significantly greater in the TG at 1 min (p = 0.028). CONCLUSION: Propofol at 1 mg/kg and thiopentone at 5 mg/kg used for modified ECT in this study resulted in significant increases in heart rates. However, a significant increase in mean arterial pressure with thiopentone and a significantly greater increase in diastolic blood pressure when the two agents are compared confer some superiority on propofol over thiopentone in attenuating haemodynamic responses to ECT.

Repeat caesarean delivery as a risk factor for abnormal blood loss, blood transfusion and perinatal mortality.

We reviewed 450 cases of caesarean delivery (January-December 2009) at the University of Ilorin Teaching Hospital in Nigeria. We analysed the association between caesarean delivery status (primary or previous) and the following outcomes: abnormal blood-loss, blood transfusion and perinatal mortality. Although significant differences were observed between primary and previous caesarean delivery groups in regards to maternal age, urgency of the caesarean delivery, booking status, and cadre of birth attendant staff, no association was noted between caesarean delivery status and any of the three outcomes. Further analyses identified parity as an important predictor for blood transfusion and abnormal blood loss. In addition, we found a dose?response relationship between parity and abnormal blood loss (< 0.05). Also, mothers with an emergency caesarean delivery of the index pregnancy were more than twice as likely to have a blood transfusion as compared with those with an elective caesarean delivery.

Negative pressure pulmonary oedema following adenoidectomy under general anaesthesia: a case series.

BACKGROUND: Negative pressure pulmonary oedema (NPPE) is a potentially life-threatening complication of laryngospasm that occurs during or after general anaesthesia. It is a complication of poorly treated or unrecognized laryngospasm occurring at extubation or later in the postoperative period. OBJECTIVE: To emphasize prompt recognition of laryngospasm during or after general anaesthesia and to prevent its progression to NPPE in a resource-challenged environment. METHODS: Three children aged two to four years, one of whom was a known sickle cell anaemia patient presented with adenoid hypertrophy. Surgery was postponed on account of upper respiratory tract infection in each of them. RESULTS: Following treatment of upper respiratory tract infection, they had adenoidectomy under general anaesthesia. They all developed severe laryngospasm at extubation. This progressed to NPPE which was diagnosed on clinical parameters. The children were subsequently admitted to the intensive care unit (ICU) for mechanical ventilation with high FiO2 (0.7-1) and PEEP between 12-24hours. While two of the children survived, the child with sickle cell anaemia died in the ICU. CONCLUSION: Negative pressure pulmonary oedema is a self limiting complication of laryngospasm if it is well managed. However, its outcome may not be good in a patient with intercurrent medical illness such as sickle cell anaemia in which hypoxaemia is deleterious.

Methicillin resistant Staphylococcus aureus: awareness, knowledge and disposition to screening among healthcare workers in critical care units of a Nigerian hospital.

BACKGROUND: Awareness level about methicillin resistant Staphylococcus aureus (MRSA) is high in the western world but the status in developing countries is not well defined. OBJECTIVE: To assess MRSA awareness level, knowledge and disposition to screening among critical healthcare givers (HCGs) in Nigeria. METHODS: A self-administered questionnaire was used to assess the level of awareness and knowledge of HCGs in critical care units of the University of Ilorin Teaching Hospital, Ilorin, Nigeria on MRSA and their willingness to submit to screening. RESULTS: Only 103 (52.0%) of the 198 participants were aware of MRSA but all were favourably disposed to screening for the organism. Awareness was through hospital rounds 65(63.1%) and journals/ textbooks 35(34.0%), and Many, 120 (60.6%) considered MRSA as a threat in the hospital, while only 27 (13.6%) thought otherwise and 51(25.8%) were indifferent. Most HCGs, 124 (87.9%) reported that there were no MRSA control measures in their respective duty post. The age, cadre of work, and number of years in the hospital's critical care units correlated positively with awareness level. CONCLUSION: Methicillin resistant Staphylococcus aureus awareness level among the HCGs in our hospital is just a little above 50.0% with substantial proportion of them not realizing the medical implication of the organism. However, majority are well disposed to MRSA screening. Inadequate publicity is a major contributor to poor knowledge and awareness. There is need for educational intervention and sensitization programs on MRSA and other infection control techniques for HCGs in developing nations especially Nigeria.

Anaesthesia management for thyroidectomy in a non-euthyroid patient following cardiac failure.

