Ashish Kulshrestha - Academia.edu (original) (raw)

Papers by Ashish Kulshrestha

Sri Lankan Journal of Anaesthesiology, Jul 22, 2015

We undertook this study to compare the analgesic efficacy of 0.1% bupivacaine and 0.1% ropivacain... more We undertook this study to compare the analgesic efficacy of 0.1% bupivacaine and 0.1% ropivacaine with fentanyl using patient controlled epidural analgesia. Materials and methods: 60 parturients of ≥ 36 weeks of gestation with cephalic presentation in spontaneous labour with cervical dilatation ≤ 5cms and baseline pain score of ≥ 30 on visual analogue scale (VAS), were enrolled in the study. Group I received 10 ml bolus of 0.1% bupivacaine with fentanyl 2µg/ml while Group II received 10 ml bolus of 0.1% ropivacaine with fentanyl 2µg/ml followed by patient controlled epidural analgesia (PCEA) using PCA pump. The primary outcome measured was analgesic efficacy using VAS. Results: VAS scores during first and second hour were found to be significantly lower in Group 1 as compared to Group 2 (Figure 1) with a significant difference from their respective baselines. Group II showed a statistically higher total drug consumption and number of boluses used (62.33 ± 26.6 vs 48.47 ± 16.7 and1.40 ± 0.8 vs 2.00 ± 0.8 respectively) as compared to group I (Table 2) (Figure 3). The motor block showed a statistically significant difference at 4 th , 5 th and 6 th hours between the two groups (Figure 4). Conclusion: The present study demonstrated that 0.1% ropivacaine or 0.1% bupivacaine with fentanyl 2µg/ml used during labour analgesia by PCEA were equally effective for controlling the labour pain with more total drug consumption and less motor blockade associated with 0.1% ropivacaine as compared to 0.1% bupivacaine.

Anaesthesia, pain & intensive care, Mar 1, 2021

Pain is an unpleasant experience which can produce changes in all the systems of the body. Pain i... more Pain is an unpleasant experience which can produce changes in all the systems of the body. Pain in children is not different from that in adults and can lead to similar detrimental effects on the body. The anticipation and effective treatment of pain in pediatric patients is thus, an essential component of care. A careful assessment of pediatric pain using age-specific pain scoring systems allows for exact quantification of pain. The use of various analgesics should be done early and in adequate doses for them to be effective. The use of multimodal approach with weaker analgesics along with regional blocks is an effective modality to control pain and prevent severe adverse effects associated with higher doses of potent analgesics. The advancement in the pharmacology of analgesics allows for their more widespread use with minimal side-effects. The use of patient or nurse controlled analgesia and continuous regional nerve blocks with the use of indwelling catheters can augment the pediatric pain management. Keywords: Pediatrics; Postoperative pain management; Neuraxial Citation: Kulshrestha A, Bajwa SJS. Management of acute postoperative pain in pediatric patients. Anaesth Pain & Intensive Care 2014;18(1):101-107

Pre-eclampsia is an important cause of mortality and morbidity in parturients with varied present... more Pre-eclampsia is an important cause of mortality and morbidity in parturients with varied presentations and controversial pathophysiology. The central pathology is a profound vasoconstriction in the vasculature leading to volume contraction and placental hypoperfusion. The management mainly involves a multi-disciplinary approach with the anesthesiologist playing a significant role for a positive outcome. Anesthesia for such parturients remains a challenge and starts with provision of labor analgesia which should be offered to all preeclamptic parturients. The neuraxial techniques of analgesia are most favourable for adequate pain relief and if contraindicated, intravenous PCA technique with the use of opioids should be used. Recent studies show favourable maternal and fetal outcomes with the use of patient controlled epidural analgesia technique with the combination of lower concentrations of local anesthetics with opioids. Regional anesthesia should be preferred in these parturient...

Indian Journal of Anaesthesia, 2016

The intra-and inter-hospital patient transfer is an important aspect of patient care which is oft... more The intra-and inter-hospital patient transfer is an important aspect of patient care which is often undertaken to improve upon the existing management of the patient. It may involve transfer of patient within the same facility for any diagnostic procedure or transfer to another facility with more advanced care. The main aim in all such transfers is maintaining the continuity of medical care. As the transfer of sick patient may induce various physiological alterations which may adversely affect the prognosis of the patient, it should be initiated systematically and according to the evidence-based guidelines. The key elements of safe transfer involve decision to transfer and communication, pre-transfer stabilisation and preparation, choosing the appropriate mode of transfer, i.e., land transport or air transport, personnel accompanying the patient, equipment and monitoring required during the transfer, and finally, the documentation and handover of the patient at the receiving facility. These key elements should be followed in each transfer to prevent any adverse events which may severely affect the patient prognosis. The existing international guidelines are evidence based from various professional bodies in developed countries. However, in developing countries like India, with limited infrastructure, these guidelines can be modified accordingly. The most important aspect is implementation of these guidelines in Indian scenario with periodical quality assessments to improve the standard of care.

Southern African Journal of Anaesthesia and Analgesia, 2008

Journal of Spine & Neurosurgery, 2013

Rapid developments in the practice of neurosurgery pose significant new challenges for the attend... more Rapid developments in the practice of neurosurgery pose significant new challenges for the attending anaesthetist. The neuroanaesthesiologist is faced with the task of modification of various anaesthetic techniques depending on the alterations in the neurophysiologic parameters present in the patient. A close cooperation between the anaesthesiologist and the neurosurgeon is mandatory for successful conduct of the procedure. A thorough preoperative preparation of the patient with careful intraoperative monitoring is required. The anaesthetic techniques should be tailored to avoid any alterations in the neurophysiologic parameters which may prove to be deleterious for the patient. With the advent of minimally invasive neurosurgical procedures, the anaesthesiologist has to be aware of different techniques used so that the use of anaesthetic drugs can be made accordingly.

Pre-eclampsia is a disease of pregnancy involving various systems with associated high blood pres... more Pre-eclampsia is a disease of pregnancy involving various systems with associated high blood pressure and other changes. The pathophysiology of this disease is not well known but the main pathological change is vasoconstriction in the vascular bed of the parturient with abnormalities in the uteroplacental circulation. A multi-disciplinary approach is essential for proper management of this disease. The provision of analgesia during labor significantly reduces the stress response and thus is helpful in reducing the elevated blood pressure and also exerts beneficial effects on uteroplacental perfusion. The neuraxial analgesia technique is considered to be the gold standard and has been found to be effective and safe in pre-eclamptic parturients. The use of lower concentrations of local anesthetic drugs in combination with opioids results in less motor blockade, lesser dose of drugs and lesser incidence of significant side-effects. The patient-controlled epidural analgesia technique is...

Auxiliary lanes are generally used to reduce the traffic turbulence created by merging and diverg... more Auxiliary lanes are generally used to reduce the traffic turbulence created by merging and diverging movements and are primarily used by vehicles either entering or exiting the freeway. The Highway Capacity Manual (HCM) does not offer explicit guidance on the benefit of adding an auxiliary lane between an on- and off-ramp. The objective of this part of the project was to quantify the additional traffic volume that can be accommodated on a freeway segment by connecting an on-ramp to an off-ramp with an auxiliary lane. The approach used was to identify the traffic volume level at which each level of service density threshold was met for the conditions of with and without an auxiliary lane. The CORSIM simulation program was used to generate the data upon which to establish the quantitative effect of an auxiliary lane. Two versions of an adjustment equation that gives the percentage increase in volume throughput due to adding an auxiliary lane were developed. The developed equations are simply a function of the number of mainline lanes, as other factors were not found to significantly affect the percentage increase in volume throughput. The capacity of a freeway segment is a critical factor for the assessment of the traffic flow operations on freeway facilities. The HCM (2000) is considered to be one of the authoritative sources on capacity values for a variety of roadway types in the U.S. It provides a single set of capacity values for basic freeway segments as a function of free-flow speed. These values are considered to be reasonably representative values for freeways located throughout the U.S., but it is recognized that lower or higher values may be more appropriate in any given location. However, the HCM does not provide any guidance on how its recommended values can be adjusted to reflect significant differences in capacity due to local conditions, nor how to directly measure or estimate capacity values. The objective of this part of the project was to investigate various methods that can be used to arrive at an estimate of freeway capacity values, and to recommend one of these methods to the Florida Department of Transportation for use in developing its own estimates of capacity for Florida freeways. Three methods were investigated: one that fits a mathematical function to speed-flow data points, from which the apex of the function is taken as capacity; one that estimates a breakdown probability distribution based on flow rates preceding breakdown events, from which capacity can be taken to correspond to a certain percentile value of the breakdown probability distribution; and one that uses a flow rate corresponding to a specified percentile within a specified range of maximum flow rates observed at a site. It is recommended that this latter method is most suitable for planning and preliminary engineering applications.