A 24-year-old male thyrotoxic student of a tertiary institution had thyroidectomy in the presence of a persistently elevated thyroxine (T4) and tri-iodothyronine (T3) levels. He was initially managed for hypertension at a private hospital before he was referred to our hospital for expert management. He had symptoms of thyrotoxicosis three years before presentation at our hospital. Physical examination revealed bilateral anterior neck masses and a diagnosis of toxic goitre was made. The serum T3 and T4 were elevated. Chest X-Ray, electrocardiogram and echocardiography showed abnormal findings. He was commenced on antithyroid drugs. Surgery was postponed several times due to persistently elevated thyroid hormones. However, he developed cardiac failure after six months on medical treatment and was treated with digoxin and frusemide. He had thyroidectomy under general anesthesia after his cardiovascular status was optimized in order to prevent further deterioration of his cardiac function. The anesthetic management is presented and discussed.

Comparison of topical lidocaine [2% gel] and injectable lidocaine [2% solution] for incision and curettage of chalazion in Ilorin, Nigeria.

AIMS AND OBJECTIVES: To compare the efficacy and side effects profile of topical 2% lidocaine gel with injectable 2% lidocaine solution as local anaesthetics for incision and curettage of chalazion. PATIENTS AND METHODS: Overa 12 month period, 61 patients with unilateral chalazia who were scheduled for incision and curettage surgery under local anaesthesia were randomized into 2 groups: A & B. Group A received 1.5 ml of injectable lidocaine as local anaesthetic while Group B received 1.5 ml of lidocaine 2% gel topically. The major outcome of interest was pain experienced during anaesthetic administration and surgery. RESULTS: Mean pain score from anaesthesia administration was significantly higher in the injection group (A = 4.46 vs. B = 0.57), (p = 0.000005). There was a statistically significant difference in mean pain score during incision and curettage with more pain in the gel group (A = 2.84 vs. B = 4.83), (p = 0.0012). However, the mean total pain score (surgery plus anaesthesia) was more in the injection than the gel group (A = 7.3 vs. B = 5.4) (p = 0.0094). The proportions that had no fear for injection were 54.8% in A and 56.7 % in B. Group A had significantly more ptosis than Group B (2.2 vs. 1.4, p = 0.00003,). Bleeding occured in 93.5% in group A while none occurred in Group B (p = 0.000). CONCLUSION: Lidocaine 2% gel is an effective, safe and convenient alternative to injectable lidocaine 2% as local anaesthetic agent in incision and curettage for Chalazion in this study.

Subarachnoid block for lower abdominal and lower limb surgery: UITH experience.

The use of subarachnoid block has become an established and reliable method of providing anaesthesia for lower abdominal and lower limb surgery. Unfortunately, it remains largely unappealing to a large number of our patients who sometimes associate it with paralysis. The aim of this study was to assess the efficiency and safety of subarachnoid block for lower abdominal and lower limb surgery in the University of Ilorin Teaching Hospital. This prospective study was carried out between January 1998 and August 2000 the University of Ilorin Teaching Hospital, Ilorin, Nigeria. One hundred and ten (110) consenting adult patients had subarachnoid block for lower abdominal and lower limb surgery over a period of two years and eight months Patients were assessed in the theatre as well as in the postanaesthetic recovery room and daily in the ward for five days. All complications related to anaesthesia were recorded and analysed. There were 75 (68%) male and 35 (32%) female patients. Ninety-six (87%) were elective and 14 (13%) were emergency cases. The specialty distribution of cases included 66 (60%) patients for Orthopaedic surgery, 16 (14.5%) for General Surgery and 13 (11.8%) for Urology. Intravenous ketamine and pentazocine were used to supplement anaesthesia in 12 (11%) of cases due to varying degrees of discomfort experienced by the patients. There was no case of total failure. Intra-operative complications included hypotension in 9(8.18%) patients which responded to saline infusion in 5 and vasoconstrictor in 4 cases, hypertension in 9 (8.18%) patients which responded to reassurance and midazolam sedation, and a brief episode of shivering in 9 (8.18%) patients treated by additional drape cover. The incidence of post-spinal headache was 2.7% in this study. Subarachnoid block still remains a very effective and safe anaesthetic technique for lower abdominal and lower limb surgery. The technique is cheap and effort should be made to increase patient awareness and its acceptability in the new millennium.