Auxiliary lanes are generally used to reduce the traffic turbulence created by merging and diverg... more Auxiliary lanes are generally used to reduce the traffic turbulence created by merging and diverging movements and are primarily used by vehicles either entering or exiting the freeway. The Highway Capacity Manual (HCM) does not offer explicit guidance on the benefit of adding an auxiliary lane between an on- and off-ramp. The objective of this part of the project was to quantify the additional traffic volume that can be accommodated on a freeway segment by connecting an on-ramp to an off-ramp with an auxiliary lane. The approach used was to identify the traffic volume level at which each level of service density threshold was met for the conditions of with and without an auxiliary lane. The CORSIM simulation program was used to generate the data upon which to establish the quantitative effect of an auxiliary lane. Two versions of an adjustment equation that gives the percentage increase in volume throughput due to adding an auxiliary lane were developed. The developed equations are simply a function of the number of mainline lanes, as other factors were not found to significantly affect the percentage increase in volume throughput. The capacity of a freeway segment is a critical factor for the assessment of the traffic flow operations on freeway facilities. The HCM (2000) is considered to be one of the authoritative sources on capacity values for a variety of roadway types in the U.S. It provides a single set of capacity values for basic freeway segments as a function of free-flow speed. These values are considered to be reasonably representative values for freeways located throughout the U.S., but it is recognized that lower or higher values may be more appropriate in any given location. However, the HCM does not provide any guidance on how its recommended values can be adjusted to reflect significant differences in capacity due to local conditions, nor how to directly measure or estimate capacity values. The objective of this part of the project was to investigate various methods that can be used to arrive at an estimate of freeway capacity values, and to recommend one of these methods to the Florida Department of Transportation for use in developing its own estimates of capacity for Florida freeways. Three methods were investigated: one that fits a mathematical function to speed-flow data points, from which the apex of the function is taken as capacity; one that estimates a breakdown probability distribution based on flow rates preceding breakdown events, from which capacity can be taken to correspond to a certain percentile value of the breakdown probability distribution; and one that uses a flow rate corresponding to a specified percentile within a specified range of maximum flow rates observed at a site. It is recommended that this latter method is most suitable for planning and preliminary engineering applications.

Http Dx Doi Org 10 1080 19439962 2011 609323, Dec 1, 2011

Http Dx Doi Org 10 1080 19439962 2011 609323, Dec 1, 2011

The Florida Department of Transportation recently implemented high occupancy/toll (HOT) lanes (kn... more The Florida Department of Transportation recently implemented high occupancy/toll (HOT) lanes (known as 95 Express) in the Miami regional area on Interstate 95. This report investigates three aspects relevant to the operations and management of HOT lanes such as 95 Express. First, two questions concerning the impact and effectiveness of dynamic tolling are investigated. One is whether a managed-lane system exhibits hysteresis-like behavior that motorists periodically shift their departure times to cope with the volatility of the toll being charged. The other is whether dynamic pricing necessarily performs better than static or time-of-day pricing. Second, this report examines whether and how the reduced lane, shoulder widths, delineators, and designs of ingress/egress points have affected the capacity and operations of the toll lanes and the general-purpose lanes of 95 Express. Lastly, the report focuses on enhancement and evaluation of the tolling algorithms for the current and future 95 Express.

The Florida Department of Transportation recently implemented high occupancy/toll (HOT) lanes (kn... more The Florida Department of Transportation recently implemented high occupancy/toll (HOT) lanes (known as 95 Express) in the Miami regional area on Interstate 95. This report investigates three aspects relevant to the operations and management of HOT lanes such as 95 Express. First, two questions concerning the impact and effectiveness of dynamic tolling are investigated. One is whether a managed-lane system exhibits hysteresis-like behavior that motorists periodically shift their departure times to cope with the volatility of the toll being charged. The other is whether dynamic pricing necessarily performs better than static or time-of-day pricing. Second, this report examines whether and how the reduced lane, shoulder widths, delineators, and designs of ingress/egress points have affected the capacity and operations of the toll lanes and the general-purpose lanes of 95 Express. Lastly, the report focuses on enhancement and evaluation of the tolling algorithms for the current and future 95 Express.

Journal of anaesthesiology, clinical pharmacology

Induced hypotension limits intra-operative blood loss to provide better visibility of the surgica... more Induced hypotension limits intra-operative blood loss to provide better visibility of the surgical field and diminishes the incidence of major complications during functional endoscopic sinus surgery (FESS). We aimed at comparing nitroglycerine, esmolol and dexmedetomidine for inducing controlled hypotension in patients undergoing FESS. One hundred and fifty American Society of Anesthesiologists physical status I or II adult patients undergoing FESS under general anesthesia were randomly allocated to three groups of 50 patients each. Group E received esmolol in a loading and maintenance dose of 1 mg/kg over 1 min and 0.5-1.0 mg/kg/h, respectively. Group D received a loading dose of dexmedetomidine 1 μg/kg over 10 min followed by an infusion 0.5-1.0 μg/kg/h, and group N received nitroglycerine infusion at a dose of 0.5-2 μg/kg/min so as to maintain mean arterial pressure (MAP) between 60 and 70 mmHg in all the groups. The visibility of the surgical field was assessed by surgeon using...

Journal of anaesthesiology, clinical pharmacology

Induced hypotension limits intra-operative blood loss to provide better visibility of the surgica... more Induced hypotension limits intra-operative blood loss to provide better visibility of the surgical field and diminishes the incidence of major complications during functional endoscopic sinus surgery (FESS). We aimed at comparing nitroglycerine, esmolol and dexmedetomidine for inducing controlled hypotension in patients undergoing FESS. One hundred and fifty American Society of Anesthesiologists physical status I or II adult patients undergoing FESS under general anesthesia were randomly allocated to three groups of 50 patients each. Group E received esmolol in a loading and maintenance dose of 1 mg/kg over 1 min and 0.5-1.0 mg/kg/h, respectively. Group D received a loading dose of dexmedetomidine 1 μg/kg over 10 min followed by an infusion 0.5-1.0 μg/kg/h, and group N received nitroglycerine infusion at a dose of 0.5-2 μg/kg/min so as to maintain mean arterial pressure (MAP) between 60 and 70 mmHg in all the groups. The visibility of the surgical field was assessed by surgeon using...

Transportation Research Record Journal of the Transportation Research Board, Dec 1, 2010

Disclaimer The contents of this report reflect the views of the authors, who are responsible for ... more Disclaimer The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the data published herein. The opinions, findings, and conclusions expressed in this publication are those of the authors and not necessarily those of the State of Florida Department of Transportation.

Transportation Research Record Journal of the Transportation Research Board, Dec 1, 2010

Disclaimer The contents of this report reflect the views of the authors, who are responsible for ... more Disclaimer The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the data published herein. The opinions, findings, and conclusions expressed in this publication are those of the authors and not necessarily those of the State of Florida Department of Transportation.

Journal of Minimal Access Surgery, 2016

The use of laparoscopy has revolutionised the surgical field with its advantages of reduced morbi... more The use of laparoscopy has revolutionised the surgical field with its advantages of reduced morbidity with early recovery. Laparoscopic procedures have been traditionally performed under general anaesthesia (GA) due to the respiratory changes caused by pneumoperitoneum, which is an integral part of laparoscopy. The precise control of ventilation under controlled conditions in GA has proven it to be ideal for such procedures. However, recently the use of regional anaesthesia (RA) has emerged as an alternative choice for laparoscopy. Various reports in the literature suggest the safety of the use of spinal, epidural and combined spinal-epidural anaesthesia in laparoscopic procedures. The advantages of RA can include: Prevention of airway manipulation, an awake and spontaneously breathing patient intraoperatively, minimal nausea and vomiting, effective post-operative analgesia, and early ambulation and recovery. However, RA may be associated with a few side effects such as the requirement of a higher sensory level, more severe hypotension, shoulder discomfort due to diaphragmatic irritation, and respiratory embarrassment caused by pneumoperitoneum. Further studies may be required to establish the advantage of RA over GA for its eventual global use in different patient populations.

Journal of Minimal Access Surgery, 2016

The use of laparoscopy has revolutionised the surgical field with its advantages of reduced morbi... more The use of laparoscopy has revolutionised the surgical field with its advantages of reduced morbidity with early recovery. Laparoscopic procedures have been traditionally performed under general anaesthesia (GA) due to the respiratory changes caused by pneumoperitoneum, which is an integral part of laparoscopy. The precise control of ventilation under controlled conditions in GA has proven it to be ideal for such procedures. However, recently the use of regional anaesthesia (RA) has emerged as an alternative choice for laparoscopy. Various reports in the literature suggest the safety of the use of spinal, epidural and combined spinal-epidural anaesthesia in laparoscopic procedures. The advantages of RA can include: Prevention of airway manipulation, an awake and spontaneously breathing patient intraoperatively, minimal nausea and vomiting, effective post-operative analgesia, and early ambulation and recovery. However, RA may be associated with a few side effects such as the requirement of a higher sensory level, more severe hypotension, shoulder discomfort due to diaphragmatic irritation, and respiratory embarrassment caused by pneumoperitoneum. Further studies may be required to establish the advantage of RA over GA for its eventual global use in different patient populations.

Sri Lankan Journal of Anaesthesiology, Jul 22, 2015

We undertook this study to compare the analgesic efficacy of 0.1% bupivacaine and 0.1% ropivacain... more We undertook this study to compare the analgesic efficacy of 0.1% bupivacaine and 0.1% ropivacaine with fentanyl using patient controlled epidural analgesia. Materials and methods: 60 parturients of ≥ 36 weeks of gestation with cephalic presentation in spontaneous labour with cervical dilatation ≤ 5cms and baseline pain score of ≥ 30 on visual analogue scale (VAS), were enrolled in the study. Group I received 10 ml bolus of 0.1% bupivacaine with fentanyl 2µg/ml while Group II received 10 ml bolus of 0.1% ropivacaine with fentanyl 2µg/ml followed by patient controlled epidural analgesia (PCEA) using PCA pump. The primary outcome measured was analgesic efficacy using VAS. Results: VAS scores during first and second hour were found to be significantly lower in Group 1 as compared to Group 2 (Figure 1) with a significant difference from their respective baselines. Group II showed a statistically higher total drug consumption and number of boluses used (62.33 ± 26.6 vs 48.47 ± 16.7 and1.40 ± 0.8 vs 2.00 ± 0.8 respectively) as compared to group I (Table 2) (Figure 3). The motor block showed a statistically significant difference at 4 th , 5 th and 6 th hours between the two groups (Figure 4). Conclusion: The present study demonstrated that 0.1% ropivacaine or 0.1% bupivacaine with fentanyl 2µg/ml used during labour analgesia by PCEA were equally effective for controlling the labour pain with more total drug consumption and less motor blockade associated with 0.1% ropivacaine as compared to 0.1% bupivacaine.

Anaesthesia, pain & intensive care, Mar 1, 2021

Pain is an unpleasant experience which can produce changes in all the systems of the body. Pain i... more Pain is an unpleasant experience which can produce changes in all the systems of the body. Pain in children is not different from that in adults and can lead to similar detrimental effects on the body. The anticipation and effective treatment of pain in pediatric patients is thus, an essential component of care. A careful assessment of pediatric pain using age-specific pain scoring systems allows for exact quantification of pain. The use of various analgesics should be done early and in adequate doses for them to be effective. The use of multimodal approach with weaker analgesics along with regional blocks is an effective modality to control pain and prevent severe adverse effects associated with higher doses of potent analgesics. The advancement in the pharmacology of analgesics allows for their more widespread use with minimal side-effects. The use of patient or nurse controlled analgesia and continuous regional nerve blocks with the use of indwelling catheters can augment the pediatric pain management. Keywords: Pediatrics; Postoperative pain management; Neuraxial Citation: Kulshrestha A, Bajwa SJS. Management of acute postoperative pain in pediatric patients. Anaesth Pain & Intensive Care 2014;18(1):101-107

Pre-eclampsia is an important cause of mortality and morbidity in parturients with varied present... more Pre-eclampsia is an important cause of mortality and morbidity in parturients with varied presentations and controversial pathophysiology. The central pathology is a profound vasoconstriction in the vasculature leading to volume contraction and placental hypoperfusion. The management mainly involves a multi-disciplinary approach with the anesthesiologist playing a significant role for a positive outcome. Anesthesia for such parturients remains a challenge and starts with provision of labor analgesia which should be offered to all preeclamptic parturients. The neuraxial techniques of analgesia are most favourable for adequate pain relief and if contraindicated, intravenous PCA technique with the use of opioids should be used. Recent studies show favourable maternal and fetal outcomes with the use of patient controlled epidural analgesia technique with the combination of lower concentrations of local anesthetics with opioids. Regional anesthesia should be preferred in these parturient...

Indian Journal of Anaesthesia, 2016

The intra-and inter-hospital patient transfer is an important aspect of patient care which is oft... more The intra-and inter-hospital patient transfer is an important aspect of patient care which is often undertaken to improve upon the existing management of the patient. It may involve transfer of patient within the same facility for any diagnostic procedure or transfer to another facility with more advanced care. The main aim in all such transfers is maintaining the continuity of medical care. As the transfer of sick patient may induce various physiological alterations which may adversely affect the prognosis of the patient, it should be initiated systematically and according to the evidence-based guidelines. The key elements of safe transfer involve decision to transfer and communication, pre-transfer stabilisation and preparation, choosing the appropriate mode of transfer, i.e., land transport or air transport, personnel accompanying the patient, equipment and monitoring required during the transfer, and finally, the documentation and handover of the patient at the receiving facility. These key elements should be followed in each transfer to prevent any adverse events which may severely affect the patient prognosis. The existing international guidelines are evidence based from various professional bodies in developed countries. However, in developing countries like India, with limited infrastructure, these guidelines can be modified accordingly. The most important aspect is implementation of these guidelines in Indian scenario with periodical quality assessments to improve the standard of care.

Southern African Journal of Anaesthesia and Analgesia, 2008

Journal of Spine & Neurosurgery, 2013

Rapid developments in the practice of neurosurgery pose significant new challenges for the attend... more Rapid developments in the practice of neurosurgery pose significant new challenges for the attending anaesthetist. The neuroanaesthesiologist is faced with the task of modification of various anaesthetic techniques depending on the alterations in the neurophysiologic parameters present in the patient. A close cooperation between the anaesthesiologist and the neurosurgeon is mandatory for successful conduct of the procedure. A thorough preoperative preparation of the patient with careful intraoperative monitoring is required. The anaesthetic techniques should be tailored to avoid any alterations in the neurophysiologic parameters which may prove to be deleterious for the patient. With the advent of minimally invasive neurosurgical procedures, the anaesthesiologist has to be aware of different techniques used so that the use of anaesthetic drugs can be made accordingly.

Pre-eclampsia is a disease of pregnancy involving various systems with associated high blood pres... more Pre-eclampsia is a disease of pregnancy involving various systems with associated high blood pressure and other changes. The pathophysiology of this disease is not well known but the main pathological change is vasoconstriction in the vascular bed of the parturient with abnormalities in the uteroplacental circulation. A multi-disciplinary approach is essential for proper management of this disease. The provision of analgesia during labor significantly reduces the stress response and thus is helpful in reducing the elevated blood pressure and also exerts beneficial effects on uteroplacental perfusion. The neuraxial analgesia technique is considered to be the gold standard and has been found to be effective and safe in pre-eclamptic parturients. The use of lower concentrations of local anesthetic drugs in combination with opioids results in less motor blockade, lesser dose of drugs and lesser incidence of significant side-effects. The patient-controlled epidural analgesia technique is...

Auxiliary lanes are generally used to reduce the traffic turbulence created by merging and diverg... more Auxiliary lanes are generally used to reduce the traffic turbulence created by merging and diverging movements and are primarily used by vehicles either entering or exiting the freeway. The Highway Capacity Manual (HCM) does not offer explicit guidance on the benefit of adding an auxiliary lane between an on- and off-ramp. The objective of this part of the project was to quantify the additional traffic volume that can be accommodated on a freeway segment by connecting an on-ramp to an off-ramp with an auxiliary lane. The approach used was to identify the traffic volume level at which each level of service density threshold was met for the conditions of with and without an auxiliary lane. The CORSIM simulation program was used to generate the data upon which to establish the quantitative effect of an auxiliary lane. Two versions of an adjustment equation that gives the percentage increase in volume throughput due to adding an auxiliary lane were developed. The developed equations are simply a function of the number of mainline lanes, as other factors were not found to significantly affect the percentage increase in volume throughput. The capacity of a freeway segment is a critical factor for the assessment of the traffic flow operations on freeway facilities. The HCM (2000) is considered to be one of the authoritative sources on capacity values for a variety of roadway types in the U.S. It provides a single set of capacity values for basic freeway segments as a function of free-flow speed. These values are considered to be reasonably representative values for freeways located throughout the U.S., but it is recognized that lower or higher values may be more appropriate in any given location. However, the HCM does not provide any guidance on how its recommended values can be adjusted to reflect significant differences in capacity due to local conditions, nor how to directly measure or estimate capacity values. The objective of this part of the project was to investigate various methods that can be used to arrive at an estimate of freeway capacity values, and to recommend one of these methods to the Florida Department of Transportation for use in developing its own estimates of capacity for Florida freeways. Three methods were investigated: one that fits a mathematical function to speed-flow data points, from which the apex of the function is taken as capacity; one that estimates a breakdown probability distribution based on flow rates preceding breakdown events, from which capacity can be taken to correspond to a certain percentile value of the breakdown probability distribution; and one that uses a flow rate corresponding to a specified percentile within a specified range of maximum flow rates observed at a site. It is recommended that this latter method is most suitable for planning and preliminary engineering applications.

Auxiliary lanes are generally used to reduce the traffic turbulence created by merging and diverg... more Auxiliary lanes are generally used to reduce the traffic turbulence created by merging and diverging movements and are primarily used by vehicles either entering or exiting the freeway. The Highway Capacity Manual (HCM) does not offer explicit guidance on the benefit of adding an auxiliary lane between an on- and off-ramp. The objective of this part of the project was to quantify the additional traffic volume that can be accommodated on a freeway segment by connecting an on-ramp to an off-ramp with an auxiliary lane. The approach used was to identify the traffic volume level at which each level of service density threshold was met for the conditions of with and without an auxiliary lane. The CORSIM simulation program was used to generate the data upon which to establish the quantitative effect of an auxiliary lane. Two versions of an adjustment equation that gives the percentage increase in volume throughput due to adding an auxiliary lane were developed. The developed equations are simply a function of the number of mainline lanes, as other factors were not found to significantly affect the percentage increase in volume throughput. The capacity of a freeway segment is a critical factor for the assessment of the traffic flow operations on freeway facilities. The HCM (2000) is considered to be one of the authoritative sources on capacity values for a variety of roadway types in the U.S. It provides a single set of capacity values for basic freeway segments as a function of free-flow speed. These values are considered to be reasonably representative values for freeways located throughout the U.S., but it is recognized that lower or higher values may be more appropriate in any given location. However, the HCM does not provide any guidance on how its recommended values can be adjusted to reflect significant differences in capacity due to local conditions, nor how to directly measure or estimate capacity values. The objective of this part of the project was to investigate various methods that can be used to arrive at an estimate of freeway capacity values, and to recommend one of these methods to the Florida Department of Transportation for use in developing its own estimates of capacity for Florida freeways. Three methods were investigated: one that fits a mathematical function to speed-flow data points, from which the apex of the function is taken as capacity; one that estimates a breakdown probability distribution based on flow rates preceding breakdown events, from which capacity can be taken to correspond to a certain percentile value of the breakdown probability distribution; and one that uses a flow rate corresponding to a specified percentile within a specified range of maximum flow rates observed at a site. It is recommended that this latter method is most suitable for planning and preliminary engineering applications.

Http Dx Doi Org 10 1080 19439962 2011 609323, Dec 1, 2011

Http Dx Doi Org 10 1080 19439962 2011 609323, Dec 1, 2011

The Florida Department of Transportation recently implemented high occupancy/toll (HOT) lanes (kn... more The Florida Department of Transportation recently implemented high occupancy/toll (HOT) lanes (known as 95 Express) in the Miami regional area on Interstate 95. This report investigates three aspects relevant to the operations and management of HOT lanes such as 95 Express. First, two questions concerning the impact and effectiveness of dynamic tolling are investigated. One is whether a managed-lane system exhibits hysteresis-like behavior that motorists periodically shift their departure times to cope with the volatility of the toll being charged. The other is whether dynamic pricing necessarily performs better than static or time-of-day pricing. Second, this report examines whether and how the reduced lane, shoulder widths, delineators, and designs of ingress/egress points have affected the capacity and operations of the toll lanes and the general-purpose lanes of 95 Express. Lastly, the report focuses on enhancement and evaluation of the tolling algorithms for the current and future 95 Express.

The Florida Department of Transportation recently implemented high occupancy/toll (HOT) lanes (kn... more The Florida Department of Transportation recently implemented high occupancy/toll (HOT) lanes (known as 95 Express) in the Miami regional area on Interstate 95. This report investigates three aspects relevant to the operations and management of HOT lanes such as 95 Express. First, two questions concerning the impact and effectiveness of dynamic tolling are investigated. One is whether a managed-lane system exhibits hysteresis-like behavior that motorists periodically shift their departure times to cope with the volatility of the toll being charged. The other is whether dynamic pricing necessarily performs better than static or time-of-day pricing. Second, this report examines whether and how the reduced lane, shoulder widths, delineators, and designs of ingress/egress points have affected the capacity and operations of the toll lanes and the general-purpose lanes of 95 Express. Lastly, the report focuses on enhancement and evaluation of the tolling algorithms for the current and future 95 Express.

Journal of anaesthesiology, clinical pharmacology

Induced hypotension limits intra-operative blood loss to provide better visibility of the surgica... more Induced hypotension limits intra-operative blood loss to provide better visibility of the surgical field and diminishes the incidence of major complications during functional endoscopic sinus surgery (FESS). We aimed at comparing nitroglycerine, esmolol and dexmedetomidine for inducing controlled hypotension in patients undergoing FESS. One hundred and fifty American Society of Anesthesiologists physical status I or II adult patients undergoing FESS under general anesthesia were randomly allocated to three groups of 50 patients each. Group E received esmolol in a loading and maintenance dose of 1 mg/kg over 1 min and 0.5-1.0 mg/kg/h, respectively. Group D received a loading dose of dexmedetomidine 1 μg/kg over 10 min followed by an infusion 0.5-1.0 μg/kg/h, and group N received nitroglycerine infusion at a dose of 0.5-2 μg/kg/min so as to maintain mean arterial pressure (MAP) between 60 and 70 mmHg in all the groups. The visibility of the surgical field was assessed by surgeon using...

Journal of anaesthesiology, clinical pharmacology

Induced hypotension limits intra-operative blood loss to provide better visibility of the surgica... more Induced hypotension limits intra-operative blood loss to provide better visibility of the surgical field and diminishes the incidence of major complications during functional endoscopic sinus surgery (FESS). We aimed at comparing nitroglycerine, esmolol and dexmedetomidine for inducing controlled hypotension in patients undergoing FESS. One hundred and fifty American Society of Anesthesiologists physical status I or II adult patients undergoing FESS under general anesthesia were randomly allocated to three groups of 50 patients each. Group E received esmolol in a loading and maintenance dose of 1 mg/kg over 1 min and 0.5-1.0 mg/kg/h, respectively. Group D received a loading dose of dexmedetomidine 1 μg/kg over 10 min followed by an infusion 0.5-1.0 μg/kg/h, and group N received nitroglycerine infusion at a dose of 0.5-2 μg/kg/min so as to maintain mean arterial pressure (MAP) between 60 and 70 mmHg in all the groups. The visibility of the surgical field was assessed by surgeon using...

Transportation Research Record Journal of the Transportation Research Board, Dec 1, 2010

Disclaimer The contents of this report reflect the views of the authors, who are responsible for ... more Disclaimer The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the data published herein. The opinions, findings, and conclusions expressed in this publication are those of the authors and not necessarily those of the State of Florida Department of Transportation.

Transportation Research Record Journal of the Transportation Research Board, Dec 1, 2010

Disclaimer The contents of this report reflect the views of the authors, who are responsible for ... more Disclaimer The contents of this report reflect the views of the authors, who are responsible for the facts and the accuracy of the data published herein. The opinions, findings, and conclusions expressed in this publication are those of the authors and not necessarily those of the State of Florida Department of Transportation.

Journal of Minimal Access Surgery, 2016

The use of laparoscopy has revolutionised the surgical field with its advantages of reduced morbi... more The use of laparoscopy has revolutionised the surgical field with its advantages of reduced morbidity with early recovery. Laparoscopic procedures have been traditionally performed under general anaesthesia (GA) due to the respiratory changes caused by pneumoperitoneum, which is an integral part of laparoscopy. The precise control of ventilation under controlled conditions in GA has proven it to be ideal for such procedures. However, recently the use of regional anaesthesia (RA) has emerged as an alternative choice for laparoscopy. Various reports in the literature suggest the safety of the use of spinal, epidural and combined spinal-epidural anaesthesia in laparoscopic procedures. The advantages of RA can include: Prevention of airway manipulation, an awake and spontaneously breathing patient intraoperatively, minimal nausea and vomiting, effective post-operative analgesia, and early ambulation and recovery. However, RA may be associated with a few side effects such as the requirement of a higher sensory level, more severe hypotension, shoulder discomfort due to diaphragmatic irritation, and respiratory embarrassment caused by pneumoperitoneum. Further studies may be required to establish the advantage of RA over GA for its eventual global use in different patient populations.

Journal of Minimal Access Surgery, 2016

The use of laparoscopy has revolutionised the surgical field with its advantages of reduced morbi... more The use of laparoscopy has revolutionised the surgical field with its advantages of reduced morbidity with early recovery. Laparoscopic procedures have been traditionally performed under general anaesthesia (GA) due to the respiratory changes caused by pneumoperitoneum, which is an integral part of laparoscopy. The precise control of ventilation under controlled conditions in GA has proven it to be ideal for such procedures. However, recently the use of regional anaesthesia (RA) has emerged as an alternative choice for laparoscopy. Various reports in the literature suggest the safety of the use of spinal, epidural and combined spinal-epidural anaesthesia in laparoscopic procedures. The advantages of RA can include: Prevention of airway manipulation, an awake and spontaneously breathing patient intraoperatively, minimal nausea and vomiting, effective post-operative analgesia, and early ambulation and recovery. However, RA may be associated with a few side effects such as the requirement of a higher sensory level, more severe hypotension, shoulder discomfort due to diaphragmatic irritation, and respiratory embarrassment caused by pneumoperitoneum. Further studies may be required to establish the advantage of RA over GA for its eventual global use in different patient populations.